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Distribution of β 7 integrins in human intestinal mucosa and organized gut‐associated lymphoid tissue
Author(s) -
FARSTAD I. N.,
HALSTENSEN T. S.,
LIEN B.,
KILSHAW P. J.,
LAZAROVITZ A. I.,
BRANDTZAEG P.
Publication year - 1996
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1046/j.1365-2567.1996.d01-727.x
Subject(s) - lamina propria , biology , cd8 , intraepithelial lymphocyte , microbiology and biotechnology , high endothelial venules , cd11c , lymphocyte homing receptor , cd3 , intestinal mucosa , cd19 , lymphocyte , antigen , immunology , flow cytometry , immune system , cell , epithelium , medicine , cell adhesion , genetics , phenotype , gene , biochemistry
Two alternative integrins involved in mucosal homing (α 4 β 7 ) or epithelial retention (α E β 7 ) of lymphocytes were examined in the human gut. The distribution of the β 7 subunit [monoclonal antibody (mAb) M301] was bimodal in that it was strongly expressed by α E β 7 + cells but weakly by α 4 β 7 + cells. More than 90% of intraepithelial lymphocytes (IEL), including the minor subsets of CD4 + , T‐cell receptor (TCR)γ/δ + , and CD3 − cells, expressed α E β 7 as did most lamina propria CD8 + (88%) and a fraction (36%) of CD4 + lymphocytes. Conversely, B‐lineage cells (CD19 + ) and macrophages (CD68 + ) were negative. In gut‐associated lymphoid tissue (GALT: Peyer's patches and appendix) only a few (<5%) cells were positive for α E β 7 (confined to CD8 + lymphocytes and CD11c + putative dendritic cells). A relatively small fraction of IEL (30–50%) expressed α 4 β 7 (mAb Act‐1), while most (70%) lamina propria T and B lymphocytes, blasts, plasma cells and macrophages were positive. In GALT, T lymphocytes expressed similar levels of α 4 β 7 as in the lamina propria whereas relatively few B lymphocytes (<50%) were positive. Isolated lamina propria CD8 + , CD4 + , CD19 + , and CD38 + cells contained mRNA for α 4 and the former three subsets as well as appendix CD8 + cells also for β 7 while only lamina propria CD8 + cells had mRNA for α E . Together, the results suggested that α E β 7 and α 4 β 7 are differentially regulated in inductive sites and effector sites of the human gut. Because lymphoid cells at both sites expressed mainly α 4 β 7 , this integrin may be a homing receptor on memory and effector cells bound for lamina propria as well as on naive lymphocytes extravasating in GALT. Conversely, because α E β 7 was mainly expressed by CD8 + cells in epithelium and lamina propria, it was probably induced after extravasation, in agreement with the observation that IEL and a fraction of lamina propria T lymphocytes (mainly CD8 + cells) generally expressed higher levels of β 7 than most CD4 + and B cells. Also a subset of putative dendritic cells located near the follicle‐associated epithelium of GALT expressed α E β 7 , perhaps reflecting epithelial interaction during primary immune responses.