TY - JOUR
T1 - Expression of newly identified secretory CEACAM1a isoforms in the intestinal epithelium
AU - Terahara, Kazutaka
AU - Yoshida, Masato
AU - Taguchi, Fumihiro
AU - Igarashi, Osamu
AU - Nochi, Tomonori
AU - Gotoh, Yoshiyuki
AU - Yamamoto, Takuya
AU - Tsunetsugu-Yokota, Yasuko
AU - Beauchemin, Nicole
AU - Kiyono, Hiroshi
N1 - Funding Information:
We thank Dr. K. McGhee for editorial help and Dr. K.V. Holmes for CC1 mAb. This work was supported in part by Grants from the Ministry of Education, Science, Sports, and Culture, and the Ministry of Health, Labour and Welfare in Japan (H.K.) and also by the Canadian Institutes of Health Research (N.B.).
PY - 2009/6/5
Y1 - 2009/6/5
N2 - Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) regulates intestinal immunological homeostasis. However, precise expression patterns of CEACAM1 isoforms remain poorly understood in the intestinal epithelia. Focusing on the small intestinal epithelium of BALB/c mice, we identified three novel splice variants encoding CEACAM1a-2, -2C1, and -4C1 by RT-PCR. CEACAM1a-2, -2C1, and -4C1 demonstrated secretory properties by transfection experiments in vitro. Among them, CEACAM1a-4C1 was the major secreted isoform in vivo due to the soluble/secreted CEACAM1a with a frameshift sequence in the C-terminus, specific for CEACAM1a-2C1 and -4C1. CEACAM1a-4C1 was capable of binding murine hepatitis virus (MHV) and was detected at approximately 120 kDa in the small intestinal secretions. Neutralizing effects of the soluble CEACAM1a on MHV infectivity in vitro were demonstrated by using recombinant CEACAM1a-4C1. Our data suggest an intrinsic mechanism operated by free CEACAM1 for surveillance of pathogens and maintenance of homeostasis in the intestine.
AB - Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) regulates intestinal immunological homeostasis. However, precise expression patterns of CEACAM1 isoforms remain poorly understood in the intestinal epithelia. Focusing on the small intestinal epithelium of BALB/c mice, we identified three novel splice variants encoding CEACAM1a-2, -2C1, and -4C1 by RT-PCR. CEACAM1a-2, -2C1, and -4C1 demonstrated secretory properties by transfection experiments in vitro. Among them, CEACAM1a-4C1 was the major secreted isoform in vivo due to the soluble/secreted CEACAM1a with a frameshift sequence in the C-terminus, specific for CEACAM1a-2C1 and -4C1. CEACAM1a-4C1 was capable of binding murine hepatitis virus (MHV) and was detected at approximately 120 kDa in the small intestinal secretions. Neutralizing effects of the soluble CEACAM1a on MHV infectivity in vitro were demonstrated by using recombinant CEACAM1a-4C1. Our data suggest an intrinsic mechanism operated by free CEACAM1 for surveillance of pathogens and maintenance of homeostasis in the intestine.
KW - CEACAM1
KW - Epithelium
KW - Intestine
KW - MHV
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U2 - 10.1016/j.bbrc.2009.04.008
DO - 10.1016/j.bbrc.2009.04.008
M3 - Article
C2 - 19358828
AN - SCOPUS:67349254468
VL - 383
SP - 340
EP - 346
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 3
ER -