title: Pig lymphocytes utilise mouse MAdCAM-1 to enter fetal gut xenografts in SCID mice.
abstract: Ileocecal junction (ICJ) and proximal intestine (PI) fragments from CD45(323-) allovariant fetal pigs were grafted subcutaneously into SCID mice. The xenografts were examined 8-12 weeks later using two-color immunohistology and the ICJ, but not PI, xenografts were found to contain three types of vessels. The first (the majority) was lined with mouse endothelium (mAb 9F1+), the second was lined with pig endothelium, and the third was chimeric. The ICJ vessels were specifically lined with mouse endothelium expressing MAdCAM-1, the mucosal addressin. Vessels lined with pig endothelium alone did not express the MAdCAM-1 epitopes. Radiolabeled allovariant pig peripheral blood lymphocytes (PBL) were introduced i.v. into the xenografted SCID mice, and entry into xenografts studied. Pig PBL were occasionally seen in MECA-367+ vessel walls after 4 h and within the ICJ but not PI xenografts after 24 h. This entry was specifically blocked by coinjection of the anti-MAdCAM-1 mAb MECA-367. The results demonstrate reendothelialization of xenografts by host endothelium that expresses its own addressin and is functional for xenogenic PBL.
authors.affiliation: Department of Immunology, Babraham Institute, Cambridge, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Whyte
authors.forename: D
authors.initials: D
authors.lastname: Locke
authors.forename: T
authors.initials: T
authors.lastname: Savidge
authors.forename: S T
authors.initials: ST
authors.lastname: Licence
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules; D002678:Chimera / Q000276:immunology; D004730:Endothelium, Vascular / Q000166:cytology; D007136:Immunoglobulins / Q000276:immunology*; D007422:Intestines / Q000166:cytology / Q000276:immunology* / Q000637:transplantation*; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology*; D051379:Mice; D016513:Mice, SCID; D009088:Mucoproteins / Q000276:immunology*; D016201:Receptors, Lymphocyte Homing / Q000276:immunology*; D013045:Species Specificity; D013552:Swine; D014183:Transplantation, Heterologous
chemical_list: D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules; D007136:Immunoglobulins; C489082:Madcam1 protein, mouse; D009088:Mucoproteins; D016201:Receptors, Lymphocyte Homing