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Understanding alterations in HIV-specific immune responses during antiretroviral therapy (ART), such as antibody-dependent cellular cytotoxicity (ADCC), is important in the development of novel strategies to control HIV-1 infection. This study included 53 HIV-1 positive individuals. We evaluated the ability of effector cells and antibodies to mediate ADCC separately and in combination using the ADCC-PanToxiLux assay. The ability of the peripheral blood mononuclear cells (PBMCs) to mediate ADCC was significantly higher in individuals who had been treated with ART before seroconversion, compared to the individuals initiating ART at a low CD4+ T cell count (<350 cells/μl blood) and the ART-naïve individuals. The frequency of CD16 expressing natural killer (NK) cells correlated with both the duration of ART and Granzyme B (GzB) activity. In contrast, the plasma titer of antibodies mediating ADCC declined during ART. These findings suggest improved cytotoxic function of the NK cells if initiating ART early during infection, while the levels of ADCC mediating antibodies declined during ART.

BackgroundThe pleiotropic TNF-α:TNFR axis plays a central role in the immune system. TNFR2 has been proposed to be both essential for the survival of T regs, as well as providing important co-stimulatory signals for T cell activation and memory generation. In addition, the therapeutic potential of targeting TNFR2 for cancer treatment has been previously indicated. To gain further insight, we characterized the biophysical properties and in vitro and in vivo activities of human and mouse α-TNFR2-specific antibodies designed to agonize the receptor.MethodsA human lead candidate (BI-1910) and a mouse surrogate (mBI-1910) α-TNFR2 were identified. Agonistic activity on T cells were demonstrated for both antibodies in vitro. mBI-1910 showed potent anti-tumor activity both as a single agent and in combination with anti-PD1 in multiple immunocompetent tumor models. The antibody showed co-stimulation through TNFR2, which enhanced T cell activation and induced CD8+ T cell-dependent anti-tumor effects. These findings were confirmed using BI-1910 in human TNFR2 transgenic mice.To address safety, a GLP toxicological study was performed in cynomolgus macaques. Three doses (1, 5, and 25 mg/kg) were given weekly for four consecutive weeks followed by a recovery period of eight weeks. In addition, cytokine release was studied in T cell stimulation assays and in a humanized mouse model. In parallel, multiple immune stimulation assays were studied in vitro using human cells to establish EC50 values and a clear relationship with dose, receptor occupancy and immune cell activation.ResultsFour administrations of BI-1910 to cynomolgus macaques were well tolerated at all doses, with no associated clinical signs and no signs of cytokine release. Pharmacokinetic studies demonstrated an expected human IgG half-life at receptor-saturating doses. Interestingly, there was a clear dose-dependent T cell activation, evidenced by an increase in several T cell activation markers and a shift from naïve to effector memory T cells supporting the proposed mode-of action. Importantly, the nature of BI-1910-induced T cell activation in cynomolgus macaques closely mirrored that in TNFR2 humanized mice, in which clear anti-tumor effects were also demonstrated.ConclusionsThe strong similarities in BI-1910 induced immune response between mice and cynomolgus macaques shows promise that similar T cell activation and following anti-tumor effects will occur also in humans. Collectively, these studies support the upcoming phase I/II study in solid cancer patients planned to start in H2 2023.Ethics ApprovalAll data utilizing human blood or animals was approved by an ethic committé before the experiments were started.Experiments using human blood were approved by the Regional committé for ethichs approval in Lund, Sweden ID numbers 2018/37 and 2010/356The murine experiments were approved by the Ethical committé of animal experiment in Lund and Malmö, Sweden ID numbers 5.8.18–19686/2022; 5.8.18–03333-2020; 5.8.18–02934-2020; 5.8.18–17196-2018The non-human primate experiments were approved by Charles River Laboratories Evreux Ethics Committee (CEC), France, ID number 2850398

