Differences in integrin-dependent phagocytosis among three hemocyte subpopulations of the Pacific oyster "Crassostrea gigas".
Integrins play a key role in immunoresponses such as attachment, spreading, and phagocytosis in invertebrate hemocytes. This study was designed to identify integrin expression patterns at the hemocyte subpopulation level, and correlate the expression levels with phagocytic ability. First, we cloned a beta integrin from Crassostreagigas hemocytes and used real-time RT-PCR to analyze the quantitative expression level of its encoding mRNA. The expression level in hyalinocytes was significantly higher than that in granulocytes and agranulocytes. Subsequently, we investigated the phagocytic ability of each subpopulation using anti-alpha(5)beta(1) integrin antibody, and found that phagocytosis of hyalinocytes was inhibited by neutralization with the antibody but enhanced against the antibody-conjugated microspheres. In contrast, phagocytic abilities of granulocytes and agranulocytes showed high and zero levels, respectively, regardless of the antibody. These results suggest that phagocytosis of hyalinocytes is regulated by an integrin-dependent mechanism and that of granulocytes is elicited by other functional receptors.
Terahara
Kazutaka
K
Laboratory of Aquacultural Biology, Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai, Miyagi 981-8555, Japan. tera@ims.u-tokyo.ac.jp
Takahashi
Keisuke G
KG
Nakamura
Akifumi
A
Osada
Makoto
M
Yoda
Masaki
M
Hiroi
Takachika
T
Hirasawa
Masatomo
M
Mori
Katsuyoshi
K
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D049896:Crassostrea / Q000276:immunology*; D005434:Flow Cytometry; D015870:Gene Expression; D006098:Granulocytes / Q000166:cytology / Q000276:immunology; D006434:Hemocytes / Q000166:cytology / Q000276:immunology*; D039641:Integrin beta Chains / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010140:Pacific Ocean; D010587:Phagocytosis; D010802:Phylogeny; D016415:Sequence Alignment; D015054:Zymosan
D039641:Integrin beta Chains; D015054:Zymosan