TY - JOUR
T1 - rOmpA is a critical protein for the adhesion of Rickettsia rickettsii to host cells
AU - Li, Han
AU - Walker, David H.
N1 - Funding Information:
The authors wish to thank Josie R. Ramirez for expert assistance in the preparation of the manuscript, to Thomas Bednarek for preparation of the illustrations and to Catherine Taylor for technical assistance with the flow cytometry. This research project was supported by a grant from the National Institute of Allergy and Infectious Diseases (AI21242).
PY - 1998/5
Y1 - 1998/5
N2 - rOmpA and rOmpB are immunodominant, surface-exposed proteins of Rickettsia rickettsii. Prior evidence suggests that adhesion of R. rickettsii to the host cell is mediated by a rickettsial protein. Five monoclonal antibodies to rOmpA, five to rOmpB, and one to the rickettsial lipopolysaccharide (LPS) were tested for inhibition of rickettsial attachment. All the monoclonal antibodies to rOmpA inhibited adhesion of rickettsiae to the L-929 cells with some inhibition rates as high as 90%. In contrast, monoclonal antibodies to rOmpB and LPS did not block attachment. When Fab fragments of monoclonal antibodies against rOmpA and rOmpB were used, similar results were observed as for the intact monoclonals, non- adhesion and adhesion, respectively. Purified rOmpA showed a competitive inhibitive effect on the attachment of R. rickettsii to host cells. Trypsin completely digested rOmpA but not rOmpB from the surface of intact R. rickettsii, resulting in loss of the ability of the rickettsiae to attach to the host cell. rOmpA appears to play an important role in the initial adhesion of R. rickettsii to the host cell.
AB - rOmpA and rOmpB are immunodominant, surface-exposed proteins of Rickettsia rickettsii. Prior evidence suggests that adhesion of R. rickettsii to the host cell is mediated by a rickettsial protein. Five monoclonal antibodies to rOmpA, five to rOmpB, and one to the rickettsial lipopolysaccharide (LPS) were tested for inhibition of rickettsial attachment. All the monoclonal antibodies to rOmpA inhibited adhesion of rickettsiae to the L-929 cells with some inhibition rates as high as 90%. In contrast, monoclonal antibodies to rOmpB and LPS did not block attachment. When Fab fragments of monoclonal antibodies against rOmpA and rOmpB were used, similar results were observed as for the intact monoclonals, non- adhesion and adhesion, respectively. Purified rOmpA showed a competitive inhibitive effect on the attachment of R. rickettsii to host cells. Trypsin completely digested rOmpA but not rOmpB from the surface of intact R. rickettsii, resulting in loss of the ability of the rickettsiae to attach to the host cell. rOmpA appears to play an important role in the initial adhesion of R. rickettsii to the host cell.
KW - Adhesin
KW - Flow cytometry
KW - Monoclonal antibodies
KW - Rickettsia rickettsii
KW - Surface protein
UR - http://www.scopus.com/inward/record.url?scp=0031803204&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031803204&partnerID=8YFLogxK
U2 - 10.1006/mpat.1997.0197
DO - 10.1006/mpat.1997.0197
M3 - Article
C2 - 9600861
AN - SCOPUS:0031803204
SN - 0882-4010
VL - 24
SP - 289
EP - 298
JO - Microbial Pathogenesis
JF - Microbial Pathogenesis
IS - 5
ER -