Open AccessThe leukotoxin of Pasteurella haemolytica binds to β 2 integrins on bovine leukocytes
Author(s) -
Ambagala Thanuja C,
Ambagala Aruna P.N,
Srikumaran Subramaniam
Publication year - 1999
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1999.tb08722.x
Subject(s) - monoclonal antibody , cd18 , integrin , integrin alpha m , microbiology and biotechnology , affinity chromatography , actinobacillus , biochemistry , chemistry , cd11a , biology , antibody , receptor , bacteria , immunology , enzyme , genetics
The putative receptor proteins of Pasteurella haemolytica leukotoxin were isolated from bovine polymorphonuclear neutrophil lysate by affinity chromatography on a leukotoxin‐specific monoclonal antibody column to which the leukotoxin was pre‐bound. SDS‐PAGE of the purified proteins showed four bands at 180 kDa, 170 kDa, 150 kDa and 95 kDa, in addition to the expected 102‐kDa leukotoxin band and a series of bands with molecular masses lower than 102 kDa representing the disintegrated leukotoxin. N‐terminal amino acid sequencing of the 170‐kDa band showed homology with human and murine CD11b. The purified proteins reacted specifically with monoclonal antibodies specific for CD11a, CD11b, CD11c (the α chains of β 2 integrins), and CD18 (the β chain of β 2 integrins). Pre‐incubation of polymorphonuclear neutrophils with a monoclonal antibody specific for CD18 reduced the cytotoxicity of the leukotoxin to the cells. These results indicate that the leukotoxin binds to the β 2 integrins on bovine leukocytes, very likely via CD18.