Proposed model for immunological damage in Mtb-H37Rv-infected macrophages pre-exposed to CS.

Abstract

<p>In normal conditions, TLR2 activation in a dose-dependent manner leads to cytokine production in the macrophages. 2) Macrophages exposed to CS have increased ASK1 and JNK1 levels (perhaps as signals of cellular stress), but decreased expression of TLR2 and levels of the anti-apoptotic molecules Bcl-2 and Mcl-1; under these conditions, the macrophage is more susceptible to cell death. 3) Where the macrophages pre-exposed to CS are infected with Mtb-H37Rv, there is an increased secretion of pro-apoptotic cytokines (TNF-α and IL-1β). When macrophages are exposed to CS, they become more susceptible to cell death, if they are also infected with M.tb, pro-inflammatory cytokines are secreted and necrosis is established, favoring the release of viable intracellular bacilli.</p