02291nas a2200277   4500000000100000008004100001260000900042653001200051653001800063653002000081653002500101653001200126653001600138653000900154653002300163653002500186653001800211100001200229700001400241700001400255245015500269300001100424490000600435520155800441022001401999       1998                            d  c199810aAnimals10aCell Division10aCells, Cultured10aCoculture Techniques10aleprosy10aMacrophages10aMice10aMice, Inbred C57BL10aMycobacterium leprae10aSchwann Cells1 aSingh N1 aBirdi T J1 aAntia N H00aDifferential in vitro modulation of Schwann cell proliferation by Mycobacterium leprae and macrophages in the murine strains, Swiss white and C57Bl/6.  a207-160 v33 a<p>The special susceptibility of Schwann cells (SCs) to parasitization by M. leprae and of macrophages to M. leprae-induced defects implicates them in leprous nerve pathogenesis. SC proliferation is an important prerequisite for peripheral nerve regeneration and is regulated by a number of secretory factors. Several of these factors are secreted by SCs themselves as well as by the macrophages which are recruited at the site of lesion to assist in regeneration. SC proliferation, as indicated by 3H-thymidine incorporation, was therefore studied in response to M. leprae infection and in the presence of macrophages in order to determine the role of SC in leprous neuropathy. Cells derived from two strains of mice, Swiss White (SW) and C57Bl/6 were used, as macrophages from these strains have been shown to differ in their response to M. leprae; such differences are similar to those observed in macrophages from lepromatous and tuberculoid leprosy patients, respectively. Infection with M. leprae for a duration of 9 days resulted in reduced proliferation of SCs from SW strain, while SCs from C57Bl/6 remained unaffected. However, in the presence of macrophages, SCs from both strains not only showed enhanced proliferation, but SW SCs also overcame the M. leprae-induced suppression of their proliferation. Altered SC proliferation, therefore, can be implicated as a factor in leprous nerve pathogenesis. The strain variation observed in the response of SCs indicate different nerve damage mechanisms in lepromatous and tuberculoid patients.</p>  a1085-9489