Expression of P23 of Cryptosporidium parvum in Toxoplasma gondii and evaluation of its protective effects.

In this study, P23 of Cryptosporidium parvum sporozoites, an immunodominant surface protein, was stably expressed in Toxoplasma gondii (Tg/P23) and its protective effects were evaluated in a mouse model. The molecular weight and antigenic property of P23 expressed by Tg/P23 were similar to those of the native P23. Mice immunized with lysed Tg/P23 tachyzoites produced specific neutralizing antibodies against C.

Mutation hot spots in the canine herpesvirus thymidine kinase gene.

The guanine and cytosine content (GC-content) of alpha-herpesvirus genes are highly variable despite similar genome structures. It is known that drug resistant HSV, which has the genome with a high GC-content (approximately 70%), commonly includes frameshift mutations in homopolymer stretches of guanine (G) and cytosine (C) within the thymidine kinase (TK) gene. However, whether such mutation hotspots exist in the TK gene of canine herpesvirus (CHV) which has a low GC-content was unknown.

Immunization with pseudorabies virus harboring Fc domain of IgG makes a contribution to protection of mice from lethal challenge.

To enhance the efficacy of an inactivated vaccine against pseudorabies virus (PRV), we evaluated the adjuvant properties of Fc domain of IgG. A cell line expressing mouse IgG Fc chimera on its surface was established. We found that when PRV was propagated in the cells expressing the Fc chimera, PRV virion incorporated the Fc.

Pseudorabies virus propagated in rabbit kidney-derived RK13 cells is neutralized by natural IgM antibodies in normal swine serum which specifically lyse host cells.

Pseudorabies virus (PRV) propagated in rabbit kidney-derived RK-13 cells (PRV-RK) was neutralized by serum obtained from specific pathogen-free pigs through the activation of complement. The virus-neutralizing activity of swine serum was lost after treatment with ethylene glycol-bis-aminoethylether-N,N,N',N'-tetraacetic acid (EGTA) or ethylenediaminetetraacetic acid (EDTA). Anti-C1q and anti-IgM antibodies also inhibited virus-neutralizing activity.

Restriction of bovine herpesvirus 1 (BHV-1) growth in non-permissive cells beyond the expression of immediate early genes.

Mouse BALB/3T3-A31-1-1 (A31) cells are non-permissive to bovine herpes virus-1 (BHV-1) but permissive to pseudorabies virus (PrV). The promoter activity of the immediate early gene of BHV-1 (BICP4) was very weak when compared with that of PrV in A31 cells. Infectious BHV-1 genomic DNA co-transfected into A31 cells with plasmids expressing BICP4 and BICP0 by a strong promoter failed to yield any progeny virus.

The neutralization of pseudorabies virus by anti-alpha-galactocyl natural antibody in normal serum.

Pseudorabies virus (PrV), a member of herpesviridae alphaherpes subfamily, can infect human cells in vitro. However, the transmission to Old World primates including humans is strongly restricted. In this study, we report the neutralizing activity of normal human serum against PrV grown in CPK cells derived from pig.

Applications of recombinant Leishmania amazonensis expressing egfp or the beta-galactosidase gene for drug screening and histopathological analysis.

Leishmania amazonensis recombinants expressing the enhanced green fluorescent protein (egfp) gene or beta-galactosidase gene (lacZ) were constructed for drug screening and histopathological analysis. The egfp or lacZ in a leishmanial transfection vector, p6.5, was introduced into L.

Recombinant bovine herpesvirus-1 expressing p23 protein of Cryptosporidium parvum induces neutralizing antibodies in rabbits.

In order to develop a vaccine against cryptosporidiosis in cattle, we constructed a recombinant bovine herpesvirus-1 (BHV-1) expressing an immunodominant surface protein, p23, of Cryptosporidium parvum sporozoites. In the recombinant virus, the p23 gene under the control of a CAG promoter and a gene coding for an enhanced green fluorescent protein were integrated into the gG gene of BHV-1. Despite a low frequency of homologous recombination, cloning of the recombinants was easy because of the specific fluorescence of the plaques formed by recombinants.

Bovine herpesvirus 1 U(S) ORF8 protein induces apoptosis in infected cells and facilitates virus egress.

