title: B lymphocyte compartments in the human splenic red pulp: capillary sheaths and periarteriolar regions.
abstract: The microvasculature of human spleens is still incompletely understood. Two enigmatic types of red pulp microvessels, penicillar arterioles and sheathed capillaries, have already been described in the nineteenth century without gaining much attention afterwards. We performed a detailed analysis of sheathed capillaries to clarify the cellular composition of their sheaths by immunohistological double-staining experiments. Capillary sheaths comprise three different cell types, namely specialized cuboidal CD271(++) inner sheath cells surrounded by CD271(-) macrophages and accumulations of B lymphocytes. The CD271(++) inner sheath cells express the chemokine CXCL13 in a unique single dot pattern. Sheath-associated B lymphocytes consist of IgM(+), IgD(++), and of "switched" cells. T lymphocytes do not accumulate in pericapillary sheaths. The predominant sheath-associated macrophage population is CD163(-)CD68(+) and thus differs from the majority of red pulp macrophages. The sheath-associated macrophages strongly express CD169 only in perifollicular sheaths, but not in sheaths located deeper in the red pulp. IgM(+), IgD(++), and "switched" B cells are also closely associated with red pulp arterioles characterized by the expression of smooth muscle actin in muscle cells and in branched periarteriolar stromal cells. Capillary sheaths are observed in a post-arteriolar position and appear to be of limited length. We suggest to change the term "Vagina periarteriolaris makrophagocytica" of the international histological and embryological terminologies to "Vagina pericapillaris."
authors: Institute of Anatomy and Cell Biology, Robert-Koch-Str. 8, 35037, Marburg, Germany, steinigb@staff.uni-marburg.de.
authors: Birte S
authors: BS
authors: Steiniger
authors: Anja
authors: A
authors: Seiler
authors: Katrin
authors: K
authors: Lampp
authors: Verena
authors: V
authors: Wilhelmi
authors: Vitus
authors: V
authors: Stachniss
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001160:Arterioles / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D001402:B-Lymphocytes / Q000166:cytology* / Q000378:metabolism; D002196:Capillaries / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D002460:Cell Line; D054382:Chemokine CXCL13 / Q000032:analysis; D006801:Humans; D008264:Macrophages / Q000166:cytology / Q000378:metabolism; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000032:analysis; D017475:Receptors, Nerve Growth Factor / Q000032:analysis; D013154:Spleen / Q000098:blood supply* / Q000166:cytology* / Q000648:ultrastructure; D055815:Young Adult
chemical_list: C110663:CXCL13 protein, human; D054382:Chemokine CXCL13; C484065:NGFR protein, human; D009419:Nerve Tissue Proteins; D017475:Receptors, Nerve Growth Factor