Immunology repertoire study of pulmonary sarcoidosis T cells in CD4+, CD8+ PBMC and tissue.

Sarcoidosis is a systemic granulomatous disorder highly related with immune response. The diversity and stability of the immune system could be measured by hypervariable complementarity-determining region 3 (CDR3) segments of the T cell receptor (TCR). Here we used a combination of multiplex PCR and next-generation sequencing to conduct a good quality analysis of the T-cell receptor BV complementarity-determining region 3 (TCR BV CDR3) gene in peripheral blood mononuclear cells (PBMCs) from 7 sarcoidosis patients and lung sarcoidosis tissue from 6 patients. The length distribution of CDR3 sequences identified a significant difference among CD4+, CD8+ and tissue samples. The analysis of Gini coefficient, Shannon entropy and HEC number showed that they all presents in sarcoidosis tissue group clones in a more skewed manner than that of in PMBCs groups. 2 nucleotide sequences and 2 amino acid sequences were shared by all samples. The comparison of TRBV, TRBJ usage and VJ combination frequency identified 2 TRBV genes, 2 TRBJ genes differentially expressed among different groups and different higher usage and lower usage of V-J combinations between each group.