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Therapeutic antibodies have improved survival of both hematologic and solid cancer patients, inducing long-lasting responses and even cures. Clinically successful antibodies exert antitumor activity by targeting tumor cells directly (e.g. anti-HER2 mAb in HER2+ breast cancer, anti-CD20 mAb in B cell cancer) or by targeting and activating immune cells that seek and destroy cancer cells in the tumor microenvironment (immune checkpoint blocking antibodies; ICB). Still, many patients fail to respond or acquire resistance to these therapies. Understanding mechanisms and overcoming resistance to distinct classes of antibody drugs, is therefore clearly warranted and has the potential to further improve cancer outcomes. The inhibitory Fc gamma receptor (FcγR) IIB imbues resistance to cancer immunotherapy by several mechanisms, acting both on tumor and immune effector cells. We previously developed an FcγRIIB blocking antibody (BI-1206) which is currently being explored in clinical trials (NCT03571568, NCT04219254, and NCT02933320). BI-1206 was found to have cytolytic activity against malignant B cells and the ability to block rituximab internalization from tumor cells, as well as enhance rituximab therapeutic activity in mice humanized for CD20 and FcγRIIB or bearing relapsed/refractory CLL in vivo. Emerging data demonstrate that FcγRs modulate the therapeutic activity of many therapeutic antibodies among them HER2 targeting antibodies such as Trastuzumab. Trastuzumab alone or in combination with chemotherapy significantly improves overall survival of HER2+ breast cancer patients. However, many patients remain uncured and develop Trastuzumab resistance resulting in relapse of the disease. Means of improving anti-HER2 therapy and overcoming resistance are therefore highly desirable. We report the generation of a fully human FcγRIIB-blocking antibody (BI-1607) engineered to eliminate Fc-mediated FcγR binding and function (Fc-null anti-FcγRIIB). Using a mechanism-of-action-matched surrogate antibody, we demonstrate that Fc-null anti-FcγRIIB enhances therapeutic efficacy, both in tumor growth and overall survival of anti-HER2 in the syngeneic immune competent TUBO mouse model. This enhanced therapeutic efficacy is associated with increased tumor influx of myeloid and NK-cells. Collectively our results provide proof-of-concept for Fc-null anti-FcγRIIB to enhance anti-HER2 in the treatment of cancer. Citation Format: Linda Mårtensson, Robert Oldham, Marie Borggren, Mathilda Kovacek, Therese Blidberg, Ulla-Carin Tornberg, Ingrid Karlsson, Steve Beers, Mark Cragg, Ingrid Teige, Björn Frendeus. A novel FcγRIIB-blocking antibody to enhance FcγR-dependent antitumor immunity with anti-HER2 therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3423.

The pleiotropic TNF-α:TNFR axis plays a central role in immune regulation. While the cellular expression of TNFR1 is broad, TNFR2 expression is mainly restricted to immune cells. The therapeutic potential of targeting TNFR2 for cancer treatment has been previously indicated and to gain further insight, we generated a wide panel of TNFR2-specific antibodies using the n-CoDeR F.I.R.S.T™ target and antibody discovery platforms. We identified antibodies against mouse or human TNFR2 that could block TNF-α binding and showed potent anti-tumor activity in several immune-competent models, both as single agent and in combination with anti-PD1. The mechanism-of-action was shown to be FcγR dependent and likely mediated through a combination of intra-tumor T reg depletion, CD8+ T cell expansion and modulation of innate immune cells e.g. neutrophils and myeloid cells. Toxicological studies of the human lead-candidate BI-1808 in non-human primates (NHP) demonstrated very good tolerability at doses up to 200 mg/kg, and in vitro studies with human cells showed no signs of harmful cytokine release. Furthermore, in vivo studies using immune competent mouse cancer experimental models showed a clear relationship between dose, receptor occupancy (RO) and efficacy. In both murine models and in the NHPs, soluble TNFR2 was clearly modulated by the treatment and closely correlated with RO. In addition, several changes in the immune cells (e.g. T cells and neutrophils) in the blood compartment were observed. Since January 2021, BI-1808 is evaluated in an ongoing Phase I/IIa trial. Similar to the preclinical studies, correlations between dose, RO and soluble TNFR2 has been clearly observed in the patients. In addition, and consistent with TNF-α:TNFR biology being conserved across the species, modulations of T cell and neutrophil numbers are also paralleled between the patients, NHPs and mice, increasing the likelihood of successful clinical translation of our findings. Citation Format: Linda Mårtensson, Kirsty Cleary, Petra Holmkvist, Mathilda Kovacek, Carolin Svensson, Monika Semmrich, Therese Blidberg, Mimoza Demiri, Osman Dadas, Marie Borggren, Vici Pitic, Sean H. Lim, Stephen A. Beers, Susanne Gertsson, Kristoffer S. Rohrberg, Ingrid Karlsson, Andres McAllister, Mark S. Cragg, Björn Frendeus, Ingrid Teige. BI-1808 - a first in class ligand-blocking αTNFR2 antibody for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4156.

Background: Influenza A virus in swine herds represents a major problem for the swine industry and poses a constant threat for the emergence of novel pandemic viruses and the development of more effective influenza vaccines for pigs is desired. By optimizing the vector backbone and using a needle-free delivery method, we have recently demonstrated a polyvalent influenza DNA vaccine that induces a broad immune response, including both humoral and cellular immunity. Objectives: To investigate the protection of our polyvalent influenza DNA vaccine approach in a pig challenge study. Methods: By intradermal needle-free delivery to the skin, we immunized pigs with two different doses (500 μg and 800 μg) of an influenza DNA vaccine based on six genes of pandemic origin, including internally expressed matrix and nucleoprotein and externally expressed hemagglutinin and neuraminidase as previously demonstrated. Two weeks following immunization, the pigs were challenged with the 2009 pandemic H1N1 virus. Results: When challenged with 2009 pandemic H1N1, 0/5 vaccinated pigs (800 μg DNA) became infected whereas 5/5 unvaccinated control pigs were infected. The pigs vaccinated with the low dose (500 μg DNA) were only partially protected. The DNA vaccine elicited binding-, hemagglutination inhibitory (HI) − as well as crossreactive neutralizing antibody activity and neuraminidase inhibiting antibodies in the immunized pigs, in a dosedependent manner. Conclusion: The present data, together with the previously demonstrated immunogenicity of our influenza DNA vaccine, indicate that naked DNA vaccine technology provides a strong approach for the development of improved pig vaccines, applying realistic low doses of DNA and a convenient delivery method for mass vaccination. info:eu-repo/semantics/publishedVersion

Introduction BI-1206 is a fully human anti-FcγRIIB antagonistic monoclonal antibody. BI-1206 enhances the activity of anti-CD20 antibodies such as rituximab by blocking the interaction of the anti-CD20 with this inhibitory receptor. This combination may overcome resistance to rituximab and enhance its activity. Methods The safety and tolerability profile of BI-1206 in combination with rituximab is currently investigated in the Phase 1/2a clinical trial 17-BI-1206-02. The study population includes subjects with follicular lymphoma (FL), marginal zone lymphoma (MZL), and mantle cell lymphoma (MCL) who have relapsed or are refractory to rituximab. Induction therapy consists of four weekly administrations of rituximab and three administrations of BI-1206, both given as i.v. infusions. In the first week of treatment rituximab is administered as single agent. In the following three weeks patients receive BI-1206 followed by rituximab. In Phase 1, a 3+3 study design is used, with escalating doses of BI-1206 and a fixed dose of rituximab (375 mg/m 2), with the aim of selecting the RP2D of BI-1206 for the expansion cohort (Phase 2a). Patients showing clinical benefit are eligible for continued maintenance therapy with dosing of BI-1206 and rituximab every 8 weeks for up to 7 cycles. The assessment of the pharmacokinetics (PK) of BI-1206 includes non-compartmental analysis (NCA), and the assessment of the pharmacodynamics (PD) includes B cell depletion, FcγRIIB expression and BI-1206 receptor occupancy (RO). Results With a cut-off date of July 20 th, 2021, 16 subjects have received doses of up to 100 mg BI-1206 in combination with rituximab (375 mg/m 2). Nine out of these received all four doses and were evaluated for therapeutic benefit. Three subjects were diagnosed with MCL, 1 with MZL and 12 with FL. The most frequent adverse advents (AEs) related to BI-1206 have been infusion related reactions (IRRs). These IRRs led to dose limiting toxicities (DLTs) in 4 subjects, 2 experienced G4 platelet drops, and 2 experienced G3 and G4 liver enzyme elevations. No signs of liver damage were observed, and all patients recovered within days of the event, leaving no sequelae. These events have been milder and less frequent after implementation of a novel pre-medication regimen. No DLTs have been observed after implementation of this regimen. Clinical responses were observed already at the starting dose (30 mg). To date three complete responses (CR) have been observed, one at the 30mg and two at the 70mg dose levels. Two complete responses completed maintenance and one is still on maintenance treatment. The two subjects who developed a CR and finished the study have remained in CR over 1,5 and 2,0 years. Three subjects achieved partial responses (PR), one at 30mg and two at 70mg. One patient on 100 mg is experiencing ongoing stable disease at the cut-off date and is on maintenance treatment. One patient with a blastic form of MCL achieved complete depletion of peripheral tumor cells and achieved a PR. Increasing doses (30 mg to 70 or 100 mg) of BI-1206 gave rise to a supra-proportional increase in C max as well as an increase in the half-life of BI-1206. A trend of accumulation after consecutive doses was also seen. When comparing the serum-concentrations against the associated RO% of FcγRIIB there was a trend that higher dose levels were close to fully saturating FcgRIIB receptors for up to 72 hours. It is therefore likely that further increases in dose will give rise to complete receptor saturation, which should be maintained for extended periods of time. Conclusions Preliminary data of the clinical trial 17-BI-1206-02, where BI-1206 is combined with rituximab is promising. BI-1206 has a good safety profile that induced IRRs that are adequately managed with a novel steroid regimen. At a cut-off date of July 20 th, 2021, 3 CR, 3 PR and one SD have been observed among the 12 evaluable patients who completed the induction treatment. Importantly, the CRs have been very long lasting. This at doses associated only with transient receptor saturation. It may be speculated that doses which enable full RO% for a longer period (e.g., the entire dosing interval), may show additional clinical benefit. Since patients are currently undergoing treatment at higher doses, these data will be updated. Disclosures Karlsson: BioInvent International AB: Current Employment. Gertsson: BioInvent International AB: Current Employment. Kilany: BioInvent International AB: Current Employment. Borggren: BioInvent International AB: Current Employment. Abrisqueta: BMS: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria. Carneiro: Novartis: Membership on an entity's Board of Directors or advisory committees; Pierre-Fabre: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; MSD: Membership on an entity's Board of Directors or advisory committees. Cordoba: Kyowa-Kirin: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees; ADCTherapeutics: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kite: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Jerkeman: Jansen-Cilag, AbbVie, Gilead, Celgene: Other: part of a research collaboration between Karolinska Institutet and Janssen Pharmaceutica NV for which Karolinska Institutet has received grant support, Research Funding. Mercadal: Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead Sciences, Inc.: Honoraria, Speakers Bureau. Cohen: Janssen, Adicet, Astra Zeneca, Genentech, Aptitude Health, Cellectar, Kite/Gilead, Loxo, BeiGene, Adaptive: Consultancy; Genentech, BMS/Celgene, LAM, BioINvent, LOXO, Astra Zeneca, Novartis, M2Gen, Takeda: Research Funding. Sancho: Takeda: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers-Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche Ltd: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees. Teige: BioInvent International AB: Current Employment, Current equity holder in publicly-traded company. Mårtensson: BioInvent International AB: Current Employment, Current equity holder in publicly-traded company. Frendéus: BioInvent International AB: Current Employment, Current equity holder in publicly-traded company. McAllister: BioInvent International AB: Current Employment, Current equity holder in publicly-traded company.

