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Abstract: Efforts to develop a subunit vaccine against genital herpes have been hampered by lack of knowledge of the protective antigens of HSV-2, the causative agent of the disease. Vaccines based either on selected antigens or attenuated live virus approaches have not demonstrated meaningful clinical activity. We present here results of a therapeutic vaccine candidate, HerpV (formerly called AG-707), consisting of 32 HSV-2 peptides derived from 22 HSV-2 proteins, complexed non-covalently to the HSP70 chaperone and formulated with QS-21 saponin adjuvant. HerpV is observed to be immunogenic, generating CD4+ and CD8+ T cell responses in three mouse strains including HLA-A2 transgenic mice. Optimal T cell stimulation was dependent on the synergistic adjuvant properties of QS-21 with hsp70. The vaccine provided significant protection from viral challenge in a mouse prophylaxis model and showed signals of activity in a guinea pig therapeutic model of existing infection. Peripheral blood mononuclear cells from human HSV-2+ subjects also showed reactivity in vitro to a subset of individual peptides and to the pool of all 32 peptides. Recombinant human Hsc70 complexed with the 32 peptides also stimulated the expansion of CD8+ T cells from HSV-2+ subjects in vitro. These studies demonstrate that HerpV is a promising immunotherapy candidate for genital herpes, and provide a foundation for evaluating HerpV in human HSV-2+ subjects with the intent of eliciting CD4+ and CD8+ T cell responses to a broad array of viral antigens. [Copyright &y& Elsevier]

Background: Immunity against the T cell receptor (TCR) is considered to play a central role in the regulation of experimental allergic encephalomyelitis (EAE), a model system of autoimmune disease characterized by a restricted usage of TCR genes. Methods of specific vaccination against the TCR of pathogenetic T cells have included attenuated T cells and synthetic peptides from the sequence of the TCR. These approaches have led to the concept that anti-idiotypic immunity against antigenic sites of the TCR, which are a key regulatory element in this disease. Methods: The present study in the Lewis rat used a conventional idiotypic immunization based on antigenized antibodies expressing selected peptide sequences of the Vβ8.2 TCR (93ASSDSSNTE101 and 39DMGHGLRLIHYSYDVNSTEKG59). Results: The study demonstrates that vaccination with antigenized antibodies markedly attenuates, and in some instances, prevents clinical EAE induced with the encephalitogenic peptide 68GSLPQKSQRSQDENPVVHF88 in complete Freunds' adjuvant (CFA). Antigenized antibodies induced an anti-idiotypic response against the Vβ8.2 TCR, which was detected by ELISA and flowcytometry. No evidence was obtained of a T cell response against the corresponding Vβ8.2 TCR peptides. Conclusions: The results indicate that antigenized antibodies expressing conformationallyconstrained TCR peptides are a simple means to induce humoral anti-idiotypic immunity against the TCR and to vaccinate against EAE. The study also suggests the possibility to target idiotypic determinants of TCR borne on pathogenetic T cells to vaccinate against disease. [ABSTRACT FROM AUTHOR]

Background: Antibody-binding of blood dendritic cell antigen 2 (BDCA2), which is expressed exclusively on plasmacytoid dendritic cells, suppresses the production of type I interferon that is involved in the pathogenesis of systemic lupus erythematosus (SLE). The safety and efficacy of subcutaneous litifilimab, a humanized monoclonal antibody that binds to BDCA2, in patients with SLE have not been extensively studied.Methods: We conducted a phase 2 trial of litifilimab involving participants with SLE. The initial trial design called for randomly assigning participants to receive litifilimab (at a dose of 50, 150, or 450 mg) or placebo administered subcutaneously at weeks 0, 2, 4, 8, 12, 16, and 20, with the primary end point of evaluating cutaneous lupus activity. The trial design was subsequently modified; adults with SLE, arthritis, and active skin disease were randomly assigned to receive either litifilimab at a dose of 450 mg or placebo. The revised primary end point was the change from baseline in the total number of active joints (defined as the sum of the swollen joints and the tender joints) at week 24. Secondary end points were changes in cutaneous and global disease activity. Safety was also assessed.Results: A total of 334 adults were assessed for eligibility, and 132 underwent randomization (64 were assigned to receive 450-mg litifilimab, 6 to receive 150-mg litifilimab, 6 to receive 50-mg litifilimab, and 56 to receive placebo). The primary analysis was conducted in the 102 participants who had received 450-mg litifilimab or placebo and had at least four tender and at least four swollen joints. The mean (±SD) baseline number of active joints was 19.0±8.4 in the litifilimab group and 21.6±8.5 in the placebo group. The least-squares mean (±SE) change from baseline to week 24 in the total number of active joints was -15.0±1.2 with litifilimab and -11.6±1.3 with placebo (mean difference, -3.4; 95% confidence interval, -6.7 to -0.2; P = 0.04). Most of the secondary end points did not support the results of the analysis of the primary end point. Receipt of litifilimab was associated with adverse events, including two cases of herpes zoster and one case of herpes keratitis.Conclusions: In a phase 2 trial involving participants with SLE, litifilimab was associated with a greater reduction from baseline in the number of swollen and tender joints than placebo over a period of 24 weeks. Longer and larger trials are required to determine the safety and efficacy of litifilimab for the treatment of SLE. (Funded by Biogen; LILAC ClinicalTrials.gov number, NCT02847598.). [ABSTRACT FROM AUTHOR]

