The serum factor from patients with ulcerative colitis that induces T cell proliferation in the mouse thymus is interleukin-7.
The disturbance of immune regulatory T cells is related to the pathogenesis of ulcerative colitis. Here we demonstrated and characterized the serum factor from ulcerative colitis patients that induced proliferation of intrathymic T cells. The factor isolated from the patient sera by a combination of gel filtration and anion-exchange chromatography induced proliferation of CD4+CD8- intrathymic T cells in the organ-cultured embryonic mouse thymus. Purification and amino acid sequence analysis of the serum factor demonstrated that the N-terminal 12 sequence was homologous to that of interleukin-7. SDS-PAGE and Western blot confirmed that purified serum factor was interleukin-7. Enzyme immunoassay demonstrated that the serum interleukin-7 concentration was significantly increased in the patients. PCR and Southern blot hybridization demonstrated that interleukin-7 mRNA expression was increased in the thymus tissues from patients but decreased in the colonic mucosa. Since interleukin-7 is a crucial cytokine for proliferation and differentiation of T cells in the thymus, the present study indicates that interleukin-7 may contribute to the disturbance of immune regulatory T cells in ulcerative colitis.
Watanabe
M
M
Keio Cancer Center, Tokyo, Japan.
Watanabe
N
N
Iwao
Y
Y
Ogata
H
H
Kanai
T
T
Ueno
Y
Y
Tsuchiya
M
M
Ishii
H
H
Aiso
S
S
Habu
S
S
Hibi
T
T
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002455:Cell Division / Q000276:immunology; D003093:Colitis, Ulcerative / Q000097:blood* / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D004847:Epithelial Cells; D004848:Epithelium / Q000276:immunology; D005260:Female; D005333:Fetus; D006801:Humans; D015851:Interleukin-7 / Q000097:blood* / Q000302:isolation & purification / Q000502:physiology*; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009924:Organ Culture Techniques; D012333:RNA, Messenger / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology* / Q000378:metabolism
D015851:Interleukin-7; D012333:RNA, Messenger