Sexual dimorphism in immune responses is well documented, but the underlying mechanisms remain incompletely understood. Here, we identified a subset of corticotropin-releasing hormone (CRH) neurons that express androgen receptors (ARs) as key mediators of sex differences in restraint-induced immunosuppression. Mechanistically, androgens directly activate AR-positive CRH neurons, enhancing the hypothalamic-pituitary-adrenal axis activation. This results in elevated corticosterone levels in response to restraint stress, leading to increased immune cell apoptosis and immune organ atrophy in male mice. Conditional knockout of ARs in CRH neurons eliminated this sexual dimorphism, highlighting ARs in CRH neurons as pivotal regulators of sex-specific immune responses to stress.

Organ transplantation is the last-resort option to treat organ failure. However, less than 10% of patients benefit from this only option due to lack of major histocompatibility complex (MHC)-matched donor organs and 25%-80% of donated organs could not find MHC-matched recipients. T cell allorecognition is the principal mechanism for allogeneic graft rejection. We herein present a "donor MHC-specific thymus vaccination" (DMTV) strategy to induce T cell tolerance to both autologous and allogeneic donor MHC. Allogeneic MHC molecules were expressed in the recipient thymus through adeno-associated virus-mediated delivery, which led to stable expression of allogeneic MHC together with the autologous MHC in the engineered thymus. During local T cell education, those T cells recognizing either autologous MHC or allogeneic MHC were equally depleted. We constructed C57BL/6-MHC and BALB/c-MHC dual immunocompatible mice via thymus vaccination of C57BL/6-MHC into the BALB/c thymus and observed long-term graft tolerance after transplantation of C57BL/6 skin and C57BL/6 mouse embryonic stem cells into the vaccinated BALB/c mice. We also validated our DMTV strategy in a bone marrow, liver, thymus (BLT)-humanized mouse model for immunocompatible allotransplantation of human embryonic stem cells. Our study suggests that the DMTV strategy is a potent avenue to introduce a donor compatible immune system in recipients, which overcomes the clinical dilemma of the extreme shortage of MHC-matched donor organs for treating patients with end-stage organ failure.
© 2024. The Author(s).

In our previously reported phase 2 and phase 3 studies, the combination of short-course radiotherapy and neoadjuvant immunochemotherapy (SIC) is established as effective cancer therapies for locally advanced rectal cancer (LARC). Here, we apply multi-omic analyses to paired pre- and post-treatment LARC specimens undergoing SIC. The peripheral blood-derived TREM1+ mono-macrophage subsets that display a pro-inflammatory phenotype are identified and correlate with complete response to SIC. Mechanically, ionizing radiation (IR) induces peripheral TREM1+ mono-macrophage expansion in tumors. Following IR, the loss of TREM1 in mono-macrophages undermines antitumor immunity by altering mono-macrophage differentiation and inhibiting CD8+ T cell infiltration and activation. The TREM1+ mono-macrophage response may rely on activation of key inflammatory pathways, including nuclear factor κB (NF-κB) signaling and Toll-like receptor pathway. Pharmacological inhibition of TREM1 signaling abolishes IR-induced immunoactivation and reduces combined IR and/or anti-PD-1 treatment. Thus, we establish a crucial role of a mono-macrophage state in mediating effective cancer therapy.
Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.

Multiple genetic associations suggest a causative relationship between Th17-related genes coding for proteins, such as IL-17A, IL-23 and STAT3, and psoriasis. Further support for this link comes from the findings that neutralizing antibodies directed against IL-17A, IL-17RA and IL-23 are efficacious in diseases like psoriasis, psoriatic arthritis and ankylosing spondylitis. RORγt is a centrally positioned transcription factor driving Th17 polarization and cytokine secretion and modulation of RORγt may thus provide additional benefit to patients. However, RORγt also plays a role in the normal development of T cells in the thymus and genetic disruption of RORγt in the mouse leads to the development of lymphoma originating in the thymus. Whilst it is not established that down-regulation of RORγt activity would lead to the same consequence in humans, further understanding of the thymus effects is desirable to support progress of this target as a potential treatment of Th17-driven disease. Herein we present the characterisation of recently disclosed RORγt inverse agonists demonstrating target engagement and efficacy in vitro and in vivo against Th17 endpoints but requiring higher concentrations in vitro to affect thymocyte apoptosis.
Copyright: © 2025 Collins et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

This research demonstrates that DCC-2036 (Rebastinib), a potent third-generation tyrosine kinase inhibitor (TKI), effectively suppresses tumor growth in colorectal cancer (CRC) models with functional immune systems. The findings underscore the capacity of DCC-2036 to enhance both the activation and cytotoxic functionality of CD8+ T cells, which are crucial for facilitating anti-tumor immune responses. Through comprehensive multi-omics investigations, significant shifts in both gene and protein expression profiles were detected, notably a marked decrease in DKK1 levels. This reduction in DKK1 was linked to diminished CD8+ T cell effectiveness, correlating with decreased FGR expression. Moreover, our findings identify FGR as a pivotal modulator that influences DKK1 expression via the PI3K-AKT-SP1 signaling cascade. Correlative analysis of clinical specimens supports the experimental data, showing that increased levels of FGR and DKK1 in CRC tissues are associated with inferior clinical outcomes and reduced efficacy of immunotherapeutic interventions. Consequently, targeting the FGR-AKT-SP1-DKK1 pathway with DCC-2036 could potentiate immunotherapy by enhancing CD8+ T cell functionality and their tumor infiltration. This strategy may contribute significantly to the refinement of therapeutic approaches for CRC, potentially improving patient prognoses.
© 2025. The Author(s).