Mapping of linear epitopes on fibre knob of human adenovirus serotype 5

Linear antigenic epitopes on the Ad5 fibre knob (FK5) were characterised with fibre- and virion-specific antisera, using 15-mer overlapping peptides covering the knob of the fibre. They were compared with epitopes on the Ad2 fibre knob (FK2) domain. The stronger reactive FK5 epitopes were represented by peptides P3 (amino acids (aa A419-L433)), P6 (aa S449-E463), P7 (aa I459-L473), P12 (aa G509-N523), P14 (aa P529-G543) and P16 (aa A549-Y563). P3 spans the B beta-strand and the left portion of the C beta-strand, P6 and P7 the D beta-strand and the adjacent parts of the CD and DE loops, P12, P14 and P16 the G, H and I beta strands and the adjacent parts of the loops, respectively. The stronger reactive epitopes on FK2 were located in P2 (aa P409-L423), P6 (aa T449-Q463), P8 (aa E469-G483), P13 (aa Q519-T533) and P16 (aa S549-K563). The positions of FK5 and FK2 derived peptides, representing epitopes, are either identical or overlapping or adjacent, as determined by amino acid sequence alignment. Antisera obtained against several longer peptides showed virus neutralising capacity, indicating neutralising epitopes in these peptides.

The subgenus-specific C-terminal region of protein IX is located on the surface of the adenovirus capsid

We have investigated the antigenicity of the C- and N-terminal halves of pIX of human adenovirus types 2 and 3 (Ad2 and Ad3) as well as their orientations in virions. We found that only the C-terminal halves of Ad2 pIX and Ad3 pIX reacted in a subgenus-specific manner by enzyme-linked immunosorbent assay and immunoblot analysis. Based on immunoelectron microscopy experiments, pIX in viral capsids appears to be positioned such that the C-terminal part of pIX constitutes the surface domain whereas the N terminus of the protein makes up the internal domain in icosahedral Ad capsids.

Receptor binding sites and antigenic epitopes on the fiber knob of human adenovirus serotype 3

The adenovirus fiber knob causes the first step in the interaction of adenovirus with cell membrane receptors. To obtain information on the receptor binding site(s), the interaction of labeled cell membrane proteins to synthetic peptides covering the adenovirus type 3 (Ad3) fiber knob was studied. Peptide P6 (amino acids [aa] 187 to 200), to a lesser extent P14 (aa 281 to 294), and probably P11 (aa 244 to 256) interacted specifically with cell membrane proteins, indicating that these peptides present cell receptor binding sites. Peptides P6, P11, and P14 span the D, G, and I beta-strands of the R-sheet, respectively. The other reactive peptides, P2 (aa 142 to 156), P3 (aa 153 to 167), and P16 (aa 300 to 319), probably do not present real receptor binding sites. The binding to these six peptides was inhibited by Ad3 virion and was independent of divalent cations. We have also screened the antigenic epitopes on the knob with recombinant Ad3 fiber, recombinant Ad3 fiber knob, and Ad3 virion-specific antisera by enzyme-linked immunosorbent assay. The main antigenic epitopes were presented by P3, P6, P12 (aa 254 to 269), P14, and especially the C-terminal P16. Peptides P14 and P16 of the Ad3 fiber knob were able to inhibit Ad3 infection of cells.

Rapid identification of subgenera of human adenovirus by serological and PCR assays

