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Introduction: Nirsevimab is an extended half-life (M252Y/S254T/T256E [YTE]-modified) monoclonal antibody to the pre-fusion conformation of the respiratory syncytial virus (RSV) Fusion protein, with established efficacy in preventing RSV-associated lower respiratory tract infection in infants for the duration of a typical RSV season. Previous studies suggest that nirsevimab confers protection via direct virus neutralization. Here we use preclinical models to explore whether fragment crystallizable (Fc)-mediated effector functions contribute to nirsevimab-mediated protection. Methods: Nirsevimab, MEDI8897* (i.e., nirsevimab without the YTE modification), and MEDI8897*-TM (i.e., MEDI8897* without Fc effector functions) binding to Fc γ receptors (FcγRs) was evaluated using surface plasmon resonance. Antibodydependent neutrophil phagocytosis (ADNP), antibody-dependent cellular phagocytosis (ADCP), antibody-dependent complement deposition (ADCD), and antibody-dependent cellular cytotoxicity (ADCC) were assessed through in vitro and ex vivo serological analyses. A cotton rat challenge study was performed with MEDI8897* and MEDI8897*-TM to explore whether Fc effector functions contribute to protection from RSV. Results: Nirsevimab and MEDI8897* exhibited binding to a range of FcγRs, with expected reductions in FcgR binding affinities observed for MEDI8897*-TM. Nirsevimab exhibited in vitro ADNP, ADCP, ADCD, and ADCC activity above background levels, and similar ADNP, ADCP, and ADCD activity to palivizumab. Nirsevimab administration increased ex vivo ADNP, ADCP, and ADCD activity in participant serum from the MELODY study (NCT03979313). However, ADCC levels remained similar between nirsevimab and placebo. MEDI8897* and MEDI8897*-TM exhibited similar dose-dependent reduction in lung and nasal turbinate RSV titers in the cotton rat model. Conclusion: Nirsevimab possesses Fc effector activity comparable with the current standard of care, palivizumab. However, despite possessing the capacity for Fc effector activity, data from RSV challenge experiments illustrate that nirsevimab-mediated protection is primarily dependent on direct virus neutralization. [ABSTRACT FROM AUTHOR]

It is of great significance to develop a drug carrier that effectively targets chemotherapeutic drugs to the tumor site, improves therapeutic efficacy and reduces side effects associated with high-dose medicines. In the present study, an intelligent drug carrier system, FA-β-CD/DOX@Cu2+@GA@Fe3O4, was synthesized by skillfully introducing metal ions as a bridge base. The performance of the prepared FA-β-CD@Cu2+@GA@Fe3O4 metal-polymer-coordinated nanocomplexes were determined by UV-visible spectroscopy, NMR, FT-IR, XPS, VSM, DLS, and TEM analysis. The data showed that these nanocomplexes had good pH/GSH-responsive drug release behavior, and enabled enhanced magnetic and folic acid-mediated tumor cell targeting. Moreover, the toxicity effects of the FA-β-CD/DOX@Cu2+@GA@Fe3O4 on 3T3 cells and 4T1 cells were measured by the MTT method, and it was found that it displayed low cytotoxicity against 3T3 cells and had a stronger effect on killing 4T1 cells than DOX alone. The results also showed that the Cu2+-based coordination polymers had a significant ability to deplete GSH and generate ROS. It could be concluded that the introduction of Cu2+ not only facilitated the assembly of nanocomplexes, but also successfully enhanced the anti-tumor effect, making FA-β-CD@Cu2+@GA@Fe3O4 a potential nanoplatform for effectively mediating combined chemotherapy and chemokinetic therapy for tumors. All these characteristics verified the great potential of FA-β-CD/DOX@Cu2+@GA@Fe3O4 in multipurpose smart drug delivery systems, accelerating the application range of metal-polymer-coordinated nanocomplexes in biomedical fields. An intelligent drug carrier system FA-β-CD/DOX@Cu2+@GA@Fe3O4 was synthesized by skillfully introducing metal ions as bridge base. Magnetic and receptor-targeting delivery of doxorubicin. It can induce the specific release of therapeutic agents through pH/GSH stimulation. Achieving an efficient tumor-specific chemotherapy/CDT therapy. [ABSTRACT FROM AUTHOR]

Antibody–drug conjugates are powerful tools for combatting a wide array of cancers. Drug conjugation to a therapeutic antibody often alters molecular characteristics, such as hydrophobicity and effector function, resulting in quality deterioration. To develop a drug conjugation methodology that maintains the molecular characteristics of the antibody, we engineered a specific peptide for conjugation to the Fc region. We used trastuzumab and the chelator (DOTA) as model antibody and payload, respectively. Interestingly, peptide/DOTA-conjugated trastuzumab exhibited enhanced antibody-dependent cellular cytotoxicity (ADCC) and increased thermal stability. Detailed structural and thermodynamic analysis clarified that the conjugated peptide blocks the Fc dynamics like a "wedge." We revealed that (1) decreased molecular entropy results in enhanced ADCC, and (2) blockade of Fc denaturation results in increased thermal stability. Thus, we believe that our methodology is superior not only for drug conjugation but also as for reinforcing therapeutic antibodies to enhance ADCC and thermal stability. [ABSTRACT FROM AUTHOR]

A cure for HIV-1 (HIV) remains unrealized due to a reservoir of latently infected cells that persist during antiretroviral therapy (ART), with reservoir size associated with adverse health outcomes and inversely with time to viral rebound upon ART cessation. Once established during ART, the HIV reservoir decays minimally over time; thus, understanding factors that impact the size of the HIV reservoir near its establishment is key to improving the health of people living with HIV and for the development of novel cure strategies. Yet, to date, few correlates of HIV reservoir size have been identified, particularly in pediatric populations. Here, we employed a cross-subtype intact proviral DNA assay (CS-IPDA) to quantify HIV provirus between one- and two-years post-ART initiation in a cohort of Kenyan children (n = 72), which had a median of 99 intact (range: 0–2469), 1340 defective (range: 172–3.84 × 104), and 1729 total (range: 178–5.11 × 104) HIV proviral copies per one million T cells. Additionally, pre-ART plasma was tested for HIV Env-specific antibody-dependent cellular cytotoxicity (ADCC) activity. We found that pre-ART gp120-specific ADCC activity inversely correlated with defective provirus levels (n = 68, r = −0.285, p = 0.0214) but not the intact reservoir (n = 68, r = −0.0321, p-value = 0.800). Pre-ART gp41-specific ADCC did not significantly correlate with either proviral population (n = 68; intact: r = −0.0512, p-value = 0.686; defective: r = −0.109, p-value = 0.389). This suggests specific host immune factors prior to ART initiation can impact proviruses that persist during ART. [ABSTRACT FROM AUTHOR]

Our data demonstrate that IgG-anaphylaxis can still occur in neutropenic mice and that neutrophil-targeting mAbs likely protect from anaphylaxis through their capacity to desensitize effector cells by engaging Fc Rs and inducing the release of PAF, rather than via neutrophil depletion I per se i . In humans, it is largely accepted that anaphylaxis relies predominately on IgE antibodies.[1] However, IgG might also contribute to anaphylaxis induced by infused drugs.[1] Several mouse models have been developed to identify key effector cells and mediators of anaphylaxis. [Extracted from the article]

Including active renal excretion in physiologically based kinetic (PBK) models can improve their use in quantitative in vitro- in vivo extrapolation (QIVIVE) as a new approach methodology (NAM) for predicting the acute toxicity of organic cation transporter 2 (OCT2) substrates like paraquat (PQ). To realise this NAM, kinetic parameters Vmax and Km for in vitro OCT2 transport of PQ were obtained from the literature. Appropriate scaling factors were applied to translate the in vitro Vmax to an in vivo Vmax. in vitro cytotoxicity data were defined in the rat RLE-6TN and L2 cell lines and the human A549 cell line. The developed PQ PBK model was used to apply reverse dosimetry for QIVIVE translating the in vitro cytotoxicity concentration-response curves to predicted in vivo toxicity dose-response curves after which the lower and upper bound benchmark dose (BMD) for 50% lethality (BMDL 50 and BMDU 50) were derived by applying BMD analysis. Comparing the predictions to the in vivo reported LD 50 values resulted in a conservative prediction for rat and a comparable prediction for human showing proof of principle on the inclusion of active renal excretion and prediction of PQ acute toxicity for the developed NAM. [Display omitted] • A new approach methodology (NAM) predicting acute paraquat toxicity was defined. • This NAM included a newly developed PBK model with active renal excretion via OCT2. • Cytotoxicity data in lung epithelial cell lines were used for QIVIVE. • QIVIVE was based on PBK model based reverse dosimetry. • The in vivo dose response curves adequately predicted acute paraquat toxicity. [ABSTRACT FROM AUTHOR]