BackgroundBI-1808 is a human IgG1 monoclonal antibody targeting TNFR2 by blocking the interaction of TNFR2 with its ligand TNF-α, confering FcγR-dependent depletion of intratumoral Tregs and mediating expansion of intratumoral CD8+ T cells. Upon co-administration of BI-1808 and anti-PD-1 surrogate antibodies to immunocompetent tumor-bearing mice, with partial sensitivity to checkpoint blockade, complete cures were observed in all treated mice, indicating a potentially synergistic activity.MethodsSafety and tolerability of BI-1808 as a single agent and in combination with pembrolizumab is currently investigated in the Phase 1/2a trial 19-BI-1808–01 in patients with advanced malignancies or cutaneous T-cell lymphoma (CTCL). The trial consists of Phase 1 Parts A and B (dose escalation with single agent and combination with pembrolizumab, respectively), and Phase 2a Parts A and B (dose expansion with single agent and combination therapy, respectively). Dose escalation uses a modified toxicity probability interval-2 protocol (mTPI-2), investigating ascending dose levels of 25–1000 mg every three weeks (Q3W). Dose escalation aims to select both single agent RP2D and combination RP2D of BI-1808 for Phase 2a.Patients are sampled for pharmacokinetics (PK) of BI-1808, antidrug-antibodies and pharmacodynamics including lymphocyte subsets, regulatory T cells, memory T-cells, soluble TNFR2 serum concentration (sTNFR2) and BI-1808 receptor occupancy (RO).ResultsAs of June 19th, 2023, 24 subjects with various advanced solid malignancies received doses of up to 1000 mg BI-1808 as single-agent treatment, and 7 subject received 225 mg doses of BI-1808 with pembrolizumab.Across the completed monotherapy arm, no Grade 3/4 AEs, AEs related to BI-1808 and no DLTs were observed. No MTD was defined. The number of potentially related AEs of Gr 1/2 are evenly distributed across the dose range, with no target system organ class of special notice identified. Best clinical response recorded are stable disease (SD) in 7/19 evaluable patients in the monotherapy arm. The first dose cohort for BI-1808 at 225 mg in combination with pembrolizumab is currently ongoing.BI-1808 exhibits a non-linear PK. At doses > 675 mg Q3W, t½ was approximately 1 week resulting in accumulation of drug, with complete RO throughout the dosing interval.ConclusionsPreliminary data from the BI-1808 monotherapy arm from the clinical trial 19-BI-1808–01 is promising. BI-1808 has a favorable safety profile, with no DLTs observed. SD was observed in 7/19 evaluable patients. Doses of 675 mg and higher are expected to provide complete RO throughout the dose interval, and will be further explored in Ph2a.