Bacterially expressed recombinant protein IX (pIX) of human adenovirus serotype 2 (Ad2) and 3 (Ad3) was evaluated for use as a subgenus-specific antigen by enzyme-linked immunosorbent assay (ELISA) and Western blotting. Patients sera positive by ELISA for the genus-specific adenovirus hexon antigen recognized the recombinant pIX of Ad2 and Ad3 in a subgenus-specific manner by both assays. Polyclonal rabbit serum raised against the recombinant Ad2pIX reacted strongly by indirect immunofluorescence assay, with Adl, 2 and 5 (subgenus C) but not with serotypes representing other subgenera. In a similar way, anti-Ad3pIX reacted with Ad3, 7, 11 and 14 (subgenus B), but not with serotypes representing other subgenera. A polymerase chain reaction showed that the complete pIX gene could be amplified in a subgenus specific fashion using primers specific for Ad3 (subgenus B), Ad2 (subgenus C), or Ad40/41 (subgenus F). The pIX gene from the available isolates of subgenus A, D and E was not amplified with these primers. The use of pIX-based serological assays is useful for subgenotyping as a primary screen of anti-Ad sera. It is much more rapid than the currently used neutralization assay or hemagglutination inhibition test. The application of anti-pIX sera by immunofluorescence and a pIX gene-based PCR are rapid methods which will improve subgenus identification of adenoviruses.

Adenovirus-receptor interaction with human lymphocytes

Lymphocytes play a key role in cell-mediated immunity and are host cells for several viral and bacterial pathogens. Their importance in adenovirus (Ad) infections is not yet fully understood. The initial event, the attachment of Ad to lymphocytes and their subsets, was examined using flow cytometry. The study included analysis of stimulated T cells in binding assays with FITC-labeled Ad fiber. The results confirm that native peripheral lymphocytes express very small amounts of Ad receptors. Stimulation with PHA and interleukin 2 induced the expression. The presence of Ad DNA as a sign of internalization in stimulated cells was demonstrated using the polymerase chain reaction. The findings suggest that lymphocytes after stimulation can turn into target cells for Ad. This is particularly important if there are indications for persistence of Ad, and in the case of immunocompromised patients severe, life-threatening diseases can develop.

Inhibition of cell adhesion to the virus by synthetic peptides of fiber knob of human adenovirus serotypes 2 and 3 and virus neutralisation by anti-peptide antibodies

The fiber knob of adenovirus (Ad) causes the first step in the interaction of adenovirus with cell membrane receptors. To obtain information on the receptor binding site(s) several synthetic peptides derived from Ad2 and Ad3 fiber head sequences and their antisera were tested for interference with virus attachment to HeLa and FL cells and cell adhesion to viruses. The anti-peptide sera were also evaluated in ELISA and virus neutralisation test. Ad2 (of subgroup C) and Ad3 (of subgroup B) attachment was not significantly inhibited by peptides corresponding to the amino acid residues 535-554, 555-573, 562-582 of Ad2 fiber or 210-225, 267-283, 291-306 and 300-319 of Ad3 fiber. However, microplate pre-adsorbed Ad3 fiber residues 210-225 and 267-283 could bind FL and HeLa cells, and 1 mg/ml of Ad3 fiber residues 267-283 inhibited the cell adhesion to Ad3 virus to approximately 90%. This peptide may participate in the receptor binding site of Ad3 fiber. ELISA reactive anti-peptide antibodies against the homologous peptide and virus did not significantly reduce the cell adhesion to the immobilised virus or the virus attachment to cells, but in the neutralisation assay antibodies raised to Ad2 fiber residues 555-573 and 562-582 and Ad3 fiber residues 210-225 caused neutralisation of the homologous virus at serum dilutions of 1:500 and 1:32, respectively. The corresponding peptides and one further peptide of Ad2 fiber and two of Ad3 fiber seem to contain neutralisation epitopes.

Quantification of adenovirus particles

A physical method for quantification of the adenovirus was tested. It implies a centrifugation of the clarified or chloroform- (or freon-) treated crude virus suspension (0.5 ml) in a gentle sucrose gradient, following the analysis in a sensitive UV flow photometer and calculation of virus mass. The result (micrograms/ml) is obtained after about 1 h. The sensitivity of detection at wavelength 254 nm, 278 nm and 226 nm was compared. Virus yield of several serotypes from monolayer cultures of FL-cells was determined in a range of < 0.1 to 7 micrograms/ml. The ratio of infectious to physically complete virus (about the 770S component), the influence of freezing and thawing, storing at 4 degrees C and the effectiveness of concentration steps were also determined. There was no significant difference between the sucrose density gradient method (sedimentation rate) and the density equilibrium ultracentrifugation in a CsCl gradient.

