Weight and organ specific immune cell profiling of sleeve gastrectomy in mice

Sleeve gastrectomy (SG) has profound, immediate weight-loss independent effects on obesity related diabetes (T2D). Our prior studies have shown that immunologic remodeling may play a part in this metabolic improvement. However, to date, little is known about how the major immune cell populations change following SG and whether these are weight loss dependent. Using mass cytometry with time of flight analysis (CyTOF), we broadly quantified the organ-specific immune cell repertoire induced by SG from splenic, jejunal, ileal, colonic, and hepatic lymphocyte fractions. Surgeries were performed in both diet-induced obese (DIO), insulin resistant mice and lean mice, which leads to sustained and non-sustained weight loss in SG animals compared to shams, respectively. Intergroup comparisons allow understanding of the relative contribution of diet, weight-loss, and surgery on immune profiling. Conserved immune changes represent surgery-specific, weight-independent, and diet-independent phenotypic changes. Initial analysis by way of visualization of t-distributed stochastic neighbor embedding analysis revealed changes in the B cell compartment following SG in both DIO and lean mice compared to Sham animals. In depth, traditional gating showed a shift within the splenic B cell compartment toward innate-like phenotype. There was a 1.3-fold reduction in follicular B cells within DIO SG (14% absolute reduction; p = 0.009) and lean SG (15% absolute reduction; p = 0.031) animals with a significant increase in innate-like B cell subsets in DIO SG mice(2.2 to 4.3-fold increase; p