Therapeutic antibodies have improved survival of both hematologic and solid cancer patients, inducing long-lasting responses and even cures. Clinically successful antibodies exert antitumor activity by targeting tumor cells directly e.g. anti-CD20 mAb in B cell cancer, or by targeting and activating immune cells that seek and destroy cancer cells in the tumor microenvironment (immune checkpoint blocking antibodies;ICB). Still, many patients fail to respond or acquire resistance to these therapies. Understanding mechanisms and overcoming resistance to distinct classes of antibody drugs, is therefore clearly warranted and has the potential to further improve cancer outcomes. The inhibitory Fc gamma receptor (FcγR) IIB may precipitate resistance to cancer immunotherapy by several mechanisms, acting both on tumor and immune effector cells. We previously developed an FcγRIIB blocking antibody (BI-1206). Based on its cytolytic activity against B cell cancer cells and ability to block rituximab internalization from tumor cells, as well as enhance rituximab therapeutic activity in mice humanized for CD20 and FcγRIIB or bearing relapsed/refractory CLL in vivo, BI-1206 is being explored in clinical trials (NCT03571568; NCT04219254). Emerging data demonstrate that FcγRs can modulate the therapeutic activity of ICB antibodies (anti-PD-1/PD-L1 and anti-CTLA-4). While both anti-CTLA-4 and anti-PD-1/L1 mAb are effective and approved for cancer therapy, and combined checkpoint blockade improves therapeutic responses, anti-CTLA-4 therapies are associated with tolerability issues. Means of enhancing the anti-CTLA-4 therapeutic window are therefore desirable in order to deliver this therapy to more patients. Recent preclinical and retrospective clinical data indicate that anti-CTLA-4 antibodies may promote antitumor immunity by dual mechanisms; “releasing the brakes” on T effector cells and depleting immune suppressive intratumoral T regulatory (Treg) cells. Anti-CTLA-4 induced Treg depletion was shown to be FcγR-dependent. Here, we report the generation of a novel, fully human FcγRIIB-blocking antibody (BI-1607) engineered to eliminate Fc-mediated FcγR binding and function (Fc-null anti-FcγRIIB). Using a mechanism-of-action-matched surrogate antibody, we demonstrate that Fc-null anti-FcγRIIB enhances therapeutic efficacy of submaximally efficacious doses of anti-CTLA-4 in responsive (MC38) or resistant (CT26) syngeneic immune competent mouse models. Of relevance to the clinical setting where low dose anti-CTLA-4/anti-PD-1 combination therapies have been approved for different indications, we further demonstrate that triplet therapy significantly enhanced survival in the checkpoint blockade-poorly responsive B16 tumor model. Collectively our results provide proof-of-concept for Fc-null anti-FcγRIIB to enhance anti-CTLA-4 ICB in the treatment of cancer. Citation Format: Linda Mårtensson, Robert Oldham, Marie Borggren, Mathilda Kovacek, Therese Blidberg, Ali Roghanian, Ulla-Carin Thornberg, Ingrid Karlsson, Stephen A. Beers, Mark S. Cragg, Ingrid Teige, Bjorn L. Frendéus. A novel FcγRIIB-blocking antibody to enhance FcγR-dependent antitumor immunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1642.

Introduction BI-1206 is a fully-human IgG1 monoclonal antibody that exquisitely recognizes and blocks FcγRIIB. BI-1206 enhances the activity of anti-CD20 antibodies such as rituximab by preventing interaction with FcγRIIB and may thus overcome resistance to those treatments. BI-1206 is currently in clinical investigation in combination with rituximab for the treatment of indolent NHL. This report presents a preliminary pharmacokinetic evaluation of the data generated in the trial. Methods The safety and tolerability profile of BI-1206 in combination with rituximab is currently investigated in the Phase 1/2a clinical trial 17-BI-1206-02. The study population includes patients with follicular lymphoma (FL), marginal zone lymphoma (MZL), and mantle cell lymphoma (MCL) who have relapsed or are refractory to rituximab. BI-1206 and rituximab are administered as i.v. infusions once per week for four weeks. In Phase 1a, a 3+3 study design is used, with escalating doses of BI-1206 and a fixed dose of rituximab (375 mg/m2), with the aim of selecting the RP2D of BI-1206 for an expansion cohort in Phase 2a. Patients showing clinical benefit, are eligible for continued maintenance therapy with dosing of BI-1206 and rituximab every 8 weeks. The assessment of the pharmacokinetics (PK) of BI-1206 included non-compartmental analysis (NCA), and the assessment of the pharmacodynamics (PD) included receptor occupancy (RO%). PK modelling was conducted to further characterize the PK behavior and to provide predictions of upcoming dose levels. In addition, the effect of BI-1206 on the PK of rituximab was investigated by comparing PK parameters of rituximab to literature values of rituximab monotherapy. Results Up to 100 mg BI-1206 has been administered in combination with rituximab (375 mg/m2). Increasing doses of BI-1206 from 30 mg to 70 or 100 mg gave rise to a supra-proportional increase in Cmax as well as an increase in the half-life of BI-1206. A trend of accumulation after consecutive doses was also seen. When comparing the serum-concentrations against the associated RO% of FcγRIIB there is a trend that higher doses almost fully saturate the receptors immediately after dosing and for up to 72 hours. It is likely that increasing the dose further, will give rise to full receptor saturation, which should be maintained for an extended period. Clinical response, assessed by reduction of tumour size, has been observed at the 70 mg cohort. This at a dose which typically does not saturate receptors for the entire dose interval. It may therefor be speculated that doses which enable full RO% over the entire dosing interval, may show additional clinical benefit for patients. PK modelling showed that there was a significant contribution of a non-linear component on the elimination of BI-1206, which may be attributed to receptor binding. A two-compartment model with linear (non-saturating) and non-linear (saturating) elimination best describes the data. Using the model for predictions of upcoming doses revealed that doses close to the ones already administered may be sufficient for full receptor saturation during the entire dosing interval. Finally, the Cmax after one dose of rituximab was in the same range as previously reported values, indicating no substantial effect on the PK of rituximab. Consequently, at the current dose levels, there is no apparent need for dose-adjustments for rituximab. Conclusions This report presents preliminary data of the clinical trial 17-BI-1206-02, where BI-1206 is combined with rituximab. The presented data is encouraging, both in terms of first clinical response against tumors, as well as showing signs of overcoming target-mediated drug disposition, which may allow weekly or even less frequent dosing at clinically relevant dose levels. Disclosures Jerkeman: Roche:Research Funding;Celgene:Research Funding;Gilead:Research Funding;Abbvie:Research Funding;Janssen:Research Funding.McAllister:BioInvent International AB:Current Employment, Current equity holder in publicly-traded company.Roos:BioInvent International AB:Current Employment.Lindell Andersson:BioInvent International AB:Current Employment.Karlsson:BioInvent International AB:Current Employment.Borggren:BioInvent International AB:Current Employment.Abrisqueta:Celgene:Consultancy, Honoraria;Janssen:Consultancy, Honoraria, Speakers Bureau;AbbVie:Consultancy, Honoraria, Speakers Bureau;Roche:Consultancy, Honoraria, Speakers Bureau.Teige:BioInvent International AB:Current Employment, Current equity holder in publicly-traded company.Frendéus:BioInvent International AB:Current Employment, Current equity holder in publicly-traded company.