Novel approaches are required to improve the efficacy of immunotherapies and increase the proportion of patients who experience a benefit. Antibody‐dependent cell‐mediated cytotoxicity (ADCC) contributes to the efficacy of many monoclonal antibodies therapies. Natural killer (NK) cells mediate ADCC, though responses are highly variable and depend on prior treatment as well as other factors. Thus, strategies to increase NK cell activity are expected to improve multiple therapies. Both cytokine treatment and NK cell receptor engineering are being explored to increase ADCC. Post‐translational modifications, including glycosylation, are widely recognized as mediators of cellular processes but minimally explored as an alternative strategy to increase ADCC. We evaluated the impact of treatment with kifunensine, an inhibitor of asparagine‐linked (N‐)glycan processing, on ADCC using primary and cultured human NK cells. We also probed affinity using binding assays and CD16a structure with nuclear magnetic resonance spectroscopy. Treating primary human NK cells and cultured YTS‐CD16a cells with kifunensine doubled ADCC in a CD16a‐dependent manner. Kifunensine treatment also increased the antibody‐binding affinity of CD16a on the NK cell surface. Structural interrogation identified a single CD16a region, proximal to the N162 glycan and the antibody‐binding interface, perturbed by the N‐glycan composition. The observed increase in NK cell activity following kifunensine treatment synergized with afucosylated antibodies, further increasing ADCC by an additional 33%. These results demonstrate native N‐glycan processing is an important factor that limits NK cell ADCC. Furthermore, optimal antibody and CD16a glycoforms are defined that provide the greatest ADCC activity. [ABSTRACT FROM AUTHOR]

Therapeutic monoclonal antibodies (mAbs) are standard care for many B-cell haematological cancers. The modes of action for these mAbs include: induction of cancer cell lysis by activating Fcg-receptors on innate immune cells; opsonising target cells for antibody-dependent cellular cytotoxicity or phagocytosis, and/or triggering the classical complement pathway; the simultaneous binding of cancer cells with T-cells to create an immune synapse and activate perforin-mediated T-cell cytotoxicity against cancer cells; blockade of immune checkpoints to facilitate T-cell cytotoxicity against immunogenic cancer cell clones; and direct delivery of cytotoxic agents via internalisation of mAbs by target cells. While treatment regimens comprising mAb therapy can lead to durable anti-cancer responses, disease relapse is common due to failure of mAb therapy to eradicate minimal residual disease. Factors that limit mAb efficacy include: suboptimal effector cell frequencies, overt immune exhaustion and/or immune anergy, and survival of diffusely spread tumour cells in different stromal niches. In this review, we discuss how immunomodulatory changes arising from exposure to structured bouts of acute exercise might improve mAb treatment efficacy by augmenting (i) antibody-dependent cellular cytotoxicity, (ii) antibody-dependent cellular phagocytosis, (iii) complement-dependent cytotoxicity, (iv) T-cell cytotoxicity, and (v) direct delivery of cytotoxic agents. [ABSTRACT FROM AUTHOR]

Arum rupicola Boiss var. rupicola is a preferred ingredient in traditional medicine in various countries, including Türkiye. The current study aims to establish the antiparasitic effect of A. rupicola Boiss var. rupicola on the eggs and larvae of T. canis in vitro. An ovicidal effect was not detected in the plant extracts, and embryogenesis in the T. canis eggs was not affected by the leaves' ethanolic extract and the distilled water extract of the rhizome during the incubation periods (6, 12, and 24 h). The larvicidal activity was observed in both extracts on the T. canis larvae after hatching. All T. canis larvae were motile after being incubated for 6 h with the leaf extract at 10 mg/mL. However, after 12 and 24 h of incubation at the same dose, the paralysed larvae rate was 9% and 15%, respectively. After 6, 12, and 24-h incubation with the leaf extract at 40 mg/mL, the paralysed larvae rates were 30%, 37%, and 42%, respectively. Dose and time factor analysis results were significant statistically in the leaf extracts (p < 0.001). The paralysed larvae rate was 10%, 12%, and 17% after 6, 12, and 24-h incubation, respectively, with the undiluted rhizome extract. Dose and time factor analysis results were statistically insignificant in the rhizome extracts (p > 0.05). Cytotoxic and haemolytic activities were observed only in the leaf extract. The paralysed larvae rate was 1.45 times higher in the leaf extracts than in the rhizome extracts (p < 0.001). Future studies may elucidate the effect of A. rupicola Boiss var. rupicola extracts on visceral larva migrans during in vivo experiments and determine the effectiveness of these plant extracts on other parasites. [ABSTRACT FROM AUTHOR]

To evaluate the anti-tumor activities of CD20/HLA-DR CrossmabCH1-CL through cell and animal models. Based on "knobs-into-holes" and "crossover" technology, CrossMab, targeting CD20 and HLA-DR, was constructed. A binding assay and a competitive inhibition assay were performed to confirm its specificity. The effects of CrossMab on antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity were measured. Cell apoptosis, lysosome-mediated cell death, and lysosomal permeability were quantified. In addition, the effects of CrossMab on peripheral blood leukocytes were tested. The pharmacokinetics were determined with a noncompartmental analysis model. Human malignant lymphoma xenograft models in CB17-SCID mice were established for an in-vivo efficacy study. The antitumor activities of CrossMab were shown both in vitro and in vivo. CrossMab exhibited strong binding to CD20 and HLA-DR at the same time in Raji cells. CrossMab also demonstrated antilymphoma effects by inducing antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. Furthermore, CrossMab altered the lysosomal membrane permeability. The toxicity of CrossMab on normal peripheral blood lymphocytes (PBLs) was specific to B cells. A mouse xenograft model demonstrated the antitumor activities of CrossMab in vivo. CrossMab exhibited an enhanced antigen recognition ability and antitumor activities in lymphoma without evident toxicity. CrossMab could be an effective immunotherapeutic strategy for non-Hodgkin lymphoma. [ABSTRACT FROM AUTHOR]

Antibody-dependent cell-mediated cytotoxicity (ADCC) by natural killer (NK) lymphocytes eliminates cells infected with viruses. Anti-viral ADCC requires three components: (1) antibody; (2) effector lymphocytes with the Fc-IgG receptor CD16A; and (3) viral proteins in infected cell membranes. Fc-afucosylated antibodies bind with greater affinity to CD16A than fucosylated antibodies; individuals' variation in afucosylation contributes to differences in ADCC. Current assays for afucosylated antibodies involve expensive methods. We report an improved bioassay for antibodies that supports ADCC, which encompasses afucosylation. This assay utilizes the externalization of CD107a by NK-92-CD16A cells after antibody recognition. We used anti-CD20 monoclonal antibodies, GA101 WT or glycoengineered (GE), 10% or ~50% afucosylated, and CD20-positive Raji target cells. CD107a increased detection 7-fold compared to flow cytometry to detect Raji-bound antibodies. WT and GE antibody effective concentrations (EC50s) for CD107a externalization differed by 20-fold, with afucosylated GA101-GE more detectable. The EC50s for CD107a externalization vs. 51Cr cell death were similar for NK-92-CD16A and blood NK cells. Notably, the % CD107a-positive cells were negatively correlated with dead Raji cells and were nearly undetectable at high NK:Raji ratios required for cytotoxicity. This bioassay is very sensitive and adaptable to assess anti-viral antibodies but unsuitable as a surrogate assay to monitor cell death after ADCC. [ABSTRACT FROM AUTHOR]

• Toxicity evaluations of Southern African plants used to treat pain and inflammation are reviewed. • Only 117 of the >500 plants traditionally used to treat pain and inflammation have been screened for toxicity. • Cell-based and brine shrimp lethality assays were identified as the most frequently used assay models. • Few species have been tested using more than one assay and substantially more study is required. • Of the plants that have been screened for toxicity, >80% were reported to be nontoxic. The harmful side effects associated with conventional anti-inflammatory pharmaceuticals has focussed attention on medicinal plants as alternative therapeutics. However, the use of medicinal plants is predominantly based on ethnobotanical knowledge and often lacks toxicity data and safety validation. A comprehensive review of the toxicity and phytochemical properties of southern African medicinal plants used for inflammation and pain-related ailments was undertaken. Various ethnobotanical books and search engines including Science direct, Sci-Finder, Google Scholar and Scopus were used to determine which medicinal plants have been screened for toxicity. A total of 117 medicinal plants have previously been evaluated by toxicity screening. The predominant toxicity test used was the MTT reduction assay (109 species), followed by the brine shrimp lethality assay (57 species), and the XTT assay (24 species). The Ames test, which was used to screen 20 species, was the most frequently used assay to determine mutagenic properties of the plant extracts. The top five most commonly screened cell lines were Vero monkey kidney cells (46 plant extracts), RAW 264.7 macrophages (23 extracts), human breast cancer cells (MCF-7, 12) (21 extracts), mouse fibroblast (3T3) (18 extracts) and Graham cells (HEK-293) (17 extracts). Over 80% of the tested medicinal plant extracts were found to be non-toxic. Although many species have been evaluated for their toxicity properties, plant extracts are often tested using one or two assays and also lack diversity in terms of choice of cell lines used for screening. Phytochemical studies remain scarce and substantial further work is required. [ABSTRACT FROM AUTHOR]

