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Inzhelevskaya, T.

Publications and source records attributed to Inzhelevskaya, T..

3 recordsLinked to original sources

Bispecific Antibody Architecture and TNFRSF Target Selection Determine CD8+ T Cell Differentiation and Anti-tumour Immunity

Tumour necrosis factor receptor superfamily (TNFRSF)-targeting bispecific antibodies (bsAb) enable tumour-localised T cell co-stimulation, yet how antibody architecture and receptor choice govern activity remains unclear. Here we define how bsAb format and TNFRSF target selection shape CD8+ T cell responses and anti-tumour immunity. Using B7-H3 as a tumour-associated antigen, we show that dual-bivalent 2x2 bsAb elicit maximal agonistic activity, whereas the corresponding monovalent 1x1 format is least active. A 2x1 format retaining TNFRSF bivalency but monovalent B7-H3 binding preserves substantial activity, identifying co-stimulatory receptor bivalency as a key determinant of efficacy. Across TNFRSF targets, 4-1BB drives the strongest cytotoxic CD8+ T cell differentiation and anti-tumour response. This superiority is conserved in human T cells and reproduced by cognate ligands, indicating that the observed functional hierarchy reflects receptor-intrinsic biology. Mechanistically, efficacy requires tumour-associated B7-H3 and T cell-dependent 4-1BB signalling. Together, these findings establish general principles linking antibody architecture and receptor biology to co-stimulatory bsAb efficacy and provide a framework for rational design leading to optimal therapeutics.

immunology↗

Synthetic STING agonists elicit powerful vaccine adjuvancy providing robust central memory and anti-tumour effects

Drugs that target the innate immune sensor STING are known to be effective in modulating the immune infiltrate of the tumour microenvironment. STING agonists have potential to enhance responses to checkpoint inhibitor therapy, however, their ability to influence and shape adaptive immune responses is poorly understood. Here, we investigated the impact of a range of synthetic STING agonists on antigen specific CD8+ T-cell responses to soluble antigen using the murine OT-1 adoptive transfer model with Ovalbumin as the antigen to monitor T cell responses. Our data demonstrate that synthetic STING agonists are able to stimulate antigen specific T-cell expansion in response to challenge in mice. This effect required expression of STING, an intact myeloid compartment and Type-I IFN and TNF signalling. Expanded T-cells post treatment differed from those induced by the established immune adjuvant, anti-CD40 antibody through lower induction of the immune checkpoint receptor PD-1. Furthermore, our data revealed a marked increase in the induction and persistence of CD8+ central memory cells after STING agonist and antigen challenge. Finally, we demonstrate that following rechallenge, STING agonism produced larger secondary responses that could be translated into enhanced tumour protection and survival. Therefore, synthetic STING agonists are capable of acting as potent immune adjuvants and can induce robust memory formation leading to better recall and tumour control. Critically, these benefits along with the lower expression of PD-1, have implications for their use as adjuvants for multiple immunotherapy and vaccine applications.

immunology↗

Domain Binding and Isotype Dictate the Activity of Anti-human OX40 Antibodies

Previous data suggests that anti-OX40 mAb can elicit anti-tumour effects in mice through deletion of Tregs. However, OX40 also has powerful costimulatory effects on T cells which could evoke therapeutic responses. The contributions of these different effector mechanisms has not previously been systematically evaluated, particularly for mAb directed to human OX40. Therefore, we generated a novel human OX40 knock-in (KI) mouse to evaluate a panel of anti-hOX40 mAb and show that their activities relate directly to two key properties: 1) isotype – with mIgG1 mAb evoking receptor agonism and CD8+ T cell expansion and mIgG2a mAb evoking deletion of Treg and; 2) epitope - with membrane-proximal mAb delivering more powerful agonism. Intriguingly, both isotypes acted therapeutically in tumour models by engaging these different mechanisms. These findings highlight the significant impact of isotype and epitope on the modulation of anti-hOX40 mAb therapy, and indicate that CD8+ T cell expansion or Treg depletion might be preferable according to the composition of different tumours.Summary Human trials with anti-OX40 antibodies have been disappointing indicating that optimal reagents have not yet been developed. Here, using a new panel of antibodies, we show that isotype and epitope combine to determine agonistic and therapeutic activity.Competing Interest StatementMSC is a retained consultant for BioInvent International and has performed educational and advisory roles for Baxalta and Boehringer Ingleheim. He has received research funding from Roche, Gilead, Bioinvent International and GSK. BF, IT, LM and MS are employees of Bioinvent International.View Full Text

immunology↗