BackgroundThe pleiotropic TNF-alpha:TNFR axis plays a central role in the immune system. While the cellular expression of TNFR1 is broad, TNFR2 expression is mainly restricted to immune cells. The therapeutic potential of targeting TNFR2 for cancer treatment has been previously indicated and to gain further insight, we characterized a wide panel antibodies, generated from the n-CoDeR F.I.R.S.T™ target and antibody discovery platform. We identified parallel human and mouse TNFR2 specific, complete ligand (TNF-alpha) blocking antibodies and could show potent anti-tumor activity in several immune-competent models, both as single agent and in combination with anti-PD1 using a BI-1808 murine surrogate. The mechanism-of-action was shown to be FcgR dependent and likely mediated through a combination of intra-tumor T reg depletion, CD8+ T cell expansion and modulation of tumor-associated myeloid cells. These findings were confirmed using BI-1808 in a humanized mouse model.MethodsTo address safety of the human lead-candidate BI-1808 two toxicological studies were performed in cynomolgus monkeys. The first study was a dose-range-finding study and the second a GLP study where three doses (2, 20 and 200 mg/kg) were given weekly for four consecutive weeks followed by a recovery period of eight weeks. In addition, cytokine release was further studied in T cell stimulation assays and in a humanized mouse model. Moreover, the BI-1808 murine surrogate was used to study the relationship between dose, receptor occupancy (RO) and efficacy in immune competent mouse cancer experimental models.ResultsFour weekly administrations of BI-1808 to cynomolgus monkeys were well tolerated at all doses, with no associated clinical signs, and no histopathological changes. Non-adverse and reversible increases in neutrophil counts and decreases in T cells were observed at all dose levels. No drug-related adverse events were observed and consequently the NOAEL for BI-1808 was determined to be 200 mg/kg. Pharmacokinetic studies demonstrated an expected half-life of two weeks at receptor saturation. There were no indications of cytokine release in any of the systems tested. Finally, we could show that to achieve max therapeutic effect, sustained RO was needed for approximately two weeks, covering the time it takes to generate a full adaptive Immune response.ConclusionsThere is a clear association between RO and therapeutic effect and BI-1808 is well tolerated at doses associated with high and sustained RO. Collectively, these studies were used to determine the starting dose in upcoming phase I/II study in solid cancer aiming for first-patient in during December 2020.Ethics ApprovalThe study on cynomolgous monkeys was conducted by Citox/Charles River Laboratories in compliance with animal health regulations, in particular: Council Directive No. 2010/63/EU of 22 September 2010 and French decree No. 2013-118 of 01 February 2013 on the protection of animals used for scientific purposes. Studies in mice were approved by the Swedish Animal Experiment Ethics Board, ethical permit/ethical license numbers 5.2.18-17196/2018 and 5.8.18-03333/2020

Induction of broadly neutralizing antibodies, such as the monoclonal antibodies IgGb12, 2F5 and 2G12, is the objective of most antibody-based HIV-1 vaccine undertakings. However, despite the relative conserved nature of epitopes targeted by these antibodies, mechanisms underlying the sensitivity of circulating HIV-1 variants to broadly neutralizing antibodies are not fully understood. Here we have studied sensitivity to broadly neutralizing antibodies of HIV-1 variants that emerge during disease progression in relation to molecular alterations in the viral envelope glycoproteins (Env), using a panel of primary R5 HIV-1 isolates sequentially obtained before and after AIDS onset. HIV-1 R5 isolates obtained at end-stage disease, after AIDS onset, were found to be more sensitive to neutralization by TriMab, an equimolar mix of the IgGb12, 2F5 and 2G12 antibodies, than R5 isolates from the chronic phase. The increased sensitivity correlated with low CD4(+) T cell count at time of virus isolation and augmented viral infectivity. Subsequent sequence analysis of multiple env clones derived from the R5 HIV-1 isolates revealed that, concomitant with increased TriMab neutralization sensitivity, end-stage R5 variants displayed envelope glycoproteins (Envs) with reduced numbers of potential N-linked glycosylation sites (PNGS), in addition to increased positive surface charge. These molecular changes in Env also correlated to sensitivity to neutralization by the individual 2G12 monoclonal antibody (mAb). Furthermore, results from molecular modeling suggested that the PNGS lost at end-stage disease locate in the proximity to the 2G12 epitope. Our study suggests that R5 HIV-1 variants with increased sensitivity to broadly neutralizing antibodies, including the 2G12 mAb, may emerge in an opportunistic manner during severe immunodeficiency as a consequence of adaptive molecular Env changes, including loss of glycosylation and gain of positive charge.

Europrise is a Network of Excellence supported by the European Commission within the 6th Framework programme from 2007 to 2012. The Network has involved over 50 institutions from 13 European countries together with 3 industrial partners and 6 African countries. The Network encompasses an integrated program of research, training, dissemination and advocacy within the field of HIV vaccines and microbicides. A central and timely theme of the Network is the development of the unique concept of co-usage of vaccines and microbicides. Training of PhD students has been a major task, and some of these post-graduate students have here summarized novel ideas emanating from presentations at the last annual Europrise meeting in Prague. The latest data and ideas concerning HIV vaccine and microbicide studies are included in this review; these studies are so recent that the majority have yet to be published. Data were presented and discussed concerning novel immunisation strategies; microbicides and PrEP (alone and in combination with vaccines); mucosal transmission of HIV/SIV; mucosal vaccination; novel adjuvants; neutralizing antibodies; innate immune responses; HIV/SIV pathogenesis and disease progression; new methods and reagents. These – necessarily overlapping topics - are comprehensively summarised by the Europrise students in the context of other recent exciting data.