Introduction Administration of therapeutic monoclonal antibodies (mAb) is often accompanied by infusion related reactions (IRR), of ill-determined mechanism. During the clinical development of BI-1206 (NCT02933320 and NCT03571568), a fully human mAb that binds specifically to hFcγRIIB (hCD32B), frequent IRR were observed, independent of sustained FcγRIIB blockade. At 100mg/patient, BI-1206 showed transient receptor saturation for up to 72h, whereas IRR most often resolved within 24h. Administration of BI-1206 was aslo associated with transient thrombocytopenia but not increased bleeding, and most episodes resolved within a week. Elevated transaminases (i.e. alanine transaminase (ALT) and aspartate transaminase (AST)) and a transient cytokine release was also observed alongside thrombocytopenia. Methods Six to eight-week-old C57BL/6 mice were injected either through intravenous (i.v.), intra-peritoneal (i.p.) or subcutaneous (s.c.) routes with a surrogate mouse anti-FcγRIIB (AT130-2 IgG2a) in doses ranging from 1-400μg/mouse. Mice were monitored post injection for changes in behavior and macroscopic symptoms such as isolation, mobility, and fur condition. Serum concentration of AT130-2 were quantified using an in-house ELISA. Platelet counts were analysed in fresh blood using a Vetscan (Triolab). Transaminases were analysed by IDEXX BioResearch. Cytokines were analysed with V-plex Proinflammatory Panel 1 Mouse kit (MesoScale Discovery), including interferon (IFN)-γ, interleukin (IL)-1β, IL-2, IL, 4, IL-5, IL-6, IL-10, IL-12p70, KC/GRO and tumor necrosis factor (TNF)-α. Results Following administration of 200μg AT130-2 i.v., rapid onset of IRR was seen within 5-7 minutes. Blood sampling of these mice indicated reduced blood pressure. The mice recovered 10-15 minutes post IRR onset and no macroscopic symptoms were observed by 1h. Tolerability was dose-dependent and showed a clear pattern of increasing IRR with regards route of administration in the order s.c. A decrease in platelet count was seen at the same time as IRRs after both i.v. and i.p. administration. The decrease was transient and normalised within 8h post injection. AST, ALT, IL-5, IL-6, IL-10 KC/GRO, TNF-α showed a transient increase, all peaking 1-3 post injection, except for IL-5. IL-5 showed a delayed peak 3-8h post injection. To investigate whether premedication with corticosteroids could inhibit the IRR and associated toxicities, mice were premedicated with betamethasone or dexamethasone 16-24h s.c. and 1h i.v. pre injection of AT130-2. Development of IRR and platelet reduction was completely inhibited with premedication. Also, the increase in liver transaminases and cytokine release was significantly reduced. A single dose of premedication at 1h pre injection did not inhibit the IRR nor prevent the decrease in platelet count, Whilst a single dose premedication 16-24h pre injection reduced the IRR and platelet decrease, it not completely block the changes, indicating that two doses of corticosteroids are optimal. Conclusions Here we demonstrate anin vivomodel that recapitulates the tolerability profile seen with BI-1206 in human cancer subjects, including IRR, decreased platelet count, elevated transaminases and transient cytokine release. In the mouse model, there was a correlation between IRR with high dose and rapid increase in serum concentration, rather than FcγRIIB saturation following administration of anti-FcγRIIB without IRR. This pre-medication regimen has been implemented in clinical trials and shown to improve tolerability to BI-1206. Disclosures Karlsson: BioInvent International AB:Current Employment.Mårtensson:BioInvent International AB:Current Employment, Current equity holder in publicly-traded company.Borggren:BioInvent International AB:Current Employment.Kovacek:BioInvent International AB:Current Employment, Current equity holder in publicly-traded company.Roos:BioInvent International AB:Current Employment.Blidberg:BioInvent International AB:Current Employment.Oldham:BioInvent International AB:Research Funding.Jerkeman:Roche:Research Funding;Abbvie:Research Funding;Janssen:Research Funding;Gilead:Research Funding;Celgene:Research Funding.Dyer:BioInvent International AB:Research Funding.Davies:Roche, Celgene, Kite Pharma, Acerta, Karyopharma, Regeneron, Incyte:Consultancy;Roche, Acerta Pharma, AstraZeneca, Celgene, Gilead, ADC Therapeutics, Gilead:Research Funding;Celegene, Roche, Kite Pharma, Celegene:Honoraria;Roche:Other: TRAVEL, ACCOMMODATIONS, EXPENSES.Córdoba:Roche:Honoraria, Other: travel and accommodation;Abbvie:Honoraria, Other: travel and accommodation;Janssen:Honoraria, Other: travel and accommodation;Takeda Farmacéutica España S.A.:Speakers Bureau;Gilead:Honoraria, Other: travel and accommodation.Abrisqueta:AbbVie:Consultancy, Honoraria, Speakers Bureau;Janssen:Consultancy, Honoraria, Speakers Bureau;Celgene:Consultancy, Honoraria;Roche:Consultancy, Honoraria, Speakers Bureau.Beers:BioInvent International AB:Research Funding.Teige:BioInvent International AB:Current Employment, Current equity holder in publicly-traded company.McAllister:BioInvent International AB:Current Employment, Current equity holder in publicly-traded company.Lim:BioInvent International AB:Patents & Royalties, Research Funding.Cragg:BioInvent International AB:Patents & Royalties, Research Funding.Frendéus:BioInvent International AB:Current Employment, Current equity holder in publicly-traded company.

När inskolning av barn i förskolan på betydande sätt förändras, uppstår behov av nya förhållningssätt till barn och föräldrar. Nya professionella roller för förskolepedagoger (förskollärare och barnskötare) skapas. Dessa roller skiljer sig betydligt från de roller som intogs tidigare. Denna artikel fokuserar dessa nya pedagogroller och deras betydelse mot bakgrund av tidigare former av inskolningsmodell (er).

The rising demand for lithium batteries is challenging battery producers to increase their production. This is causing an accumulation of production scrap which must be treated to allow re-utilization of cathode material in production. Several industrial lithium battery recycling processes use thermal pre-treatment in an oxidative or inert atmosphere, or in a vacuum, to separate the battery components and remove organic material. However, a comparison of the effects of incineration, dynamic pyrolysis (under a constant flow of inert gas), and pyrolysis under vacuum on the microstructure and composition of scrap cathode material has not been explored. Scrap cathodes, with active material based on Li(NixMnyCoz)Oj, were subjected to incineration, dynamic pyrolysis, and pyrolysis under vacuum at 450˚, 550˚, and 650°C for 30, 60, 90, and 150 min to determine the best approach to cathode material recovery. While the incineration did not cause any chemical transformation of cathode material, under pyrolysis conditions the organic components in the cathodes triggered carbothermic reduction of the active material, yielding Co3O4, NiO, Mn3O4, and Li2CO3 as products. In the gas by-products, formed from the decomposition of the organic material, CO, CO2, and HF were determined. The decomposition especially of the binder in polyvinylidene fluoride (PVDF) facilitated the separation of the active material from the current collector by mechanical treatment. By subsequent ball milling, the best technique to recover cathode material is the incineration at a temperature higher than 550˚ C and below 650˚ C for at least 90 min, with >95% of recovered active material.

BACKGROUND: Pigs are natural hosts for influenza A viruses, and the infection is widely prevalent in swine herds throughout the world. Current commercial influenza vaccines for pigs induce a narrow immune response and are not very effective against antigenically diverse viruses. To control influenza in pigs, the development of more effective swine influenza vaccines inducing broader cross-protective immune responses is needed. Previously, we have shown that a polyvalent influenza DNA vaccine using vectors containing antibiotic resistance genes induced a broadly protective immune response in pigs and ferrets using intradermal injection followed by electroporation. However, this vaccination approach is not practical in large swine herds, and DNA vaccine vectors containing antibiotic resistance genes are undesirable.OBJECTIVES: To investigate the immunogenicity of an optimized version of our preceding polyvalent DNA vaccine, characterized by a next-generation expression vector without antibiotic resistance markers and delivered by a convenient needle-free intradermal application approach.METHODS: The humoral and cellular immune responses induced by three different doses of the optimized DNA vaccine were evaluated in groups of five to six pigs. The DNA vaccine consisted of six selected influenza genes of pandemic origin, including internally expressed matrix and nucleoprotein and externally expressed hemagglutinin and neuraminidase.RESULTS: Needle-free vaccination of growing pigs with the optimized DNA vaccine resulted in specific, dose-dependent immunity down to the lowest dose (200μg DNA/vaccination). Both the antibody-mediated and the recall lymphocyte immune responses demonstrated high reactivity against vaccine-specific strains and cross-reactivity to vaccine-heterologous strains.CONCLUSION: The results suggest that polyvalent DNA influenza vaccination may provide a strong tool for broad protection against swine influenza strains threatening animal as well as public health. In addition, the needle-free administration technique used for this DNA vaccine will provide an easy and practical approach for the large-scale vaccination of swine.

The development of therapeutic and prophylactic HIV vaccines for African countries is urgently needed, but the question of what immunogens to use needs to be answered. One approach is to include HIV envelope immunogens derived from HIV-positive individuals from a geographically concentrated epidemic with more limited viral genetic diversity for a region-based vaccine. To address if there is a basis for a regional selected antibody vaccine, we have screened two regionally separate cohorts from Guinea-Bissau and Denmark for neutralizing antibody activity and antibody-dependent cellular cytotoxicity (ADCC) against local and nonlocal circulating HIV-1 strains. The neutralizing activity did not demonstrate higher potential against local circulating strains according to geography and subtype determination, but the plasma from Danish individuals demonstrated significantly higher inhibitory activity than that from Guinea-Bissau individuals against both local and nonlocal virus strains. Interestingly, an opposite pattern was observed with ADCC activity, where Guinea-Bissau individual plasma demonstrated higher activity than Danish plasma and was specifically against the local circulating subtype. Thus, on basis of samples from these two cohorts, no local-specific neutralizing activity was detected, but a local ADCC response was identified in the Guinea-Bissau samples, suggesting potential use of regional immunogens for an ADCC-inducing vaccine.