Multifunctional nanocarriers are presently used to solve crucial unmet challenges in cancer treatment. In this project, we reported an intelligent amine mesoporous silica (MSN-NH2)-based nanocarrier with a potent fluorescence emission and imaging capacity for the delivery of the payload to the tumor cells. Gemcitabine (GEM)-loaded MSN-NH2 has been used as a drug model. Hydroxyl and carboxylic acid carbon dots (CDs) were used to electrostatically coat the surface of MSN-NH2@GEM to yield biocompatible CDs‐capped MSN-NH2 (CDs/MSN-NH2@GEM). Folic acid (FA) was covalently grafted onto the carboxyl groups of CDs/MSN-NH2@GEM to form (FA/CDs/MSN-NH2@GEM) to deliver the nanocarrier to the site of action. GEM release from the formulation is sustained and dependent on pH (pH 5.4 > pH 7.4), according to the in vitro release assessment at different pH values. FA-targeted CDs/MSN-NH2@GEM developed had higher cytotoxicity compared with the non-targeted NPs in HeLa and K562 (human cervical carcinoma and chronic myeloid leukemia cell lines, respectively), as shown by the MTT assay. Fluorescence microscopic images and flow cytometry assay were used to comprehend anticancer activity and express targeting ability and cellular uptake FA/CDs/MSN-NH2@GEM toward the HeLa cancer cells. Moreover, molecular docking was used to evaluate the interactions of GEM molecule with the human deoxycytidine kinase (dCK). The present study may present a new understanding of the development of targeted, intelligent CDs‐capped MSN-NH2--based hybrid materials in cancer therapy. [ABSTRACT FROM AUTHOR]

The complement system is a crucial part of the innate immune response, providing defense against invading pathogens and cancer cells. Recently, it has become evident that the complement system plays a significant role in anticancer activities, particularly through complement-dependent cytotoxicity (CDC), alongside antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cell-mediated phagocytosis (ADCP). With the discovery of new roles for serum complement molecules in the human immune system, various approaches are being pursued to develop CDC-enhanced antibody therapeutics. In this review, we focus on successful antibody engineering strategies for enhancing CDC, analyzing the lessons learned and the limitations of each approach. Furthermore, we outline potential pathways for the development of antibody therapeutics specifically aimed at enhancing CDC for superior therapeutic efficacy in the future. [ABSTRACT FROM AUTHOR]

COVID-19 and influenza both cause enormous disease burdens, and vaccines are the primary measures for their control. Since these viral diseases are transmitted through the mucosal surface of the respiratory tract, developing an effective and convenient mucosal vaccine should be a high priority. We previously reported a recombinant vesicular stomatitis virus (rVSV)-based bivalent vaccine (v-EM2/SPΔC1Delta) that protects animals from both SARS-CoV-2 and influenza viruses via intramuscular and intranasal immunization. Here, we further investigated the immune response induced by oral immunization with this vaccine and its protective efficacy in mice. The results demonstrated that the oral delivery, like the intranasal route, elicited strong and protective systemic immune responses against SARS-CoV-2 and influenza A virus. This included high levels of neutralizing antibodies (NAbs) against SARS-CoV-2, as well as strong anti-SARS-CoV-2 spike protein (SP) antibody-dependent cellular cytotoxicity (ADCC) and anti-influenza M2 ADCC responses in mice sera. Furthermore, it provided efficient protection against challenge with influenza H1N1 virus in a mouse model, with a 100% survival rate and a significantly low lung viral load of influenza virus. All these findings provide substantial evidence for the effectiveness of oral immunization with the rVSV bivalent vaccine. [ABSTRACT FROM AUTHOR]

Therapies that boost the antitumor immune response have shown a great deal of success. Although most of these therapies have focused on enhancing T cell functions, there is a growing interest in developing therapies that can target other immune cell subsets. Like T cells, natural killer (NK) cells are cytotoxic effector cells that play a key role in the antitumor response. To advance the development of NK-based therapies, we developed a functional screen to rapidly identify antibodies that can activate NK cells. We displayed antibodies on a mammalian target cell line and probed their ability to stimulate NK cell-mediated cytotoxicity. From this screen, we identified five antibodies that bound with high affinity to NK cells and stimulated NK cell-mediated cytotoxicity and interferon-γ (IFN-γ) secretion. We demonstrate that these antibodies can be further developed into bispecific antibodies to redirect NK cell-mediated cytotoxicity toward CD20+ B cell lymphoma cells and HER2+ breast cancer cells. While antibodies to two of the receptors, CD16 and NCR1, have previously been targeted as bispecific antibodies to redirect NK cell-mediated cytotoxicity, we demonstrate that bispecific antibodies targeting NCR3 can also potently activate NK cells. These results show that this screen can be used to directly identify antibodies that can enhance antitumor immune responses.

The role of vaccine-induced anti-V2 Abs was tested in three protection experiments in rhesus macaques. In an experiment using immunogens similar to those in the RV144 vaccine trial (Anti-envelope [Env]), nine rhesus macaques were coimmunized with gp16092TH023 DNA and SIV gag and gp120A244 and gp120MN proteins. In two V2-focused experiments (Anti-V2 and Anti-V2 Mucosal), nine macaques in each group were immunized with V1V292TH023 DNA, V1V2A244 and V1V2CasaeA2 proteins, and cyclic V2CaseA2 peptide. DNA and protein immunogens, formulated in Adjuplex, were given at 0, 4, 12, and 20 weeks, followed by intrarectal SHIVBaL.P4 challenges. Peak plasma viral loads (PVL) of 106-107 copies/ml developed in all nine sham controls. Overall, PVL was undetectable in one third of immunized macaques, and two animals tightly controlled the virus with the Anti-V2 Mucosal vaccine strategy. In the Anti-Env study, Abs that captured or neutralized SHIVBaL.P4 inversely correlated with PVL. Conversely, no correlation with PVL was found in the Anti-V2 experiments with nonneutralizing plasma Abs that only captured virus weakly. Titers of Abs against eight V1V2 scaffolds and cyclic V2 peptides were comparable between controllers and noncontrollers as were Ab-dependent cellular cytotoxicity and Ab-dependent cell-mediated virus inhibition activities against SHIV-infected target cells and phagocytosis of gp120-coated beads. The Anti-Env experiment supports the role of vaccine-elicited neutralizing and nonneutralizing Abs in control of PVL. However, the two V2-focused experiments did not support a role for nonneutralizing V2 Abs alone in controlling PVL, as neither Ab-dependent cellular cytotoxicity, Ab-dependent cell-mediated virus inhibition, nor phagocytosis correlated inversely with heterologous SHIVBaL.P4 infection.

The article discusses the importance of anti-D prophylaxis in protecting newborns from haemolytic disease, emphasizing the need for effective and safe treatments globally. It highlights the challenges faced in low- and middle-income countries due to substandard medications and limited availability of prophylaxis, leading to adverse outcomes for infants. The text also raises concerns about the efficacy and safety of monoclonal anti-D products, particularly those marketed by Bharat Serums and Vaccines Ltd., calling for rigorous evaluation and monitoring to ensure public health safety worldwide. [Extracted from the article]

The kinetics of Fc-mediated functions following SARS-CoV-2 infection or vaccination in people living with HIV (PLWH) are not known. We compared SARS-CoV-2 spike-specific Fc functions, binding, and neutralization in PLWH and people without HIV (PWOH) during acute infection (without prior vaccination) with either the D614G or Beta variants of SARS-CoV-2, or vaccination with ChAdOx1 nCoV-19. Antiretroviral treatment (ART)–naïve PLWH had significantly lower levels of IgG binding, neutralization, and antibody-dependent cellular phagocytosis (ADCP) compared with PLWH on ART. The magnitude of antibody-dependent cellular cytotoxicity (ADCC), complement deposition (ADCD), and cellular trogocytosis (ADCT) was differentially triggered by D614G and Beta. The kinetics of spike IgG-binding antibodies, ADCC, and ADCD were similar, irrespective of the infecting variant between PWOH and PLWH overall. However, compared with PWOH, PLWH infected with D614G had delayed neutralization and ADCP. Furthermore, Beta infection resulted in delayed ADCT, regardless of HIV status. Despite these delays, we observed improved coordination between binding and neutralizing responses and Fc functions in PLWH. In contrast to D614G infection, binding responses in PLWH following ChAdOx-1 nCoV-19 vaccination were delayed, while neutralization and ADCP had similar timing of onset, but lower magnitude, and ADCC was significantly higher than in PWOH. Overall, despite delayed and differential kinetics, PLWH on ART develop comparable responses to PWOH, supporting the prioritization of ART rollout and SARS-CoV-2 vaccination in PLWH. [ABSTRACT FROM AUTHOR]

The study of Aronia melanocarpa's (A. melanocarpa) biological activity is focused on obtaining the crude extract and separation of the flavonol compounds. The extraction and fractionation of A. melanocarpa fruits, followed by quantitative analysis, were accomplished using high-performance liquid chromatography and Darco G-60 filtering. This approach enabled the quantification of flavonoids within each fraction. The antioxidative, immunomodulating activities and cytotoxicity with respect to the lymphoblast cell line RPMI-1788 were studied. The flavonol extract of A. melanocarpa has been shown to have a high capacity to neutralize free DPPH and AAPH radicals in vitro. It also caused an accelerated 'respiratory burst' formation of neutrophils and an increase in the metabolic reserves of cells in rats exposed to cyclophosphamide. The reference solution (an equivalent quercetin-rutin blend) contributed to a decrease in lipid peroxidation, intensifying phagocytosis processes. The studied compounds demonstrated their low influence on the leukocyte blood profile in animals. [ABSTRACT FROM AUTHOR]

