Pathomechanism of cellular infiltration in the perivascular region of several organs in SAMP1/Yit mouse.
We investigated the histological changes of extra-intestinal organs, such as the liver, kidney, lung and pancreas in SAMP1/Yit mice, a human Crohn's disease model, using immunohistochemical techniques. The perivascular cellular infiltration was detected around the small vessels after 30 weeks. These infiltrating cells consisted of many CD4-positive T-lymphocytes, and small numbers of CD8- positive T-lymphocytes and IgG-positive B-lymphocytes. MAdCAM-1 and VCAM-1 were detected in vascular endothelial cells in non-affected regions of 13 and 20 week-old, as well as in the affected regions showing perivascular cellular infiltration after 30 weeks. In addition, integrin alpha4beta7 was detected on these infiltrating cells in the perivascular regions after 30 week-old. LT-beta and IL-12, cytokines of the Th-1-type immune response, were not observed in these affected regions. However, IL-4, one of the cytokines of the Th-2-type immune response, was detected on the perivascular infiltrating cells after 30 week-old. These results revealed that the changes in extra-intestinal organs were mainly caused by infiltration of CD4-positive T-lymphocytes into the perivascular regions in SAMP1/Yit mice. These cellular infiltrations were thought to be initiated by adhesion of CD4-positive T-lymphocytes to the endothelial cells mediated by MAdCAM-1 and integrin beta7. Immunohistochemistry for Th related cytokines indicated that the perivascular cellular infiltration was developed by the Th-2-type immune response in the extra-intestinal organs of SAMP1/Yit mouse.
Chosa
Mizuki
M
Department of Anatomy 1, School of Veterinary Medicine, Azabu University, Kanagawa Pref 229-8501, Japan.
Soeta
Satoshi
S
Ichihara
Nobutsune
N
Nishita
Toshiho
T
Asari
Masao
M
Matsumoto
Satoshi
S
Amasaki
Hajime
H
D000818:Animals; D000906:Antibodies / Q000378:metabolism; D015209:Cholangitis, Sclerosing / Q000473:pathology; D003424:Crohn Disease / Q000473:pathology*; D016207:Cytokines / Q000378:metabolism; D007668:Kidney / Q000098:blood supply* / Q000473:pathology; D008099:Liver / Q000098:blood supply* / Q000473:pathology; D008168:Lung / Q000098:blood supply* / Q000473:pathology; D051379:Mice; D010179:Pancreas / Q000098:blood supply* / Q000473:pathology; D013601:T-Lymphocytes / Q000502:physiology
D000906:Antibodies; D016207:Cytokines