Mantle cell lymphoma (MCL) is a rare but aggressive B-cell non-Hodgkin's lymphoma that represents 6% of all lymphomas in the United States. Recent therapies including anti-CD20 antibody rituximab, BTK inhibitors, and BCL-2 inhibitors alone or in combination have shown great anti-MCL efficacy. However, primary and acquired resistance to one or multiple therapies commonly occurs, resulting in poor clinical outcome. Therefore, resistance to such therapies is currently an unmet clinical challenge in MCL patients. Therapeutic strategies to overcome this resistance holds promise to significantly improve survival of refractory/relapsed MCL patients. Recent studies showed Fc gamma receptors (FcγRs) play important roles in enhancing the efficacy of antibody-based immunotherapy. In particular, FcgRIIB (CD32B), an inhibitory member of the FcγR family, is implicated in the immune cell desensitization and tumor cell resistance through the internalization of therapeutic antibodies such as rituximab. Based on our flow cytometry analysis, we demonstrated that FcgRIIB is highly expressed on the cell surface of MCL cell lines (n=10) and primary MCL patient samples (n=22). This indicates that FcgRIIB may play an important role in MCL malignancy and identifies FcgRIIB is a potential therapeutic target for the treatment of MCL. To address this, we tested the in vivo efficacy of BI-1206, a fully humanized monoclonal antibody targeting FcgRIIB, alone, or in combination with clinically approved or investigational drugs including rituximab, ibrutinib and venetoclax. In the first in vivo cohort, BI-1206, as a single agent, dramatically inhibited the tumor growth of ibrutinib-venetoclax dual-resistant PDX tumor models, suggesting that targeting FcgRIIB by BI-1206 alone has high anti-MCL activity in vivo. Next, we assessed whether BI-1206 can boost anti-MCL activity of antibody-based therapy such as rituximab in combination with ibrutinib or venetoclax using additional mice cohorts of cell line-derived xenograft and patient-derived xenograft models. BI-1206 significantly enhanced the in vivo efficacy of ibrutinib plus rituximab, and venetoclax plus rituximab, on tumor growth inhibition, including the JeKo-1 derived xenograft models, previously proven to be partially resistant to ibrutinib and venetoclax in vivo. This tumor-sensitizaton effect was further confirmed in the ibrutinib and venetoclax dual-resistant PDX models of MCL where BI-1206 was combined with venetoclax and rituximab. More detailed mechanistic studies are currently ongoing to reveal the mechanism of action of BI-1206-based combinations or as single therapy with the possibility that BI-1206 itself may have a cytotoxic anti-tumor direct activity in MCL. In conclusion, BI-1206 as single agent showed potent efficacy in overcoming ibrutnib-venetoclax dual resistance. Moveover, BI-1206 enhanced the in vivo efficacy of ibrutinib plus rituximab and venetoclax plus rituximab and overcomes resistance to these treatments resulting in enhanced anti-tumor effects. Disclosures Karlsson: BioInvent International AB: Current Employment. Mårtensson:BioInvent International AB: Current Employment, Current equity holder in publicly-traded company. Kovacek:BioInvent International AB: Current Employment, Current equity holder in publicly-traded company. Teige:BioInvent International AB: Current Employment, Current equity holder in publicly-traded company. Frendéus:BioInvent International AB: Current Employment, Current equity holder in publicly-traded company. Wang:Pulse Biosciences: Consultancy; Loxo Oncology: Consultancy, Research Funding; Kite Pharma: Consultancy, Other: Travel, accommodation, expenses, Research Funding; BioInvent: Research Funding; Juno: Consultancy, Research Funding; Beijing Medical Award Foundation: Honoraria; OncLive: Honoraria; Verastem: Research Funding; Molecular Templates: Research Funding; Dava Oncology: Honoraria; Guidepoint Global: Consultancy; Nobel Insights: Consultancy; Oncternal: Consultancy, Research Funding; InnoCare: Consultancy; Acerta Pharma: Research Funding; VelosBio: Research Funding; MoreHealth: Consultancy; Targeted Oncology: Honoraria; OMI: Honoraria, Other: Travel, accommodation, expenses; Celgene: Consultancy, Other: Travel, accommodation, expenses, Research Funding; AstraZeneca: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Janssen: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Lu Daopei Medical Group: Honoraria.

Disease progression of human immunodeficiency virus type 1 (HIV-1) is delayed by HIV type 2 (HIV-2) in individuals with dual HIV-1/HIV-2 infection. The protective mechanisms, however, are still to be revealed. In the current study we examined type-specific and cross-reactive antibody-dependent cellular cytotoxicity (ADCC) in HIV-1 and HIV-2 monoinfection or dual infection. Of note, intertype cross-reactive antibodies that mediated HIV-1 envelope glycoprotein (Env)–targeted ADCC were frequently identified in HIV-2–infected individuals. Furthermore, the magnitude of HIV-1 cross-reactive ADCC activity during HIV-2 infections depended on the HIV-1 Env origin and was associated with the duration of infection. These results suggest that preexisting antibodies against HIV-2, which mediate intertype ADCC, might contribute to control of HIV-1 during dual infection., Antibody-dependent cellular cytotoxicity (ADCC) was analyzed in human immunodeficiency virus (HIV) 1 and 2 infections. Cross-reactive antibodies that mediated HIV-1 envelope glycoprotein–targeted ADCC were identified in HIV-2–infected individuals, suggesting that preexisting HIV-2 antibodies might help control HIV-1 during dual infection.

The induction of both neutralizing antibodies and non-neutralizing antibodies with effector functions, for example, antibody-dependent cellular cytotoxicity (ADCC), is desired in the search for effective vaccines against HIV-1. In the pursuit of novel immunogens capable of inducing an efficient antibody response, rabbits were immunized with selected antigens using different prime-boost strategies. We immunized 35 different groups of rabbits with Env antigens from clinical HIV-1 subtypes A and B, including immunization with DNA alone, protein alone, and DNA prime with protein boost. The rabbit sera were screened for ADCC activity using a GranToxiLux-based assay with human peripheral blood mononuclear cells as effector cells and CEM.NKRCCR5 cells coated with HIV-1 envelope as target cells. The groups with the highest ADCC activity were further characterized for cross-reactivity between HIV-1 subtypes. The immunogen inducing the most potent and broadest ADCC response was a trimeric gp140. The ADCC activity was highest against the HIV-1 subtype corresponding to the immunogen. The ADCC activity did not necessarily reflect neutralizing activity in the pseudovirus-TZMbl assay, but there was an overall correlation between the two antiviral activities. We present a rabbit vaccination model and an assay suitable for screening HIV-1 vaccine candidates for the induction of ADCC-mediating antibodies in addition to neutralizing antibodies. The antigens and/or immunization strategies capable of inducing antibodies with ADCC activity did not necessarily induce neutralizing activity and vice versa. Nevertheless, we identified vaccine candidates that were able to concurrently induce both types of responses and that had ADCC activity that was cross-reactive between different subtypes. When searching for an effective vaccine candidate, it is important to evaluate the antibody response using a model and an assay measuring the desired function.

The threat posed by the 2009 pandemic H1N1 virus emphasized the need for new influenza A virus vaccines inducing a broad cross-protective immune response for use in both humans and pigs. An effective and broad influenza vaccine for pigs would greatly benefit the pork industry and contribute to public health by diminishing the risk of emerging highly pathogenic reassortants. Current inactivated protein vaccines against swine influenza produce only short-lived immunity and have no efficacy against heterologous strains. DNA vaccines are a potential alternative with advantages such as the induction of cellular and humoral immunity, inherent safety and rapid production time. We have previously developed a DNA vaccine encoding selected influenza proteins of pandemic origin and demonstrated broad protective immune responses in ferrets and pigs. In this study, we evaluated our DNA vaccine expressed by next-generation vectors. These new vectors can improve gene expression, but they are also efficiently produced on large scales and comply with regulatory guidelines by avoiding antibiotic resistance genes. In addition, a new needle-free delivery of the vaccine, convenient for mass vaccinations, was compared with intradermal needle injection followed by electroporation. We report that when our DNA vaccine is expressed by the new vectors and delivered to the skin with the needle-free device in the rabbit model, it can elicit an antibody response with the same titers as a conventional vector with intradermal electroporation. The needle-free delivery is already in use for traditional protein vaccines in pigs but should be considered as a practical alternative for the mass administration of broadly protective influenza DNA vaccines.

DNA vaccines induce broad immunity, which involves both humoral and strong cellular immunity, and can be rapidly designed for novel or evolving pathogens such as influenza. However, the humoral immunogenicity in humans and higher animals has been suboptimal compared with that of traditional vaccine approaches. We tested whether the emulsion-based and α-tocopherol containing adjuvant Diluvac Forte® has the ability to enhance the immunogenicity of a naked DNA vaccine (i.e., plasmid DNA). As a model vaccine, we used plasmids encoding both a surface-exposed viral glycoprotein (hemagglutinin) and an internal non-glycosylated nucleoprotein in the Th1/Th2 balanced CB6F1 mouse model. The naked DNA (50 µg) was premixed at a 1:1 volume/volume ratio with Diluvac Forte®, an emulsion containing different concentrations of α-tocopherol, the emulsion alone or endotoxin-free phosphate-buffered saline (PBS). The animals received 2 intracutaneous immunizations spaced 3 weeks apart. When combined with Diluvac Forte® or the emulsion containing α-tocopherol, the DNA vaccine induced a more potent and balanced immunoglobulin G (IgG)1 and IgG2c response, and both IgG subclass responses were significantly enhanced by the adjuvant. The DNA vaccine also induced CD4+ and CD8+ vaccine-specific T cells; however, the adjuvant did not exert a significant impact. We concluded that the emulsion-based adjuvant Diluvac Forte® enhanced the immunogenicity of a naked DNA vaccine encoding influenza proteins and that the adjuvant constituent α-tocopherol plays an important role in this immunogenicity. This induction of a potent and balanced humoral response without impairment of cellular immunity constitutes an important advancement toward effective DNA vaccines.