Infant antibody responses to viral infection can differ from those in adults. However, data on the specificity and function of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in infants, and direct comparisons between infants and adults are limited. Here, we characterize antibody binding and functionality against Wuhan-Hu-1 (B lineage) strain SARS-CoV-2 in convalescent plasma from 36 postpartum women and 14 of their infants infected with SARS-CoV-2 from a vaccine-naïve prospective cohort in Nairobi, Kenya. We find significantly higher antibody titers against SARS-CoV-2 Spike, receptor binding domain and N-terminal domain, and Spike-expressing cell-surface staining levels in infants versus mothers. Plasma antibodies from mothers and infants bind to similar regions of the Spike S2 subunit, including the fusion peptide (FP) and stem helix-heptad repeat 2. However, infants display higher antibody levels and more consistent antibody escape pathways in the FP region compared to mothers. Finally, infants have significantly higher levels of antibody-dependent cellular cytotoxicity (ADCC), though, surprisingly, Spike pseudovirus neutralization titers between infants and mothers are similar. These results suggest infants develop distinct SARS-CoV-2 binding and functional antibody activities and reveal age-related differences in humoral immunity to SARS-CoV-2 infection that could be relevant to protection and COVID-19 disease outcomes. Data on antibody response to SARS-CoV-2 in infants directly compared with their mothers is limited. Stoddard et al. find distinct antibody profiles in infants, including elevated levels of antibody binding to Spike, elevated ADCC, and convergent antibody binding escape profiles in the Spike fusion peptide. [ABSTRACT FROM AUTHOR]

Fibroblast growth factor (FGF)-inducible 14 (Fn14) activates the classical and alternative NFkB (nuclear factor 'kappa-light-chain-enhancer' of activated Bcells) signaling pathway but also enhances tumor necrosis factor (TNF)-induced cell death. Fn14 expression is upregulated in non-hematopoietic cells during tissue injury and is also often highly expressed in solid cancers. In view of the latter, there were and are considerable preclinical efforts to target Fn14 for tumor therapy, either by exploiting Fn14 as a target for antibodies with cytotoxic activity (e.g. antibody-dependent cellular cytotoxicity (ADCC)-inducing IgG variants, antibody drug conjugates) or by blocking antibodies with the aim to interfere with protumoral Fn14 activities. Noteworthy, there are yet no attempts to target Fn14 with agonistic Fc effector function silenced antibodies to unleash the proinflammatory and cell death-enhancing activities of this receptor for tumor therapy. This is certainly not at least due to the fact that anti-Fn14 antibodies only act as effective agonists when they are presented bound to Fcg receptors (FcgR). Thus, there are so far no antibodies that robustly and selectively engage Fn14 signaling without triggering unwanted FcgR-mediated activities. In this study, we investigated a panel of variants of the anti-Fn14 antibody 18D1 of different valencies and domain architectures with respect to their inherent FcgRindependent ability to trigger Fn14-associated signaling pathways. In contrast to conventional 18D1, the majority of 18D1 antibody variants with four or more Fn14 binding sites displayed a strong ability to trigger the alternative NFkB pathway and to enhance TNF-induced cell death and therefore resemble in their activity soluble (TNF)-like weak inducer of apoptosis (TWEAK), one form of the natural occurring ligand of Fn14. Noteworthy, activation of the classical NFkB pathway, which naturally is predominately triggered by membrane-bound TWEAK but not soluble TWEAK, was preferentially observed with a subset of constructs containing Fn14 binding sites at opposing sites of the IgG scaffold, e.g. IgG1-scFv fusion proteins. A superior ability of IgG1-scFv fusion proteins to trigger classical NFkB signaling was also observed with the anti-Fn14 antibody PDL192 suggesting that we identified generic structures for Fn14 antibody variants mimicking soluble and membrane-bound TWEAK. [ABSTRACT FROM AUTHOR]

γδ T cells, with their properties of both the innate and acquired immune systems, are suitable candidates for cellular immunotherapy in cancer. Because of their non-major histocompatibility complex (MHC) binding T cell receptor, allogenic transfer is feasible without relevant graft versus host reactions. In recent years, much experience has been gained with ex vivo expansion and stimulation of γδ T cells using bisphosphonates and Interleukin 2. Unfortunately, many current stimulation protocols are based on the use of xenogenic materials and other potentially hazardous supplements, which conflicts with basic principles of Good Manufacturing Practice (GMP). Adherence to the concept and current guidelines of GMP is state of the art for production of Advanced Therapy Medicinal Products (ATMP) like cell therapeutics and a necessity for clinical use under a regulatory perspective. In this study, we developed a new stimulation protocol that induces a marked increase of γδ T cell counts and allows for an easier transition from research to clinical applications with minimized regulatory workload. It reliably leads to a cell product with a purity of more than 90% γδ T cells and improved in vitro anti-tumor activity compared to our previous standard procedure. Furthermore, by investigating correlations between properties of unstimulated γδ T cells and proliferation rate as well as degranulation ability of stimulated γδ T cells, we can draw conclusions about suitable donors. Finally, we examined if expansion can be improved by pulsing zoledronate and/or using Interleukin 15 with or without Interleukin 2. Significant improvements can be achieved with respect to intrinsic and antibody-dependent cell-mediated cytotoxicity. Our results demonstrate that the stimulation protocol presented here leads to an improved γδ T cell product for future clinical applications. [ABSTRACT FROM AUTHOR]

• South African plants used traditionally to treat inflammation were tested for the ability to modulate cytokine release in RAW 264.7 cells. • Toxicity of the extracts was evaluated in RAW 264.7 and human dermal fibroblasts. • Nontoxic extract does were tested in unstimulated and LPS-stimulated RAW 264.7 cells and the media was screened using cytokine multiplex bead assays. • Ethanol and aqueous extracts had upregulated the secretion of IL-2 and IL-10 in unstimulated cells, but significantly decreased cytokine secretion in LPS-stimulated cells. • Cytokine modulatory activity of Erythrina lysistemon bark, as well as Warburgia salutaris and Zantedeschia albomaculata leaf extracts were particularly noteworthy. The use of medicinal plants to treat inflammatory and auto-immune disorders is a common practice in southern African. However, the mechanisms of action related to the traditional use of herbal remedies as immunomodulatory agents remain relatively unknown. This study aims to investigate the cytotoxic and immunomodulatory properties of important southern African medicinal plants used traditionally to treat inflammation and pain. Cytokine multiplex-bead assays were used to evaluate the anti-inflammatory effects of seventeen medicinal plants against interleukin-2 (IL-2) and interleukin-10 (IL-10) activity. The assay was conducted using lipopolysaccharide (LPS)-stimulated and unstimulated murine RAW 264.7 macrophage cells treated with aqueous and ethanol extracts. The MTS assay was used to determine the percentage cell viability and 50% cytotoxic concentration (IC 50) in RAW 264.7 and human dermal fibroblast (HDF) cell lines. The aqueous extracts showed minimal cytotoxicity at the highest concentration screened (5mg/mL). Unstimulated RAW 264.7 cells treated with the plant extracts exhibited immunomodulatory effects by significantly up-regulating the production of an anti-inflammatory cytokine IL-10 compared to the LPS-stimulated extracts. The aqueous bark extract of Erythrina lysistemon Hutch., as well as the leaves of Warburgia salutaris (G. Bertol.) Chiov., and Zantedeschia albomaculata (Hook.) Baill showed the greatest stimulation of IL-10 and IL-2 production in RAW 264.7 cells. Of note, E. lysistemon showed exceptional results by regulation the levels of IL-10 up to 7000-fold increase compared to the negative LPS unstimulated control. This study provides insights to the possible mechanisms involved in the use of southern African medicinal plants as immunomodulatory agents. [ABSTRACT FROM AUTHOR]

Though binding sites for the complement factor C1q and the canonical fragment crystallizable (Fc) gamma receptors (Fc γ Rs) on immunoglobulin G (IgG) molecules overlap, how C1q decoration of immune complexes (ICs) influences their ability to engage Fc γ Rs remains unknown. In this report, we use recombinant human Fc multimers as stable IC mimics to show that C1q engagement of ICs directly and transiently inhibits their interactions with Fc γ RIII (CD16) on human natural killer (NK) cells. This inhibition occurs by C1q engagement alone as well as in concert with other serum factors. Furthermore, the inhibition of Fc γ RIII engagement mediated by avid binding of C1q to ICs is directly associated with IC size and dependent on the concentrations of both C1q and Fc multimers present. Functionally, C1q-mediated Fc blockade limits the ability of NK cells to induce the upregulation of the cosignaling molecule, 4-1BB (CD137), and to mediate antibody-dependent cell-mediated cytotoxicity (ADCC). Although C1q is traditionally viewed as a soluble effector molecule, we demonstrate that C1q may also take on the role of an "immunologic rheostat," buffering Fc γ R-mediated activation of immune cells by circulating ICs. These data define a novel role for C1q as a regulator of immune homeostasis and add to our growing understanding that complement factors mediate pleiotropic effects. [ABSTRACT FROM AUTHOR]

