The presence of both antivirus and antiself antibodies in sera from patients with adenovirus and influenza B.

Using the ELISA method we examined serum samples from 62 male patients aged 19-23 infected with adenovirus (serotype 7), 22 children aged 7-14 infected with influenza B (B/Norway 1/84) and 113 normal subjects aged 5-30. The infections were diagnosed serologically by complement fixation, by inhibition of hemagglutination, by ELISA and by viral culture. Moreover using enzyme-linked short-time culture assay, the production of specific antivirus antibodies and autoantibodies in vitro by spleen cells (1 x 10(6) cells/well) from normal mice and from mice immunized with adenovirus and influenza B was studied. At the same time their sera antibody titers were determined. All the serum samples were tested against the following antigens: adenovirus, influenza B, ds-DNA, actin, myosin, myoglobin, thyroglobulin, H. transferrin, H. interferon a and BSA. FV. For the further characterization of positive sera, an evaluation of specificity by competitive ELISA-test and by preparations of F(ab')2 fragments from patients' sera was also carried out. It was found that the percentage of positivity for the specific virus and other antigens was higher in the patients' samples than in the samples from the normal subjects. The specific antivirus antibody was of IgG class and their titers ranged from 1/4, 800 up to 1/19,200. Autoantibodies belonged to IgM, IgA, IgG classes and their titers ranged from 1/400 to 1/1,600. In comparison, titers of normal subjects' sera ranged from 1/150 to 1/600 and 1/150 to 1/300, respectively and both were IgG classes. Both specific virus antibodies and autoantibodies appeared at the same time. The competitive ELISA-test showed a marked inhibition (95-98%) of antivirus antibodies with the specific antigen, whereas autoantibodies were less inhibited (40-50%) by homologous antigens. The antigen-antibody reaction occurred at the Fab portion of the immunoglobulin molecule, since these fragments inhibited antibody reactivity. The same results were observed with spleen cells from immunized mice and the above-mentioned antigens when cultured in vitro.

Antiactin and antitubulin antibodies in canine visceral leishmaniasis.

Visceral leishmaniasis, a chronic and often fatal disease, is caused by the protozoan parasite Leishmania donovani. Both specific and nonspecific antibodies are produced in the course of the disease, and autoantibodies may be involved in pathogenesis. Tubulin and actin have been found to be associated with L. donovani. To learn whether antiactin and antitubulin antibodies are present in visceral leishmaniasis, we tested sera from 263 infected dogs by enzyme-linked immunosorbent assay for antibodies to the antigens L. donovani, actin, and tubulin. All samples reacted positively with L. donovani, and a high percentage reacted positively with all three antigens. Sera from 202 uninfected dogs were also tested, none reacted with L. donovani antigen, although positive reactions were observed for 8 of the samples with actin or tubulin. It was found that the antibody-antigen reaction occurred at the Fab portion of the immunoglobulin molecule. Competitive enzyme immunoassays showed that the reaction was inhibited if the positive serum was first incubated with L. donovani antigen, actin, or tubulin and then tested by enzyme-linked immunosorbent assay. These results suggest that antiactin and antitubulin antibodies are present in the sera of dogs infected with visceral leishmaniasis.

Study of host antigens in the envelopes of different myxo- and paramyxoviruses cultivated in the embryonated hen egg.

By immunoelectrophoretic analysis it was shown that different viruses--such as myxo- (influenza A0PR8) and paramyxoviruses (Sendai, SV5, NDV, mumps)--cultivated in the same host cells (chorioallantoic membranes) incorporate similar host antigens into their envelopes. The amount of host cell antigens incorporated into the virus envelopes differs from one virus to another. The fact that incorporation of host cell antigens occurs only after a virus-induced modification seems to be a general characteristic of enveloped viruses such as myxo- and paramyxoviruses.

Immunoelectrophoretic study on the host antigens of Sendai virus cultivated in different substrates (embryonated hen eggs and KB cells). Note II. Analysis of KB cell host antigens.

It could be demonstrated by immunoelectrophoretic analysis that the host antigen incorporated in the envelopes of Sendai virus cultivated in KB cells (Sendai/KB) is characteristic of these cells and does not occur in the envelopes of the same virus grown in the embryonated hen egg (Sendai/egg). This host antigen appears from the first passage in KB cells and is constantly maintained over subsequent passages. The glycoproteins released by Triton X-100 disruption from Sendai/KB envelopes have a concomitant antigenic specificity for both virus and host. In the case of Sendai/egg virus, exclusively virus-specific macromolecules are also released.