Introduction: Mantle cell lymphoma (MCL) is a rare but aggressive non-Hodgkin lymphoma (NHL). CD20 antibodies (e.g. rituximab), BTK inhibitors (e.g. ibrutinib and acalabrutinib), and BCL-2 inhibitors (e.g. venetoclax) alone or in combination have shown great anti-MCL efficacy. However, primary and acquired resistance to one or multiple therapies commonly occurs, resulting in poor clinical outcome. Overcoming such mechanisms of resistance holds promise to significantly improve survival, meeting a significant medical need for patients with refractory/relapsed MCL. Recent studies showed Fc gamma receptors (FcγRs) play important roles in controlling therapeutic efficacy. FcgRIIB (CD32B), the inhibitory FcγR, negatively controls antibody efficacy through distinct inhibitory mechanisms in immune effector cells and lymphoma cells, respectively. When expressed on leukemic or lymphoma cells, FcgRIIB promotes rituximab internalization and removal from the tumor cell surface, resulting in reduced immune effector cell activation and ultimately decreased in vivo therapeutic efficacy. We recently developed antagonistic antibodies to FcgRIIB and demonstrated that these antibodies blocked rituximab internalization and helped prevent and overcome rituximab resistance in a PDX model of CLL. In this study, we investigated the expression of FcgRIIB in MCL cell lines and primary patient MCL samples, and we assessed the in vivo efficacy of BI-1206, a monoclonal antibody against FcgRIIB, in MCL PDX models. Methods: Flow cytometry analysis was performed to examine the cell surface expression of FcgRIIB in MCL cell lines (n=8) and primary patient MCL samples (n=27). An orthotopic patient-derived xenograft (PDX) model was established from a MCL patient with dual resistance to ibrutinib-venetoclax. In the first mouse cohort, single-agent ibrutinib, venetoclax, or vehicle control were administrated in mice carrying the orthotopic PDX model to assess their in vivo efficacies. In the second mouse cohort, mice were treated with vehicle, single agent BI1206, rituximab plus lenalidomide, or a combination of BI-1206, rituximab, and lenalidomide (triple combination) to assess their in vivo efficacies in the same PDX model. Results: Flow cytometry analysis showed that all 8 MCL cell lines and all 27 primary patient MCL samples expressed high levels of FcgRIIB, highlighting the potential importance of FcgRIIB on the control of therapeutic efficacy in MCL. In the first mouse cohort, we validated the ibrutinib and venetoclax resistance in the PDX model established from a MCL patient with resistance to both therapies. In the second mouse cohort, single agent BI-1206 (10 mg/kg, twice a week) potently diminished PDX growth in spleen, liver, bone marrow, and peripheral blood (Figure 1). Treatment with rituximab (10 mg/kg, twice per week) plus lenalidomide (50mg/kg, daily) or the triple combination showed similar potency (Figure 1). To investigate whether BI-1206 mediates boosting of rituximab-based targeted drug therapies, and/or overcoming of resistance to such therapies, a follow-up experiment with revised treatment setting using the same PDX model or an alternative CD20/FcγRIIb co-expressing PDX model is currently under investigation. Conclusions: All MCL cell lines and all primary MCL cells tested highly express FcγRIIb on the tumor cell surface. Single agent BI-1206 has potent anti-MCL activity in the FcγRIIb-expressing MCL PDX model to overcome ibrutinib-venetoclax dual resistance. Our data suggests FcγRIIb may be an important target for anti-MCL therapies. Disclosures Wang: Guidepoint Global: Consultancy; Kite Pharma: Consultancy, Research Funding; Acerta Pharma: Consultancy, Research Funding; MoreHealth: Consultancy, Equity Ownership; AstraZeneca: Consultancy, Honoraria, Research Funding, Speakers Bureau; Pharmacyclics: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; BioInvent: Consultancy, Research Funding; Aviara: Research Funding; Juno Therapeutics: Research Funding; Celgene: Honoraria, Research Funding; Loxo Oncology: Research Funding; VelosBio: Research Funding; Dava Oncology: Honoraria.

Table of contents A1 Introduction to the 2nd synchronicity forum of GHRI/CHVI-funded Canadian and African HIV prevention and vaccine teams O1 Voluntary medical male circumcision for prevention of heterosexual transmission of HIV in adult males in Soweto: What do indicators and incidence rate show? Hillary Mukudu, Neil Martinson, Benn Sartorius O2 Developing a peer-led community mobilization program for sex workers in Soweto: HIV risk and demographics Jenny Coetzee, Janan Dietrich, Kgaugelo Mokgatswana, Rachel Jewkes, Glenda E. Gray O3 Salient beliefs about adherence: A qualitative survey conducted as part of the demonstration study on "treatment as prevention" (TasP) and "pre-exposure prophylaxis" (PrEP) among female sex workers (FSWS) in Cotonou, Benin Marylène Dugas, Luc Béhanzin, Fernand A. Guédou, Marie-Pierre Gagnon, Michel Alary O4 Relative perception of risk as a driver of unsafe sexual practices among key populations: Cases of fisherfolk and women and their partners involved in multiple sexual partnerships in Uganda Rwamahe Rutakumwa, Martin Mbonye, Thadeus Kiwanuka, Sarah Nakamanya, Richard Muhumuza, Winfred Nalukenge, Janet Seeley O5 Exploring the acceptability of new biomedical HIV prevention technologies among MSM, adolescents and heterosexual adults in South Africa Millicent Atujuna, Melissa Wallace, Ben Brown, Linda Gail Bekker, Peter A. Newman O6 HIV-susceptible target cells in foreskins after voluntary medical male circumcision in South Africa Rushil Harryparsad, Abraham J. Olivier, Heather B. Jaspan, Douglas Wilson, Janan Dietrich, Neil Martinson, Hillary Mukudu, Nonhlanhla Mkhize, Lynn Morris, Gianguido Cianci, Minh Dinh, Thomas Hope, Jo-Ann S. Passmore, Clive M. Gray O7 HIV-1 proteins activate innate immune responses via TLR2 heterodimers Bethany M. Henrick, Xiao-Dan Yao, Kenneth L. Rosenthal, the INFANT Study Team O8 Characterization of an innate factor in human milk and mechanisms of action against HIV-1 Bethany M. Henrick, Xiao-Dan Yao, Anna G. Drannik, Alash’le Abimiku, Kenneth L. Rosenthal, the INFANT Study Team O9 Secretor status and susceptibility to HIV infections among female sex workers in Nairobi, Kenya Nadia Chanzu, Walter Mwanda, Julius Oyugi, Omu Anzala O10 Natural Killer cell recall responsiveness to Gag-HIV-1 peptides of HIV-1 exposed but uninfected subjects are associated with peripheral CXCR6+ NK cell subsets Moustapha Mbow, Sabelle Jallow, Moussa Thiam, Alberta Davis, Assane Diouf, Cheikh T. Ndour, Moussa Seydi, Tandakha N. Dieye, Souleymane Mboup, Martin Goodier, Eleanor Rilley, Assan Jaye O11 Profiles of resistance: Local innate mucosal immunity to HIV-1 in commercial sex workers Xiao-Dan Yao, RW. Omange, Bethany M. Henrick, Richard T. Lester, Joshua Kimani, T. Blake Ball, Francis A. Plummer, Kenneth L. Rosenthal O12 Early antiretroviral therapy and pre-exposure prophylaxis for HIV prevention among female sex workers in Cotonou, Benin: A demonstration project Luc Béhanzin, Fernand A. Guédou, Nassirou Geraldo, Ella Goma Mastétsé, Jerôme Charles Sossa, Marcel Djimon Zannou, Michel Alary O13 Building capacity for HIV prevention trials: Preliminary data from a Nigerian cohort of HIV exposed sero-negatives (HESN) Sophia Osawe, Evaezi Okpokoro, Felicia Okolo, Stephen Umaru, Rebecca Abimiku, Sam Audu, Pam Datong, Alash’le Abimiku O14 Equipping healthcare professionals with skills required for the conduct of clinical trials in an effort to build capacity. Lessons learned Jacquelyn Nyange, Joyce Olenja, Gaudensia Mutua, Walter Jaoko, Gloria Omosa-Manyonyi, Bashir Farah, Maureen Khaniri, Omu Anzala O15 Educational technology to support active learning for HIV researchers and planners Anne Cockcroft, Kendra Tonkin, Indu Girish, Puna Mhati, Ashley Cunningham, Neil Andersson O16 From Lake Kivu (Rwanda) and Lake Malawi (Tanzania) to the shores of Lake Victoria (Uganda): Strengthening laboratory capacity through Good Clinical Laboratory Practice training Bashir Farah, Jackton Indangasi, Walter Jaoko, Gaudensia Mutua, Maureen Khaniri, Jacquelyn Nyange, Omu Anzala O17 Rilpivirine and etravirine resistance mutations in HIV-1 subtype C infected patients on a non-nucleoside reverse transcriptase inhibitor-based combination antiretroviral therapy in Botswana Thabo Diphoko, Simani Gaseitsiwe, Victoria Maiswe, Thato Iketleng, Dorcas Maruapula, Keabetswe Bedi, Sikhulile Moyo, Rosemary Musonda, Mark Wainberg, Joseph Makhema, Vladimir Novitsky, Richard Marlink, Max Essex O18 From home-based HIV testing to initiation of treatment: The AIDS Support Organization (TASO) Experience with Home-based HIV Counselling and Testing (HBHCT) among Adolescents in Uganda, 2005-2011 Stephen Okoboi, Livingstone Ssali, Sam Kalibala, Josephine Birungi, Aggrey Egessa, Jonathan Wangisi, Lyavala Joanne Okullu, Celestin Bakanda, Francis Obare41 O19 Feasibility study on using real time medication monitoring among HIV infected and Tuberculosis patients in Kilimanjaro, Tanzania I. Marion Sumari-de Boer, Hadija H. Semvua, Jossy van den Boogaard, Krisanta W. Kiwango, Kennedy M. Ngowi, Pythia T. Nieuwkerk, Rob E. Aarnoutse, Ireen Kiwelu, Eva Muro, Gibson S. Kibiki O20 Deaths still among sero-discordant cohort in Nigeria despite Access to treatment Ruth Datiri, Grace Choji, Sophia Osawe, Evaezi Okpokoro, Felicia Okolo, Stephen Umaru, Rebecca Abimiku, Samuel Audu, Pam Datong, Alash’le Abimiku O21 Therapeutic HIV-1 vaccine trials in Denmark and Guinea-Bissau Fomsgaard A, Karlsson I, Jensen KJ, Jensen SS, Leo-Hansen C, Jespersen S, Da Silva Té D, Rodrigues CM, da Silva ZJ, Janitzek CM, Gerstoft J, Kronborg G, the WAPHIR Group O22 Willingness to participate in a HIV vaccine Trial among HIV exposed sero-negative (HESN) persons in Jos, Nigeria Evaezi Okpokoro, Sophia Osawe, Ruth Daitiri, Grace Choji, Stephen Umaru, Felicia Okolo, Pam Datong, Alash'le Abimiku O23 Clinical research volunteers’ perceptions and experiences of screening for enrolment at KAVI-Institute of Clinical Research, Kenya Nyariki Emily, Olenja Joyce, Lorway R. Robert, Anzala Anzala O24 Gut microbiome, HIV-exposure, and vaccine responses in South African infants Katie Viljoen, Jerome Wendoh, Elvis Kidzeru, Ulas Karaoz, Eoin Brodie, Gerrit Botha, Nicola Mulder, Clive Gray, William Cameron, Alain Stintzi, Heather Jaspan, for the INFANT study team O25 Analysis of HIV pol diversity in the concentrated HIV epidemic in Saskatchewan Paul N. Levett, David Alexander, Naveed Gulzar, Prabvir S. Grewal, Art F. Y. Poon, Zabrina Brumme, P. Richard Harrigan, James I. Brooks, Paul A. Sandstrom, Stryker Calvez, Stephen E. Sanche, Jamie K. Scott P1 Evaluating a HIV vaccine research community engagement programme at two HIV prevention research centres in the Western Cape Leslie Swartz, Ashraf Kagee, Anthea Lesch, Zuhayr Kafaar, Anneliese De Wet P2 Validating HIV acquisition risk score using a cohort HIV exposed sero-negative persons in a discordant relationship in Jos, Nigeria, West Africa Evaezi Okpokoro, Sophia Osawe, Ruth Daitiri, Grace Choji, Stephen Umaru, Felicia Okolo, Pam Datong, Alash'le Abimiku P3 Bridging the gap between adults and adolescents and youth adults (AYA) – Employing a youth-centred approach to investigate HIV risk among AYA in Soweto and Durban, South Africa Janan Dietrich, Tricia Smith, Laura Cotton, Stefanie Hornschuh, Martin van der Watt, Cari L. Miller, Glenda Gray, Jenni Smit, Manjeetha Jaggernath, Thumbi Ndung’u, Mark Brockman, Angela Kaida, on behalf of the AYAZAZI study teams P4 Neighbours to sex workers: A key population that has been ignored Maureen Akolo, Joshua Kimani, Prof Larry Gelmon, Michael Chitwa, Justus Osero P5 Young women’s access to structural support programmes in a district of Botswana Anne Cockcroft, Nobantu Marokoane, Leagajang Kgakole, Boikhutso Maswabi, Neo Mpofu, Umaira Ansari, Neil Andersson P6 Voices for action from peri-urban Ugandan students, teachers and parents on HIV/STI prevention: Qualitative research results Nakinobe Elizabeth, Miiro George Mukalazi, Zalwango Flavia, Nakiyingi-Miiro Jessica, Kaleebu Potiano P7 Engaging Social Media as an education tool on the fly: The use of Facebook for HIV and Ebola prevention and awareness amongst adolescents in Uganda John Ross Semwanga, Emily Nyanzi, Saidat Namuli Musoke, Elizabeth Nakinobe, George Miiro, Edward Katongole Mbidde, Tom Lutalo, Pontiano Kaleebu P8 Circulating HIV-1 subtypes among sexual minority populations in Zambia Ray Handema, Graham P. Chianzu P9 The Development of HIV Bio-bank resource management to support clinical trial and Intervention research: WAPHIR experience Moussa Thiam, Diabou Diagne-Gueye, Mame K. Ndiaye, Moustapha Mbow, Birahim P. Ndiaye, Ibrahima Traore, Mamadou C. Dia, Gilleh Thomas, Coumba Tour-Kane, Souleymane Mboup, Assan Jaye P10 Capacity building for clinical trials as a novel approach for scaling up HIV prevention research initiatives in East Africa: achievements and challenges Emily Nyanzi, Edward Katongole Mbidde, Pontiano Kaleebu, Juliet Mpendo, Joshua Kimani, Josephine Birungi, Winnie Muyindike, Andrew Kambugu P11 Community and media perspective of research; an advocacy workshop on HIV prevention research Hachizovu Sebastian, Handema Ray, Chaponda Mike, Kabuya Jean Bertin, Mulenga Modest P12 Development of a quantitative HIV-1 and HIV-2 real time PCR (qRT-PCR) viral load assay Moussa Thiam, Omar Janha, Alberta Davis, Alfred Amambua-Ngwa, Davis C. Nwakanma, Souleymane Mboup, Assan Jaye P13 Differential effects of sex in a West African Cohort of HIV-1, HIV-2 and HIV-1/2 dual infected patients: Men are worse off Sanne Jespersen, Bo Langhoff Hønge, Joakim Esbjörnsson, Candida Medina, David Da Silva TÉ, Faustino Gomes Correira, Alex Lund Laursen, Lars Østergaard, Andreas Andersen, Peter Aaby, Christian Erikstrup, Christian Wejse, for the Bissau HIV Cohort study group P14 HIV-infected adolescents in transition from pediatric to adult HIV care in Dakar, Senegal: sample characteristics and immunological and virological profiles Siry Dieye, Moussa Sarr, Haby Sy, Helene D Mbodj, Marianne Ndiaye, Amy Ndiaye, Seydi Moussa, Assan Jaye, Souleymane Mboup100 P15 Molecular characterization of vertically transmitted HIV-1 among children born to HIV-1 seropositive mothers in Northern Tanzania Balthazar M. Nyombi, Elichilia R. Shao, Innocent B. Chilumba, Sikhulile Moyo, Simani Gaseitsiwe, Rosemary Musonda P16 Breast-fed HIV-1 exposed infants play catch up. A preliminary report Pam Datong, Bucky Inyang, Sophia Osawe, Abel Izang, Chundung Cole, Felicia Okolo, Bill Cameron, Kenneth Rosenthal, Clive Gray, Heather Jaspan, Alash’le Abimiku, the INFANT study team P17 The frequency of N348I mutation in patient failing combination antiretroviral treatment In Botswana Boitumelo Seraise, Kerstin Andrea-Marobela, Sikhulile Moyo, Rosemary Musonda, Joseph Makhema, Max Essex, Simani Gaseitsiwe