Abstract: HSV-2, the primary causative agent of genital herpes, establishes latency in sensory ganglia and reactivates causing recurrent lesions and viral shedding. Induction or expansion of CD4+ and CD8+ T cell responses are expected to be important for a successful therapeutic vaccine against HSV-2. A candidate vaccine consisting of 32 synthetic 35mer HSV-2 peptides non-covalently complexed with recombinant human Hsc70 protein (named HerpV, formerly AG-707) was tested for safety and immunogenicity in a Phase I study. These peptides are derived from 22 HSV-2 proteins representative of all phases of viral replication. Thirty-five HSV-2 infected participants were randomized and treated in one of four groups: HerpV+QS-21 (saponin adjuvant), HerpV, QS-21, or vehicle. The vaccine was well tolerated and safe. All seven participants with evaluable samples who were administered HerpV with QS-21 demonstrated a statistically significant CD4+ T cell response to HSV-2 antigens, and the majority of such participants demonstrated a statistically significant CD8+ T cell response as well. To our knowledge, this is the first candidate vaccine against HSV-2 to demonstrate a broad CD4+ and CD8+ T cell response in HSV-2+ participants, and the first HSP-based vaccine to show immune responses against viral antigens in humans. [Copyright &y& Elsevier]

Background: Blood dendritic cell antigen 2 (BDCA2) is a receptor that is exclusively expressed on plasmacytoid dendritic cells, which are implicated in the pathogenesis of lupus erythematosus. Whether treatment with litifilimab, a humanized monoclonal antibody against BDCA2, would be efficacious in reducing disease activity in patients with cutaneous lupus erythematosus has not been extensively studied., Methods: In this phase 2 trial, we randomly assigned adults with histologically confirmed cutaneous lupus erythematosus with or without systemic manifestations in a 1:1:1:1 ratio to receive subcutaneous litifilimab (at a dose of 50, 150, or 450 mg) or placebo at weeks 0, 2, 4, 8, and 12. We used a dose-response model to assess whether there was a response across the four groups on the basis of the primary end point, which was the percent change from baseline to 16 weeks in the Cutaneous Lupus Erythematosus Disease Area and Severity Index-Activity score (CLASI-A; scores range from 0 to 70, with higher scores indicating more widespread or severe skin involvement). Safety was also assessed., Results: A total of 132 participants were enrolled; 26 were assigned to the 50-mg litifilimab group, 25 to the 150-mg litifilimab group, 48 to the 450-mg litifilimab group, and 33 to the placebo group. Mean CLASI-A scores for the groups at baseline were 15.2, 18.4, 16.5, and 16.5, respectively. The difference from placebo in the change from baseline in CLASI-A score at week 16 was -24.3 percentage points (95% confidence interval [CI] -43.7 to -4.9) in the 50-mg litifilimab group, -33.4 percentage points (95% CI, -52.7 to -14.1) in the 150-mg group, and -28.0 percentage points (95% CI, -44.6 to -11.4) in the 450-mg group. The least squares mean changes were used in the primary analysis of a best-fitting dose-response model across the three drug-dose levels and placebo, which showed a significant effect. Most of the secondary end points did not support the results of the primary analysis. Litifilimab was associated with three cases each of hypersensitivity and oral herpes infection and one case of herpes zoster infection. One case of herpes zoster meningitis occurred 4 months after the participant received the last dose of litifilimab., Conclusions: In a phase 2 trial involving participants with cutaneous lupus erythematosus, treatment with litifilimab was superior to placebo with regard to a measure of skin disease activity over a period of 16 weeks. Larger and longer trials are needed to determine the effect and safety of litifilimab for the treatment of cutaneous lupus erythematosus. (Funded by Biogen; LILAC ClinicalTrials.gov number, NCT02847598.)., (Copyright © 2022 Massachusetts Medical Society.)

Efforts to develop a subunit vaccine against genital herpes have been hampered by lack of knowledge of the protective antigens of HSV-2, the causative agent of the disease. Vaccines based either on selected antigens or attenuated live virus approaches have not demonstrated meaningful clinical activity. We present here results of a therapeutic vaccine candidate, HerpV (formerly called AG-707), consisting of 32 HSV-2 peptides derived from 22 HSV-2 proteins, complexed non-covalently to the HSP70 chaperone and formulated with QS-21 saponin adjuvant. HerpV is observed to be immunogenic, generating CD4(+) and CD8(+) T cell responses in three mouse strains including HLA-A2 transgenic mice. Optimal T cell stimulation was dependent on the synergistic adjuvant properties of QS-21 with hsp70. The vaccine provided significant protection from viral challenge in a mouse prophylaxis model and showed signals of activity in a guinea pig therapeutic model of existing infection. Peripheral blood mononuclear cells from human HSV-2(+) subjects also showed reactivity in vitro to a subset of individual peptides and to the pool of all 32 peptides. Recombinant human Hsc70 complexed with the 32 peptides also stimulated the expansion of CD8(+) T cells from HSV-2(+) subjects in vitro. These studies demonstrate that HerpV is a promising immunotherapy candidate for genital herpes, and provide a foundation for evaluating HerpV in human HSV-2(+) subjects with the intent of eliciting CD4(+) and CD8(+) T cell responses to a broad array of viral antigens., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

