1995 Jul 1;155(1):35-44.A novel canine leukointegrin, alpha d beta 2, is expressed by specific macrophage subpopulations in tissue and a minor CD8+ lymphocyte subpopulation in peripheral blood.1, , , , , , .Author information1Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis 95616, USA.AbstractThe beta 2 or leukointegrin family is comprised of three structurally related leukocyte surface heterodimers: LFA-1 (CD11a/CD18), Mac-1/Mo-1 (CD11b/CD18), and p150,95 (CD11c/CD18). In this work, we describe a novel canine beta 2 (CD18)-associated leukointegrin, designated alpha d. Expression of alpha d in tissues was prominent in macrophages in splenic red pulp, lymph node medullary regions, and bone marrow. In peripheral blood, alpha d expression was limited to a minor subpopulation of CD8+ T cells, which included small lymphocytes and large granular lymphocytes. A minor subpopulation of either CD8+ or CD4-CD8- splenic red pulp lymphocytes also expressed alpha d. Immunoprecipitation of alpha d from canine splenocytes revealed a heterodimer of 155 kDa and 95 kDa. Prior clearance of splenocyte extracts with an anti-CD18 mAb resulted in complete removal of alpha d. In addition, prior clearance of canine splenocyte extracts with anti-CD11a, anti-CD11b, or anti-CD11c mAb failed to clear alpha d. These immunoclearance data indicated that canine alpha d was antigenically distinct from the three known CD11 molecules, and occurred as an alpha d beta 2 heterodimer. Amino acid sequencing of canine alpha d affinity isolated from spleen further suggested that canine alpha d beta 2 probably represented a fourth member of the canine leukointegrin family via its homology to a subsequently discovered, novel human leukointegrin, alpha d beta 2, which further supported the uniqueness of the canine protein. The discovery of canine alpha d, and the demonstration of its highly restricted cell and tissue distribution, support a re-evaluation of leukointegrin-dependent inflammatory and immunologic interactions that involve cells now known to express alpha d.PMID: 7541420 [Indexed for MEDLINE] Publication types, MeSH terms, SubstancesPublication typesMeSH termsSubstancesLinkOut - more resourcesFull Text SourcesHighWire - PDFOther Literature SourcesCOS Scholar UniverseCited by Patents in - The LensMiscellaneous12-O-TETRADECANOYLPHORBOL-13-ACETATE - Hazardous Substances Data Bank. The b 2 integrin subfamily is comprised of 4 members, a L b 2 (CD11a/CD18), a M b 2 (CD11b/CD18), a X b 2 (CD11c/ CD18), and the most recently identified a D b 2 (CD11d/CD18), which share a common . 1. J Immunol. 1995 Jul 1;155(1):35-44. A novel canine leukointegrin, alpha d beta 2, is expressed by specific macrophage subpopulations in tissue and a minor CD8+ lymphocyte subpopulation in peripheral blood..