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Human adenovirus serotypes 4 and 11 show higher binding affinity and infectivity for endothelial and carcinoma cell lines than serotype 5.

Adenoviruses are promising vectors for human cancer gene therapy. However, the extensively used adenoviruses serotypes 2 and 5 (Ad2 and Ad5) from species C have a major disadvantage in being highly prevalent; thus, most adults have an immunity against the two viruses. Furthermore, the expression of coxsackievirus and adenovirus receptors for Ad2 and Ad5 varies in different cells. This study aims to identify adenovirus serotypes with specific tropism for endothelial cells and epithelial tumour cells. Comparison of the binding affinities of Ad31, Ad11, Ad5, Ad37, Ad4 and Ad41, belonging to species A-F, respectively, to established cell lines of hepatoma (HepG2), breast cancer (CAMA and MG7), prostatic cancer (DU145 and LNCaP) and laryngeal cancer (Hep2), as well as to endothelial cells (HMEC), was carried out by flow cytometric analysis. Ad11 from species B showed markedly higher binding affinity than Ad5 for the endothelial cell line and all carcinoma cell lines studied. Ad4 showed a specific binding affinity for hepatoma cells and laryneal carcinoma cells. The ability of Ad11, Ad4 and Ad5 to be expressed in hepatoma, breast cancer and endothelial cell lines was studied by immunostaining and (35)S-labelling of viral proteins in infected cells. Ad11 and Ad4 manifested a higher proportion of infected cells and a higher degree of hexon expression than Ad5.

Adenoviruses, Human↗

Identification of the common antigenic determinant shared by Streptococcus pneumoniae serotypes 35A and 20 capsular polysaccharides--structural analysis of the Streptococcus pneumoniae serotype 35A capsular polysaccharide.

The specific polysaccharide antigen of Streptococcus pneumoniae serotype 35A was shown, by a combination of one- and two-dimensional NMR methods and chemical analyses, to be a high-molecular-mass polymer composed of D-galactose, D-glucose, mannitol, and phosphate (3:1:1:1). The pentasaccharide repeating unit is polymerized through phosphate diester linkages to give the structure, [formula in text] O-Acetyl substituents are present at positions 5 and 6 of the 3)-beta-D-Galf residue and at position 2 of the 6)-beta-D-Galf residue. The capsular polysaccharides of S. pneumoniae serotypes 20 and 35A both contain the disaccharide unit -->3)-beta-D-Galf-(1-->3)-beta-D-Glcp-(1--> which is the probable structural determinant responsible for the serological cross reactivity of the two polysaccharides.

Bacterial Capsules↗

Diethylaminoethyl-cellulose-bacterial cell immunoadsorbent columns: preparation of serotype-specific globulin and immunofluorescent conjugates for Streptococcus mutans serotypes a and d.

Diethylaminoethyl (DEAE)-cellulose was used as a support material for preparing bacterial cell columns. Pretreatment of the bacterial cells with formalin was essential in obtaining satisfactory adherence of the cells to DEAE-cellulose. Cross-reacting antibodies were removed from antibody preparations against strains of Streptococcus mutans serotypes a and d by adsorption on appropriate bacterial cell columns. S. mutans serotype d was further divided into two subtypes on the basis of immunofluorescent staining with conjugates of immunospecifically adsorbed immunoglobulin G. The DEAE-cellulose-bacterial cell columns were regenerated after use by desorbing the cross-reacting antibodies with low-pH buffer and were used repeatedly over and 18-month period with no detectable loss in effectiveness.

Adsorption↗

Enzyme-linked immunosorbent assay compared with immunoprecipitation for serotyping Neisseria meningitidis and its use in demonstrating serotype polymorphism.

Rabbit antisera generated against 11 prototype strains of group B Neisseria meningitidis were tritiated by using the enzyme-linked immunosorbent assay and the Ouchterlony immunoprecipitation technique. The relative insensitivity of the immunoprecipitation technique in detecting antibody compared with the enzyme-linked immunosorbent assay was demonstrated. Cross-reactions within the group and among the 11 serotypes were characterized with respect to established serological techniques. Serotype polymorphism among the strains of N. meningitidis was demonstrated with the enzyme-linked immunosorbent assay.

Agglutination Tests↗

Inter- and intraclade neutralization of human immunodeficiency virus type 1: genetic clades do not correspond to neutralization serotypes but partially correspond to gp120 antigenic serotypes.