One of several effector mechanisms thought to contribute to Ab efficacy against cancer is complement-dependent cytotoxicity (CDC). Serological analysis of a series of clinical trials conducted over a 10-year period suggested that six vaccines containing different glycolipids induced Abs mediating CDC whereas four vaccines containing carbohydrate or peptide epitopes carried almost exclusively by mucin molecules induced Abs that did not mediate CDC. To explore this further, we have now compared cell surface reactivity using flow cytometry assays (FACS), complement-fixing ability, and CDC activity of a panel of mAbs and immune sera from these trials on the same two tumor cell lines. Abs against glycolipids GM2, globo H and Lewis Y, protein KSA (epithelial cell adhesion molecule, also known as EpCAM) and mucin Ags Tn, sialylated Tn, Thomsen Friedenreich (TF), and MUC1 all reacted comparably by FACS with tumor cells expressing these Ags. Compared with the strong complement binding and CDC with Abs against glycolipids and KSA, complement binding was diminished with Abs against mucin Ags and no CDC was detected. A major difference between these two groups of Ags is proximity to the cell membrane. Glycolipids and globular glycoproteins extend less than 100 A from the cell membrane while mucins extend up to 5000 A. Although complement activation at sites remote from the cell membrane has long been known as a mechanism for resistance from complement lysis in bacteria, it is identified here for the first time as a factor which may contribute to resistance from CDC against cancer cells.

Purpose: We report the synthesis of a mucin-related O-linked glycopeptide, alpha-N-acetylgalactosamine-O-serine/threonine (Tn), which is highly simplistic in its structure and can induce a relevant humoral response when given in a trimer or clustered (c) formation. We tested for an antitumor effect, in the form of a change in the posttreatment versus pretreatment prostate-specific antigen (PSA) slopes, that might serve as a surrogate for effectiveness of vaccines in delaying the time to radiographic progression., Methods: We compared the antibody response to immunization with two conjugates, Tn(c)-keyhole limpet hemocyanin (KLH) and Tn(c)-palmitic acid (PAM) with the saponin immunologic adjuvant QS21, in a phase I clinical trial in patients with biochemically relapsed prostate cancer. Patients received Tn(c)-KLH vaccine containing either 3, 7, or 15 microg of Tn(c) per vaccination. Ten patients received 100 microg of Tn(c)-PAM. QS21 was included in all vaccines. Five vaccinations were administered subcutaneously during 26 weeks with an additional booster vaccine at week 50., Results: Tn(c), when given with the carrier molecule KLH and QS21, stimulated the production of high-titer immunoglobulin M (IgM) and IgG antibodies. Inferior antibody responses were seen with T(c)-PAM. There was no evidence of enhanced immunogenicity with increasing doses of vaccine. An antitumor effect in the form of a decline in posttreatment versus pretreatment PSA slopes was also observed., Conclusion: A safe synthetic conjugate vaccine in a trimer formation was developed that can break immunologic tolerance by inducing specific humoral responses. It seemed to affect the biochemical progression of the disease as determined by a change in PSA log slope.

We conducted a randomized trial in HLA*A0201+ patientswith American Joint Committee on Cancer stage III or IV melanoma immunized with tyrosinase 368-376(370D) peptide and gp100 209-217(210M) peptide to compare the potency of three different adjuvants. Patients received 3 monthly immunizations with 500 microg of each peptide either with incomplete Freund's adjuvant (IFA), QS-21, or granulocyte macrophage colony-stimulating factor (GM-CSF). The primary end point was induction of IFN-gamma release by CD8+ T cells against tyrosinase and gp100 peptides measured by enzyme-linked immunospot assays without in vitro prestimulation measured pretreatment, 2 and 8 weeks after the third vaccination. Four of 9 and 4 of 8 patients immunized using QS-21 and GM-CSF, respectively, developed increased frequencies of CD8+ T cells against tyrosinase 370D peptide compared with 0 of 9 patients immunized using IFA (P = 0.045). T-cell responses against a gp100-related peptide showed similar results, but their relevance to T-cell reactivity against native gp100 209-217 is uncertain. These results show that: (a) QS-21 and GM-CSF are superior to IFA as immunological adjuvants for vaccination against tyrosinase 370D peptide; and (b) with appropriate adjuvants, increased frequencies of peptide-specific T cells after vaccination can be detected by enzyme-linked immunospot without prolonged prestimulation in vitro.