Purpose: Zolbetuximab (IMAB362) is engineered to induce antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity. We evaluated ADCC activity and the impact of the immune-modulating drugs zoledronic acid (ZA) and interleukin-2 (IL-2) as co-treatment with zolbetuximab on relevant immune cell populations and ADCC lysis activity. Methods: This phase 1, multicenter, open-label study investigated the immunological effects and activity, safety, tolerability, and antitumor activity of multiple doses of zolbetuximab alone (n = 5) or in combination with ZA (n = 7) or with ZA plus two different dose levels of IL-2 (low dose: 1 million international units [mIU] [n = 9]; intermediate dose: 3 mIU [n = 7]) in pretreated patients with advanced gastric and gastroesophageal junction (G/GEJ) adenocarcinoma. Results: Twenty-eight patients with previously treated advanced G/GEJ adenocarcinoma that was CLDN18.2-expressing were enrolled into four treatment arms. Treatment with zolbetuximab + ZA + IL-2 induced short-lived expansion and activation of ADCC-mediating cell populations, namely γ9δ2 T cells and natural killer cells, within 2 days after administration; this effect was more pronounced with intermediate-dose IL-2. Expansion and activation of regulatory T cells treated with either IL2 dose was moderate and short-lived. Strong ADCC activity was observed with zolbetuximab alone. Short-lived ADCC activity was observed in several patients treated with ZA + intermediate-dose IL-2, but not lower-dose IL-2. In the clinical efficacy population, the best confirmed response was stable disease (n = 11/19; 58%). Conclusions: Zolbetuximab mediates proficient ADCC in patients with pretreated advanced G/GEJ cancers. Co-treatment with ZA + IL-2 did not further improve this effect. Trial registration: NCT01671774 [ABSTRACT FROM AUTHOR]

Abnormal remodeling of collagen and extracellular matrix caused by the accumulation of senescent fibroblasts in the dermis is the most likely cause of skin aging. Therefore, the application of "senolysis," in which only senescent cells are cleared from the body, has a potential in the development of antiaging treatments for skin. However, markers that label senescent fibroblasts only reflect the state of senescence, and it is important to develop markers as therapeutic targets to aid senolysis application. We investigated the potential of serotonin 2A receptor (HTR2A), which is involved in melanin production in response to ultraviolet light, as a senescent cell marker. The results showed that HTR2A is upregulated in aging dermal fibroblasts but is expressed at low levels in proliferating young cells. Flow cytometry demonstrated the presence of many HTR2A-positive cells in the aging cell population and few in the young cells. Furthermore, antibody-dependent cytotoxicity assays revealed that HTR2A preferentially sensitizes senescent fibroblasts and specifically damages only senescent cells by natural killer cells that recognize it. In conclusion, selective labeling of the novel senescent cell marker, HTR2A, could preferentially eliminate senescent cells and may contribute to the future development of novel skin senolysis approaches. [ABSTRACT FROM AUTHOR]

The large majority of patients with HER2-positive metastatic breast cancer (MBC) will eventually develop resistance to anti-HER2 therapy and die of this disease. Despite, relatively high levels of stromal tumor infiltrating lymphocytes (sTILs), PD1-blockade has only shown modest responses. Monalizumab targets the inhibitory immune checkpoint NKG2A, thereby unleashing NK- and CD8 T cells. We hypothesized that monalizumab synergizes with trastuzumab by promoting antibody-dependent cell-mediated cytotoxicity. In the phase II MIMOSA-trial, HER2-positive MBC patients were treated with trastuzumab and 750 mg monalizumab every two weeks. Following a Simon's two-stage design, 11 patients were included in stage I of the trial. Treatment was well tolerated with no dose-limiting toxicities. No objective responses were observed. Therefore, the MIMOSA-trial did not meet its primary endpoint. In summary, despite the strong preclinical rationale, the novel combination of monalizumab and trastuzumab does not induce objective responses in heavily pre-treated HER2-positive MBC patients. • The MIMOSA trial investigated the novel combination of monalizumab and trastuzumab for HER2+ MBC. • The novel combination was well-tolerated, but no clinical responses were observed. • Combination strategies are warranted to induce a more inflamed tumor microenvironment. • Enrichment of inflamed HER2+ MBC with high TIL is likely to increase response to ICB. [ABSTRACT FROM AUTHOR]

Herpes simplex viruses (HSV) cause chronic infections with significant morbidity. Prior vaccines, designed to generate neutralizing antibodies (nAbs) targeting glycoprotein D (gD), failed to provide durable protection. We adopted a different strategy and evaluated a single-cycle virus deleted in gD (ΔgD-2). ΔgD-2elicits antibodies that primarily mediate antibody-dependent cell mediated cytolysis (ADCC) and provides complete protection against clinical isolates of HSV in multiple lethal mouse models. To assess durability, we vaccinated mice (2 doses administered intramuscularly) with ΔgD-2, adjuvanted recombinant gD-2 (rgD-2/Alum-MPL), or uninfected cells as a control, and quantified antibody responses over one year. Mice (n = 5/group) were lethally challenged at 2, 4, 6, 8, and 10-months post-boost. ΔgD-2-vaccinated mice elicited a durable ADCC-mediating response, which provided complete protection against challenge at all timepoints. In contrast, rgD-2/Alum-MPL elicited only nAbs, which declined significantly within 6 months, provided only partial protection at early timepoints, and no protection after 6 months. Serum sampling after viral challenge showed that infection elicited low levels of ADCC-mediating antibodies in rgD-2/Alum-MPL-vaccinated mice and boosted the nAb response, but only after 6 months. Conversely, infection significantly and consistently boosted both the ADCC and nAbs responses in ΔgD-2-vaccinated mice. Results recapitulate clinical trial outcomes with gD vaccines, highlight the importance of ADCC, and predict that ΔgD-2 will elicit durable responses in humans. [ABSTRACT FROM AUTHOR]

Gene-engineered immune cell therapies have partially transformed cancer treatment, as exemplified by the use of chimeric antigen receptor (CAR)-T cells in certain hematologic malignancies. However, there are several limitations that need to be addressed to target more cancer types. Natural killer (NK) cells are a type of innate immune cells that represent a unique biology in cancer immune surveillance. In particular, NK cells obtained from heathy donors can serve as a source for genetically engineered immune cell therapies. Therefore, NK-based therapies, including NK cells, CAR-NK cells, and antibodies that induce antibody-dependent cellular cytotoxicity of NK cells, have emerged. With recent advances in genetic engineering and cell biology techniques, NK cell-based therapies have become promising approaches for a wide range of cancers, viral infections, and senescence. This review provides a brief overview of NK cell characteristics and summarizes diseases that could benefit from NK-based therapies. In addition, we discuss recent preclinical and clinical investigations on the use of adoptive NK cell transfer and agents that can modulate NK cell activity. [ABSTRACT FROM AUTHOR]

Neutralizing monoclonal antibodies (nMABs) have been proved to be effective therapeutics in treating coronavirus disease (COVID-19). To enhance the potency of nMAB 553–15, we generated a novel monospecific tetravalent IgG1-(scFv)2 version. This was achieved by covalently fusing two forms of 553–15-derived single chain variable fragments (scFv) to the C-terminus of the hIgG1 (human Immunoglobulin G1) Fc fragment. We found that the Fc-fused VL-linker-VH format achieved similar binding affinity and neutralizing behavior as 553–15. The tetravalent versions were constructed by fusing the scFv domains to the C-terminus of nMAB 553–15. As a result, the tetravalent version 55,315-VLVH exhibited significantly higher binding activity to target spike protein variants and enhanced neutralization against VOCs (variants of concern) pseudovirus compared to 553–15. We also measured the Fc effector responses of candidates using wild-type Spike-expressing CHOK1 cells. The 55,315-VLVH enhanced the function of ADCP (antibody-dependent cellular phagocytosis) but had similar IL-6 release levels compared to the bivalent 553–15. It seemed that the novel tetravalent version avoids the pro-inflammatory effect induced by macrophage activation. However, the 55,315-VLVH displayed slightly increased potency in ADCC (antibody-dependent cell-mediated cytotoxicity) and CDC (complement-dependent cytotoxicity), which might contribute to higher systemic inflammation. Further investigation is necessary to determine whether the tetravalent version is beneficial to balance efficiency and safety against COVID-19. [ABSTRACT FROM AUTHOR]

