Protective
immunity against intracellular pathogen
Mycobacterium leprae is dependent on the activation of
T cells . Repeated stimulation of
T cells by M. leprae
antigens MLCwA (M. leprae total
cell wall antigen ) and ManLAM (
mannose capped lipoarabinomannan) may
lead to
apoptosis in
leprosy patients . In the present study, inhibition of the Fas-induced
apoptosis of
peripheral blood mononuclear cells of
leprosy patients was investigated using above M. leprae
antigen (s), in combination with
immunomodulators murabutide (MB) and a Trat
peptide in particulate form (
liposome ). Incubation of the
cells with particulate mode of
antigen presentation led to both decreased percentage of
propidium iodide (PI) positive
cells and
T cells expressing Fas-FasL, as well as decreased
caspase-8 /-3 activities in the lepromatous
patients , thereby inhibiting
apoptosis , while converse was true with stimulation with soluble
antigen . Concurrently, there was an
upregulation of antiapoptotic
protein Bcl-X(L) in the lepromatous
patients , thereby inhibiting
apoptosis . Thus, the liposomal formulation of
antigen promoted proliferation of anergized
T cell by inhibiting
apoptosis through decreased expression of
death receptors and
caspase activities and increased expression of
anti-apoptotic protein Bcl-X(L) in these
patients .