Effect of adjuvant formulations on the induction of virus-neutralizing and virus-binding antibodies by chemosynthetic peptides of VP1 of foot-and-mouth-disease virus

Synthetic peptides corresponding to the 141-160 amino acid sequence of the protein VP1 of virus type O1 Kaufbeuren (O1K) and A5 Riems (A5R) were conjugated to thyroglobulin and mixed with complete Freund's adjuvant (CFA) or incomplete Freund's adjuvant (IFA) together with Quil A. Although the peptide of A5R, together with IFA and Quil A, or with CFA, elicited a high antibody response to the virus in the ELISA, formula containing both IFA and Quil A induced only high titres of virus-neutralizing antibodies in rabbits. These adjuvant formulas did not display significant differences with regard to side effects.

T-lymphocyte responses in guinea pigs vaccinated with foot-and-mouth disease virus

The guinea pig provides an alternative experimental model for analysis of the immune response against foot-and-mouth disease virus (FMDV). The cellular immune response against FMDV in this experimental animal is unknown and was analyzed by in vivo and in vitro studies. In guinea pigs immunized with an FMDV A5 vaccine, a marked change in T-lymphocyte count appeared. For analyzing which functional T-cell compartment was affected, immunofluorescence studies, using monoclonal antibodies directed against differentiation antigens on guinea pig lymphoid cells, were performed. The proliferating T-cells were predominantly CD4-positive and, therefore, helper cells. T-cells from these animals were re-stimulated in vitro with homologous inactivated virus. The antigen-specific proliferative response of the T-cells in vitro was measured using the thymidine incorporation assay. A proliferative response to FMDV was observed that depended on the dose of the antigen. High concentration of virus had an inhibitory effect on T-cell proliferation. These data indicate that the guinea pig is a useful model for analysis of T-cell mediated mechanisms in the pathogenesis and immunity of foot-and-mouth disease.

[Comparative studies of the detection of antibodies against BHV-5 using the enzyme-linked immunosorbent assay, serum neutralization test, cell assay and immunofluorescence test]

A comparison of the analyses of 490 serum samples from various flocks of sheep for the detection of BHV-5 antibodies using ELISA, serum neutralisation test, cell assay and immunofluorescence assay showed nearly identical results regarding the distinction between positive and negative serum samples. The percentage of serum samples with antibodies against BHV-5 antigen differed from test to test: ELISA 268 (54.7%), cell assay 323 (65.8%), immunofluorescence assay 222 (46.6%) and serum neutralisation test 221 (45.1%). With ELISA, cell assay and immunofluorescence assay the experiment can be carried out more simply and rapidly than with serum neutralisation test.

[Development of an enzyme-linked immunosorbent assay for the detection of antibodies against bovine herpesvirus type 5 (BHV-5) in sheep sera]

The indirect enzyme-linked immunosorbent assay (ELISA) was first developed for the detection of antibodies against BHV-5 in sheep sera. Investigations of various antigen (Ag) preparations revealed that BHV material which had been purified across a sucrose gradient using sonification followed by ultracentrifugation gave satisfactory results during application in ELISA. Optimal coating of the solid phase was achieved with Ag adsorption at 4 degrees C overnight with 5 micrograms of virus material/ml in a carbonate-bicarbonate-buffer, pH 9.7. The background reactions were significantly reduced by blocking the free bonding points with 1% gelafusal after Ag adsorption. As the extinction values of all the sera investigated which a dilution of 1:50 or more below 0.2, the difference threshold between positive and negative sera was set at 0.2. A total of 490 sera from various stocks of sheep were investigated with regard to the occurrence of antibodies against BHV-5 in ELISA. The growing rate of infection with herpesviruses among ruminants and the subsequent economic loss have resulted in the increased significance in the last few years of bovine herpes-virus (BHV) disease.