Development of a universal influenza vaccine that can provide robust and long-lasting protection against heterologous infections is a global public health priority. A variety of vaccine antigens are designed to increase the antigenicity of conserved epitopes to elicit cross-protective antibodies that often lack virus-neutralizing activity. Given the contribution of antibody effector functions to cross-protection, adjuvants need to be added to modulate antibody effector functions as well as to enhance antibody quantity. We previously showed that post-fusion influenza vaccine antigens elicit non-neutralizing but cross-protective antibodies against conserved epitopes. Here, using a murine model, we comparably assessed the adjuvanticity of the newly developed SA-2 adjuvant containing a synthetic TLR7 agonist DSP-0546 and squalene-based MF59 analog as representative Th1- or Th2-type adjuvants, respectively. Both types of adjuvants in the post-fusion vaccine comparably enhanced cross-reactive IgG titers against heterologous strains. However, only SA-2 skewed the IgG subclass into the IgG2c subclass in association to its Th1-polarizing nature. SA-2-enhanced IgG2c responses exhibited antibody-dependent cellular cytotoxicity against heterologous virus strains, without cross-neutralizing activity. Eventually, the SA-2-adjuvanted vaccination provided protection against lethal infection by heterologous H3N2 and H1N1 viruses. Together, we conclude that the combination with a SA-2 is advantageous for enhancing the cross-protective capability of post-fusion HA vaccines that elicit non-neutralizing IgG antibodies. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the toxic effects of most commonly used plasticizer Di-(2-ethylhexyl) phthalate (DEHP) in the peripheral blood and liver of adult female mice, and protective effect of a commonly used spice (Allium sativum) against DEHP induced pathology. Animals were treated with aqueous garlic extract, DEHP, and DEHP+Garlic extract (aqueous) at dosage of 500 mg/kg body weight each (intra-gastric treatment) (n=10) for 28 days. DEHP treatment resulted in a significant decline in mean body weight while a significant increase in the mean liver weight was noticed as compared to the control group. Results indicated various liver histopathologies in DEHP exposed animals including sinusoid dilation, deshaped hepatic parenchyma cells with nuclear anomalies, and increased number of inflammatory cells. A significant increase in average cross-sectional area (ACSA) of the central vein and number of mononucleated, binucleated, and oval cells was noticed in the DEHP group as compared to the garlic group. A significant increase in cellular diameter of hepatocytes in DEHP and DEHP+Garlic group was also observed. Aqueous garlic extract treatment significantly ameliorated the DEHP-induced histopathological and micrometric alterations in the DEHP+Garlic group. Serum ALT, AST, and ALP levels were significantly decreased in the DEHP+Garlic group as compared to the DEHP group. DEHP treatment caused different nuclear anomalies in the white blood cells of female mice, however, no significant signs of recovery were observed by the aqueous garlic extract treatment. The results showed that DEHP is highly toxic to the female mice's liver, and garlic extract could potentially protect and rescue DEHP-induced liver damage in the female mice. [ABSTRACT FROM AUTHOR]

A novel targeted tumor contrast agent in magnetic resonance imaging (MRI) was synthesized based on Fe3O4@Au nanoparticle coated with polyethylene glycol (PEG) and decorated with trastuzumab (TZ). The prepared system was fully characterized, and relaxivity, cytotoxicity, colloidal stability, blood compatibility, in vitro cell targeting ability, cytotoxicity, and in vivo MR contrast enhancement were evaluated. The developed system with a size of about 30 nm exhibited excellent stability, blood compatibility, proper relaxivity, negligible in vitro cytotoxicity, and suitable in vivo negative contrast enhancement. Appropriate negative signal enhancement in MRI confirmed the efficiency of the system to be suggested as an encouraging candidate for accurate cancer diagnosis. [ABSTRACT FROM AUTHOR]

Annually, millions of new cancer cases are reported, leading to millions of deaths worldwide. Among the newly reported cases, breast and colon cancers prevail as the most frequently detected variations. To effectively counteract this rapid increase, the development of innovative therapies is crucial. Small molecules possessing pyridine and urea moieties have been reported in many of the currently available anticancer agents, especially VEGFR2 inhibitors. With this in mind, a rational design approach was employed to create hybrid small molecules combining urea and pyridine. These synthesized compounds underwent in vitro testing against breast and colon cancer cell lines, revealing potent submicromolar anticancer activity. Compound 8a, specifically, exhibited an impressive GI50 value of 0.06 μM against the MCF7 cancer cell line, while compound 8h displayed the highest cytotoxic activity against the HCT116 cell line, with a GI50 of 0.33 ± 0.042 μM. Notably, compounds 8a, 8h, and 8i demonstrated excellent safety profiles when tested on normal cells. Molecular docking, dynamic studies, and free energy calculations were employed to validate the affinity of these compounds as VEGFR2 inhibitors. [ABSTRACT FROM AUTHOR]

Biomarker-based targeted therapies have changed the cancer treatment paradigm. While early-stage gastric and gastro-oesophageal junction (GOJ) adenocarcinomas can benefit from surgery, advanced presentations of these diseases have limited therapeutic options and poor prognoses. Zolbetuximab, a chimeric monoclonal antibody targeting Claudin 18.2 (CLDN18.2), exerts its effect through antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. It has emerged as a promising treatment for advanced gastric/GOJ cancer. Clinical trials have assessed its efficacy and safety across multiple phases, demonstrating significant improvements in progression-free survival and overall survival. The safety profile of zolbetuximab primarily includes manageable gastrointestinal adverse events, namely nausea and vomiting. Zolbetuximab's potential extends beyond its primary indication, with on-going trials exploring its efficacy in other CLDN18.2-expressing malignancies, such as pancreatic adenocarcinoma. This review highlights zolbetuximab's potential as a first-line therapy for CLDN18.2-positive, HER2-negative gastric and GOJ adenocarcinomas, shedding light on its mechanism of action, clinical trial results, safety profile and current treatment landscape. [ABSTRACT FROM AUTHOR]

Via an insufficient coat protein complex I (COPI) retrieval signal, the majority of SARS-CoV-2 spike (S) is resident in host early secretory organelles and a tiny amount is leaked out in cell surface. Only surface-exposed S can be recognized by B cell receptor (BCR) or anti-S therapeutic monoclonal antibodies (mAbs) that is the trigger step for B cell activation after S mRNA vaccination or infected cell clearance by S mAbs. Now, a drug strategy to promote S host surface exposure is absent. Here, we first combined structural and biochemical analysis to characterize S COPI sorting signals. A potent S COPI sorting inhibitor was then invented, evidently capable of promoting S surface exposure and facilitating infected cell clearance by S antibody-dependent cellular cytotoxicity (ADCC). Importantly, with the inhibitor as a probe, we revealed Omicron BA.1 S is less cell surface exposed than prototypes because of a constellation of S folding mutations, possibly corresponding to its ER chaperone association. Our findings not only suggest COPI is a druggable target against COVID-19, but also highlight SARS-CoV-2 evolution mechanism driven by S folding and trafficking mutations. SARS-CoV-2 spike is largely hidden in cell organelles, resulting in compromised host immune surveillance. We invented a COPI inhibitor capable of promoting spike surface exposure to enhance host immune response. [Display omitted] [ABSTRACT FROM AUTHOR]

The DiversitabTM system produces target specific high titer fully human polyclonal IgG immunoglobulins from transchromosomic (Tc) bovines shown to be safe and effective against multiple virulent pathogens in animal studies and Phase 1, 2 and 3 human clinical trials. We describe the functional properties of a human monoclonal antibody (mAb), 38C2, identified from this platform, which recognizes recombinant H1 hemagglutinins (HAs) and induces appreciable antibody‐dependent cellular cytotoxicity (ADCC) activity in vitro. Interestingly, 38C2 monoclonal antibody demonstrated no detectable neutralizing activity against H1N1 virus in both hemagglutination inhibition and virus neutralization assays. Nevertheless, this human monoclonal antibody induced appreciable ADCC against cells infected with multiple H1N1 strains. The HA‐binding activity of 38C2 was also demonstrated in flow cytometry using Madin‐Darby canine kidney cells infected with multiple influenza A H1N1 viruses. Through further investigation with the enzyme‐linked immunosorbent assay involving the HA peptide array and 3‐dimensional structural modeling, we demonstrated that 38C2 appears to target a conserved epitope located at the HA1 protomer interface of H1N1 influenza viruses. A novel mode of HA‐binding and in vitro ADCC activity pave the way for further evaluation of 38C2 as a potential therapeutic agent to treat influenza virus infections in humans. [ABSTRACT FROM AUTHOR]

Crataegus oxyacantha is used in the treatment of cardiovascular diseases. The aim of this study was to evaluate the transplacental genotoxicity effect of aqueous (AE) and hydroalcoholic extract (HE) of leaves C. oxyacantha in a rat model and the quantification of malondialdehyde (MDA) in the liver. Three different doses of the AE and HE of the C. oxyacantha leaf were administered orally (500, 1000 and 2000 mg/kg) to Wistar rats during 5 days through the pregnancy term (16–21 days), and sampling in rats occurred every 24 h during the last 6 days of gestation, while only one sample was taken in neonates at birth. A sample of the mother's and the neonate's liver was taken for the determination of MDA. The results show that, at the hepatic level, the evaluated doses of extracts C. oxyacantha in pregnant rats and their pups did not show cytotoxicity. However, the AE and HE generated cytotoxic and genotoxic damage in the short term. On the other hand, only the AE showed a teratogenic effect. Based on these results, the AE and HE of the C. oxyacantha leaf should not be administered during pregnancy. [ABSTRACT FROM AUTHOR]