Immunoelectrophoretic study of the host antigens of Sendai virus cultivated in different substrates (embryonated hen eggs and KB cells). Note I. Analysis of chorioallantoic membrane host antigens.

The immunoelectrophhoretic analysis of two preparations of the same virus cultivated in different substrates (Sendai/egg and Sendai/KB) demonstrate that virus envelopes contain: a) identical virus-specific antigens (but also some virus antigens with only partial immunochemical identity, or even non-identity); b) antigens incorporated by the virus from the host cell, during assembly and release. The latter differ according to the host, and some of them are only partially identical with the corresponding antigens of the host cell, which suggests that host cell glycoproteins are incorporated into the virus envelope after certain virus-induced modifications.

Immunoelectrophoretic study of Sendae virus envelope antigens with hyperimmune sera prepared in different laboratory animals.

At similar HAI titers rabbit sera reveal a larger number of fractions (ten) in immunoelectrophoretic analysis of Sendai virus envelopes than do guinea pig sera, which only yield three distinct fractions. These differences are observed in both rocket and crossed immunoelectrophoresis, and are more marked in the latter. The number of fractions revealed does not differ in relation to the antigen used for hyperimmunization (intact Sendai virus, Triton-disrupted virus or envelope fractions extracted by Triton or Tween-ether). Solubilized Sendai virus envelopes obtained by Tween-ether or Triton treatment contain host antigens in their structure, the same as intact virus.

Immunoelectrophoretic investigations on Sendai virus envelope antigens in relation to host antigens.

The different antigenic fractions characteristic of egg-cultivated Sendai virus envelopes were studied by immunoelectrophoresis. Virus-specific and host-specific fractions were identified. It was proved that incorporation of the host membrane fragments into the viral envelopes is not a passive phenomenon. During the last stages of its assembly and release, the virus incorporates into the envelopes some host glycoproteins, after an active biochemical processing resulting in a considerable reduction of their molecular weight, while the host antigenic determinants remain almost unaltered.

Immunoelectrophoretic characterization of Sendai virus antigens.

Antigens extracted from Sendai virus by solubilization with Triton X-100 (Tx). Tween-20 (Tw) or Triton X-100 and SDS (Tx-SDS) were analysed by rocket, crossed and tandem immunoelectrophoresis. The migration of these antigens through 1% agarose supplemented with guinea pig anti-viral envelope protein anti-serum shows that Tx and Tw antigens consist of three fractions differing in their quantitative ratios, while Tx-SDS exhibits five different fractions. The method proved to be useful for the identification of anti-host antibodies in immune antisera by means of an antigen extracted from the chorio-allantoic membrane of embryonated hen eggs.

Photodynamic effect of toluidine blue on MM virus.

The photodynamic effect of toluidine blue (TB) was studied on MM virus cultivated in L cells and on the RNA extracted form MM virus inoculated to mice by intracerebral route. MM virus infectivity is completely inhibited by the photodynamic action of TB, due to lesions at the molecular level of the viral RNA.

Interaction between ceruloplasmin and Sendai virus envelope components. Note ii. Some characteristics of Tween 20-solubilized envelope components isolated by gel-filtration.

Biological activities of Tween 20-solubilized Sendai virus envelope differ according to the structure of the components obtained, which depends on: conditions of virus disruption, presence or absence of detergent during gel-filtration, duration of maintenance, type of fragments contained in the samples, and can be correlated neither with the size of fragments, nor with protein concentration.

Specific cleavage of Sendai virus nucleocapsid protein subunits during virus storage.

The alteration of whole Sendai virus and especially of its nucleocapsid polypeptides, during storage of the virus at 4 degree C in the allantoic fluids in which it was cultivated, has cultivated, has been studied by sodium dodecyl sulfate gel electrophoresis. During virus storage the nucleocapsid protein subunits with a molecular weight of 60,000 and the putative inner envelope protein with a molecular weight of 38,000 were mainly affected. Both virus components were partially degraded to smaller components. Examination of nucleocapsids isolated from "stored" virus showed that, in addition to the 60,000-molecular weight polypetide component, a smaller polypeptide component with a molecular weight of 46,000 appeared. The relative proportion of the small component increased with the storage period: a kind of specific conversion of large to small components occurred during storage. Since viruses kept in the absence of allantoic fluids revealed no similar modifications of their polypeptides, we concluded that a cellular component present in the allantoic fluids - very likely of enzymatic nature - is responsible for the observed cleavage of virus polypeptides.