The bovine herpesvirus 1 (BHV-1) U(S) ORF8 protein with homology to the Us9 protein of other alphaherpesviruses induces apoptosis in rabbit kidney (RK13) cells without the presence of other BHV-1-encoded proteins. In this article, we have characterized the cytotoxicity and growth behavior of a BHV-1 recombinant, BHV-1/D8, which fails to express the U(S) ORF8 protein in infected cells. BHV-1/D8 exhibited a reduced cytotoxicity to RK13 cells when compared to the cytotoxicity of control BHV-1 strains.

Pretreatment of leishmania homologue of receptors for activated C kinase (LACK) promotes disease progression caused by Leishmania amazonensis.

A cDNA coding Leishmania homologue of receptors for activated C kinase (LACK), which was known to play an important role in the early phase of Leishmania infection, was molecularly cloned from Leishmania amazonensis promastigote by using reverse transcription and nested polymerase chain reaction, and was sequenced. The L. amazonenis LACK cDNA showed 97.

Bovine herpesvirus-1 (BHV-1) recombinant expressing pseudorabies virus (PrV) glycoproteins B and C induces type 1 immune response in BALB/c mice.

Bovine herpesvirus 1 (BHV-1) attached poorly and penetrated into a mouse cell line, BALB 3T3/A31, but a recombinant BHV-1/TF7-6, which expresses pseudorabies virus (PrV) gB and gC genes, did attach and penetrated into cells more efficiently. In this study the gene green fluorescent protein (GFP) has been integrated into genome of BHV-1/TF7-6 and its parental line of BHV-1. When the mouse mesenteries were incubated in vitro and infected with BHV-1/TF7-6/GFP, strong fluorescence was observed while BHV-1/GFP infection hardly demonstrated fluorescence, suggesting that BHV-1 recombinant expressing PrV gB and gC can infect mouse tissue cells more efficiently than the parental BHV-1 does.

Mechanisms of apoptosis in murine fibroblasts by two intracellular protozoan parasites, Toxoplasma gondii and Neospora caninum.

Studies to clarify the mechanisms of apoptosis in host cells, A31 (BALB/3T3 clone A31 fibroblasts), caused by two intracellular protozoan parasites, Toxoplasma gondii and Neospora caninum, were carried out in an in vitro system. The viability of N. caninum-infected cells was significantly reduced following treatment with mouse interferon (IFN)-gamma.

Induction of apoptosis in rabbit kidney cell under high-level expression of bovine herpesvirus 1 U(s) ORF8 product.

Objective: The open reading frame 8 (ORF8) within the short unique (U(s)) region of the bovine herpesvirus 1 (BHV-1) genome was predicted to encode a protein with homology to U(s)9 protein of other alpha herpesviruses. The aim of this study is to identify the protein encoded by the U(s) ORF8 and to examine the effect of its expression in mammalian cells.

Methods: A polyclonal antiserum was raised against U(s) ORF8 protein expressed in Escherichia coli.

Canine herpesvirus ORF2 is a membrane protein modified by N-linked glycosylation.

Canine herpesvirus (CHV) ORF2, located downstream of the glycoprotein C (gC) gene, has homologues with some of the alphaherpesviruses. To characterize CHV OFR2, a recombinant CHV carrying a LacZ gene in the ORF2 locus, and recombinant vaccinia virus expressing ORF2 protein were constructed. Northern blot analysis revealed ORF2 and a gamma2 class late gene, and its protein product was detectable in CHV-infected cells reacted with ORF2 protein antiserum.

Pseudorabies virus (PRV) is protected from complement attack by cellular factors and glycoprotein C (gC).

Swine kidney derived CPK cells were resistant to swine complement attack in vitro while rabbit kidney derived RK13 cells were destroyed by swine complement. To rabbit complement, RK13 cells were resistant but CPK cells were sensitive. This phenomenon was known as homologous restriction (Proc.

Bovine herpesvirus 1 glycoprotein G is necessary for maintaining cell-to-cell junctional adherence among infected cells.

Glycoproteins gE and gG of bovine herpesvirus 1 (BHV-1) are involved in viral cell-to-cell transmission. We have compared the subcellular localizations of gE and gG and examined the cell-to-cell adherence of bovine kidney (MDBK) cells infected with BHV-1 mutants lacking gE or gG. In BHV-1-infected MDBK cells, gE was observed at cell junctions but did not localize at apical or basal plasma membranes.