ALTERATIONS IN EARLY BIOCHEMICAL EVENTS FOLLOWING T-CELL ACTIVATION IN LEPROSY PATIENTS

The early events of activation and cytokine profiles (IL-2, 4, and 6) were studied in lymphocytes of paucibacillary (TT/BT) and multibacilla ry (BL/LL) leprosy patients after stimulation with PMA/A23187 and Myco bacterium leprae antigen (PGL-1). Lymphocytes from BT/TT patients show ed proliferation in response to both PMA/A23187 and PGL-1 compared to BL/LL. The levels of early activation signaling molecules such as IP3, calcium, and protein kinase C (PKC) in the particulate fraction were found to be elevated in BT/TT and BULL patients and showed a further s ignificant increase after stimulation with PMA/A23187 in BT/TT patient s. PGL-1 marginally increased the IP3 levels in BT/TT patients, wherea s in BULL patients, it had no effect. The levels of IL-2 were enhanced in lymphocytes of BT/TT leprosy patients and were further augmented b y PPD and PGL-1, while the levels of IL-4 and IL-6 were increased in L L/BL lymphocytes and further augmented by PGL-1. Thus PGL-1 seems to b e a major culprit in inducing the T(H)2-type cytokine response observe d in lepromatous leprosy patients. (C) 1998 Academic Press.