01810nas a2200301   4500000000100000008004100001260000900042653002300051653002500074653001100099653001200110653002500122100001400147700001400161700001200175700001100187700001300198700001000211700001400221700001300235700001300248700001400261245009300275300002600368490000600394520109400400022001401494       1989                            d  c198910aBacterial Vaccines10aDeveloping countries10aHumans10aleprosy10aMycobacterium leprae1 aBloom B R1 aSalgame P1 aMehra V1 aKato H1 aModlin R1 aRea T1 aBrennan P1 aConvit J1 aLugozi L1 aSnapper S00aVaccine development. On relating immunology to the Third World: some studies on leprosy.  a87-9; discussion 91-20 v23 a<p>Leprosy is of interest to immunologists because the varied clinical manifestations of the disease correlate closely with the immunological spectrum. Resistance to infection is dependent on appropriate cell-mediated immunity, but patients with the lepromatous form fail to respond to antigens of M. leprae. In vitro studies have revealed the existence of T-suppressor cells of the phenotype CD8+, CD3+, HLA-DR+, FcR+, 9.3-, which are restricted by major histocompatibility complex (MHC) class II antigens. Several new candidate vaccines against leprosy have been effective in breaking immunological unresponsiveness and engendering cell-mediated immunity in lepromatous leprosy patients, including the combination of BCG+ killed M. leprae. Because BCG has unique adjuvant properties, we have begun to use molecular genetic approaches to develop BCG into a multivaccine vehicle capable of immunizing simultaneously against several pathogens. Both phage-based and plasmid-based strategies have been successfully developed for introducing selectable markers into BCG for the first time.</p>  a0953-4954