The novel acute phase protein, IHRP, inhibits actin polymerization and phagocytosis of polymorphonuclear cells.
OBJECTIVE
In the present study, the involvement of the binding of IHRP (inter-alpha-trypsin inhibitor family heavy chain-related protein) and actin in phagocyte activity was investigated.


METHODS
The actin polymerization and the phagocytic activity of the polymorphonuclear (PMN) cells were studied in the presence of IHRP.


RESULTS
IHRP inhibited the polymerization of actin and the phagocytic activity of the PMN cells.


CONCLUSIONS
1) IHRP may bind to actin released from the damaged cells and suppress its toxic action by preventing the formation of actin fibril. 2) IHRP may bind to cell surface actin on PMN cells and inhibit their phagocytic activities. 3) From these results, IHRP may act as an anti-inflammatory protein.
Department of Physiological Chemistry, School of Pharmaceutical Sciences, Showa University, Shinagawa, Tokyo, Japan. nammiura@pharm.showa-u.ac.jp
N H
NH
Choi-Miura
K
K
Takahashi
M
M
Yoda
K
K
Saito
M
M
Hori
H
H
Ozaki
T
T
Mazda
M
M
Tomita
D000199:Actins / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism / Q000494:pharmacology*; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D009504:Neutrophils / Q000187:drug effects* / Q000502:physiology; D010587:Phagocytosis / Q000187:drug effects*; D011108:Polymers / Q000378:metabolism; D053491:Proteinase Inhibitory Proteins, Secretory
D000199:Actins; D001798:Blood Proteins; D002352:Carrier Proteins; D006023:Glycoproteins; C091236:ITIH4 protein, human; D007106:Immune Sera; D011108:Polymers; D053491:Proteinase Inhibitory Proteins, Secretory