Tumor escape mechanisms from immunosurveillance: induction of unresponsiveness in a specific MHC-restricted CD4+ human T cell clone by the autologous MHC class II+ melanoma.

The co-existence of tumor specific immunity with a progressing tumor is observed in a variety of experimental systems and remains one of the major paradoxes of tumor immunology. We now report that a human melanoma cell line (SMC) expressing MHC class II was able to induce clonal anergy in a specific, MHC-restricted CD4+ T cell clone (STC3). Clonal anergy is a mechanism of T lymphocyte tolerance induced by antigen receptor stimulation in the absence of co-stimulation.

[Congenital "ectromelia" in fur-bearing animals caused by Orthopoxvirus muris].

Orthopox virus infection is endemic in farms with fur-bearing animals in the Czech Republic (Bohemia and Moravia). This disease is called ectromelia of silver foxes and minks. The infection is congenitally transmitted and manifests itself in reproductive disorders, stillbirth or birth of sick neonates.

A rapid antigen capture ELISA for the detection of orthopox viruses.

A genus-specific antigen capture enzyme-linked immunosorbent assay (ELISA) for the detection orthopox viruses (OPV) was established, testing various combinations of monoclonal antibodies (MAbs) and rabbit hyper-immune sera. The most sensitive assay was based on capturing antigen with a non-neutralizing MAb against a highly conserved antigenic site of the OPV fusion protein. Bound antigen was detected by a mixture of the two broadly-reactive rabbit anti-monkey-pox- and rabbit anti-vaccinia virus hyper-immune sera.

Investigation of living cells in the nanometer regime with the scanning force microscope.

Membrane structures of different types of cells are imaged in the nanometer regime by scanning force microscopy (SFM). The images are compared to those obtained with a scanning electron microscope (SEM). The SFM imaging can be done on the outer cell membrane under conditions that keep the cells alive in aqueous solutions.

[Magnetic resonance tomography in pulmonary hypertension].

We examined 23 patients with pulmonary hypertension of varying aetiology by MRI and compared the results with those of right heart catheterisation. The best correlation was obtained between right ventricular mural thickness and mean pulmonary pressure (R = 0.91, p = 0.

Immunohistological detection of orthopox virus antigen.

This paper describes the immunohistochemical staining of orthopox virus (OPV) antigen in liver tissue of experimentally infected mice and in cell cultures. Using two different monoclonal antibodies, virus detection was achieved in cryostat-, but not in paraffin-sections.

Animal poxviruses transmitted from cat to man: current event with lethal end.

We report about the infection of an 18-year-old man with an orthopox virus (OPV) which was transmitted by a cat. The infectious route from cat to man could be proved by epidemiological, virological and serological methods. The corresponding techniques are described.

Structural and functional analysis of orthopoxvirus epitopes with neutralizing monoclonal antibodies.

Neutralizing monoclonal antibodies (MAbs) were produced in BALB/c mice immunized with live modified vaccinia virus Ankara or infected with sublethal doses of the neurovirulent vaccinia virus strain Munich 1. The immunization scheme proved to be important for obtaining MAbs of different specificity. The MAbs could be classified into three epitope groups (1 A, 1 B and 2).

[Recent information about the orf virus of small ruminants].

New scientific findings in the field of immunobiology and diagnosis of parapoxvirus ovis (Orf-virus) as the causal agent of a zoonosis are presented. The adaptation of Orf-virus to cell lines and its in vitro multiplication without difficulties offer the possibility for extensive studies into the biology of parapoxviruses. The development of monoclonal antibodies (MAB) against an attenuated Orf-virus strain (D-1701) led to the elaboration of a simplified, cheap and highly sensitive "antigen detection ELISA" as a diagnostic tool.

Establishment of an ELISA for the detection of orthopox viruses based on neutralizing monoclonal and polyclonal antibodies.

Various combinations of polyclonal and neutralizing monoclonal antibodies (MAbs) of distinct specificity were evaluated as capture or detecting antibodies in an orthopox virus antigen ELISA. Acceptable results were achieved in an assay based on polyclonal antibodies. A 10 times higher sensitivity, however, was obtained using a combination of one monoclonal catching antibody reactive with viral envelope epitopes and polyclonal detection antibodies.

Characterization of monoclonal and polyclonal antibodies to bovine enteric coronavirus: establishment of an efficient ELISA for antigen detection in feces.

Monoclonal antibodies to bovine enteric coronavirus (BEC) were produced. Additionally, polyclonal antibodies were made in rabbits and guinea pigs and extracted from the yolk of immunized hens. The antibodies were characterized by neutralization test, hemagglutination inhibition test, enzyme-linked immunosorbent assay (ELISA) and immunoblotting.

[The detection and identification of poxvirus in domestic cats].

Two cases in Southern Germany of pox in cats could be diagnosed virologically. A cowpox-like virus was isolated, its biological and serological characteristics defined. The source of infection could not be traced.

[Testing the immunity to orthopoxviruses in the white mouse with vaccinia virus].

An infection model was developed, which allows the study of humoral and cellular immune response mechanisms induced by Orthopox viruses in mice. The optimal infection route for neurovirulent vaccinia virus strains was investigated and resulted in well-defined clinical symptoms in non-immunized susceptible mice. Signs of disease were taken as a basis for comparison.

[Experimental detection of the paraspecific effects of purified and inactivated poxviruses].

The paraspecific effect of pox viruses i.e. stimulation of the nonspecific part of the complex immune system, was demonstrated in vitro and in vivo for 3 different types of virus (vaccinia virus, avipox virus, parapox virus).