We have studied genetic variation among clades A through E of human immunodeficiency virus type 1 (HIV-1) at the levels of antibody binding to gp120 molecules and virus neutralization. We are unable to identify neutralization serotypes that correspond to the genetic clades. Instead, we observe that inter- and intraclade neutralization of primary isolates by HIV-1-positive sera is generally weak and sporadic; some sera show a reasonable degree of neutralization breadth and potency whereas others are relatively sensitive to neutralization, but no consistent pattern was found. However, a few sera were able to neutralize across clades with significant potency, an observation which may have implications for the feasibility of a broadly effective HIV-1 vaccine involving humoral immunity. Serological assays measuring anti-gp120 antibody binding also failed to identify serotypes that correspond precisely to the genetic clades, but some indications of clade-specific binding were observed, notably with sera from clades B and E. A representative protein for each clade (A through E) was selected on the basis of its specificity, defined as high seroreactivity with sera from individuals infected with virus of that clade and lower reactivity with sera from individuals infected with viruses from other clades. The seroreactivity patterns against these five proteins could be used to predict the genotype of the infecting virus with moderate success.

Amino Acid Sequence↗

Rotavirus serotype G9 strains belonging to VP7 gene phylogenetic sequence lineage 1 may be more suitable for serotype G9 vaccine candidates than those belonging to lineage 2 or 3.

A safe and effective group A rotavirus vaccine that could prevent severe diarrhea or ameliorate its symptoms in infants and young children is urgently needed in both developing and developed countries. Rotavirus VP7 serotypes G1, G2, G3, and G4 have been well established to be of epidemiologic importance worldwide. Recently, serotype G9 has emerged as the fifth globally common type of rotavirus of clinical importance. Sequence analysis of the VP7 gene of various G9 isolates has demonstrated the existence of at least three phylogenetic lineages. The goal of our study was to determine the relationship of the phylogenetic lineages to the neutralization specificity of various G9 strains. We generated eight single VP7 gene substitution reassortants, each of which bore a single VP7 gene encoding G9 specificity of one of the eight G9 strains (two lineage 1, one lineage 2 and five lineage 3 strains) and the remaining 10 genes of bovine rotavirus strain UK, and two hyperimmune guinea pig antisera to each reassortant, and we then analyzed VP7 neutralization characteristics of the eight G9 strains as well as an additional G9 strain belonging to lineage 1; the nine strains were isolated in five countries. Antisera to lineage 1 viruses neutralized lineage 2 and 3 strains to at least within eightfold of the homotypic lineage viruses. Antisera to lineage 2 virus neutralized lineage 3 viruses to at least twofold of the homotypic lineage 2 virus; however, neutralization of lineage 1 viruses was fourfold (F45 and AU32) to 16- to 64-fold (WI61) less efficient. Antisera to lineage 3 viruses neutralized the lineage 2 strain 16- to 64-fold less efficiently, the lineage 1 strains F45 and AU32 8- to 128-fold less efficiently, and WI61 (prototype G9 strain) 128- to 1024-fold less efficiently than the homotypic lineage 3 viruses. These findings may have important implications for the development of G9 rotavirus vaccine candidates, as the strain with the broadest reactivity (i.e., a prime strain) would certainly be the ideal strain for inclusion in a vaccine.

Amino Acid Sequence↗

Isolation of a serotype G6P11 bovine rotavirus showing two-way cross-neutralization with the serotype G10P11 virus.

Four stains designated as OB94-1 to OB94-4 of group A bovine rotavirus (BRV) were isolated from 35 fecal samples of calves with diarrhea in sporadic outbreaks. In VP7 (G) and VP4 (P) serotyping of these isolates, OB94-1 to OB94-3 were determined as G6P5, G6P5 and G10P5, respectively, by cross neutralization (NT) test and the G- and P- serotyping polymerase chain reaction (PCR) analysis. OB94-4 showed a one-way antigenic relation with the Lincoln stain (G6P1) and a weak antigenic relationship with the KK3 strain (G10P11), and was determined as G6P11 by the PCR method. Thus, OB94-4 was shown to be a new G6 BRV with different antigenic properties from the others in the NT test.

Animals↗

Dissemination of Salmonella enterica serotype agona and multidrug-resistant Salmonella enterica serotype typhimurium in Cuba.

