Lymphocyte accumulation during Pseudomonas aeruginosa-induced pneumonia in rodents does not require CD11a and intercellular adhesion molecule-1.
During Pseudomonas aeruginosa-induced pneumonia in rodents, the acute infiltrate of neutrophils is followed by accumulation of lymphocytes in the perivascular connective tissue. The roles of the adhesion molecules CD11a/CD18 and intercellular adhesion molecule-1 (ICAM-1) in this accumulation of lymphocytes were investigated. The numbers of lymphocytes in P. aeruginosa-induced pneumonia were compared in animals treated with blocking antibodies to either CD11a, ICAM-1, IgG, or no antibody. In other experiments, the lymphocyte accumulation during P. aeruginosa-induced pneumonia in ICAM-1 mutant mice was compared with that in wild-type mice. In rats, both a murine anti-rat CD11a antibody and nonspecific murine IgG partially inhibited the lymphocyte accumulation by 30 to 40% compared with animals that received no antibodies. In mice, blocking antibodies to either CD11a or ICAM-1 did not decrease the lymphocyte accumulation compared with mice given IgG or no antibody. Further, there was no attenuation of the lymphocyte accumulation induced by P. aeruginosa in the ICAM-1 mutant mice compared with wild-type mice, either in the total number of lymphocytes or the number of CD4+, CD8+, or B cells. We conclude that neither CD11a/CD18 nor ICAM-1 are required for lymphocyte accumulation during P. aeruginosa-induced pneumonia in rodents. The partial inhibition of the lymphocyte accumulation in both the anti-CD11a- and IgG-treated rats may be due to nonspecific effects of foreign proteins on cellular functions.
Wiebke
J L
JL
Department of Pediatrics, Indiana University, Indianapolis 46202-5225, USA.
Quinlan
W M
WM
Doyle
N A
NA
Sligh
J E
JE
Smith
C W
CW
Doerschuk
C M
CM
D000818:Animals; D007111:Immunity, Cellular; D018799:Intercellular Adhesion Molecule-1 / Q000502:physiology; D016169:Lymphocyte Function-Associated Antigen-1 / Q000502:physiology; D016131:Lymphocyte Subsets / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011014:Pneumonia / Q000276:immunology*; D011552:Pseudomonas Infections / Q000276:immunology*; D011550:Pseudomonas aeruginosa; D051381:Rats; D011917:Rats, Inbred Lew
D016169:Lymphocyte Function-Associated Antigen-1; D018799:Intercellular Adhesion Molecule-1