Background Virus-specific CD8(+) T-cell responses are believed to play an important role in the control of HIV-1 infection; however, what constitutes an effective HIV-1 CD8(+) T-cell response remains a topic of debate. The ex vivo viral suppressive capacity was measured of CD8(+) T cells from 44 HIV-1-positive individuals. The phenotypic and cytokine profiles, and also the specificity of the CD8(+) T cells, were correlated with the suppression of HIV-1 replication. We also aimed to determine whether antiretroviral therapy (ART) had any positive effect on the HIV-1 suppressive CD8(+) T cells. Method Ex vivo suppression assay was used to evaluate the ability of CD8(+) T cells to suppress HIV-1 replication in autologous CD4(+) T cells. The CD107a, interferon-γ, interleukin-2, tumor necrosis factor-α (TNF-α), and macrophage inflammatory protein-1β (MIP-1β) responses to HIV-1 were evaluated by intracellular staining. The phenotypic profile of CD8(+) T cells was determined by whole blood staining. Results The expression of CD57 on effector CD8(+) T cells correlated with the suppression of HIV-1 replication and to the duration of ART. CD107a and tumor necrosis factor-α expression levels were significantly higher in individuals with ex vivo suppressive activity compared with individuals without suppressive activity. Conclusions Standard in vitro assays measuring one or several cytokines do not correlate with the functional viral suppressive capacity of CD8(+) T cells from HIV-1-positive individuals. The best correlation of viral suppression was found to be CD57 expression. CD57 expression correlated with the duration of ART, suggesting that ART restores the cytotoxic capacity of CD8(+) T lymphocytes.

Background: A subgroup of HIV-1―infected individuals, elite controllers, have spontaneous viral control and offer an exceptional opportunity to study virological and immunolocigal factors of possible involvement in control of HIV-1 infection. Methods: The frequencies of Tregs and TH17 cells was evaluated and correlated to markers of disease progression in peripheral blood mononuclear cells from 3 different groups of individuals infected with HIV-1: treatment-naive viremic individuals, individuals on successful highly active antiretroviral therapy, and elite controllers. In addition, a group of HIV-1―negative individuals were included. Results: We demonstrate that elite controllers have lower levels of Tregs compared with HIV-1―infected viremic individuals, but that the low Treg level does not differ between individuals with HIV-1 control, whether natural or therapy induced. We also show that T-cell activation and proliferation both correlate to the level of Tregs. Finally, the TH17/Treg ratio was similar in Elite Controllers and uninfected controls, whereas in viremic and treated HIV-1―infected individuals, the TH17/Treg ratio was lower compared with uninfected controls. Conclusions: We show that one feature of spontaneous HIV-1 control is a maintained balance between regulatory T cells and TH 17 cells.

For a CD8 epitope-based vaccine to match different geographic locations, the targeted epitopes for cytotoxic T-lymphocytes (CTLs) must be present in the local circulating HIV-1 strains. Secondly, the vaccine epitopes should match the host population HLA types. We characterized two new HIV-1 isolates from Guinea-Bissau. Also, we have identified 15 subdominant CD8 epitopes representing common HLA super-types theoretically covering most HLA alleles in any population. Herein we demonstrate that the selected vaccine epitopes are well conserved and simultaneously present in sequences from West Africa and Denmark. Use of the selected epitopes will likely ensure ≥10 immune targets in the majority of candidates for experimental therapeutic vaccination in both geographic regions. Our results warrant testing of the selected vaccine epitopes in both geographic locations.

