ISSN:0300-5526    

DOI:10.1159/000150159

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

Packaging genes 3of Salmonella phage P22 wild type and two mutants with altered packaging properties (HT12/4 and NT1/1) have been cloned in an expression vector. By plasmid transduction, it has been shown that the amino terminus of gene 3 is not functional in DNA packaging when fused with the Escherichia coli lacZ gene. The reconstituted genes 3, however, express functional gp3. The transduction experiments also have shown that the pac signal, which is part of gene 3, is intact in all three phages. Expression of gene product gp3 has been demonstrated in the minicell system.

ISSN:0300-5526    

DOI:10.1159/000150160

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

In an attempt to elucidate the role of viruses in certain neuroendocrine disorders, we have demonstrated that infection of endocrine cells (GH-3 and Y-1) in vitro by moloney murine leukemia virus (M-MuLV) resulted in diminution of cell-specific secretory function, hormone secretion into culture. In GH-3 (rat anterior pituitary gland) active (initial) and persistent infection by M-MuLV resulted in approximately 80% reduction in prolactin and growth hormone secretion. The adrenal cortex tumor cell line (Y-1), when actively infected with the same virus, showed a transient increase in fluorogenic steroid secretion; however, on subsequent passages of infected cell cultures, steroid secretion was markedly reduced to about 10% of the uninfected Y-1 cells. The virus yield from M-MuLV-infected cultures of Y-1 and GH-3 cells produced a significantly lower amount of virus than the control NIH-3T3-infected cell cultures.

ISSN:0300-5526    

DOI:10.1159/000150161

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

IgG antibodies reactive with simian immunodeficiency virus isolated from a rhesus monkey suffering from simian acquired immunodeficiency syndrome (SIVmac, strain 239, a virus which is very closely related to human immunodeficiency virus type 2-HIV-2) were found in 18 of 120 Swedish and 8 of 11 east African confirmed HIV-1 antibody positive (HIV-1 ab + ) sera, both by enzyme immunoassay and electrophoretic immunoblotting (p = 1 × 10 6). In electrophoretic immunoblotting most of the cross-reactivity of SlVmac-reactive sera occurred on p27, the major gag protein of SIVmac. The possibility that SIVmac antibody reactivity could be due to double infection with HIV-1 and a SIVmac-related virus was eliminated by the results of absorptions between sera of Swedish and west and east African origin and viral antigens (SIVmac and North American or African/Haitian strains of HIV-1) coupled to agarose beads. HIV-2 ab+ and SIVmac reactive west African sera recognized SIVmac epitopes unrelated to HIV-1, whereas HIV-1 ab + , SIVmac reactive east African, and Swedish sera recognized SIVmac epitopes cross-reactive with epitopes present in both African and North American HIV-1 strains. No unique SIVmac-reactive African HIV-1 epitopes could thus be defined. Neither did absorption of Swedish and African HIV-1-positive sera with different HIV-1 strains (1 Haitian, 2 Zairian, and 1 North American) give evidence for unique epitopes

ISSN:0300-5526    

DOI:10.1159/000150162

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

Herpesvirus type 1 could be propagated most efficiently in cultured fetal neurons, to a lesser extent in NG108–15 neurohybridoma cells, and with the lowest titer in glial cells. Herpesvirus type 2 could not be cultured in neurohybridoma cells, and in fetal neurons a titer 100-fold lower than for herpesvirus type 1 was obtained. Cells infected with herpesvirus type 1 were used in an infectivity assay for acyclovir dose-response studies. The ED50 values were 7.4 nmol/l for fetal neurons, 180 for neurohybridoma cells, and 275 nmol/l for glial cell

ISSN:0300-5526    

DOI:10.1159/000150163

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

We synthesized three peptides, MAI – Thr19-Val28( + Tyr) - MA2 – Ser807-Ala816 - and MA3 – Ser718-Glu729( + Tyr) from the sequence of Epstein-Barr virus gp350/220 and immunized rabbits with these peptides. Rabbit antisera to the peptides had antipeptide radioimmunoassay titers of 1:400 for anti-MAl, 1:200 for anti-MA2, and 1:1600 for anti-MA3. The anti-MAl serum recognized gp350/220 in Western blotting to SDS-electrophoresed proteins from 12–0-tetradecanoylphorbol-13-acetate- and n-butyrate-treated B95–8 cells, but anti-M A2 and MA3 sera did not. None of the sera reacted with gp350/220 by membrane or cytoplasmic immunofluorescence or by immunoprecipitation of Triton X-100 solubilized

ISSN:0300-5526    

DOI:10.1159/000150164

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

Viral envelope glycoproteins are important in antiviral immunity; however, their precise role in both generating virus-neutralizing antibodies as well as in viral binding to target cell receptors remains largely unexplored. We studied nine monoclonal antibodies (MoAbs) to Epstein-Barr virus (EBV) envelope glycoproteins in order to define the role(s) of their respective epitopes in both EBV neutralization and binding to cellular receptors. Only four MoAbs neutralized EBV infectivity, one requiring complement, and only 1 of these 4 did inhibit EBV binding to target cell receptors. Our results suggest that (1) the epitopes recognized by a majority of these MoAbs play no role in viral neutralization and (2) that the majority of epitopes recognized by the neutralizing antibodies play no role in EBV binding to target cell receptors. This and previous studies would also suggest that only one epitope is involved in EBV binding to its receptor or that, until now, we were able to identify only one EBV-neutralizing Mo Ab (i. e., 72 Al) which is specific for the receptor-binding viral epitope. It is probable that the epitope recognized by 72 Al Mo Ab is the only glycoprotein domain with a dual role, i.e., in EBV neutralization and binding to target cell receptors.

ISSN:0300-5526    

DOI:10.1159/000150165

出版商:S. Karger AG    

年代:1990

数据来源: Karger