TCR-seq of tissue-infiltrating lymphocytes in obese patients

White adipose tissue (WAT) plays a role in immune defense, with diverse cell types and fat-associated lymphoid clusters contributing to its functions. WAT contains a significant population of memory T cells reactive to viral antigens but only limited murine research has explored it. Here, we performed TCR-seq from blood, omental WAT, subcutaneous WAT, and liver samples from 11 obese patients to explore the landscape of tissue infiltrating T cells antigen specificity. Briefly, library preparation involves a multiplex PCR with custom designed primers, "fishing" of the molecules of interest by magnetic particles, and addition of the adaptors' sequences for Ion S5 through the extension of the DNA strands covalently bound to the particles. This last step is critical since it avoids ligation bias. TCR beta chain sequencing was performed in the Ion S5 platform using Ion-530 chips (Ion Torrent, Thermo Fisher Scientific).