Extracellular MicroRNA Signature of Human Helper T Cell Subsets in Health and Autoimmunity

Abstract

Upon T cell receptor stimulation, CD4 T helper (Th) lymphocytes release extracellular vesicles (EVs) containing microRNAs. However, no data are available on whether human CD4 T cell subsets release EVs containing different pattern of microRNAs. The present work aimed at filling this gap by assessing the microRNA content in EVs released upon T cell receptor stimulation of Th1, Th17, and T regulatory (Treg) cells. Our results indicate that EVs released by Treg cells are significantly different compared with those released by the other subsets. In particular, miR-146a-5p, miR-150-5p, and miR-21-5p are enriched, whereas miR-106a-5p, miR-155-5p, and miR-19a-3p are depleted in Treg-derived EVs. The identified EV-associated microRNA signature was increased in serum of autoimmune patients with psoriasis and returned to healthy levels upon effective treatment with etanercept, a biological drug targeting the TNF pathway and suppressing inflammation. Moreover, Gene Set Enrichment Analysis showed an over-representation of genes relevant for T cell activation, such as CD40L, IRAK1, IRAK2, STAT1, and c-Myb in the list of validated targets of Treg-derived EV miRNAs. At functional level, Treg-derived (but not Th1/Th17-derived) EVs inhibited CD4 T cell proliferation and suppressed two relevant targets of miR-146a-5p: STAT1 and IRAK2. In conclusion, our work identified the miRNAs specifically released by different human CD4 T cell subsets and started to unveil the potential use of their quantity in human serum to mark the pathological elicitation of these cells and their biological effect in cell to cell communication during the adaptive immune response.

HIV‐1 inhibits haematopoiesis via microRNA secreted by virus‐infected CD4+ T cells

“…Several investigators have shown different roles for miRNAs in haematopoiesis . A comprehensive miRNA profile of all hematopoietic cells, cell lineages and progenitors, miRNA from various subsets of CD4+ T cells, whereas the extracellular miRNA signature of T cells has been reported. On the other hand, miRNAs important for haematopoiesis and self‐renewal have also been reported .…”

“…In order to understand which miRNA may be involved, we used the following approach. miRNA data reported to be either associated with CD4+ T cells, infected or uninfected with HIV were mined on PubMed. miRNA data reported to be associated with hematopoietic or myeloblastic differentiation were mined from PubMed. Databases were downloaded from the original references and their corresponding table number in the publication was noted (as indicated in Appendix ). To avoid duplications in between data sets reported by the various authors, Venn diagram analysis was carried out using GeneVenn for CD4+ T cell‐associated miRNA data and CD34+ differentiation‐associated miRNA data separately. Since GeneVenn can only analyse 3 sets of data simultaneously, the miRNA data sets associated with CD34+ were analysed in 2 batches and a compiled list of both batches together was used for final analysis. Finally, Venn analysis was carried out to determine miRNA common to both processes namely CD4+ T cell and CD34+ differentiation. …”

“…3. Databases were downloaded from the original references [18][19][20][21][22][23] and their corresponding table number in the publication was noted (as indicated in Appendix S1).…”

Immunometabolism of human autoimmune diseases: from metabolites to extracellular vesicles

“…This study simply correlates blood miRNA quantity with the knowledge that CD4 + T effector cells (in particular Th1 and Th17) are dramatically augmented in the skin of psoriasis patients, while the proportion of Treg cells is significantly increased upon anti‐TNF‐α therapies . The same study strongly suggests that the relative quantities of blood ‘proinflammatory’ versus ‘anti‐inflammatory’ extracellular miRNAs may be used as readout of the inflammatory state of autoimmune patients, before and after anti‐inflammatory drug treatment .…”

“…Treg cells are traditionally known to directly suppress T cells by multiple mechanisms, including anti‐inflammatory cytokine release (IL‐10, TGF‐β, IL‐35) and high expression of IL‐2 receptor α chain, able to effectively compete for IL‐2 binding by Tconv cells. Similarly to other T‐cell subsets, Treg cells release EVs upon TCR stimulation, and these EVs contain a signature of miRNAs that differs from that released by Tconv cells in both mouse and human system, and not necessarily mirrors miRNA differential expression at the intracellular level . In particular, human Treg‐derived EVs are highly enriched with the anti‐inflammatory miR‐146a‐5p (Fig.…”