The cellular receptor for murine coronavirus mouse hepatitis virus (MHV)-A59 is a member of the carcinoembryonic antigen (CEA) family of glycoproteins in the immunoglobulin superfamily. We isolated a cDNA clone (MHVR1) encoding the MHV receptor. The sequence of this clone predicts a 424-amino-acid glycoprotein with four immunoglobulinlike domains, a transmembrane domain, and a short intracytoplasmic tail. MHVR, is closely related to the murine CEA-related clone mmCGM, (Mus musculus carcinoembryonic antigen gene family member). Western blot (immunoblot) analysis performed with antireceptor antibodies detected a glycoprotein of 120 kDa in BHK cells stably transfected with MHVR,. This corresponds to the size of the MHV receptor expressed in mouse intestine and liver. Human and hamster fibroblasts transfected with MHVR1 became susceptible to infection with MHV-A59. Like MHV-susceptible mouse fibroblasts, the MHVR,-transfected human and hamster cells were protected from MHV infection by pretreatment with monoclonal antireceptor antibody CCL. Thus, the 110to 120-kDa CEA-related glycoprotein encoded by

PCR is a technology born of the modern molecular biology era. The enzyme used for PCR, Taq DNA polymerase, supplied with the 10x buffer, is purchased as a cloned product, and the nucleoside triphosphates are ultrapure, buffered, and available at a convenient concentration. Yet, with all of these commercially available starting materials, PCR still fails, particularly for the novice. Assuming that all of the reagents have been added in the proper concentrations, two critical PCR components are left to the researcher. The first is the nucleic acid template, which should be of sufficient quality and PARAMETERS USED IN BASIC PCR PRIMER DESIGN Primer design is aimed at obtaining a balance between two goals: specificity and efficiency of amplification. Specificity is defined as the frequency with which a mispriming event occurs. Primers with mediocre to poor specificity tend to produce PCR products with extra unrelated and undesirable ampli-$30 PCR Methods and Applications

Mouse hepatitis virus-A59 (MHV-A59), a murine coronavirus, can utilize as a cellular receptor MEIVR, a murine glycoprotein in the biliary glycoprotein (BGP) subfamily of the carcinoembryonic antigen (CEA) family in the immunoglobulin superfamily (G.

Murine coronaviruses such as mouse hepatitis virus (MHV) infect mouse cells via cellular receptors that are isoforms of biliary glycoprotein (Bgp) of the carcinoembryonic antigen gene family (G.

Mouse hepatitis virus (MHV) strain A59 uses as cellular receptors members of the carcinoembryonic antigen family in the immunoglobulin superfamily. Recombinant receptor proteins with deletions of whole or partl immunogbulin domains were used to identify the regions of receptor Mouse hepatitis virus (MHV) strain A59 is a coronavirus that infects the respiratory and digestive tracts and nervous system of susceptible strains of mice (1, 2). Antireceptor monoclonal antibody (mAb) CC1 blocks MHV-A59

PSG1, PSG6, PSG6N, and PSG11 induce dose-dependent secretion of anti-inflammatory cytokines by human monocytes. Human and murine PSGs exhibit cross-species activity. Our results are consistent with a role for PSGs in modulation of the innate immune system.

The pregnancy-specific glycoproteins (PSGs) are the most abundant trophoblastic proteins in maternal blood during human pregnancy and they appear to be exclusive to species with hemochorial placentation. There are ten protein-coding human PSG genes (PSG1 -PSG9, PSG11) and also multiple PSG genes in non-human primates, rodents and bats. Several studies indicate that PSGs have immunoregulatory, pro-angiogenic, and anti-platelet functions. Some PSGs have been shown to bind different moieties on the surface of cells, including the tetraspanin CD9, heparan sulphate, and specific integrins. Recently, PSG1 was shown to associate with and activate the anti-inflammatory cytokines transforming growth factor (TGF)-b1 and TGF-b2 making PSG1 one of the few known biological activators of these important cytokines. TGF-bs regulate many biological processes essential for pregnancy success including trophoblast invasion and proliferation, angiogenesis, extracellular matrix formation and tolerance to the fetal semi-allograft. As summarized in this review, progress has been made in recent years towards a better understanding of the functions of these proteins which were originally described in the early 1970s, but more research will likely contribute to demonstrate their importance for a successful pregnancy.

Pregnancy-specific glycoproteins (PSGs) are a family of highly similar secreted proteins produced by the placenta. PSG homologs have been identified in primates and rodents. Members of the human and murine PSG family induce secretion of antiinflammatory cytokines in mononuclear phagocytes. For the purpose of cloning the receptor, we screened a RAW 264.7 cell cDNA expression library. The PSG17 receptor was identified as the tetraspanin, CD9. We confirmed binding of PSG17 to CD9 by ELISA, flow cytometry, alkaline phosphatase binding assays, and in situ rosetting. Anti-CD9 monoclonal antibody inhibited binding of PSG17 to CD9-transfected cells and RAW 264.7 cells. Moreover, PSG17 binding to macrophages from CD9-deficient mice was significantly reduced. We then tested whether PSG17 binds to other members of the murine tetraspanin family. PSG17 did not bind to cells transfected with CD53, CD63, CD81, CD82, or CD151, suggesting that PSG17–CD9 binding is a specific interaction. We have identified the first receptor for a murine PSG as well as the first natural ligand for a member of the tetraspanin superfamily.