title: Patterns of major histocompatibility complex class II expression on T cell subsets in different immunological compartments. 1. Expression on resting T cells.
abstract: In this study we have investigated the expression of major histocompatibility complex (MHC) class II molecules on T cells from various lymphoid compartments in the sheep. Monoclonal antibodies which react specifically with sheep MHC class II molecules homologous to the human DQ and DR molecules have been characterized. These antibodies have been used, together with the monoclonal antibodies specific for sheep CD4-, CD8- and T19-positive T cells, to quantitate DQ and DR expression on T cell subsets in adult and fetal peripheral blood, afferent lymph, lymph node and efferent lymph. The results show that expression of class II by T cells depends on the age of the animal and the physiological location of the T cell. In fetal blood there is no expression of class II on CD8+ or T19+ cells and very low expression on CD4+ T cells. In adult peripheral blood and efferent lymph a significant proportion of cells express DR but not DQ. A very different situation is found in afferent lymph and the peripheral lymph node: in afferent lymph the majority of T cells in all three subsets express both DQ and DR molecules; in the lymph node over 50% of T cells express DR and 30% are DQ+. These results suggest that within all T cell subsets there is a progression from DQ-DR- to DQ-DR+ and DQ+DR+ which correlates with physiological stages of T cell differentiation in vivo.
authors.affiliation: Department of Veterinary Pathology, University of Edinburgh, GB.
authors.forename: B M
authors.initials: BM
authors.lastname: Dutia
authors.forename: I
authors.initials: I
authors.lastname: McConnell
authors.forename: K
authors.initials: K
authors.lastname: Bird
authors.forename: P
authors.initials: P
authors.lastname: Keating
authors.forename: J
authors.initials: J
authors.lastname: Hopkins
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D015870:Gene Expression; D005802:Genes, MHC Class II; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008221:Lymphoid Tissue / Q000166:cytology / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D010641:Phenotype; D017386:Sequence Homology, Amino Acid; D012756:Sheep; D013045:Species Specificity; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000949:Histocompatibility Antigens Class II