Functional and ligand binding specificity of the rabbit neutrophil IL-8 receptor.
IL-8 mediates migration and activation of neutrophils. This study describes the functional and ligand binding specificity of the human intercrine peptides IL-8, neutrophil-activating peptide 2 (NAP-2), melanoma growth stimulatory activity (GRO), and platelet factor 4 (PF4) to rabbit neutrophils and mammalian cell lines transfected with rabbit IL-8 receptor cDNA (F3R). Rabbit neutrophil membranes bound 125I-labeled IL-8 and 125I-labeled NAP-2 but did not bind 125I-labeled GRO or 125I-labeled PF4. Rabbit neutrophils mobilized intracellular Ca2+ in response to IL-8 and NAP-2 but not to GRO or PF4. Monkey kidney cells (COS-7) and hamster lung fibroblasts (CCL-39) were transiently and stably transfected with the rabbit neutrophil IL-8 receptor F3R cDNA. COS-7 cells transfected with F3R cDNA bound 125I-labeled IL-8 but did not bind other IL-8-related peptides such as 125I-labeled NAP-2, 125I-labeled GRO, or 125I-labeled PF4. Furthermore, bound 125I-labeled IL-8 was only displaced by unlabeled IL-8 but not by unlabeled NAP-2, GRO alpha, or PF4. Consistent with this observation, stably transfected CCL 39 cells expressing F3R cDNA mobilized Ca2+ only in response to IL-8. We conclude that F3R cDNA encodes a functional IL-8 receptor isotype with strict ligand binding specificity for IL-8, that rabbit neutrophils do not bind human GRO alpha, and it is suggested that rabbit neutrophils contain in addition to the F3R protein another IL-8 receptor isotype with broad ligand specificity or a distinct NAP-2 receptor.
Thomas
K M
KM
Boston University School of Medicine, Department of Physiology, MA 02118.
Taylor
L
L
Prado
G
G
Romero
J
J
Moser
B
B
Car
B
B
Walz
A
A
Baggiolini
M
M
Navarro
J
J
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D054360:Chemokine CXCL1; D019743:Chemokines, CXC; D002630:Chemotactic Factors / Q000378:metabolism; D006224:Cricetinae; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D006133:Growth Substances / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D036341:Intercellular Signaling Peptides and Proteins; D016209:Interleukin-8 / Q000378:metabolism; D007700:Kinetics; D009504:Neutrophils / Q000276:immunology* / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D010978:Platelet Factor 4 / Q000378:metabolism; D011817:Rabbits; D018123:Receptors, Interleukin / Q000235:genetics / Q000378:metabolism*; D023062:Receptors, Interleukin-8A; D014162:Transfection; D001620:beta-Thromboglobulin
C475829:CXCL1 protein, human; D054360:Chemokine CXCL1; D019743:Chemokines, CXC; D002630:Chemotactic Factors; D018076:DNA, Complementary; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D016209:Interleukin-8; C061615:PPBP protein, human; D010455:Peptides; D018123:Receptors, Interleukin; D023062:Receptors, Interleukin-8A; D001620:beta-Thromboglobulin; D010978:Platelet Factor 4; C009862:connective tissue-activating peptide; D002118:Calcium