The immune response to Mycobacterium tuberculosis

Mycobacteria are worldwide spread and satisfactory vaccines against pathogenic species have not been developed, yet. Mycobacteria, inside phagocytic cells, are able to escape humoral attack and maintain viability for long periods of time. T cells are engaged in the activation and regulation of macrophages and subsequently, in the control of mycobacterial growth. It appears that different T cell sets including CD4 alpha/beta T cells, CD8 alpha/beta T cells and gamma/delta T cells are involved in antimycobacterial immunity. Both, phagocyte and microorganism synthesize heat shock proteins in order to facilitate their survival. HSP possesses potent immunogenicity, a high degree of homology among different species and hence may play an important role in resistance against and pathogenesis of mycobacterial infections.