Biology subjects

Narula, M.

Publications and source records attributed to Narula, M..

3 recordsLinked to original sources

bioRxiv2026

Engineering CAR-Vδ2 T cells to boost persistence and anti-tumor function

Chimeric antigen receptor (CAR)-modified V{delta}2 T cells are an attractive therapeutic cell platform for cancer immunotherapy. However, their clinical efficacy is limited by short in vivo persistence due to insufficient cytokine support and high susceptibility to activation-induced cell death (AICD). Through comparison of membrane-bound (mb) cytokines, we identified mbIL-18 to support superior anti-tumor activity of CAR-V{delta}2 T cells in vitro and in vivo. To reduce constitutive surface exposure of IL-18 and enable antigen-driven signal 3, we fused MyD88 - the key IL-18R signaling mediator - to an extracellular domain of Fas (Fas88). Antigen stimulation-induced FasL engagement of Fas88 triggered IL-18 signaling while simultaneously protecting V{delta}2 T cells from AICD. Fas88-armed human CAR-V{delta}2 T cells produced superior yet stimulation-dependent in vivo expansion and functional persistence in xenograft models of hematologic and solid malignancies. Together, these findings highlight the importance of IL-18 signaling and AICD resistance for CAR-V{delta}2 T cell activity, enabling a single-transgene modification to limit inflammatory risk and facilitate clinical translation.

synthetic biology↗

bioRxiv2024

Epigenetic signature and key transcriptional regulators of human antigen-specific type 1 regulatory T cells

Human adaptive immunity is orchestrated by effector and regulatory T (Treg) cells. Natural Tregs arise in the thymus where they are shaped to recognize self-antigens, while type 1 Tregs or Tr1 cells are induced from conventional peripheral CD4+ T cells in response to peripheral antigens, such as alloantigens and allergens. Tr1 cells have been developed as a potential therapy for inducing antigen-specific tolerance, because they can be rapidly differentiated in vitro in response to a target antigen. However, the epigenetic landscape and the identity of transcription factors (TFs) that regulate differentiation, phenotype, and functions of human antigen-specific Tr1 cells is largely unknown, hindering Tr1 research and broader clinical development. Here, we reveal the unique epigenetic signature of antigen-specific Tr1 cells, and TFs that regulate their differentiation, phenotype and function. We showed that in vitro induced antigen-specific Tr1 cells are distinct both clonally and transcriptionally from natural Tregs and other conventional CD4+ T cells on a single-cell level. An integrative analysis of Tr1 cell epigenome and transcriptome identified a TF signature unique to antigen-specific Tr1 cells, and predicted that IRF4, BATF, and MAF act as their transcriptional regulators. Using functional genomics, we showed that each of these TFs play a non-redundant role in regulating Tr1 cell differentiation, suppressive function, and expression of co-inhibitory and cytotoxic proteins. By using the Tr1-specific TF signature as a molecular fingerprint, we tracked Tr1 cells in peripheral blood of recipients of allogeneic hematopoietic stem cell transplantation treated with adoptive Tr1 cell therapy. Furthermore, the same signature identified Tr1 cells in resident CD4+ T cells in solid tumors. Altogether, these results reveal the epigenetic signature and the key transcriptional regulators of human Tr1 cells. These data will guide mechanistic studies of human Tr1 cell biology and the development and optimization of adoptive Tr1 cell therapies.

immunology↗

bioRxiv2022

Loss of FOXP3 function causes expansion of two pools of autoreactive T cells in patients with IPEX syndrome.

The monogenic autoimmune disease Immunedysregulation polyendocrynopathy entheropathy X-linked syndrome (IPEX) has elucidated the essential function of the transcription factor FOXP3 and of thymic-derived regulatory T (Treg) cells in controlling autoimmunity. However, the presence of autoreactive T cells in IPEX remains undetermined, thus representing a crucial gap in understanding the origin of autoimmunity in a FOXP3 deficient immune system. Combining epigenetic analysis as a lineage marker of Treg identity and TCR sequencing to assess the self-reactive clones, we showed that IPEX patients have two pools of expanded autoreactive T cells. The first originates from the expansion of autoreactive effector T cells (Teff), likely due to loss of Treg suppressive function since it is absent in carrier mothers, in whom Treg cells are functional. The second pool originates, unexpectedly, from Treg cells which lose their phenotypic markers, including CD25 and FOXP3. We call these loss of identity Treg cells and show that they are i) suppressed by healthy donor Treg in a patient post hematopoietic transplantation despite low donor chimerism, and ii) not detectable in patients with Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED), a monogenic autoimmune disease of thymic origin. Moreover, we demonstrate that FOXP3 knock-out in Treg cells leads to increased Treg expansion and production of Th17 and Th2 cytokines, known to be increased in IPEX patients. These results suggest that the loss of identity Treg cells could directly contribute to immune dysregulation in IPEX. Collectively, we provide a better understanding of autoimmunity and novel ways to monitor the effects of Treg cell therapies in IPEX disease or other autoimmune diseases. One Sentence SummaryMutations of FOXP3 gene in humans cause expansion of autoreactive T cells originating from both effector T cells and regulatory T cells which gain effector function.

immunology↗