Bovine alpha-1 acid glycoprotein can reduce the chemotaxis of bovine monocytes and modulate CD18 expression.
The acute phase protein alpha(1)-acid glycoprotein (AGP--Orosomucoid) is a lipocalin with immunomodulatory functions. The present study provides evidence that the plasma glycoforms of AGP inhibit the migration of bovine monocytes in response to classical chemoattractants. The inhibition is specific, since neutrophils are apparently not affected. To investigate the molecular basis of this finding, the expression of the molecules mostly involved in chemotaxis, including CD18, CD11b and CD47 was studied. It was found that the incubation of activated monocytes with acute phase concentration of AGP (0.9 mg/mL) induces a down-regulation of CD18, and has no apparent influence on CD11b and CD47. RT-PCR expression studies on CD18, CD11b and CD47 mRNA revealed that AGP treatment does not modify the expression rate of these genes. Since AGP treatment is related to a down-regulation of CD18 on the surface of the monocytes, the authors suggest that one of its possible functions consists in specifically reducing the firm adhesion phase of bovine monocytes to the endothelium.
Lecchi
Cristina
C
Dipartimento di Patologia Animale, Igiene e Sanità Pubblica Veterinaria, Facoltà di Medicina Veterinaria, Università degli Studi di Milano, Italy.
Ceciliani
Fabrizio
F
Bernasconi
Sergio
S
Franciosi
Federica
F
Bronzo
Valerio
V
Sartorelli
Paola
P
D000818:Animals; D039481:CD11b Antigen / Q000378:metabolism; D018821:CD18 Antigens / Q000235:genetics / Q000378:metabolism*; D051928:CD47 Antigen / Q000378:metabolism; D002417:Cattle; D002633:Chemotaxis / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism*; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D009961:Orosomucoid / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D039481:CD11b Antigen; D018821:CD18 Antigens; D051928:CD47 Antigen; D009961:Orosomucoid; D012333:RNA, Messenger