EUROPRISE is a Network of Excellence sponsored from 2007 to 2011 by the European Commission within the 6th Framework Program. The Network encompasses a wide portfolio of activities ranging from an integrated research program in the field of HIV vaccines and microbicides to training, dissemination and advocacy. The research program covers the whole pipeline of vaccine and microbicide development from discovery to early clinical trials. The Network is composed of 58 partners representing more than 65 institutions from 13 European countries; it also includes three major pharmaceutical companies (GlaxoSmithKline, Novartis and Sanofi-Pasteur) involved in HIV microbicide and vaccine research. The Network displays a dedicated and informative web page: http://www.europrise.org . Finally, a distinguishing trait of EUROPRISE is its PhD School of students from across Europe, a unique example in the world of science aimed at spreading excellence through training. EUROPRISE held its second annual conference in Budapest in November, 2009. The conference had 143 participants and their presentations covered aspects of vaccine and microbicide research, development and discovery. Since training is a major task of the Network, the students of the EUROPRISE PhD program summarized certain presentations and their view of the conference in this paper.

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

HIV-1 DNA vaccines have many advantageous features. Evaluation of HIV-1 vaccine candidates often starts in small animal models before macaque and human trials. Here, we selected and optimized DNA vaccine candidates through systematic testing in rabbits for the induction of broadly neutralizing antibodies (bNAb). We compared three different animal models: guinea pigs, rabbits and cynomolgus macaques. Envelope genes from the prototype isolate HIV-1 Bx08 and two elite neutralizers were included. Codon-optimized genes, encoded secreted gp140 or membrane bound gp150, were modified for expression of stabilized soluble trimer gene products, and delivered individually or mixed. Specific IgG after repeated i.d. inoculations with electroporation confirmed in vivo expression and immunogenicity. Evaluations of rabbits and guinea pigs displayed similar results. The superior DNA construct in rabbits was a trivalent mix of non-modified codon-optimized gp140 envelope genes. Despite NAb responses with some potency and breadth in guinea pigs and rabbits, the DNA vaccinated macaques displayed less bNAb activity. It was concluded that a trivalent mix of non-modified gp140 genes from rationally selected clinical isolates was, in this study, the best option to induce high and broad NAb in the rabbit model, but this optimization does not directly translate into similar responses in cynomolgus macaques.

EUROPRISE is a Network of Excellence sponsored from 2007 to 2011 by the European Commission within the 6th Framework Program. The Network encompasses a wide portfolio of activities ranging from an integrated research program in the field of HIV vaccines and microbicides to training, dissemination and advocacy. The research program covers the whole pipeline of vaccine and microbicide development from discovery to early clinical trials. The Network is composed of 58 partners representing more than 65 institutions from 13 European countries; it also includes three major pharmaceutical companies (GlaxoSmithKline, Novartis and Sanofi-Pasteur) involved in HIV microbicide and vaccine research. The Network displays a dedicated and informative web page: http://www.europrise.org. Finally, a distinguishing trait of EUROPRISE is its PhD School of students from across Europe, a unique example in the world of science aimed at spreading excellence through training. EUROPRISE held its second annual conference in Budapest in November, 2009. The conference had 143 participants and their presentations covered aspects of vaccine and microbicide research, development and discovery. Since training is a major task of the Network, the students of the EUROPRISE PhD program summarized certain presentations and their view of the conference in this paper.