Studies concerning etiology of sheep-associated malignant catarrhal fever in Europe

The etiological agent of sheep-associated malignant catarrhal fever (MCF) in Europe has not been isolated directly from sheep. The occurrence of antibodies against the African bovine herpesvirus (BHV-3, WC 11) in cattle and sheep was examined using recently modified indirect immunofluorescence test (IIFT) and neutralization test (NT) methods. Studies revealed that sheep and cattle sera in Europe were free from neutralizing antibodies of BHV-3. The IIFT could not establish the presence of antibodies to African BHV-3 in cattle but revealed that about 22.4% of sheep sera reacted to it. Apart from the well known ovine herpesvirus (BHV-5), occurrence of another herpesvirus in Europe had been expected. This virus is not identical with the WC 11 strain, but it is in antigenic relationship to it. We had for the first time substantial serological evidence to the effect that sheep-associated MCF in Europe is a herpesvirus related to the African strain.

Some physicochemical properties of the virus of rabbit haemorrhagic disease

Purified and concentrated preparations of virus from liver extracts of infected rabbits contain virus specific components with sedimentation coefficients of about 175, 110 and sometimes 133S and more slow units. Full and empty virus particles with a diameter of about 34 nm were shown electron microscopically in the corresponding 175 and 110S fractions of the sucrose density gradient. The average of buoyant density of the 175, 133, 110S and more slow units are 1.36, 1.32 and 1.31 g/ml respectively. The extinction coefficient E260 nm is 4.3 +/- 0.7 cm2/mg. The RNA content is 17 +/- 4%. SDS-PAGE shows a "65" kD protein as a single or major component. Beside smaller polypeptides with lower intensities, the 67 kD polypeptide reacts positively in the Western blot with polyclonal antibodies of rabbits. The molecular weight of the virus is 15 +/- 4 x 10(6)D. The pH stability of the 175S unit was also tested.

[Hemorrhagic septicemia of rabbits (rabbit hemorrhagic disease, RHD)--quantitative antigen detection]

The efficiency of a vaccine of inactivated virus is influenced to a great deal by the mass of antigen per dose of application. Therefore it is essential to known the concentration of the antigen. We tested a physical method for quantification of the RHD-Virus. It implies a centrifugation of the prepurified, if necessary, preconcentrated infectious or inactivated virus in a gentle sucrose gradient. It is followed by analysis in a sensitive UV flow-through photometer with a computer calculated virus mass. The extinction coefficient (optical density) of the virus (175S-component) at 254 nm is 3.9 cm2/mg. The haemagglutination test and the ELISA were used to prove the virus specificity of the optical peak and partial for comparing them with the method mentioned above.

RGD-containing peptides of VP1 of foot-and-mouth disease virus (FMDV) prevent virus infection in vitro

RGD-containing peptides from the immunodominant region of VP1 between amino acids 135-160 from foot-and-mouth disease virus (FMDV) type O1 Kaufbeuren (O1K) prevented virus adsorption to piglet kidney (PK) cells. The highly conserved amino acid RGD sequence (Arg.-Gly.-Asp.) was a prerequisite of this effect. To prevent infection with 100-200 TCID50 in 10(6) PK cells, 20-250 micrograms of each peptide should have been added.

Detection of T1-oligonucleotides of the foot-and-mouth disease virus RNA [correction of DNA] by silver staining

Viral (v) RNA was isolated from purified foot-and-mouth disease virus (FMDV) by phenol-chloroform-isoamylalcohol treatment, digested by RNase T1 and separated by one-dimensional polyacrylamide gel electrophoresis (PAGE). The oligonucleotides were detected by silver staining. About 45 micrograms of vRNA corresponding to about 100 ml of infectious BHK-21 cell culture fluid yielded a pattern of nearly 20 bands sufficient to differentiate between the FMD viruses.