Background: The cytotoxicity of NK cells is largely dependent on IgG Fc receptor CD16a, which mediates antibody-dependent cell-mediated cytotoxicity (ADCC). The high-affinity and non-cleavable CD16 (hnCD16) is developed and demonstrated a multi-tumor killing potential. However, the hnCD16 receptor activates a single CD16 signal and provides limited tumor suppression. How to exploit the properties of hnCD16 and incorporate NK cell-specific activation domains is a promising development direction to further improve the anti-tumor activity of NK cells. Methods: To expand the applications of hnCD16-mediated ADCC for NK cell-based immunotherapy in cancer, we designed the hnCD16 Fusion Receptor (FR) constructs with the ectodomain of hnCD16 fused with NK cell-specific activating domains in the cytoplasm. FR constructs were transduced into CD16-negative NK cell line and human iPSC-derived NK (iNK) cells and effective FR constructs were screened. The up-regulation of immune activation- and cytokine-releasing-related pathways in FR-transduced NK cells was screened and validated by RNA sequencing and multiplex cytokines release assay, respectively. The tumor-killing efficiency was tested in vitro and in vivo via co-culture with tumor cell lines and xenograft mice-bearing human B-cell lymphoma, respectively. Results: We screened the most effective combination to kill B cell lymphoma, which was fused with the ectodomain of hnCD16a, NK-specific co-stimulators (2B4 and DAP10) and CD3ζ in cytoplasmic domains. The screened construct showed excellent cytotoxicity effects and sharp multiple cytokines releasing both in the NK cell line and iNK cells. The transcriptomic analysis and validation assays of hnCD16- and hnCD16FR-transduced NK cells showed that hnCD16FR transduction remodeled immune-related transcriptome in NK cells, where significant upregulation of genes related to cytotoxicity, high cytokines releasing, induced tumor cell apoptosis, and ADCC in comparison with hnCD16 transduction were highlighted. In vivo xenograft studies demonstrated that a single low-dose regimen of engineered hnCD16FR iPSC-derived NK cells co-administered with anti-CD20 mAb treatment mediated potent activity and significantly improved survival. Conclusion: We developed a novel hnCD16FR construct that exhibits more potent cytotoxicity than reported hnCD16, which is a promising approach to treat malignancies with improved ADCC properties. We also offer a rationale for NK activation domains that remodel immune response to enhance CD16 signaling in NK cells. [ABSTRACT FROM AUTHOR]

Background: Although trastuzumab and other HER2-targeted therapies have significantly improved survival in patients with HER2 overexpressed or amplified (HER2+) breast cancer, a significant proportion of patients do not respond or eventually develop clinical resistance. Strategies to reverse trastuzumab resistance remain a high clinical priority. We were the first to report the role of CXCR4 in trastuzumab resistance. The present study aims to explore the therapeutic potential of targeting CXCR4 and better understand the associated mechanisms. Methods: Immunofluorescent staining, confocal microscopy analysis, and immunoblotting were used to analyze CXCR4 expression. BrdU incorporation assays and flow cytometry were used to analyze dynamic CXCR4 expression. Three-dimensional co-culture (tumor cells/breast cancer-associated fibroblasts/human peripheral blood mononuclear cells) or antibody-dependent cellular cytotoxicity assay was used to mimic human tumor microenvironment, which is necessary for testing therapeutic effects of CXCR4 inhibitor or trastuzumab. The FDA-approved CXCR4 antagonist AMD3100, trastuzumab, and docetaxel chemotherapy were used to evaluate therapeutic efficacy in vitro and in vivo. Reverse phase protein array and immunoblotting were used to discern the associated molecular mechanisms. Results: Using a panel of cell lines and patient breast cancer samples, we confirmed CXCR4 drives trastuzumab resistance in HER2+ breast cancer and further demonstrated the increased CXCR4 expression in trastuzumab-resistant cells is associated with cell cycle progression with a peak in the G2/M phases. Blocking CXCR4 with AMD3100 inhibits cell proliferation by downregulating mediators of G2-M transition, leading to G2/M arrest and abnormal mitosis. Using a panel of trastuzumab-resistant cell lines and an in vivo established trastuzumab-resistant xenograft mouse model, we demonstrated that targeting CXCR4 with AMD3100 suppresses tumor growth in vitro and in vivo, and synergizes with docetaxel. Conclusions: Our findings support CXCR4 as a novel therapeutic target and a predictive biomarker for trastuzumab resistance in HER2+ breast cancer. [ABSTRACT FROM AUTHOR]

Since the beginning of the SARS-CoV-2 pandemic, several variants of concern (VOCs), such as the Alpha, Beta, Gamma, Delta and Omicron variants, have arisen and spread worldwide. Today, the predominant circulating subvariants are sublineages of the Omicron variant, which have more than 30 mutations in their Spike glycoprotein compared to the ancestral strain. The Omicron subvariants were significantly less recognized and neutralized by antibodies from vaccinated individuals. This resulted in a surge in the number of infections, and booster shots were recommended to improve responses against these variants. While most studies mainly measured the neutralizing activity against variants, we and others previously reported that Fc-effector functions, including antibody-dependent cellular cytotoxicity (ADCC), play an important role in humoral responses against SARS-CoV-2. In this study, we analyzed Spike recognition and ADCC activity against several Omicron subvariants by generating cell lines expressing different Omicron subvariant Spikes. We tested these responses in a cohort of donors, who were recently infected or not, before and after a fourth dose of mRNA vaccine. We showed that ADCC activity is less affected than neutralization by the antigenic shift of the tested Omicron subvariant Spikes. Moreover, we found that individuals with a history of recent infection have higher antibody binding and ADCC activity against all Omicron subvariants than people who were not recently infected. With an increase in the number of reinfections, this study helps better understand Fc-effector responses in the context of hybrid immunity. [ABSTRACT FROM AUTHOR]

• M. urundeuva lectins were potentially toxic to human lymphocytes and non-hemolytic. • M. urundeuva lectins showed weak genotoxicity to human lymphocytes. • MuHL and MuLL were moderately active against cancer cell lines. • MuHL non-cytotoxic or genotoxic doses were fungicidal against Cryptococcus. • MuHL acted synergistically with fluconazole and inhibited C. neoformans biofilm. This study evaluated the lectins from bark (MuBL), heartwood (MuHL) and leaf (MuLL) of Myracrodruon urundeuva for cytotoxicity on cancer and normal cells; hemolytic activity; genotoxicity using comet and micronucleus tests; and antifungal activity against Cryptococcus through determination of minimal inhibitory (MIC) and minimal fungicidal (MFC) concentration, antibiofilm formation effect and evaluation of synergism with other drugs. MuBL, MuHL and MuLL showed IC 50 on mononuclear peripheral blood cells of 58.41, 43.19 and 62.28 µg/mL, respectively. MuHL and MuLL (25 µg/mL) were moderately active on the cancer cell lines HL-60 (promyelocytic leukemia), NCI-H292 (lung mucoepidermoid carcinoma) and MCF-7 (breast adenocarcinoma). The percentage of hemolysis promoted by lectins ranged from 0 to 11.6%. Data from comet assay revealed that MuBL (100 µg/mL), MuHL and MuLL (50 µg/mL) showed frequency of damage of 33.5%, 35.67% and 65.2%, respectively. On micronucleus test, the number of micronuclei was 7.91, 7.41 and 8.91 to MuBL (100 µg/mL), MuHL and MuLL (50 µg/mL), and did not differ from the negative control. Only MuHL exhibited fungistatic and fungicidal activity with MIC of 6.25 and 12.5 µg/mL and MFC of 12.5 and 25 µg/mL against Cryptococcus neoformans and Cryptococcus gattii , respectively. MuHL also potentialized antibiotic action and reduced in 80% biofilm formation by C. neoformans. In conclusion, lectins from M. urundeuva did not promote damage to erythrocytes and presented low cytotoxicity and absence of genotoxicity on lymphocytes. Nontoxic concentrations of MuHL and MuLL showed moderate cytotoxicity on cancer cell lines. MuHL presented antifungal activity against Cryptococcus isolates. [ABSTRACT FROM AUTHOR]

The genus Aloe has been used as medicinal plants for many years; mainly reported to prevent diabetes, cancer and cardiovascular diseases, and it has been used as an ingredient in food supplements, cosmetic formulations and drug design. This study aimed to determine the physicochemical and pharmacological properties of the compounds determined in extracts obtained from the Aloe vera leaves. The extraction was realized by maceration using different solvents. The chemical profile was determined by liquid chromatography-mass spectrometry (LC-MS). The pharmacological and toxicologic properties (ADMET) were determined using SWISS ADME server. The cytotoxicity was also determined in silico using online server CLC-Pred. The findings revealed that aloenin B and aloenin 2′- p -coumaroyl-ester didn´t obey to Lipinski rule of five. For pharmacokinetic properties of selected molecules, results indicated that all compounds could be well absorbed in the intestine except aloenin, while all of them could not cross the brain blood barrier. The mitochondria is the oriented organelle for all tested compounds. In the term of metabolism, all molecules excluding aloe-emodin could be potential substrates for the CYP3A4 isoform. The results disclosed that all molecules could be an activator of UGT catalysis. Aloenin B and aloenin 2′-p-coumaroyl ester could be inhibitors of P-glycoprotein. In the elimination step, the data stated that all examined molecules could not inhibit OCT2 and MATE1. While all compounds were inhibitors of OATP1B3, aloenin and aloenin 2′- p -coumaroyl ester could inhibit BSEP and OATP2B. Inatoxicity approach, there is no carcinogenicity presented by all molecules. Aloe-emodin could provoke eye irritation, while aloe-emodin, aloin B and aloin A could cause mutagenesis, hepatotoxicity, respiratory, mitochondrial and nephro toxicities. To the best of our knowledge, the current research is the first report about the physicochemical, pharmacokinetic and cytotoxicity effect of molecules determined in Aloe vera leaves extracts. [ABSTRACT FROM AUTHOR]