The molecular epidemiology, antimicrobial susceptibility, and mechanisms of resistance of 34 Salmonella spp. strains causing acute gastroenteritis, isolated from different provinces in Cuba, were determined. Sixty-four percent of the strains showed multiresistance. Salmonella typhimurium was the most frequent with 15 strains (44%), 13 of which belonged to phagotype 104 and presented similar genetic profiles of pulsed field gel electrophoresis. High levels of resistance to tetracycline (53%), spectinomycin (50%), ampicillin (44%), and chloramphenicol (41%) were found. Resistance to tetracycline was associated with the tet G and tet A genes. Resistance to ampicillin was caused by the presence of beta-lactamases, mainly the CARB type. The floR gene was the main mechanism of resistance to chloramphenicol. Our results showed an antimicrobial susceptible clone of Salmonella enterica serotype Agona in two separate regions. This is the first report of the widespread dissemination of a multiresistant clone of S. enterica serotype Typhimurium definitive phage type 104 in Cuba.

Anti-Bacterial Agents↗

VP7 from African horse sickness virus serotype 9 protects mice against a lethal, heterologous serotype challenge.

An established mouse model system was used to evaluate the effectiveness of the major outer core protein VP7 of African horse sickness virus (AHSV) serotype 9 as a subunit vaccine. Balb C mice were immunised with VP7 crystals purified from AHSV infected BHK cells. In groups of mice, each of which was immunised with > or = 1.5 micrograms of the protein in Freund's adjuvant, > or = 80% of mice survived challenge with a virulent strain of a heterologous AHSV serotype (AHSV 7), that killed > or = 80% of the mice in the uninoculated control groups. This level of protection was significantly greater than that observed in mice inoculated with equivalent amounts of either denatured VP7 (50% survival), or GST/VP7 fusion protein (50-70% survival), or which were vaccinated with AHSV 9 (40-50% survival). The VP7 protein folding, or its assembly into crystals, are thought to play some role in the effectiveness of the protective response observed. Titres of circulating antibodies against AHSV VP7 were determined by competitive ELISA but did not appear to correlate with the levels of protection observed. Passive transfer of these antibodies to syngeneic recipients also failed to protect Balb C mice from the AHSV 7 challenge. The observed protection is therefore unlikely to be due to an antibody mediated immune response.

African Horse Sickness↗

Conserved and non-conserved regions of the outer coat protein, VP2, of the Australian bluetongue serotype 1 virus, revealed by sequence comparison to the VP2 of North American BTV serotype 10.

The complete nucleotide sequence of the outer coat protein, VP2, of the Australian BTV serotype 1 was determined and found to be 2940 nucleotides in length. An open reading frame of 961 amino acids was found, defining a protein of 112,115 Daltons having a charge of +15 at neutral pH. This coding region was flanked by 5' and 3' non-coding regions of 17 and 37 nucleotides, respectively. When compared to VP2 of the North American BTV serotype 10 (Purdy et al., 1985, J. Virol. 55, 826-830) a homology of 52% at the nucleotide level, and 40% at the amino acid level, was observed. Significant conservation of amino acid sequence was found in eleven distinct regions; the overall hydropathy of the protein, as well as 9 of its 12 cysteine residues, was conserved. The importance of this conservation, in relation to similar observations for the other outer coat protein, VP5, is discussed.

Amino Acid Sequence↗

Serotype-selective, small-molecule inhibitors of the zinc endopeptidase of botulinum neurotoxin serotype A.

Botulinum neurotoxin serotype A (BoNTA) is one of the most toxic substances known. Currently, there is no antidote to BoNTA. Small molecules identified from high-throughput screening reportedly inhibit the endopeptidase--the zinc-bound, catalytic domain of BoNTA--at a drug concentration of 20 microM. However, optimization of these inhibitors is hampered by challenges including the computational evaluation of the ability of a zinc ligand to compete for coordination with nearby residues in the active site of BoNTA. No improved inhibitor of the endopeptidase has been reported. This article reports the development of a serotype-selective, small-molecule inhibitor of BoNTA with a K(i) of 12 microM. This inhibitor was designed to coordinate the zinc ion embedded in the active site of the enzyme for affinity and to interact with a species-specific residue in the active site for selectivity. It is the most potent small-molecule inhibitor of BoNTA reported to date. The results suggest that multiple molecular dynamics simulations using the cationic dummy atom approach are useful to structure-based design of zinc protease inhibitors.

Botulinum Toxins, Type A↗

Protection of gnotobiotic pigs against Salmonella enterica serotype Typhimurium by rough mutant of the same serotype is accompanied by the change of local and systemic cytokine response.

