02391nas a2200325   4500000000100000008004100001260001600042653001200058653002000070653001300090653003400103653001700137653001200154653001200166653002800178653002700206653000900233653002300242653002500265653001800290100001200308700001400320700002000334700001400354245012900368300001000497490000800507520153600515022001402051       1997                            d  c1997 Oct 0310aAnimals10aCells, Cultured10aCollagen10aExtracellular Matrix Proteins10aFibronectins10aLaminin10aleprosy10aMacrophages, Peritoneal10aMembrane Glycoproteins10aMice10aMice, Inbred C57BL10aMycobacterium leprae10aSchwann Cells1 aSingh N1 aBirdi T J1 aChandrashekar S1 aAntia N H00aSchwann cell extracellular matrix protein production is modulated by Mycobacterium leprae and macrophage secretory products.  a13-220 v1513 a<p>Extracellular matrix (ECM) protein deposition is an important feature of leprous nerves, where Schwann cells (SCs) and macrophages are the main hosts for Mycobacterium leprae. Since, SCs are involved in the synthesis of ECM proteins and its production is regulated by macrophage secretory factors, the present study aimed to determine in vitro, the effect of M. leprae infection and macrophage secretory products on secretion of ECM proteins by SCs in two strains of mice, Swiss White (SW) and C57BL/6, that are known to differ in their nerve pathology and macrophage functions in response to infection. Following six days of M. leprae infection, SCs from SW mice responded with increased secretion of 14C-leucine radiolabelled proteins and a concomitant increase in laminin and collagens type I, III and IV, as determined by enzyme-linked immunosorbent assay. In contrast infected C57BL/6 SCs responded with decreased secretion of total proteins and fibronectin. Exposure of SCs to macrophage conditioned medium resulted in decreased ECM protein secretion in both strains of mice. This decrease was a function of protein breakdown by macrophage derived proteases and also active regulation by macrophage secreted cytokines. A similar effect of M. leprae and macrophage secretory products on SC metabolism in leprous nerves would have major ramifications on damage and repair activities. In addition ECM proteins would also influence the composition of the infiltrating cell population in lepromatous and tuberculoid nerves.</p>  a0022-510X