DESIGN:: CCR5-using HIV-1 (R5 viruses) are usually isolated during acute infection from both adults and children. We have recently demonstrated that R5 viruses with a flexible use of CCR5 (called R5broad) can be detected in children close to birth and are predictive of a fast immunological failure. The aim of the present work was to investigate viral phenotype variation during disease progression in HIV-1 infected children, six slow and eight fast progressors. METHODS:: A total of 74 viral isolates obtained sequentially from 14 HIV-1 infected children were tested for their ability to infect U87.CD4 cells expressing a set of six different CCR5/CXCR4 chimeric receptors or wild-type coreceptors. The sensitivity of 35 R5 viruses to inhibition with the CC-chemokine RANTES (regulated upon activation, normal T-cell expressed and secreted) was evaluated in a peripheral blood mononuclear cells based assay. RESULTS:: Viral evolution to R5broad or to R5X4 phenotype occurred with one exception, in all children, although at a different time point according to rate of disease progression. Immune deficiency in the children was significantly associated with the appearance of R5broad phenotype or R5X4 viruses. Analysis of the sensitivity to inhibition by RANTES revealed a significant correlation between the R5broad phenotype and an augmented resistance to this CC-chemokine. CONCLUSION:: We demonstrate that the viral evolution to a more flexible CCR5-use is sufficient to explain the immunological failure in the absence of CXCR4 usage. These results warrant detailed analysis of the R5 phenotype in forthcoming clinical studies introducing CCR5 inhibitors for the treatment of pediatric HIV-1 infection. (Less)

The recent introduction of entry inhibitors in the clinic as components of antiretroviral treatment has heightened the interest in coreceptor use of human immunodeficiency virus type 1 (HIV-1). Viruses using CCR5 as coreceptor (R5 viruses) are generally present over the entire course of infection whereas viruses using the CXCR4 coreceptor (R5X4/X4 viruses) emerge in about 50% of infected individuals during later stages of infection. The CCR5-to-CXCR4 switch represents a concern because CCR5 inhibitors, while suppressing R5 viruses, may allow the emergence of CXCR4-tropic viruses. In this study, HIV-1 populations that maintained CCR5 usage during infection were compared with populations that switched coreceptor usage to include CXCR4 later during infection, with the aim to find molecular properties of the virus populations associated with the CCR5-to-CXCR4 switch. We amplified and molecularly cloned the V1-V3 region of the HIV-1 envelope from 51 sequential HIV-1 isolates derived from 4 to 10 serial samples for each of the patients. Four of the patients had virus populations that switched coreceptor usage to include CXCR4 (switch populations: SP) during infection and four patients had viral populations that maintained exclusive CCR5 usage (non-switch populations: nSP). Coreceptor usage was determined experimentally on individual clones from dualtropic R5X4 isolates. In nSP we found that the number of potential N-linked glycosylation sites (PNGS) increased over time, whereas no pattern of change was observed in SP. We also found differences in V2 length and V3 charge between R5 viruses of nSP and R5 viruses of SP before the switch. The V2 region was significantly longer in R5 viruses of SP compared to viruses of nSP throughout the course of infection, and the V3 charge increased with time in R5 populations from SP, while it remained unchanged or decreased in nSP. These molecular properties could prove important for understanding the evolution of coreceptor usage in HIV-1 populations, and maybe even for predicting an upcoming coreceptor switch at early stages after primary infection.

Objective: To investigate the potential to induce additional cytotoxic T-lymphocyte (CTL) immunity during chronic HIV-1 infection. Design: We selected infrequently targeted or subdominant but conserved HLA-A * 0201-binding epitopes in Gag, Pol, Env, Vpu and Vif. These relatively immune silent epitopes were modified as anchor-optimized peptides to improve immunogenicity and delivered on autologous monocyte-derived dendritic cells (MDDCs). Methods: Twelve treatment-naive HLA-A * 0201 HIV-1-infected Danish individuals received 1 × 10 7 MDDCs subcutaneously (s.c.) (weeks 0, 2, 4 and 8), pulsed with seven CD8 + T-cell epitopes and three CD4 + T-cel epitopes. Epitope-specific responses were evaluated by intracellular cytokine staining for interferon-γ, tumor necrosis factor α and interleukin-2 and/or pentamer labeling 3 weeks prior to, 10 weeks after and 32 weeks after the first immunization. Results: Previously undetected T-cell responses specific for one or more epitopes were induced in all 12 individuals. Half of the participants had sustained CD4 + T-cell responses 32 weeks after immunization. No severe adverse effects were observed. No overall or sustained change in viral load or CD4 + T-cell counts was observed. Conclusion: These data show that it is possible to generate new T-cell responses in treatment-naive HIV-1-infected individuals despite high viral loads, and thereby redirect immunity to target new multiple and rationally selected subdominant CTL epitopes. Further optimization could lead to stronger and more durable cellular responses to selected epitopes with the potential to control viral repl ication and prevent disease in HIV-1-infected individuals.

Recent human immunodeficiency virus type 1 (HIV-1) vaccination strategies aim at targeting a broad range of cytotoxic T lymphocyte (CTL) epitopes from different HIV-1 proteins by immunization with multiple CTL epitopes simultaneously. However, this may establish an immune hierarchical response, where the immune system responds to only a small number of the epitopes administered. To evaluate the feasibility of such vaccine strategies, we used the human leukocyte antigen (HLA)-A*0201 transgenic (tg) HHD murine in vivo model and immunized with dendritic cells pulsed with seven HIV-1-derived HLA-A*0201 binding CTL epitopes. The seven peptides were simultaneously presented on the same dendritic cell (DC) or on separate DCs before immunization to one or different lymphoid compartments. Data from this study showed that the T-cell response, as measured by cytolytic activity and gamma-interferon (IFN-gamma)-producing CD8(+) T cells, mainly focused on two of seven administered epitopes. The magnitude of individual T-cell responses induced by immunization with multiple peptides correlated with their individual immunogenicity that depended on major histocompatibility class I binding and was not influenced by mode of loading or mode of immunization. These findings may have implications for the design of vaccines based on DCs when using multiple epitopes simultaneously.

Cellular immune responses make an important contribution to both the control of human immunodeficiency virus (HIV) replication and disease progression. We used a pathogenic model of SIVmac251 infection of cynomolgus macaques to longitudinally evaluate cellular immune responses in association with various rates of disease progression. We found an inverse relationship between plasma viral load and the simian immunodeficiency virus (SIV)-specific T cells responses in peripheral blood and lymph nodes. SIV-specific T-cell responses in peripheral blood were transient during primary infection, with the highest responses detected around 3 months after infection. There was also a transient increase of central memory CD8 + T cells in peripheral blood during primary infection, and effector memory T-cell counts in peripheral lymph nodes were increased. This study emphasizes the importance of the early virus-specific immune responses in the outcome of HIV/SIV disease and provides details about the changes of virus-specific immune responses over time.

The early immune response fails to prevent the establishment of chronic human immunodeficiency virus (HIV) infection but may influence viremia during primary infection, thereby possibly affecting long-term disease progression. CD25+FoxP3+regulatory T cells may contribute to HIV/simian immunodeficiency virus (SIV) pathogenesis by suppressing efficient antiviral responses during primary infection, favoring high levels of viral replication and the establishment of chronic infection. In contrast, they may decrease immune activation during chronic infection. CD4+regulatory T cells have been studied in the most detail, but CD8+CD25+FoxP3+T cells also have regulatory properties. We monitored the dynamics of CD25+FoxP3+T cells during primary and chronic SIVmac251 infection in cynomolgus macaques. The number of peripheral CD4+CD25+FoxP3+T cells paralleled that of memory CD4+T cells, with a rapid decline during primary infection followed by a rebound to levels just below baseline and gradual depletion during the course of infection. No change in the proportion of CD25+FoxP3+T cells was observed in peripheral lymph nodes. A small number of CD4+CD25+FoxP3+T cells at set point was associated with a high plasma viral load. In contrast, peripheral CD8+CD25+FoxP3+T cells were induced a few days after peak plasma viral load during primary infection. The number of these cells was positively correlated with viral load and negatively correlated with CD4+T-cell activation, SIV antigen-specific proliferative responses during primary infection, and plasma viral load at set point, with large numbers of CD8+CD25+FoxP3+T cells being indicative of a poor prognosis.

BACKGROUND: Natural killer (NK) cell phenotype and function have recently gained much attention as playing crucial roles in antibody-dependent cellular cytotoxicity (ADCC). We investigated NK cell function, as measured by ADCC, in HIV-1-positive individuals before and 6 months after highly active antiretroviral therapy (HAART) initiation.METHOD: The ability of antibodies and NK cells to mediate ADCC was investigated separately and in combination in an autologous model. The NK cell subset distribution and NK cell phenotype (ie, expression of maturation and activation markers within NK cell subsets) were analyzed.RESULTS: The ability of NK cells to mediate ADCC was significantly increased after only 6 months of HAART and was not explained by a normalization of NK cell subsets (CD56 CD16 and CD56 CD16 NK cells) but rather by normalization in the frequency of NK cells expressing CCR7 and CD27. For individuals with no increase in ADCC after 6 months of HAART, the frequency of NK cells expressing NKp46 was downregulated. The ability of antibodies to mediate ADCC alone and in combination in an autologous model was not improved.CONCLUSIONS: HAART improves the ability of NK cells to mediate ADCC after 6 months. This improvement does not correlate with general immune restoration, as measured by CD4 T-cell counts, but rather to a decrease in the frequency of NK cells expressing CCR7 and CD27.

Understanding alterations in HIV-specific immune responses during antiretroviral therapy (ART), such as antibody-dependent cellular cytotoxicity (ADCC), is important in the development of novel strategies to control HIV-1 infection. This study included 53 HIV-1 positive individuals. We evaluated the ability of effector cells and antibodies to mediate ADCC separately and in combination using the ADCC-PanToxiLux assay. The ability of the peripheral blood mononuclear cells (PBMCs) to mediate ADCC was significantly higher in individuals who had been treated with ART before seroconversion, compared to the individuals initiating ART at a low CD4+ T cell count (

The evolution of human immunodeficiency virus type 1 (HIV-1) coreceptor use has been described as the acquisition of CXCR4 use linked to accelerated disease progression. However, CXCR4-using virus can be isolated only from approximately one-half of individuals with progressive HIV-1 disease. The other half continue to yield only CCR5-using viruses (R5 phenotype) throughout the course of disease. In the present work, the use of receptor chimeras between CCR5 and CXCR4 allowed us to study the evolution of HIV-1 with the R5 phenotype, which was not revealed by studies of wild-type coreceptor use. All together, 246 isolates (173 with the R5 phenotype) from 31 individuals were tested for their ability to infect cells through receptor chimeras. R5 narrow virus was able to use only wild-type CCR5, whereas R5 broad(1) to R5 broad(3) viruses were able to use one to three chimeric receptors, respectively. Broad use of chimeric receptors was interpreted as an increased flexibility in the mode of receptor use. R5 broad isolates showed higher infectivity in cells expressing wild-type CCR5 than R5 narrow isolates. Also, the increased flexibility of R5 broad isolates was concomitant with a lower sensitivity to inhibition by the CC chemokine RANTES. Our results indicate a close relationship between HIV-1 phenotypic changes and the pathogenic process, since the mode and efficiency of CCR5 use as well as the decrease in the RANTES sensitivities of isolated viruses are significantly correlated with CD4 + -T-cell decline in a patient. One possible explanation is that ligand competition at the CCR5 receptor or changed CCR5 availability may shape the outcome of HIV-1 infection.