We have demonstrated that severe systemic disease caused by virulent LT2 strain Salmonella enterica serotype Typhimurium in gnotobiotic piglets can be alleviated by oral inoculation with an avirulent rough (R) mutant of the same serotype 24 h before challenge with the virulent strain. Protected piglets had no signs of enteritis. The concentrations of TNF-alpha, IL-1beta, IL-8 and IL-10 were measured by ELISA in ileal washings and plasma of uninfected and infected pigs. The cytokines were not detected in plasma of germ-free piglets, and low concentrations of IL-1beta and IL-8 were found in their ileal washings. The pre-inoculation of the rough mutant induced an increase in IL-8 and decrease in IL-1beta and IL-10 in plasma. The virulent LT2 strain induced very high TNF-alpha concentrations in the ileum which were reduced in the pigs pre-inoculated with the R mutant.

Animals↗

Mannheimia haemolytica serotype 1 and Pasteurella trehalosi serotype 10 culture supernatants contain fibrinogen-binding proteins.

Fibrinogen-binding proteins were found in the culture supernatants of Mannheimia haemolytica serotype 1 (ATCC 43270) and Pasteurella trehalosi serotype 10 (ECO-100). Sheep fibrinogen was biotinylated and shown to bind to proteins in the culture supernatants by modified western blot. Fibrinogen-binding proteins in the culture supernatant may be important virulence factors leading to the characteristic fibrinous pneumonia caused by these organisms and may be critical antigenic targets for immune prophylaxis.

Animals↗

Effect of endobronchial challenge with Actinobacillus pleuropneumoniae serotype 10 of pigs vaccinated with bacterins consisting of A. pleuropneumoniae serotype 10 grown under NAD-rich and NAD-restricted conditions.

The efficacy of two bacterins containing an Actinobacillus pleuropneumoniae serotype 10 strain was evaluated. The bacterial cells constituting bacterin 1 and 2 were grown under nicotinamide adenine dinucleotide (NAD)-rich (low-adherence capacity to alveolar epithelial cell cultures) and NAD-restricted (high-adherence capacity to alveolar epithelial cell cultures) conditions, respectively. Ten pigs were vaccinated twice with the bacterin 1 and nine pigs with the bacterin 2. Ten control animals were injected twice with a saline solution. Three weeks after the second vaccination, all pigs were endobronchially inoculated with 106.5 colony-forming units (CFU) of an A. pleuropneumoniae serotype 10 strain. In the bacterin 1 and 2 group, three and two pigs died after inoculation, respectively. Only two pigs of the control group survived challenge. Surviving pigs were killed at 7 days after challenge. The percentage of pigs with severe lung lesions (> 10% of the lung affected) was 100% in the control group, 70% in the bacterin 1 group and 22% in the bacterin 2 group. Actinobacillus pleuropneumoniae was isolated from the lungs of all animals. The mean bacterial titres of the caudal lung lobes were 7.0 x 10(6) CFU/g in the control group, 6.3 x 10(5) CFU/g in the bacterin 1 group and 1.3 x 10(6) CFU/g in the bacterin 2 group. It was concluded that both bacterins induced partial protection against severe challenge. Furthermore, there are indications that the bacterin 2, containing A. pleuropneumoniae bacteria grown under conditions resulting in high in vitro adhesin, induced better protection than the bacterin 1.

Actinobacillus Infections↗

Reduced susceptibility to ciprofloxacin and gyra gene mutation in North Indian strains of Salmonella enterica serotype Typhi and serotype Paratyphi A.

