GSE98590
Tolerogenic transcriptome landscape in CD8+ T lymphocytes after exposure to erythrocyte-targeted antigen
Our group has recently shown induction of antigen-specific T cell tolerance through targeting antigen to erythrocytes in situ, based on the premise that as the erythrocytes age and are cleared eryptotically, their carried antigen payload is processed tolerogenically. The tolerogenic state is characterized by initial proliferation of antigen-specific CD4+ and CD8+ T cells, and subsequent acquisition of deletional, anergic and CD25+FOXP3+ regulatory T cell phenotypes. In this study, we wished to further understand the molecular mechanisms behind induction of tolerance by erythrocyte-targeted antigens. RNA sequencing was performed to determine how genes are regulated in tolerized ovalbumin-specific CD8+ T cells and which pathways are activated after treatment with this technology. High similarity between the gene response reported during self-tolerance, deletional tolerance and tolerance induced by erythrocyte-targeted antigens was observed. Treatment with erythrocyte-targeted antigens led to the upregulation of genes encoding several TCR co-inhibitory receptors such as CTLA4, PD1, LAG3, TIGIT and CD200R1, and lack of upregulation of cytotoxic and pro-inflammatory signaling molecule genes. Modulation in expression of the master transcription factors Egr2/NFatc1, Nur77 family and E2f1 was also observed, all known to be associated with the process of peripheral tolerance. Expression of these genes differed in response to treatment with soluble ovalbumin or free SIINFEKL MHCI peptide, suggesting a specific mechanism of T cell modulation and tolerance induction in response to the erythrocyte-associated forms. Together these results provide novel insights to further understand the mechanisms and potential of erythrocyte-targeted antigens for induction of antigen-specific immune tolerance. Overall design: Gene response was evaluted in adoptively transfered ovalbumin-specific CD8+ T cells in mice treated with erythrocyte-targeted ovalbumin (N=3), erythrocyte-targeted SIINFEKL (N=3), soluble ovalbumin (N=3), soluble SIINFEKL (N=2) or in naïve mice (N=3). Naïve group is used as control group to determine background gene levels in resting cells.