Hypercholesterolemia is a major risk for the development of cardiovascular diseases (CVDs), the main cause of mortality worldwide, and it is characterized by high levels of circulating cholesterol. The drugs currently available for hypercholesterolemia control have several side effects, so it is necessary to develop new effective and safer therapies. Seaweeds serve as sources of several bioactive compounds with claimed beneficial effects. Eisenia bicyclis (Aramé) and Porphyra tenera (Nori) are edible seaweeds that were previously recognized as rich in bioactive compounds. In the present study, we aim to evaluate the anti-hypercholesterolemia effect of these two seaweed extracts and their health potential. Both extracts, but more efficiently Aramé extract, have liver 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) inhibitory activity as well as the capability to reduce approximately 30% of cholesterol permeation through human Caco-2 cells by simulating the intestinal lining, which is a target for hypercholesterolemia treatments. An untargeted metabolomic assay on human intestinal Caco-2 and liver Hep-G2 cell lines exposed to Aramé and Nori extracts revealed changes in the cells' metabolism, indicating the extracts' health beneficial effects. The metabolic pathways affected by exposure to both extracts were associated with lipid metabolism, such as phospholipids, and fatty acid metabolism, amino acid pathways, cofactors, vitamins, and cellular respiration metabolism. The effects were more profound in Aramé-treated cells, but they were also observed in Nori-exposed cells. The metabolite modifications were associated with the protection against CVDs and other diseases and to the improvement of the cells' oxidative stress tolerance. The results obtained for the anti-hypercholesterolemia properties, in addition to the revelation of the positive impact on cell metabolism, offer an important contribution for further evaluation of these seaweed extracts as functional foods or for CVD prevention. [ABSTRACT FROM AUTHOR]

Biological properties of Sonoran propolis (SP) are influenced by harvest time. Caborca propolis showed cellular protective capacity against reactive oxygen species, which might be implicated in anti-inflammatory effects. However, the anti-inflammatory activity of SP has not been investigated so far. This study investigated the anti-inflammatory activity of previously characterized seasonal SP extracts (SPE) and some of their main constituents (SPC). The anti-inflammatory activity of SPE and SPC was evaluated by measuring nitric oxide (NO) production, protein denaturation inhibition, heat-induced hemolysis inhibition, and hypotonicity-induced hemolysis inhibition. SPE from spring, autumn, and winter showed a higher cytotoxic effect on RAW 264.7 cells (IC50: 26.6 to 30.2 µg/mL) compared with summer extract (IC50: 49.4 µg/mL). SPE from spring reduced the NO secretion to basal levels at the lowest concentration tested (5 µg/mL). SPE inhibited the protein denaturation by 79% to 100%, and autumn showed the highest inhibitory activity. SPE stabilized erythrocyte membrane against heat-induced and hypotonicity-induced hemolysis in a concentration-dependent manner. Results indicate that the flavonoids chrysin, galangin, and pinocembrin could contribute to the anti-inflammatory activity of SPE and that the harvest time influences such a property. This study presents evidence of SPE pharmacological potential and some of their constituents. [ABSTRACT FROM AUTHOR]

Obinutuzumab is a therapeutic antibody for B cell non-Hodgkin's Lymphoma (BNHL), which is a glyco-engineered anti-CD20 antibody with enhanced antibody-dependent cellular cytotoxicity (ADCC) and causes binding-induced direct cell death (DCD) through lysosome membrane permeabilization (LMP). Tumour necrosis factor receptor 1 (TNFR1), a pro-inflammatory death receptor, also evokes cell death, partly through lysosomal rupture. As both obinutuzumab- and TNFR1-induced cell deaths are mediated by LMP and combining TNFR1 and obinutuzumab can amplify LMP-mediated cell death, we made dual-targeting antibody for CD20 and TNFR1 to enhance DCD of obinutuzumab. Obinutuzumab treatment-induced CD20 and TNFR1 colocalisation, and TNFR1-overexpressing cells showed increased obinutuzumab-induced DCD. Two targeting modes, anti-CD20/TNFR1 bispecific antibodies (bsAbs), and obinutuzumab-TNFα fusion proteins (OBI-TNFαWT and OBI-TNFαMUT), were designed to cluster CD20 and TNFR1 on the plasma membrane. OBI-TNFαWT and OBI-TNFαMUT showed significantly enhanced LMP, DCD, and ADCC compared with that induced by obinutuzumab. TNFR1 expression is upregulated in many BNHL subtypes compared to that in normal B cells; OBI-TNFαMUT specifically increased DCD and ADCC in a B cell lymphoma cell line overexpressing TNFR1. Further, OBI-TNFαMUT blocked NF-κB activation in the presence of TNF-α, implying that it can antagonise the proliferative role of TNF-α in cancers. Our study suggests that dual targeting of CD20 and TNFR1 can be a new therapeutic strategy for improving BNHL treatment. The OBI-TNFαMUT fusion protein enhances DCD and ADCC and prevents the proliferating effect of TNFα signalling; therefore, it may provide precision treatment for patients with BNHL, especially those with upregulated TNFR1 expression. [ABSTRACT FROM AUTHOR]

Chimeric antigen receptor T cell therapy (CAR-T) is a novel treatment that has produced unprecedented clinical effects in patients with hematological malignancies. Acute adverse events often occur following adoptive immunotherapy. Therefore, a suicide gene is helpful, which is a genetically encoded mechanism that allows selective destruction of adoptively transferred T cells in the face of unacceptable toxicity. RQR8 is a gene that integrates CD34 and CD20 epitopes. In our study, we incorporated the suicide gene RQR8 into CAR-T cells, so it enabled rituximab to eliminate vector/transgene-expressing T cells via antibody-dependent cell-mediated cytotoxicity and complement dependent cytotoxicity. In this work, we explored the functionality of RQR8 CAR-T cells in vitro and in vivo. We believe that RQR8 as a safety switch will make CAR-T cell therapy safer and less costly. [ABSTRACT FROM AUTHOR]

This study aimed to improve the use of YF8, a matrine derivative obtained through chemical transformation of matrine extracted from Sophora alopecuroides. YF8 has demonstrated improved cytotoxicity compared to matrine, but its hydrophobic nature hinders its application. To overcome this, the lipid prodrug YF8-OA was synthesized by linking oleic acid (OA) to YF8 through an ester bond. Although YF8-OA could self-assemble into unique nanostructures in water, it was not sufficiently stable. To enhance the stability of YF8-OA lipid prodrug nanoparticles (LPs), we employed the strategy of PEGylation using DSPE-mPEG2000 or DSPE-mPEG2000 conjugated with folic acid (FA). This resulted in the formation of uniform spherical nanoparticles with greatly improved stability and a maximum drug load capacity upto 58.63%. Cytotoxicity was evaluated in A549, HeLa, and HepG2 cell lines. The results showed that in HeLa cells, the IC50 value of YF8-OA/LPs with FA-modified PEGylation was significantly lower than that of YF8-OA/LPs modified by PEGylation alone. However, no significant enhancement was observed in A549 and HepG2 cells. In conclusion, the lipid prodrug YF8-OA can form nanoparticles in aqueous solution to address its poor water solubility. Modification with FA resulted in further enhanced cytotoxicity, providing a potential avenue for exerting the antitumor activity of matrine analogs. [ABSTRACT FROM AUTHOR]

Featured Application: Nutritional Profiling for subsequent dietary supplements/nutraceuticals development and formulation as well as by-products valorification. In recent years, the scientific community has made significant progress in understanding nutrition, leading consumers to shift their preferences away from animal-based protein products and towards natural, plant-based protein sources. This study aimed to determine the nutritional value, in vitro cytotoxicity and antioxidant activity for different sources of high protein content products (pea, yeast, almond, spirulina and Pleurotus spp.) with potential usage as raw materials for dietary supplements, especially since these products do not benefit from stricter regulation requirements regarding their actual health benefits. The characterization of raw materials consisted in evaluation of their nutritional profile (by addressing moisture content, crude protein content, extractable fat, ash, carbohydrates) and microbial contamination (TAMC, TYMC, Enterobacteriaceae and β-glucuronidase positive Escherichia coli), total content of free amino acids, soluble proteins, phenols and flavonoids, as well as antioxidant activity through chemical assays. We used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) release to evaluate the potential cytotoxicity of selected raw materials. Results obtained indicate high percentages of proteins for the pea powder (77.96%) and Spirulina powder (64.79%), Pleurotus spp. flour had strong antioxidant activity, while the highest contamination values were registered for Pleurotus spp. powder (4.6 × 105 CFU/g or 5.66 log CFU/g). Cytotoxicity results demonstrate that tested ingredients have an impact on the metabolic activity of cells, affecting cellular integrity and provoking leakage of DNA at several concentrations. While plant-based protein supplementation may appear to be a promising solution to balance our busy lives, there are several advantages and disadvantages associated with them, including issues related to their absorption rate, bioavailability, cytotoxicity and actual nutritional benefits. [ABSTRACT FROM AUTHOR]