B lymphocyte and macrophage expression of carcinoembryonic antigen‐related adhesion molecules that serve as receptors for murine coronavirus

Abstract

The expression of carcinoembryonic antigen (CEA)-related glycoproteins that have been associated with intercellular adhesion and that serve as receptors for mouse hepatitis virus (MHV) was analyzed in cells from the immune system of BALB/c mice using immunolabeling and RNA polymerase chain reaction amplification of receptor transcripts. These glycoproteins, which are called biliary glycoproteins, were highly expressed in B lymphocytes, including cells of the B-1a (CD5+) lineage, and in macrophages, but were not detectable in resting T lymphocytes. Similarly, murine cell lines of B cell and macrophage origin expressed messenger RNA encoding CEA-related molecules, while the corresponding mRNA was only slightly detectable in a T cell line. These CEA-related cell adhesion glycoproteins were also expressed in endothelial cells. Therefore, their specific interaction with their so far unknown ligand may be of functional importance in cellular interactions in the immune response. Monoclonal antibody directed against these glycoproteins blocked MHV-A59 infection of the B cell-derived SP20 cell line. Thus, the functional receptors for MHV on B lymphocytes, like those on murine fibroblasts, are isoforms of CEA-related glycoproteins. Treatment of B cells with anti-receptor antibody also blocked B cell-mediated cytotoxicity against MHV-A59-infected fibroblasts, indicating that this phenomenon is mediated by interaction of viral attachment protein on the infected target cells with specific CEA-related receptor glycoproteins on the effector B cells.

Mechanisms of Central Nervous System Viral Persistence: the Critical Role of Antibody and B Cells

“…The ability of B cells from naive donors to lyse virus-infected cells through an interaction between the viral S protein and the viral receptor is unique to mouse hepatitis virus (29,46). Although B cells express the mouse hepatitis virus receptor in vivo (29,47), they appear resistant to infection in vivo based on the inability to detect viral Ag in lymphocytes (22)(23)(24). As cytolysis is inhibited by anti-S protein Ab (29,47,48), a B cell cytolytic mechanism in vivo can only be active before anti-S protein Ab secretion.…”

“…Although B cells express the mouse hepatitis virus receptor in vivo (29,47), they appear resistant to infection in vivo based on the inability to detect viral Ag in lymphocytes (22)(23)(24). As cytolysis is inhibited by anti-S protein Ab (29,47,48), a B cell cytolytic mechanism in vivo can only be active before anti-S protein Ab secretion. However, similar kinetics of virus replication and clearance in mIgM, (mϩs)IgM, and J H D mice argue against an innate immune function of B cells during acute infection, consistent with the limited recruitment of B cells into the CNS during acute infection (49).…”

“…Whether this mechanism involves direct B cell-mediated cytolysis or an indirect effect of B cells on other cell types is unclear. B cell cytolysis is solely dependent on viral S protein expressed on target cells (29,47,48) but independent of Fas-FasL interactions, perforin, and TNF-␣ in vitro (29,50). If a cytolytic mechanism is indeed functional in vivo, it implies that oligodendroglia are resistant to B cell-mediated lysis, reminiscent to their resistance to perforin-mediated cytolysis by CD8 ϩ T cells (24).…”

Association of biliary glycoprotein with protein tyrosine phosphatase SHP-1 in malignant colon epithelial cells

“…Bgp proteins possess cytoplasmic domains of either 10 or 71 (73 in mouse) amino acids which are produced by alternative splicing of a conserved 53 bp exon (Barnett et al, 1989;Ne dellec et al, 1995). They are mainly expressed in epithelial cells of the gastro-intestinal tract, endothelial cells and hematopoietic cells, particularly B cells, neutrophils and macrophages (Hinoda et al, 1988;Barnett et al, 1989;O È brink, 1991;Coutelier et al, 1994;Ne dellec et al, 1995).…”

The Carboxyl-terminal Region of Biliary Glycoprotein Controls Its Tyrosine Phosphorylation and Association with Protein-tyrosine Phosphatases SHP-1 and SHP-2 in Epithelial Cells

“…In addition, the Bgp1 protein is expressed in epithelial cells of the reproductive system, where its expression is hormonally controlled (7). Bgp1 is also present at the surface of endothelial cells and in hemopoietic cells, in particular in B cells, macrophages, and interleukin-2-activated T cells (7)(8)(9)(10).…”