Gene expression profiling of suppressor mechanisms in tuberculosis

MIP3alpha and platelet factor 4 (v1) are both significantly enriched (p ≤ 0.001) in the GO category “chemokine activity”. Repressed genes were significantly (p ≤ 0.001) over-represented in the GO terms “response to pathogenic bacteria”, “inflammatory response”, “coagulation” and “apoptosis”. Indeed, SC significantly reduced numbers of Annexin V/CD4+ cells, while inducing hypoproliferation in CD4+ and non-adherent lymphocytes. This may indicate that M.tb renders a portion of the CD4+ T cell population unresponsive. Furthermore, validating QRT-PCR analysis suggests that monocytes provide an immuno-modulatory signal to CD4+ T cells in M.tb infection. These observations will allow development of new therapeutic interventions to restore the desired T helper 1 response.