title: Surface expression of differentiation antigens on lymphocytes in the ileal and jejunal Peyer's patches of lambs.
abstract: The surface phenotype of lymphocytes in the ileal (IPP) and jejunal (JPP) Peyer's patches (PP) of lambs was compared using flow cytometry and immunohistology with a panel of monoclonal antibodies (mAb). The B-cell markers p220, BAS9A and surface Ig molecules were detected on 70-95% of cells from the IPP. T-cell markers were detected on less than 1% of IPP lymphocytes, confirming that the IPP in lambs contains virtually only B lymphocytes. The JPP contained a lower proportion of B cells and 16% T cells, nearly all of which expressed the CD4 molecule. Interestingly, the reactivity of a fourth B-cell markers, BAQ44a, differed from this pattern; only 12% of IPP lymphocytes were positive whereas 70% of JPP lymphocytes expressed this marker. A majority of both IPP and JPP lymphocytes (80-95%) expressed the cell adhesion molecules CD11a (LFA-1) and LFA-3. Other adhesion molecules, such as CD2 and CD44, were expressed by fewer cells from the IPP than from the JPP. MHC class I antigens were detected on more than 95% of lymphocytes from both the IPP and JPP. In the case of MHC class II antigens, more positive cells occurred in the IPP (greater than 95%) than in the JPP (80%). The in situ localization of cell-surface antigens was assessed by immunohistology. CD4+ T cells occurred in the interfollicular T-cell regions and in JPP follicles, whereas CD8+ T cells localized only in the interfollicular regions and were absent from follicles. The pattern of expression of B-cell markers, adhesion molecules and MHC antigens indicated that a gradient of increasing maturity of B cells existed within follicles from the base towards the dome region. The data presented here lend support to the notion that the IPP in lambs represents a novel B-cell lymphoid tissue with a function different from that of the conventional Peyer's patches found in the jejunum.
authors.affiliation: Basel Institute for Immunology, Switzerland.
authors.forename: W R
authors.initials: WR
authors.lastname: Hein
authors.forename: L
authors.initials: L
authors.lastname: Dudler
authors.forename: C R
authors.initials: CR
authors.lastname: Mackay
mesh_terms: D000818:Animals; D000943:Antigens, Differentiation / Q000032:analysis*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology; D006649:Histocompatibility Antigens / Q000032:analysis; D007082:Ileum / Q000276:immunology; D007583:Jejunum / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D010581:Peyer's Patches / Q000276:immunology*; D012756:Sheep / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000943:Antigens, Differentiation; D000944:Antigens, Differentiation, B-Lymphocyte; D000945:Antigens, Differentiation, T-Lymphocyte; D006649:Histocompatibility Antigens