Results so far indicate that these surface antigens belong to a class of molecules which is different from the traditionally studied antigen presenting molecules. Significant advancements have been made toward characterization of the molecular changes that antigen presenting cells are undergoing upon exposure to mycobacterial antigens. Rapid upregulation of several cellular proteins has been found. The early induction of PCNA is regulated at a post-transcriptional level and is restricted to T cells. The signaling pathway involved in the induction of PCNA is currently being studied.
Preliminary results indicate that phosphotyrosine phosphatases and kinases are both involved.
Unlike activation of T cells through the T cell receptor, no calcium flux or PKC activation is involved in the induction of PCNA by mycobacteria. The cellular requirements, the antigenetic specificity and the biological significance of the observed phenomenon are currently being studied. Haftel HM, Chang Y, Hinderer R, Hanash S. Holoshitz J . Induction of the autoantigen proliferating cell nuclear antigen in T lymphocytes by a mycobacterial antigen. Holoshitz J .