Detection of antibodies to bovid herpesvirus 2 infection of cattle in Syria

Neutralising antibody to bovid herpesvirus 2 was demonstrated in the serum of 31 (10.8%) of 286 heads of cattle in north, south, and west Syria. 38% of titres were 1:2 to 1:8. There is no published report on isolation of this virus in Syria.

[Virulence factors of animal pathogenic Salmonellae with reference to plasmid typing]

All the representatives of the genus Salmonella belong to one pathogenic species S. enterica. The virulence intensification of Salmonella are due mainly to endo-, entero- and cytotoxins, fimbria, cilia, the invasion capacity and the serum resistance. The plasmid code is among a series of virulence factors. Studies about the plasmid profile of the salmonella strains is of great importance to the characterisation of the isolates from the epidemiological point of view as well as for research purposes.

Problems concerning the taxonomy of the 'Movar-type' bovine herpesviruses

The inconsistency in naming and labeling bovine herpesviruses (BHVs), other than BHV types 1 and 2 (BHV-1 and BHV-2), found in the literature is reviewed. To resolve the confusion and misunderstanding caused by the use of BHV-3, BHV-4 and BHV-5 for the same kind of BHVs, the most used label BHV-4 is proposed for designating Movar-type BHVs (which also were named 'orphan viruses' or 'cytomegaloviruses').

[Vaccinations therapy of laryngeal papillomatosis (author's transl)]

Our experiences with 49 cases of laryngeal papillomae of which 22 were submitted to a vaccine therapy are encouraging. 1. Tracheotomy as a remedial and therapeutic procedure is dispensable by ablation of papillomae in respiratory-laryngoscopy. 2. Additional application of a virus-vaccine contributes to healing by reducing the frequency of ablations. In few cases papilloma healed without endo-surgicals ablations after application of vaccine Charge 4. 3. 4 in 11 cases with delayed or complicated healing processes, a part of them after papillomatosis lasting for decades, could surprisingly be cured. In 2 females laryngectomy had finally to be carried out because of the development of laryngeal cancer, with and without preceeding vaccination, respectively. 4. Side-effects during and after vaccination could not be stated, five years ago. 5. We think vaccination to be an effective complement of the wellproved surgical ablation of papillomae under optimal endoscopical working conditions.

The central control of shivering and non-shivering thermogenesis in the rat

1. To test whether the preoptic area controls only non-shivering and the spinal cord only shivering thermogenesis, ten rats were chronically implanted with a preoptic and a spinal cord thermode each. The following were then studied: (a) the effect of propranolol (8 mg/kg.hr) on the metabolic response to cooling the preoptic area, and the spinal cord, (b) the effect of exogenous noradrenaline (0.5 mg/kg) on the metabolic response to cooling the preoptic area, and the spinal cord, and (c) the effect of warming the preoptic area on the metabolic response to cooling the spinal cord, and vice versa. 2. Administration of propranolol inhibited the metabolic response to cooling each of the thermosensitive areas, but the response to cooling the preoptic area was more strongly inhibited than that to cooling the spinal cord. 3. Administration of exogenous noradrenaline did not prevent the metabolic response to cooling either the preoptic area or the spinal cord. 4. Warming the spinal cord completely inhibited the metabolic response to cooling the preoptic area, and warming the preoptic area fully inhibited the metabolic response to cooling the spinal cord. 5. It is concluded that exogenous noradrenaline underestimates the capacity for non-shivering thermogenesis, and that both thermosensitive areas can control both forms of thermogenesis, but that the preoptic area threshold of non-shivering thermogenesis is probably lower than that of shivering, while the spinal cord threshold of shivering is probably lower than that of non-shivering thermogenesis.