title: CD38 is a marker of human lacteals.
abstract: CD38 is a type II transmembrane glycoprotein involved in signaling and adhesion which is expressed mainly by immature hematopoietic cells and activated lymphoid cells. Central lymphatic channels of human small intestinal villi, the so-called lacteals, were coincidentally found to express CD38. Gastric and large intestinal mucosae, pancreas, liver, lung, nasal mucosa, kidney, thymus, palatine tonsil, Peyer's patches, appendix, and mesenteric lymph nodes, and rodent intestinal mucosa were subsequently examined for lymphatic expression of CD38. Cryosections prepared from biopsy or surgical resection specimens were immunostained with four different antibodies to CD38 combined with antibodies to von Willebrand factor and CD31 to differentiate lymphatics from blood vessels, or with antibody to lysosomal protein. Sections were evaluated by ordinary and confocal immunofluorescence microscopy. Jejunal cryosections were subjected to in situ hybridization for CD38. All CD38 antibodies decorated human lacteals, and some of these were positive for CD38 mRNA. Lymphatics draining Peyer's patches and appendix as well as afferent lymphatics of mesenteric lymph nodes expressed CD38 weakly. CD38 was not detected on lymphatics in other organs or in rodent lacteals. We propose that CD38 is a novel marker of human small intestinal lymphatic vessels.
authors.affiliation: Laboratory for Immunohistochemistry and Immunopathology, Rikshospitalet, University of Oslo, Norway. i.n.farstad@labmed.uio.no
authors.forename: Inger Nina
authors.initials: IN
authors.lastname: Farstad
authors.forename: Fabio
authors.initials: F
authors.lastname: Malavasi
authors.forename: Guttorm
authors.initials: G
authors.lastname: Haraldsen
authors.forename: Henrik Sverre
authors.initials: HS
authors.lastname: Huitfeldt
authors.forename: Per
authors.initials: P
authors.lastname: Brandtzaeg
mesh_terms: D036541:ADP-ribosyl Cyclase / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D051997:ADP-ribosyl Cyclase 1; D000818:Animals; D015703:Antigens, CD / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D015415:Biomarkers / Q000032:analysis; D002675:Child, Preschool; D004064:Digestive System / Q000098:blood supply; D005856:Germ-Free Life; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008208:Lymphatic System / Q000166:cytology* / Q000378:metabolism; D008562:Membrane Glycoproteins; D051379:Mice; D008807:Mice, Inbred BALB C; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D012039:Regional Blood Flow
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; C498155:Cd38 protein, mouse; C498156:Cd38 protein, rat; D051997:ADP-ribosyl Cyclase 1