Ex-vivo immunophenotyping and high dimensionality UMAP analysis of leucocyte subsets in tuberculous lymphadenitis.

Tuberculous lymphadenitis (TBL) is defined by reduced proinflammatory cytokines and elevated CD4, CD8 T cells and decreased CD8 cytotoxic markers. However, ex-vivo phenotyping of diverse leucocytes in TBL has not been done. We show activated and atypical B cells, myeloid dendritic cells (mDCs), classical, non-classical and intermediate monocytes, T regulatory (T regs) cells, CD4 T cell effector memory RA (TEMRA), CD4 effector and CD8 central memory phenotypes were significantly increased in TBL compared to LTB individuals. In contrast, classical memory and plasma B cells, plasmacytoid DCs (pDCs), CD8 TEMRA, CD4 naïve and central memory cells were significantly decreased in TBL compared to LTB individuals. Some of the leucocyte frequencies (atypical memory B cells, pDCs, myeloid-derived suppressor cells, CD4 effector and CD8 central memory was increased; activated memory and plasma B cell, mDCs, classical, non-classical, intermediate monocytes, T regs, CD4 TEMRA, CD4, CD8 naïve and effector memory cells and CD8 central memory cells were decreased) were significantly modulated after anti-TB treatment among TBL individuals. UMAP analysis show that leucocyte subsets or islands expressing specific markers were significantly different in TBL baseline and post-treatment individuals. Overall, we suggest altered frequencies of diverse leucocytes influences the disease pathology and protective immunity in TBL individuals.