Immunomodulatory potential of in vivo natural killer T (NKT) activation by NKTT320 in Mauritian-origin cynomolgus macaques

CD1d-iNKT Axis in Infectious Diseases: Lessons Learned From the Past

CD1d is an antigen-presenting molecule that presents lipid or glycolipid antigens to iNKT cells, a distinct subset of T lymphocytes characterised by their innate-like properties and restricted use of Vα, Jα and Vβ segments. The CD1d-iNKT axis represents an interesting aspect of the immune system with significant potential for therapeutic interventions against infectious diseases. Upon recognition of lipid antigens, iNKT cells initiate rapid and potent immune responses, releasing a diverse array of cytokines such as IL-4, IL-13, IFN-γ etc. that profoundly influence immune reactions against various pathogens, including bacteria and parasites, bridging innate and adaptive immunity. We identify and describe the key features of lipidic antigens and their derivatives that determine the nature of their antigenicity. Furthermore, modulating CD1d-driven iNKT cell responses by an array of lipid and glycolipid antigens holds promise as adjunctive therapy to existing antimicrobial treatments. Understanding the complexities of the CD1d-iNKT axis and exploiting its therapeutic potential in the case of infectious diseases could lead to innovative immunotherapeutic strategies, ushering in a new era of immunotherapy against pathogenic insults.

Exploring HIV Vaccine Progress in the Pre-Clinical and Clinical Setting: From History to Future Prospects

The human immunodeficiency virus (HIV) continues to pose a significant global health challenge, with millions of people affected and new cases emerging each year. While various treatment and prevention methods exist, including antiretroviral therapy and non-vaccine approaches, developing an effective vaccine remains the most crucial and cost-effective solution to combating the HIV epidemic. Despite significant advancements in HIV research, the HIV vaccine field has faced numerous challenges, and only one clinical trial has demonstrated a modest level of efficacy. This review delves into the history of HIV vaccines and the current efforts in HIV prevention, emphasizing pre-clinical vaccine development using the non-human primate model (NHP) of HIV infection. NHP models offer valuable insights into potential preventive strategies for combating HIV, and they play a vital role in informing and guiding the development of novel vaccine candidates before they can proceed to human clinical trials.

T Cell Receptor-Engaging Monoclonal Antibodies Mobilize the Anti-Tumor Functions of Invariant Natural Killer T Cells

Invariant natural killer T cells (iNKTs) are innate-type T lymphocytes that directly kill tumor cells or tumor-growth promoting immunosuppressive cells such astumor-associated macrophages. Additionally, iNKTs robustly transactivate the antitumor functions of T, B, natural killer, and dendritic cells as well as reinvigorate exhausted immune cells in the tumor microenvironment. As such, iNKTs make excellent candidates for inclusion in anti-cancer cellular therapies. However, to capitalize on the potential benefits of iNKT cell-based approaches, it is imperative that we develop new and clinically viable strategies to enhance their antitumor function. To that end, two novel monoclonal antibodies (mAbs) that selectively bind to the human (NKTT320) or murine (NKT14m) invariant T cell receptor have been recently developed and characterized. Studies using purified human iNKTs (in vitro) and a model of non-human primate (in vivo) reveal that NKTT320 promotes swift, vigorous and sustained iNKT cell activation that is accompanied by robust production of inflammatory mediators and bystander immune cell activation. Furthermore, NKTT320 augments expression of cytotoxic markers and human iNKT cell degranulation. Similarly, NKT14m prompts dramatic murine iNKT cell activation and functional response both in vitro and in vivo. However, antitumor efficacy of a single dose of NKT14m injection in tumor-bearing mice is limited and tumor-model dependent. In contrast, combination treatment of NKT14m with either low dose interleukin (IL)-12 or the chemotherapeutic agent, cyclophosphamide results in a superior antitumor response in vivo. This is evident by activation of both iNKTs and other immune cells, prolonged survival of the tumor-challenged mice, and long-lasting immunity. Collectively, these recent studies justify further development of anti-iTCR mAbs that can be used alone or in conjunction with immunomodulatory agents to enhance iNKT cell antitumor immunity against various cancers.