The emergence of reduced susceptibility to ciprofloxacin among Salmonella enterica serotype Typhi and serotype Paratyphi A leading to clinical failure of treatment poses a great therapeutic challenge. The mechanism of fluoroquinolone resistance in clinical isolates of S. Typhi and S. Paratyphi A is not very well documented. The present study was carried out with the objective of molecular characterization of reduced quinolone susceptibility amongst the strains of S. Typhi and S. Paratyphi A isolated from the patients with enteric fever during January, 2000, to April, 2003, in a North Indian hospital. A total of 422 culture-positive cases of enteric fever were reported to the hospital during the period of study, of which S. Typhi was isolated from 350 cases and S. Paratyphi A from 72 cases. The antimicrobial susceptibility of these strains was determined by disk diffusion and agar dilution method according to NCCLS guidelines, and E-test method. A total of 140 randomly selected strains, isolated during the years 1993-1999, that were available from the laboratory stocks were also studied to compare with the present strains. To study the quinolone susceptibility, the strains were divided into nalidixic acid sensitive (NAS), nalidixic acid intermediate resistant, (NAI) and nalidixic acid resistant (NAR) on the basis of susceptibility to nalidixic acid. Clinical history was available from 174 patients, of which 93 needed hospitalization due to severe disease. Of these, 82 patients were infected with NAR strains and 22 patients had a documented evidence of clinical failure to ciprofloxacin therapy. The patients infected with NAR strains were younger and had a significantly longer duration of fever (p value < 0.05) than those infected with NAS strains. It was observed that the proportion of NAR strains increased gradually over the years. These strains had a significantly higher range of MIC of ciprofloxacin (0.023-1.0 microg/ml) as compared to the NAS strains (0.002-0.125 microg/ml) (p value < 0.05). The sequencing of quinolone resistance determining region (QRDR) of the gyrA gene showed the presence of mutation at either Ser 83 or at Asp 87 in all the NAR and NAI strains. None of the NAS strains had a mutation, suggesting that the gyrA gene mutation is sufficient to confer resistance to nalidixic acid and reduced susceptibility to ciprofloxacin. This mutation, although phenotypically expressed as decreased susceptibility to ciprofloxacin, goes undetected by the disk diffusion method using the present NCCLS guidelines. Hence, it can increase morbidity and mortality due to delay in appropriate antibiotic treatment.

Adolescent↗

Widespread dispersion of adeno-associated virus serotype 1 and adeno-associated virus serotype 6 vectors in the rat central nervous system and in human glioblastoma multiforme xenografts.

The transduction patterns of recombinant adeno-associated virus serotype 1 (AAV1) and serotype 6 (AAV6) vectors were assessed in human glioblastoma multiforme (GBM) cell lines, in human GBM biopsy spheroids, and in tumor xenografts growing in nude rat brains. All the cell lines tested (A172, D37, GaMg, HF66, and U373Mg) were found to be permissive to both AAV1 and AAV6 vectors, and thus displayed a transduction pattern similar to AAV2 vectors. For every cell line tested, the transduction efficiency displayed by AAV2 vectors was better than by isogenic and isopromoter AAV1 vectors. Transduction efficiency was dependent on the viral particle number used, suggesting that the receptors for these vectors are widely distributed in GBM tissues. Interestingly, AAV1, AAV2, and AAV6 vectors were able to infect and transduce the same cells when added simultaneously to monolayer cultures. Infection of human GBM biopsy spheroids with AAV1 and AAV6 vectors resulted in transgene expression both at the surface layers and in the core of the spheroids. Following injection of AAV1 and AAV6 vectors into human GBM biopsy xenografts growing in nude rat brains, reporter gene expression was seen both in the periphery as well as in the central regions of the tumors. When injected into the normal rat brain, both AAV1 and AAV6 vectors were found to transduce several central nervous system (CNS) regions. The presented results suggest a potential therapeutic role for AAV1 and AAV6 vectors in gene therapy for GBM and also for other CNS malignancies.

Animals↗

Effect of serotype 5 adenoviral and serotype 2 adeno- associated viral vector-mediated gene transfer to salivary glands on the composition of saliva.

Key to the development of a useful clinical therapy is the minimization of side effects. Routine safety testing, however, does not provide information about the physiological status of many potentially useful gene transfer target sites. In this study, we evaluated the longitudinal effects of intrasalivary duct delivery of recombinant serotype 5 adenoviral (rAd5; 10(9)-10(10) particles/gland in rats) and recombinant serotype 2 adeno-associated viral (rAAV2; 10(8)-10(9) particles/gland in mice) vectors on salivary composition. Both vectors led to modest, transient alterations in several salivary components that thereafter returned to normal. The changes suggested two initial specific consequences of rAd5 and rAAV2 vector administration: (1) a modest breach of the mucosal barrier in the targeted glands, indicated by elevations in salivary albumin, total protein, and Na+ levels, and (2) an innate host response, indicated by transient elevations in either salivary lactoferrin and IgA levels (rAd5) or mucin (rAAV2). These studies are consistent with the notion that administration of modest doses of rAd5 and rAAV2 vectors to salivary glands for a therapeutic purpose can be accomplished without severe or permanent injury to the target tissue, or compromise to its essential exocrine physiological function.

Adenoviridae↗