Heterogeneous Expression and Release of CD14 by Human Gingival Fibroblasts: Characterization and CD14-Mediated Interleukin-8 Secretion in Response to Lipopolysaccharide

To identify the role in periodontal inflammatory diseases of human gingival fibroblasts (HGF), the major constituents of gingival tissue, the expression of CD14, a possible lipopolysaccharide (LPS) receptor, and the release of soluble CD14 (sCD14) by HGF were examined. Among the HGF samples from the nine donors tested, more than 50% of the HGF from five donors expressed CD14 but less than 20% of HGF from the other four donors did so, as determined by flow cytometric analysis. The CD14 expression on the cell surface was correlated with the expression of CD14 mRNA. The HGF and skin and lung fibroblasts tested expressed no CD18, which indicates that fibroblasts do not possess other LPS receptors, such as CD11b/CD18 and CD11c/CD18. The CD14 expression by the HGF was decreased after subculturing and was highest at the confluent stage of culture. The treatment of high-CD14-expressing (CD14^high) HGF with phosphatidylinositol-phospholipase C reduced CD14 expression; this result and the increase in a 55-kDa CD14 indicate that the membrane CD14 (mCD14) on the HGF may be a 55-kDa glycosylphosphatidylinositol-anchored protein. CD14^high HGF spontaneously released 48- and 57-kDa sCD14. The total release of sCD14 by the HGF was augmented by gamma interferon and Escherichia coli LPS in accordance with the increased expression of mCD14. The CD14^high HGF secreted interleukin-8 in response to LPS, and the secretion was completely inhibited by anti-CD14 antibody. These results suggest that (i) HGF consist of populations that are heterogeneous on the basis of different levels of expression of CD14 and (ii) CD14^high HGF secrete inflammatory cytokines in response to LPS via CD14.     

Chromosome 1q terminal deletion resulting fromde novo translocation with an acrocentric chromosome

Summary Distal deletion of chromosome 1q has been reported in nearly 30 patients, all being associated with a deletion ranging from the 1q42 or q43 band to 1qter region. Here, we describe a girl with 1q terminal deletion resulting from an unbalancedde novo translocation t(1;D or G)(q44; p11), as revealed by the presence of a satellited feature and an NOR-stained region at the tip of 1q. We suggest that most of the phenotypic abnormalities seen in patients with 1q distal deletion are attributable to the monosomy for band 1q44.     

Induction of interferon-inducible protein-10 and monokine induced by interferon-gamma from human endothelial cells infected with Influenza A virus

Primary human umbilical vein endothelial cells (HUVECs) were infected with Influenza virus A/Aichi/2/68 (H3N2) in order to determine the role of endothelial cells in mediating inflammation induced upon virus infection. Structural proteins of the virus and mRNA of the M2 protein were detected in the infected cells, indicating that virus infection had occurred in HUVECs. The Influenza A virus-infected HUVECs showed elevated levels of gene expression of interferon (IFN)-inducible protein (IP)-10 and monokine induced by IFN-gamma (Mig), while heat-, formalin- and diethyl ether-inactivated viruses did not enhance the IP-10 and Mig gene expression. The results thus indicate that infection of live Influenza A virus is responsible for elevation of IP-10 and Mig gene expression. The elevation of IP-10 and Mig gene expression in infected HUVECs was not accompanied by the elevation of IFN-gamma gene expression, indicating that the elevation of IP-10 and Mig gene expression was independent of the IFN-gamma pathway.     

Precursor genes of future pandemic influenza viruses are perpetuated in ducks nesting in Siberia

Summary.  Influenza A viruses of different subtypes were isolated from fecal samples of ducks in their nesting areas in Siberia in summer from 1996 to 1998. Phylogenetic analysis of the NP genes of the isolates in Siberia and those in Hokkaido, Japan on their flyway of migration from Siberia to the south in autumn revealed that they belong to the Eurasian lineage of avian influenza viruses. It is noted that the genes of the isolates in Siberia are closely related to those of H5N1 influenza virus strains isolated from chickens and humans in Hong Kong in 1997 as well as to those of isolates from domestic birds in southern China. The results indicate that influenza viruses perpetuated in ducks nesting in Siberia should have contributed genes in the emergence of the H5N1 virusin Hong Kong. Vaccine prepared from avirulent A/duck/Hokkaido/4/96 (H5N3) influenza virus was potent enough to protect mice from challenge with lethal dose of the pathogenic H5N1 virus [19]. Intensive surveillance study of aquatic birds especially in Siberia is, therefore, stressed to provide information on the future pandemic influenza virus strains and for vaccine preparation. Received August 24, 1999/Accepted January 7, 2000     

The T-cell receptor alpha, beta and gamma polymorphism in Japanese

Polymorphism in the genes encoding the alpha (alpha), beta (beta) and gamma (gamma) chains of the human T-cell receptors was analyzed both in population and family studies. Against twelve unrelated Japanese, several out of the 15 restriction endonucleases tested, revealed restriction fragment length polymorphism. The segregation of the polymorphic fragments were confirmed among 15 members of three families. In most of the cases paternal and/or maternal haplotypes could be assigned. By testing the polymorphic enzymes among the random healthy Japanese, the frequency of each polymorphic fragment was then determined. Although the polymorphism found in this study was similar to that reported in Caucasians, some differences were observed. Such differences are discussed. The restriction fragment length polymorphism in both population and family studies, derived from alpha, beta and gamma chains of the T-cell receptor found in this report, might be useful markers for genetic analysis of the T-cell function in relation to immunological disorders.     

Liver tumor-promoting effect of beta-naphthoflavone, a strong CYP 1A1/2 inducer, and the relationship between CYP 1A1/2 induction and Cx32 decrease in its hepatocarcinogenesis in the rat

Interrelationships among induction of cytochrome P-450 (CYP) 1A1/2, decrease in connexin 32 (Cx32), and liver tumor-promoting activity by beta-naphthoflavone (BNF) in the promotion stage were examined in a 2-stage liver carcinogenesis model. A total of 20 male Fischer 344 rats were initiated with a single intraperitoneal injection of 150 mg/kg of diethylnitrosamine (DEN) or were given the saline vehicle alone. Starting 2 weeks later, they were fed a diet containing 2%, 1%, or 0% BNF for 6 weeks. All animals were subjected to a two-thirds partial hepatectomy at week 3 and were sacrificed at week 8. Absolute and relative liver weights were significantly increased in the DEN+BNF groups as compared to the DEN-alone group. Diffuse hepatocellular hypertrophy with cytoplasmic eosinophilia, sometimes accompanied by development of adenoma-like hepatic foci, was observed in the BNF-treated rats. Remarkable induction of cytochrome CYP 1A1/2 and significant increase in CYP 2E1 were noted in the DEN+BNF groups, and positive immunohistochemical staining for both was observed diffusely. The areas of Cx32-positive spots per hepatocyte in the centrilobular areas of livers of the BNF-treated rats were significantly decreased, but no changes were observed in periportal areas. The numbers and areas of foci positive for glutathione S-transferase placental form were increased in the BNF-treated groups. These results suggest that BNF is a liver tumor promoter that, unlike phenobarbital, does not induce CYP 2B1/2 isozymes, and there seems to be no direct relationship between CYP 1A1/2 induction and Cx32 reduction in BNF hepatocarcinogenesis.