Differential function of intestinal intraepithelial lymphocyte subsets.
It has been proposed that intestinal intraepithelial lymphocytes (I-IEL) perform immune surveillance of the epithelial layer (1) and regulate mucosal humoral responses to exogenous Ag (2). To better understand the functional potential of this unique population, purified murine I-IEL were analyzed phenotypically and functionally. Initial studies determined that I-IEL could be distinguished based on several phenotypic characteristics including: TCR (TCR-alpha beta vs TCR-gamma delta); Thy-1, CD45R/B220, CD5, and CD8 (CD8 alpha alpha vs CD8 alpha beta) expression. Using anti-TCR mAb, individual I-IEL subsets were activated and examined functionally. Both TCR-alpha beta and TCR-gamma delta I-IEL were found to synthesize an array of lymphokines that included IL-2, IL-3, and IL-6 but not IL-4 or IL-5. Additionally, a number of lymphokines were detected that directly influence epithelial function (IFN-gamma, TNF-alpha, and TGF-beta 1). However, the majority of the I-IEL function was localized within the Thy-1+, CD45R/B220- I-IEL subset. In addition those TCR-alpha beta I-IEL expressing the CD8 alpha beta heterodimer were more easily activated. Thus, a subset of I-IEL have the capacity to respond to TCR-mediated stimuli. The functional activities of these cells may influence both local immune cell populations as well as epithelial differentiation.
Barrett
T A
TA
Ben May Institute, University of Chicago, IL 60637.
Gajewski
T F
TF
Danielpour
D
D
Chang
E B
EB
Beagley
K W
KW
Bluestone
J A
JA
D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis; D017252:CD3 Complex; D018956:CD5 Antigens; D016827:CD8 Antigens / Q000276:immunology; D005434:Flow Cytometry; D006649:Histocompatibility Antigens / Q000276:immunology; D007413:Intestinal Mucosa / Q000276:immunology*; D017493:Leukocyte Common Antigens; D008213:Lymphocyte Activation; D016131:Lymphocyte Subsets / Q000276:immunology*; D008222:Lymphokines / Q000096:biosynthesis; D008562:Membrane Glycoproteins / Q000032:analysis; D051379:Mice; D008810:Mice, Inbred C57BL; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology; D018800:Thy-1 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D017252:CD3 Complex; D018956:CD5 Antigens; D016827:CD8 Antigens; D006649:Histocompatibility Antigens; D008222:Lymphokines; D008562:Membrane Glycoproteins; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D018800:Thy-1 Antigens; D017493:Leukocyte Common Antigens