Idiopathic pulmonary fibrosis (IPF) is a severe diffuse progressive fibrosing interstitial disease leading to respiratory failure and death in the absence of organ transplantation. Substantial evidence has confirmed the pivotal role of fibroblasts in the progression of IPF, yet effective therapeutic options are scarce. Single-cell transcriptomics profiling revealed that among the diverse fibroblast subsets, FAP1+ alveolar fibroblasts (AFs) are pivotal for the progression of IPF. On the basis of these findings, we developed FAP1-targeting chimeric antigen receptor cytotoxic effector regulatory T (CAR-cTregs) cells, which leverage the targeted killing advantage of the currently trending CAR-based immunotherapy for tumors and incorporate the immunosuppressive functions of Tregs to mitigate the inflammation caused by both the disease itself and CAR-T-cell infusion. Accordingly, CAR-cTregs were constructed to effectively eliminate FAP1+ fibroblasts in vitro. This cytotoxic effect can be abrogated by inhibitors of the granzyme-perforin pathway. In the bleomycin-induced PF model, CAR-cTregs were found to reverse fibrosis characterized by diminished recruitment of fibrocytes and improved remodeling of epithelial cells. Together, our results demonstrate that CAR-cTregs can serve as a promising therapeutic option for IPF and provide a novel strategy for treating multiple chronic inflammatory diseases by inducing both cytotoxicity and immunosuppression.

Activated immune cells infiltrate the vasculature during the pathophysiology of hypertension by establishing a vascular-immune interface that contributes to blood pressure dysregulation and organ failure. Many observations indicate a key role of CD8+ T cells in hypertension but mechanisms regulating their activation and interplay with the cardiovascular system are still unknown. In murine model, here we show that a specific member of the phosphoinositide-3-kinases (PI3K) family of lipid kinases, PI3Kγ, is a key intracellular signaling of CD8+ T cells activation and RANTES/CCL5 secretion in hypertension: CCL5-CCR5 signaling is crucial for the establishment of the vascular-immune interface in peripheral organs, lastly contributing to CD8+ tissue infiltration, organ dysfunction and blood pressure elevation. Our studies identify PI3Kγ as a booster of effector CD8+ T cell function, even in the absence of external stimuli. Lastly, an enhanced PI3Kγ signaling mediates the bystander activation of CD8+ T cells and proves effective in transferring the hypertensive phenotype between mice.
© 2025. The Author(s).

Vaccines are widely regarded as one of the most effective strategies for combating infectious diseases. However, significant challenges remain, such as insufficient antibody levels, limited protection against rapidly evolving variants, and poor immune durability, particularly in subunit vaccines, likely due to their short in vivo exposure. Recent advances in extending the half-life of protein therapeutics have shown promise in improving drug efficacy, yet whether increasing in vivo persistence can enhance the efficacy of subunit vaccines remains underexplored. In this study, we developed two trimeric SARS-CoV-2 subunit vaccines with distinct pharmacokinetic profiles to evaluate the impact of vaccine persistence on immune efficacy. A self-assembling trimeric subunit vaccine (RBD-HR/trimer) was designed, followed by an extended-persistence variant (RBD-sFc-HR/trimer) incorporating a soluble monomeric IgG1 fragment crystallizable. We demonstrated that RBD-sFc-HR/trimer elicited more robust and higher levels of neutralizing antibodies, with potent and broad neutralization activity against multiple SARS-CoV-2 variants. Notably, RBD-sFc-HR/trimer induced a durable immune response, significantly increasing the number of memory B cells and T cells. This study provides critical insights for designing vaccines that achieve potent and long-lasting immune responses against infectious diseases.
Copyright: © 2025 Shen 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.

Retinoic acid-inducible gene I (RIG-I) is a pattern recognition receptor involved in innate immunity, but its role in adaptive immunity, specifically in the context of CD8+ T-cell antitumour immunity, remains unclear. Here, we demonstrate that RIG-I is upregulated in tumour-infiltrating CD8+ T cells, where it functions as an intracellular checkpoint to negatively regulate CD8+ T-cell function and limit antitumour immunity. Mechanistically, the upregulation of RIG-I in CD8+ T cells is induced by activated T cells, and directly inhibits the AKT/glycolysis signalling pathway. In addition, knocking out RIG-I enhances the efficacy of adoptively transferred T cells against solid tumours, and inhibiting RIG-I enhances the response to PD-1 blockade. Overall, our study identifies RIG-I as an intracellular checkpoint and a potential target for alleviating inhibitory constraints on T cells in cancer immunotherapy, either alone or in combination with an immune checkpoint inhibitor.
© 2024. The Author(s).