The numbers of leukocyte subsets in lung sections differ between intercellular adhesion molecule-1-/-, lymphocyte function-associated antigen-1-/- mice and intercellular adhesion molecule-1-/- mice after aerosol exposure to Haemophilus influenzae type-b.
In order to investigate the role of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) in pulmonary immunological processes, leukocyte populations were stained immunohistochemically on cryostat lung sections of ICAM-1-/- and LFA-1-/- mice. A further group of ICAM-1-/- mice was exposed to Haemophilus influenzae type-b (Hib) 24 h before being sacrificed. Comparison of the numbers of leukocytes in these groups revealed different behaviors of the leukocyte subsets: granulocytes were significantly increased in all three groups. Lymphocytes were increased in ICAM-1-/- mice, while there was no significant difference in LFA-1-/- and even a decrease in ICAM-1-/- mice after Hib exposure. Neither in ICAM-1-/- nor in LFA-1-/- mice did macrophages and dendritic cells (DCs) show significant differences to control animals. After Hib exposure, a significant elevation of DCs was observed. The following conclusions can be drawn: (1) all investigated leukocyte subsets can use ICAM-1- and LFA-1-independent pathways in the lungs of mice; (2) the pathways used by the leukocytes are cell-type specific; (3) ICAM-1 plays an important role in the enhanced recruitment of lymphocytes during Hib challenge in the lung; and (4) the alternative migratory mechanisms are able to compensate for the absence of ICAM-1 or LFA-1 or even lead to increased cell numbers. This overcompensation can be seen as a result of a balance between active alternative migratory mechanisms, which takes place in the absence of ICAM-1 or LFA-1.
Sinikovic
B
B
Department of Anatomy 4120, Medical School of Hannover, 30623 Hannover, Germany.
Larbig
M
M
Hedrich
H J
HJ
Pabst
R
R
Tschernig
T
T
D000336:Aerosols; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002452:Cell Count; D002465:Cell Movement; D004195:Disease Models, Animal; D006192:Haemophilus Infections / Q000378:metabolism* / Q000473:pathology; D019741:Haemophilus influenzae type b / Q000472:pathogenicity / Q000502:physiology*; D007150:Immunohistochemistry; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D008168:Lung / Q000378:metabolism* / Q000473:pathology; D016169:Lymphocyte Function-Associated Antigen-1 / Q000235:genetics / Q000378:metabolism*; D016131:Lymphocyte Subsets / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout
D000336:Aerosols; D016169:Lymphocyte Function-Associated Antigen-1; D018799:Intercellular Adhesion Molecule-1