Biology subjects

Ascui, G.

Publications and source records attributed to Ascui, G..

2 recordsLinked to original sources

bioRxiv2026

IL-27 induces a cytotoxic state in CD4+ T cells distinct from the Th1 lineage

CD4+ cytotoxic T lymphocytes (CD4-CTLs) are understudied immune mediators with ambiguous origins. Despite expressing RUNX3, granzyme B (GZMB), and perforin (PRF1), CD4-CTLs are frequently classified as Th1 extensions due to shared interferon-{gamma} (IFN{gamma}) and T-BET expression. Here, we identify interleukin-27 (IL-27) as a independent inducer of a distinct CD4-CTL program. Proteomics reveals that while IL-27-polarized CD4+ T cells share protein signatures with conventional Th1s and CD8+ T cells, they possess a unique molecular landscape with re-wired cytokine signaling networks and a potent cytotoxic protein profile. Mechanistically, this program requires STAT1 and T-BET but operates independently of the autocrine IFN{gamma} feedback that sustains Th1 cells. During acute murine cytomegalovirus infection, IL-27 receptor signaling contributes to CD4-CTL differentiation in vivo, as its loss leads to reduced GZMB expression and skews CD4+ T cells toward IFN{gamma}+ and FOXP3+ subsets. Together, these findings establish IL-27 as a potent and previously unappreciated inducer of CD4-CTLs.

immunology↗

bioRxiv2021

Transcriptomes and metabolism define mouse and human MAIT cell heterogeneity

Mucosal-associated invariant T (MAIT) cells are a subpopulation of T lymphocytes that respond to microbial metabolites. We performed single-cell RNA sequencing and metabolic analyses of MAIT cell subsets in thymus and peripheral tissues from mice and humans to define the heterogeneity and developmental pathway of these innate-like lymphocytes. We show that the predominant mouse subset, which produces IL-17 (MAIT17), and the subset that produces IFN{gamma} (MAIT1), have greatly different transcriptomes and metabolic states in the thymus and periphery. A splenic MAIT subset has a transcriptome similar to circulating lymphocytes, and in mice these also are found in recent thymic emigrants, suggesting partially mature cells emigrate from the thymus. Human MAIT cells are predominantly MAIT1 cells, but have a different metabolism from their mouse counterparts with increased fatty acid uptake and storage. Although mouse and human subsets are similar in thymus, in the periphery they diverge, likely reflecting environmental influences.

immunology↗