Biosynthesis of B2-integrin, intracellular calcium signalling and functional responses of normal and CD18-deficient bovine neutrophils.
1Biosynthesis of CD11/CD18 in bovine leucocytes, intracellular Ca2+ ([Ca2+]i) signalling, chemiluminescent responses and membrane fluidity of neutrophils and the effects of D-mannose on neutrophils from control heifers and a heifer with bovine leucocyte adhesion deficiency (BLAD) were measured. The synthesis of CD11/CD18 complex was clearly detected in leucocytes from a normal heifer, but not in a BLAD-affected heifer. The transient phase of increased [Ca2+]i was clearly detected in neutrophils from a heifer with BLAD stimulated with opsonised zymosan, aggregated bovine immunoglobulin G or concanavalin A, whereas the sustained phase was deficient or significantly decreased compared with control heifers. [Ca2+]i signalling of neutrophils from control heifers and a heifer with BLAD stimulated with phorbol myristate acetate via an 11b/CD18-independent pathway showed no transient phase, and the subsequent increase in [Ca2+]i was almost identical in neutrophils from affected and control heifers. [Ca2+]i concentration and chemiluminescent responses of neutrophils from a control heifer were clearly decreased by treatment with anti-CD18 and anti-IgG antibodies. No differences in membrane fluidity were detected between neutrophils derived from control and CD18-deficient cattle. D-mannose binds mainly to Fc rather than CD18 receptors, and decreased Agg-IgG induced [Ca2+]i and the chemiluminescent response of neutrophils. The [Ca2+]i responses and Agg-IgG induced chemiluminescent responses of neutrophils from control heifers and a BLAD-affected heifer were inhibited by D-mannose. The characteristic changes of [Ca2+]i signalling and functional responses of B2-integrin-deficient neutrophils were demonstrated.
Nagahata
H
H
Department of Animal Health, School of Veterinary Medicine, Rakuno Gakuen University, Hokkaido, Japan.
Higuchi
H
H
Nochi
H
H
Tamoto
K
K
Araiso
T
T
Noda
H
H
Kociba
G J
GJ
D000818:Animals; D018845:CD11 Antigens / Q000096:biosynthesis; D018821:CD18 Antigens / Q000096:biosynthesis* / Q000097:blood; D002118:Calcium / Q000097:blood*; D002417:Cattle; D002418:Cattle Diseases; D005260:Female; D005454:Fluorescence Polarization; D018370:Leukocyte-Adhesion Deficiency Syndrome / Q000097:blood / Q000276:immunology / Q000662:veterinary*; D008163:Luminescent Measurements; D008214:Lymphocytes / Q000276:immunology*; D008560:Membrane Fluidity; D009504:Neutrophils / Q000502:physiology*; D012016:Reference Values; D015398:Signal Transduction
D018845:CD11 Antigens; D018821:CD18 Antigens; D002118:Calcium