Unknown

Dataset Information

0

Comparison of the microbicidal and muramidase activities of mouse lysozyme M and P.


ABSTRACT: Lysozyme is one of the most abundant antimicrobial proteins in the airspaces of the lung. Mice express two lysozyme genes, lysozyme M and P, but only the M enzyme is detected in abundance in lung tissues. Disruption of the lysozyme M locus significantly increased bacterial burden and mortality following intratracheal infection with a Gram-negative bacterium. Unexpectedly, significant lysozyme enzyme activity (muramidase activity) was detected in the airspaces of uninfected lysozyme M-/- mice, amounting to 25% of the activity in wild-type mice. Muramidase activity in lysozyme M-/- mice was associated with increased lysozyme P mRNA and protein in lung tissue and bronchoalveolar lavage fluid respectively. The muramidase activity of recombinant lysozyme P was less than that of recombinant M lysozyme. Recombinant P lysozyme was also less effective in killing selected Gram-negative bacteria, requiring higher concentrations than lysozyme M to achieve the same level of killing. The lower antimicrobial activity of P lysozyme, coupled with incomplete compensation by P lysozyme in lysozyme M-/- mice, probably accounts for the increased susceptibility of null mice to infection. Recombinant lysozyme M and P were equally effective in killing selected Gram-positive organisms. This outcome suggests that disruption of both M and P loci would significantly increase susceptibility to airway infections, particularly those associated with colonization by Gram-positive organisms.

SUBMITTER: Markart P 

PROVIDER: S-EPMC1224176 | BioStudies | 2004-01-01

REPOSITORIES: biostudies

Similar Datasets

2007-01-01 | S-EPMC1933452 | BioStudies
2012-01-01 | S-EPMC3416594 | BioStudies
1000-01-01 | S-EPMC179095 | BioStudies
1000-01-01 | S-EPMC177418 | BioStudies
2013-01-01 | S-EPMC3798531 | BioStudies
2008-01-01 | S-EPMC2575207 | BioStudies
2014-01-01 | S-EPMC4243810 | BioStudies
2018-01-01 | S-EPMC6033460 | BioStudies
2005-01-01 | S-EPMC1070375 | BioStudies
2015-01-01 | S-EPMC4535491 | BioStudies