340 Proteomic profiling of skin associated ILC and T cells reveals functional differences

Innate lymphoid cells (ILC) are key players in tissue homeostasis and the regulation of local immunity barrier organs such as skin. The functional properties ILC reflected by their protein expression, proteins being end-stage products active genes. To characterize proteome human skin ILC, we performed in-depth proteomic analyses (mass spectrometry-based) on ILC2 ILC3 purified from healthy (N=10), T cell counterparts (N=6). Skin derived lacked archetypical cytokine receptor signatures other organs, but expressed IL-18R, confirming previous observations mice. Steady-state showed constitutive expression IL-14, IL-16, IL-36γ, IL-37 TGF-β1. We determined presence known CD markers, transcription factors, immune checkpoints, homing pathogen sensors subsets, found that multiple molecules were significantly differentially two types. For example, CD26, CD106, CD200R1, OX40L, CD280 highly ILC2, whereas high CD11c, CD63, CD224, CD314, GITR XCL1. In differential analysis cells, higher involved homeostasis, wound healing repair, FGA, VTN, HGF BMP1. Conversely, also significant proteins, including CD6. conclusion, proteomes reveal unreported constitute an important resource for understanding biology. Our data support hypothesis differs among tissues.