In a phase I clinical trial in Guinea-Bissau, we have tested an immunotherapeutic HIV-1 vaccine candidate in HIV-1-infected subjects (V. R. Gomez Roman, K. J. Jensen, S. S. Jensen, C. Leo-Hansen, S. Jespersen, D. S. Te, C. M. Rodrigues, C. M. Janitzek, L. Vinner, T. L. Katzenstein, P. Andersen, I

The group B streptococcus (GBS) is the most important cause of life-threatening bacterial infections in newborn infants. Protective immunity to GBS infection is elicited by several surface proteins, one of which, the beta protein, is known to bind human IgA-Fc. Here, we show that the beta protein also binds human factor H (FH), a negative regulator of complement activation. Absorption experiments with whole human plasma demonstrated binding of FH to a GBS strain expressing beta protein but not to an isogenic beta-negative mutant. This binding was due to a direct interaction between beta and FH, as shown by experiments with purified proteins. Inhibition tests and studies with beta fragments demonstrated that FH and IgA-Fc bind to separate and nonoverlapping regions in beta. Heparin, a known ligand for FH, specifically inhibited the binding between beta and FH, suggesting that FH has overlapping binding sites for beta and heparin. Bacteria-bound FH retained its complement regulatory activity, implying that beta-expressing GBS may use bound FH to evade complement attack. The finding that beta protein binds FH adds to a growing list of interactions between human pathogens and complement regulatory proteins, supporting the notion that these interactions are of general importance in bacterial pathogenesis.

edited by Sue Adler and Diana Leonard, Stoke‐on‐Trent, Trentham Books, 2006, xiv + 238 pp., £23.99, ISBN 978 1 85856 401 2 Oxford, UK, Oxfam Publishing, 2007, 141 pp., £16.95, ISBN 9780855985998 We...

BACKGROUND Still no effective HIV-1 prophylactic or therapeutic vaccines are available. However, as the proportion of HIV-1-infected individuals on antiretroviral treatment is increasing, knowledge about the residual immune response is important for the possible development of an HIV-1 vaccine. METHODS In this study, the magnitude, breadth, and quality of the HIV-1-specific T-cell response in HIV-1-infected viremic individuals (n = 19) and individuals on highly active antiretroviral treatment (HAART) (n = 14) using multicolor flow cytometry were determined. RESULTS We found that magnitude and breadth of the CD8 T-cell response were significantly higher in viremic individuals than individuals on HAART (P < 0.0001 and P < 0.0001, respectively) and that the functionality of the overall HIV-1-specific response was significantly different in individuals on HAART and viremic individuals (P = 0.0020). In individuals on HAART, the remaining responses were primarily detected upon stimulation with overlapping peptides from Gag p24, integrase, and Nef. The Gag p24 response was more polyfunctional than corresponding responses observed in viremic individuals. CONCLUSIONS Identification of highly immunogenic regions also recognized by individuals on HAART may be important for HIV-1 vaccine development. Irrespective of HLA haplotype, specific regions within the HIV-1 genome that is targeted more frequently in individuals on HAART have been identified. However, further studies are required to establish if these particular regions could be interesting for a future vaccine that might limit the time and opportunity for escape mutations.

We investigated the potential of inducing additional T-cell immunity during chronic HIV-1 infection directed to subdominant HIV-1 epitopes from common HLA-supertypes. Ten treatment-naïve HIV-1-infected individuals were immunized with peptides in the adjuvant CAF01. One individual received placebo. T-cell immunogenicity was examined longitudinally by a flow cytometry (CD107a, IFNγ, TNFα, IL-2 and/or MIP1β expression) as well as IFNγ ELISPOT. Safety was evaluated by clinical follow up combined with monitoring of biochemistry, hematology, CD4 T-cell counts and viral load. New CD4 and CD8 T-cell responses specific for one or more vaccine epitopes were induced in 10/10 vaccinees. The responses were dominated by CD107a and MIP1β expression. There were no significant changes in HIV-1 viral load or CD4 T-cell counts. Our study demonstrates that the peptide/CAF01 vaccine is safe and that it is possible to generate new HIV-1 T-cell responses to defined epitopes in treatment-naïve HIV-1-infected individuals.

Background Spontaneous long-term HIV/SIV control in HIV-controller patients and SIV-controller macaques (SIC) is usually associated to protective MHC-class-I alleles and efficient CD8 T-cell responses. However, many HIV-controllers efficiently control HIV-infection despite of non-protective MHC background and weak CD8 T-cell responses, raising the question of real contribution of this response in maintaining viral control. We addressed this question by depleting in vivo CD8+ cells in SIC bearing or not protective MHC and weak CD8 T-cell responses.

For a CD8 epitope-based vaccine to match different geographic locations, the targeted epitopes for cytotoxic T-lymphocytes (CTLs) must be present in the local circulating HIV-1 strains. Secondly, the vaccine epitopes should match the host population HLA types. We characterized two new HIV-1 isolates from Guinea-Bissau. Also, we have identified 15 subdominant CD8 epitopes representing common HLA super-types theoretically covering most HLA alleles in any population. Herein we demonstrate that the selected vaccine epitopes are well conserved and simultaneously present in sequences from West Africa and Denmark. Use of the selected epitopes will likely ensure ≥10 immune targets in the majority of candidates for experimental therapeutic vaccination in both geographic regions. Our results warrant testing of the selected vaccine epitopes in both geographic locations.

Therapeutic immunization of HIV-1-infected individuals with or without anti-retroviral therapy is a new promising disease prevention. To induce a new cytotoxic T(CD8) lymphocyte (CTL) immunity during chronic HIV-1 infection 15 infrequently targeted but conserved HLA-supertype binding CTL epitopes from Gag, Pol, Nef, Env, Vpu and Vif were identified. The 15 T(CD8) and three T(CD4) helper peptides were GMP synthesised and formulated with a new adjuvant CAF01 which is a synthetic two-component liposomic adjuvant comprising the quaternary ammonium dimethyl-dioctadecyl-ammonium (DDA) and the immune modulator trehalose 6,6'-dibehenate (TDB). Using IFN-γ ELISPOT assay, T-cell immune induction by the vaccine was found to both CD4 and CD8 T-cell restricted peptides in HLA-A2 transgenic mice. Comprehensive toxicity studies of the CAF01 adjuvant-alone and together with different vaccines showed that CAF01 when tested at human dose levels was safe and well tolerated with only local inflammation at the site of injection and no systemic reactions. No pharmacological safety issues were observed in Beagle dogs. The HIV-1 vaccine toxicity study in the Gottingen Minipig(®) showed no systemic toxicity from five repetitive i.m. injections, each with a 2-week interval, of either the 18 HIV-1 peptide antigen solution (AFO18) or the AFO18-CAF01, in which the 18 HIV-1 peptides were formulated with the CAF01 adjuvant. Distinct inflammatory responses were observed in the injected muscles of the AFO18-CAF01 vaccine treated animals as a result of the immune stimulating effect of the adjuvant on the vaccine. The results of the toxicity studies provide optimism for phase I clinical trials evaluating the therapeutic HIV-1 T-cell vaccination approach using multiple subdominant minimal epitope peptides applying the novel cationic adjuvant CAF01.

Pregnancy represents a major challenge to immunologic tolerance. How the fetal “semiallograft” evades maternal immune attack is unknown. Pregnancy success may involve alteration of both central (thymic) and peripheral tolerance mechanisms. HIV infection is characterized by CD4+ T-cell depletion, chronic immune activation, and altered lymphocyte subsets. We studied immunologic consequences of pregnancy in 20 HIV-infected women receiving highly active antiretroviral therapy (HAART), and for comparison in 16 HIV-negative women. Lymphocyte subsets, thymic output, and cytokine profiles were measured prospectively during pregnancy and postpartum. A significant expansion of CD4+CD25+CD127lowFoxP3+ regulatory T cells indicating alteration of peripheral tolerance was seen during second trimester, but only in HIV-negative women. HIV-infected women had lower CD4 counts, lower thymic output and Th-2 cytokines, and more immune activation at all time points compared with controls. Immune activation was decreased in HIV-infected patients during pregnancy. In contrast, CD4 counts were increased in both groups. In conclusion, the study does not indicate that pregnancy adversely affects the immunologic course of HIV infection. However, despite HAART during pregnancy, HIV-infected women display different immunologic profiles from HIV-negative women, which may have importance for the induction of fetal-maternal tolerance and in part explain the increased risk of abortion in HIV-infected women.

Background: HIV-exposed, uninfected (HIV-EU) infants present hematologic and immunologic abnormalities at birth, and it remains to be clarified whether these abnormalities persist beyond infancy, for instance, affecting vaccination responses. Methods: Thymic size and thymic output were evaluated in 20 HIV-EU children at 15 months of age and compared with 10 age- and gender-matched controls. Regulatory T-cells (Tregs) and immune activation as well as cytokine profiles were determined, and the antibody response to Haemophilus influenzae Type b (Hib) vaccination was evaluated. Results: Thymic size was significantly lower in HIV-EU children (P = 0.011). However, CD4 and CD8 counts did not differ between HIV-EU and control children. Likewise, thymic output estimated as CD4+ cells expressing naive (CD45RA+CD62L+CD27+, P = 0.31) or recent thymic naive (CD45RA+CD27+CD31+, P = 0.13) phenotype, or CD4+ cells containing T-cell receptor excision circles (P = 0.47) were comparable. HIV-EU children and controls had similar levels of activated cells (CD4+CD38+HLA-DR+, P = 0.87; CD8+CD38+HLA-DR+, P = 0.22), Tregs (CD4+CD25+CD127lowFOXP3+, P = 0.53), and naive Tregs (CD4+CD25+CD127lowFOXP3+CD45RA+CD27+, P = 0.65). Finally, comparable titers of Haemophilus influenzae Type b antibodies in the 2 groups were found (P = 0.43). Conclusion: The study demonstrates reduced thymic size in HIV-EU children compared with children born to HIV-negative mothers, but no evidence of impaired thymic function, immune regulation, or antibody vaccination response was detected, suggesting that no qualitative immune deficits persist in HIV-EU children at 15 months of age.