Tuberculin-Specific T Cells Are Reduced in Active Pulmonary Tuberculosis Compared to LTBI or Status Post BCG Vaccination
journal contribution
posted on 2023-06-07, 16:06authored byMathias Streitz, Stephan Fuhrmann, Fiona Powell, Ali Quassem, Laurel Nomura, Holden Maecker, Peter Martus, Hans-Dieter Volk, Florian KernFlorian Kern
Functional characteristics of tuberculosis (TB)-specific CD4 T cells were studied in clinically active pulmonary TB (n = 21) and high TB exposure including LTBI (n = 17). Following tuberculin stimulation, activated CD4 T cells were identified by flow-cytometry (CD154 up-regulation, degranulation, interferon gamma [IFN-gamma], tumor necrosis factor alpha [TNF-alpha], and interleukin 2 [IL-2\ production). Interestingly, CD154 up-regulation accounted for similar to 80% of activated CD4 T cells in the active TB group but just 40% in the controls, whereas IFN-gamma accounted for only similar to 50% of activated cells in each group. The frequencies of CD4 T cells displaying at least 1 activation marker discriminated better between the groups than those displaying degranulation or IFN-gamma production alone.