Functional heterogeneity of murine intestinal intraepithelial lymphocytes: studies using TCR-alpha beta+ IEL lines and fresh IEL isolates reveal multiple cytotoxic subsets differentiated by CD5, CD8 alpha/alpha, and CD8 alpha/beta expression.
Three T-cell lines, isolated from murine small intestine epithelia, have been studied with respect to phenotypic properties and cytotoxic activity. All lines were TCR-alpha beta+, Thy-1+, CD3+, CD4-, CD8+ but differed in that one line was CD8 alpha/alpha+, CD5-; one line was CD8 alpha/alpha+, CD5+; and one line was CD8 alpha/beta+, CD5+. Both the CD8 alpha/alpha+, CD5-, and the CD8 alpha/beta+, CD5+ lines lysed antigen-bearing target cells; however, the latter line also spontaneously lysed natural killer (NK)-sensitive target cells. The CD8 alpha/alpha+, CD5+ IEL line was nonlytic for antigen-bearing target cells, for NK-sensitive target cells, and in assays that detect lytic activity regardless of specificity. Three-color flow cytometric analyses of intestinal intraepithelial lymphocytes (IEL) in freshly-extracted preparations indicated that cells with the phenotypes of the three IEL lines are normally present in the murine intestine epithelium, and revealed considerable variability in the distribution and density of CD5 expression on murine IEL. In freshly extracted IEL depleted of CD5 or CD8 beta by cell sorting, cytotoxicity was found to reside both within the CD5+ and the CD5- IEL subsets, as well as in the CD8 beta-depleted (i.e., CD8 alpha/alpha+) subset. These findings demonstrate: that cytotoxicity of murine IEL resides among multiple phenotypic subsets; that the distribution and density of CD5 on IEL is more complex than previously described; and that T-cell lines of IEL origin are valuable for dissecting functional properties of specific IEL subsets, particularly those that constitute a small proportion of the total IEL.
Mosley
R L
RL
Department of Biological Science, University of Tulsa, OK 74104.
Wang
J
J
Hamad
M
M
Klein
J R
JR
D000818:Animals; D015703:Antigens, CD / Q000032:analysis*; D018956:CD5 Antigens; D016827:CD8 Antigens / Q000032:analysis*; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D005260:Female; D016130:Immunophenotyping; D007422:Intestines / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis*; D016176:T-Lymphocyte Subsets / Q000276:immunology*
D015703:Antigens, CD; D018956:CD5 Antigens; D016827:CD8 Antigens; D016693:Receptors, Antigen, T-Cell, alpha-beta