Single-cell expression profiling reveals new roles for G-protein-coupled receptors in the regulation of Th17 pathogenicity

G-protein coupled receptors (GPCRs) are pivotal in regulating T cell responses in steady state and inflammation. GPCR expression was intensively studied in bulk cDNA of T cell populations, but limited data are available with respect to expression in individual cells. We here present an analysis of a selected set of 125 different GPCRs expressed on distinct single T cells under naive conditions and during experimental autoimmune encephalomyelitis (EAE), the mouse model of multiple sclerosis. We found that neuroinflammation induces characteristic changes in GPCR heterogeneity and patterning, and we identified functionally relevant subgroups with specific GPCR expression profiles among spinal cord-infiltrating CD4 T cells. In spinal cord-infiltrating T helper 17 (Th17) cells, for example, expression of receptors such as Cxcr3, Cxcr4, P2ry10, or S1pr1 was associated with reduced pathogenicity, and we show that these correlations also exists on the protein level. Using CXCR4 and S1P1 as examples, we demonstrate that pharmacological targeting of these receptors is able to modulate Th17 pathogenicity in vitro and in vivo. Taken together, GPCR single-cell expression analysis provides a basis for the development of new strategies for pharmacological modulation of pathogenic immune cell subtypes. Overall design: Investigation of RNA expression in HUVEC in response to siRNA based Lphn2 knockdown, scrambled siRNA as control, two siRNA knockdowns for Lphn2 with two replicates each