IL-8 is involved in homologous TNF alpha-, but not in IL-1 beta-induced neutrophil infiltration in rabbits.
OBJECTIVE
We examined the involvement of IL-8 in TNF alpha and IL-1 beta neutrophil infiltration, using homologous reagents.


METHODS
Female New Zealand white rabbits (n = 211).


METHODS
After injection of TNF alpha (1 microgram) or rrIL-1 beta (300 pg) into rabbit knee joints, the leukocyte influx and the production of IL-8 were estimated. Anti-TNF alpha mAb, rrIL-1Ra, and anti-IL-8 IgG (10 micrograms each) were administrated simultaneously with either TNF alpha or IL-1 beta.


RESULTS
Administration of TNF alpha or IL-1 beta induced IL-8 production; both of which peaked at 1 h after the injection. Maximum neutrophil infiltration induced by TNF alpha was inhibited by 38-56% by anti-IL-8 IgG, 22-43% by rrIL-1Ra, and 77-83% by anti-IL-8 IgG plus rrIL-1Ra. In contrast, maximum neutrophil infiltration induced by IL-1 beta was not inhibited by anti-IL-8 IgG whereas anti-TNF alpha mAb reduced the infiltration by 68-75%.


CONCLUSIONS
The involvement of IL-8 in TNF alpha- and IL-1 beta-induced neutrophil infiltration is limited. Factor(s) other than IL-8 appear to function as major neutrophil chemo-attractants.
Miyamoto
K
K
Department of Pathology, Kumamoto University School of Medicine, Japan. kazu@kaiju.medic.kumamoto-u.ac.jp
Matsukawa
A
A
Ohkawara
S
S
Takagi
K
K
Yoshinaga
M
M
D000818:Animals; D000911:Antibodies, Monoclonal; D002630:Chemotactic Factors / Q000633:toxicity; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007074:Immunoglobulin G / Q000378:metabolism; D007249:Inflammation / Q000209:etiology / Q000503:physiopathology*; D007375:Interleukin-1 / Q000008:administration & dosage / Q000633:toxicity*; D016209:Interleukin-8 / Q000276:immunology / Q000378:metabolism*; D007719:Knee Joint / Q000187:drug effects / Q000473:pathology; D009504:Neutrophils / Q000473:pathology*; D011817:Rabbits; D011994:Recombinant Proteins / Q000633:toxicity; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage / Q000633:toxicity*
D000911:Antibodies, Monoclonal; D002630:Chemotactic Factors; D007074:Immunoglobulin G; D007375:Interleukin-1; D016209:Interleukin-8; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha