Expression of mast cell proteases in rat lung during helminth infection: Mast cells express both rat mast cell protease II and tryptase in helminth infected lung
M. Tomita et al., Expression of mast cell proteases in rat lung during helminth infection: Mast cells express both rat mast cell protease II and tryptase in helminth infected lung, INT A AL IM, 120(4), 1999, pp. 303-309
Background: The phenotype of proliferated mast cells in Nippostrongylus bra
siliensis-infected rat lung has been identified as mucosal mast cells (MMC)
but not connective tissue mast cells (CTMC), However, a previous study of
ours showed that the expression of rat mast cell tryptase (RMCT) mRNA, whic
h has been reported to be confined to CTMC, significantly increased in rat
lung 14 days after infection. Methods: The expression of four mast cell pro
teases in rat lung during the course of infection with N, brasiliensis was
examined by RNA blot analysis. Immunohistochemical analysis of RMCT and rat
mast cell protease (RMCP) II, which has been reported to be confined to MM
C was also performed. Results: The number of lung mast cells did not change
until 7 days after infection, then gradually increased until 21 days after
infection. The expression of the RMCP II gene had increased 14 and 21 days
after infection. In addition, the expression of the RMCP I and RMCT genes
had also increased at the same time points, but RMCP III had not. By immuno
histochemistry, most of the mast cells in infected lung were identified as
RMCP II+/RMCT- (MMC), but both RMCP II+ and RMCT+ mast cells were also obse
rved. Conclusions: The present results suggest that mast cell phenotype alt
eration or a distinct mast cell subset might be present in N. brasiliensis-
infected rat lung, and therefore N. brasiliensis-infected rat lung may be a
useful tool for studying the differentiation mechanism of mast cells, Copy
right (C) 1999 S. Karger AG. Basel.