Association of mycobacterial antigen-specific CD4+ memory T cell subsets with outcome of pulmonary tuberculosis

SummaryObjectivesMemory T cells are hallmark of acquired immunological responses. The relationship of mycobacterial antigen-specific CD4+ memory T cell subsets with pulmonary tuberculosis was investigated.MethodsThe mycobacterial antigen-specific CD4+ T cells were detected based on CD154 expression and phenotypes of memory T cell were analyzed by surface staining of CD45RA and CCR7 and flow cytometrical analysis in patients with pulmonary tuberculosis and in tuberculin-positive healthy controls. The association of antigen-specific CD4+ memory T cell subsets with disease severity and anti-TB treatment was analyzed in patients with pulmonary tuberculosis.ResultsPatients with pulmonary tuberculosis had significantly lower frequencies of antigen-specific central memory T cells (TCM) (p = 0.019) and higher frequencies of effector memory T cells (TEM) (p = 0.022) compared with tuberculin-positive healthy controls without tuberculosis. Patients with smear/culture positive results showed lower population frequencies of TCM and significantly higher frequencies of TEM (p = 0.015) than those with smear/culture negative results. Treatment of TB patients with standard antibiotic regimens for more than one month led to significantly increased frequencies of TCM (p = 0.031).ConclusionsThe frequencies of mycobacterial antigen-specific TCM and TEM are associated with disease severity of pulmonary tuberculosis and TCM are associated with short-term effects of anti-TB chemotherapy.