Sham, H. P. | Search bioRxiv

bioRxiv2024

TYK2 inhibition enhances Treg differentiation and function while preventing Th1 and Th17 differnetiation

Janus kinase (JAK) inhibitors are widely use to inhibit inflammatory cytokine signalling in autoimmune and inflammatory diseases but their effect on regulatory T cells (Tregs) is poorly characterized. We investigated the effect of JAK inhibition on human Treg differentiation, phenotype, and function using a JAK inhibitor, upadacitinib, in comparison to BMS-986202, a selective Tyrosine kinase 2 (TYK2) inhibitor. Both upadacitinib and BMS-986202 blocked the differentiation of naive CD4+ T cells into Th1 and Th17 cells, but only BMS-986202 spared IL-2 signalling and Treg differentiation. BMS-986202 also increased Treg suppressive function and stability under Th1- and Th17-polarizing conditions, whereas upadacitinib significantly impaired the phenotype and viability of ex vivo Tregs. Analysis of lamina propria mononuclear cells from patients with inflammatory bowel disease revealed that, under Th17 polarizing conditions, BMS-986202 redirected CD4+ T cells towards a Treg phenotype. The Treg-sparing and enhancing properties of TYK2 inhibition suggest that TYK2 inhibitors are a promising pharmacological approach for tolerance induction. eTOC SUMMARYTuomela et al. report that TYK2 inhibition does not affect human Treg induction from naive CD4+ T cells, promotes Treg differentiation in lamina propria-derived T cells, and increases blood-derived Treg stability/function. In contrast, JAK inhibition strongly impairs Treg function.

immunology↗

bioRxiv2019

The right microbial stimulus can direct innate immune effector cells to specific organ sites to clear pathology

Recent developments in understanding how the functional phenotype of the innate immune system is programmed has led to paradigm-shifting views on immunomodulation. These advances have overturned two long-held dogmas: only adaptive immunity confers immunological memory and innate immunity lacks specificity. This work describes the novel observation that innate immune effector cells can be recruited to specific tissues of the body where pathology is present by using a microbial-based immune stimulus that consists of an inactivated pathogen that typically resides or causes infection in that target tissue site. We demonstrate this principle using experimental models of cancer and infection for which different subcutaneously delivered microbial-based treatments were shown to induce the recruitment of immune effector cells to specific diseased organs. Amelioration of disease in a given organ niche was dependent on matching the correct microbial stimulus for the affected organ site but was independent of the nature of the pathology. This observation intriguingly suggests that the immune system, upon pathogen recognition, tends to direct its resources to the compartment in which the pathogen has previously been encountered and would be the most likely source of infection. Importantly, this phenomenon provides a novel means to therapeutically target innate immune effector cells to sites of specific disease localization to potentially treat a wide spectrum of pathologies, including cancer, infection, and chronic inflammatory disorders.\n\nAUTHOR SUMMARYVaccines that target adaptive immune memory have revolutionized medicine. This study describes a novel strategy that works as a modified innate immune \"vaccine\" that exploits the trained response of innate immune effector cells to clear pathology in a specific tissue site. Unlike memory of the adaptive immune system, which functions like a lock and key, innate immune memory is more akin to a reflex response - like experienced muscle or neural cells that are changed by a stimulus to respond more efficiently upon re-exposure. This change in behavior through experience is the definition of learning. Our study suggests that this innate immune learning occurs at different levels. Emergency hematopoiesis trains new innate immune cells in the bone marrow to respond quickly and effectively to a non-specific threat; whereas, pathogen-specific training occurs at sites where cells making up the immunologic niche have had interactions with a particular pathogen and have been trained to respond more robustly to it upon re-presentation in the context of a danger signal. The speed with which new immune cells are trained in the bone marrow in response to an imminent microbial threat and their subsequent recruitment to the target organ site where that microbe typically resides suggests there are ways the immune system communicates to coordinate this rapid response that are yet to be fully delineated. These findings provide a novel highly proficient way to harness the potent effector functions of the innate immune system to address a wide range of immune-based diseases.

immunology↗