Inácio, DanielAmado, TiagoPamplona, AnaSobral, DanielCunha, CarolinaLesourne, RenaudGomes, Anita Q.Silva-Santos, Bruno2024-01-152024-01-152023-06Inácio D, Amado T, Pamplona A, Sobral D, Cunha C, Gomes AQ, et al. Dissection of the IFN-γ versus IL-17-specific transcriptomes of γδ T cells: a new role for signaling adaptor Themis. In: 10th International γδ T Cell Conference, Fundação Champalimaud (Lisbon), June 20-23, 2023.http://hdl.handle.net/10400.21/16884The crucial role of murine γδ T cells in several (patho)physiological contexts stems from a complex process of ‘developmental pre-programming’ in the thymus, after which a significant fraction of γδ T cells populate peripheral sites already endowed with the capacity to secrete either IL-17 or IFN-γ. However, despite the relevance of these γδ T cell effector subsets, we still lack knowledge on the transcriptomes that specifically associate with IL-17 or IFN-γ production. To address this, we established a double reporter IL-17-GFP:IFN-γ-YFP mouse strain, which allowed us to isolate pure peripheral IL-17-producing (γδ17) or IFN-γ-producing (γδIFN) γδ T cells to perform RNA-sequencing. This led to the identification of the distinct transcriptomes of γδ17 and γδIFN cells, which surprisingly diverged in 6337 differentially (over 1.5-fold) expressed genes. Pathway and gene ontology analyses indicated that γδ17 cells differ from γδIFN cells in their selective ability to sense and integrate external cues, whereas γδIFN stands out in replication, transcription, and translation processes. A detailed analysis of the top differentially expressed genes between γδ17 and γδIFN cells revealed that most of the signature genes of each subset increased their expression levels in the periphery (compared to the thymus), suggesting that γδ17 and γδIFN cells only terminate their differentiation process at peripheral sites. Among the top differentially expressed genes, we found Themis, a T cell-specific gene involved in the regulation of TCR signal strength, to be enriched in γδIFN cells. Importantly, we found that Themis deficiency leads to a dysregulated effector γδ T cell peripheral compartment at steady state, which upon infection with Plasmodium berguei ANKA sporozoites confers Themis-deficient mice full protection from experimental cerebral malaria, a γδIFN-dependent pathology. Accordingly, we observed a less activated and less proliferative γδIFN population in the peripheral lymph nodes of infected Themis-deficient mice compared to Themis-sufficient controls. This work demonstrates the relevance of the characterization of the γδIFN and γδ17 transcriptomes to uncover new players in the regulation of γδ T cell effector functions, which may open new avenues for their manipulation in disease settings.engIFN-γIL-17-specific transcriptomesγδ T lymphocytesThemisconference object