Rabies virus cross-reactive murine T cell clones: analysis of helper and delayed-type hypersensitivity function.

Three T cell clones derived from rabies virus-immunized BALB/c mice were analysed for specificity and function. The clones proved to be broadly cross-reactive by responding to different rabies virus isolates (PM, ERA, CVS, HEP) and other representatives of the genus Lyssavirus, like the Duvenhage-6 (DUV6) and Mokola (MOK) viruses. The clones detected three different epitopes: an epitope expressed on the matrix protein (M) shared by PM, HEP, MOK and DUV6 viruses (clone AA8), an epitope expressed on the M-protein shared by PM, ERA, CVS, HEP and MOK viruses (clone 35A) and finally an epitope expressed on the glycoprotein (G-protein) shared by PM, ERA, CVS, HEP and MOK viruses (clone BG2). Antigen recognition of all clones proved to be MHC-restricted and they all displayed the CD4+ CD8- phenotype. Intravenous inoculation of the T cells in syngeneic mice, which had been injected intracutaneously in the ear with HEP virus, resulted in a localized DTH reaction characteristic for TH1 cells. In vitro, the clones were able to provide help to rabies virus-primed B cells, resulting in the production of virus-specific antibodies directed against all the four structural proteins of rabies virus. Further analysis of this antibody response revealed that part of it was directed against antigenic determinants of the G-protein which induce virus neutralizing antibody.

Antibodies to Bordetella pertussis adenylate cyclase are produced in man during pertussis infection and after vaccination.

Bordetella pertussis produces several potential virulence factors. One of these is an adenylate cyclase which penetrates eukaryotic cells, is activated by calmodulin and generates high levels of intracellular cAMP. We have found that pertussis infection in man leads to production of high titres (2000-8000) of anti-B. pertussis adenylate cyclase antibodies. Such antibodies also are produced after pertussis vaccination. They persist into adulthood, cross the placenta and disappear a few months after birth. The anti-adenylate cyclase antibodies found in human serum during pertussis infection do not neutralise the catalytic and penetrative activities of the enzyme.

Rabies virus-specific human T cell clones provide help for an in vitro antibody response against neutralizing antibody-inducing determinants of the viral glycoprotein.

Human T cell clones were prepared from peripheral blood mononuclear cells from a vaccinated human donor and kept in culture in the presence of rabies virus antigen and growth factors. Phenotypic analysis of the T cell clones revealed expression of the CD3 and CD4 cell surface markers, but not of CD8, consistent with a phenotype of helper/inducer T cells. The rabies virus specificity of the T cell clones was established by virus-specific proliferation in response to the rabies virus Pitman-Moore strain (PM) produced in three different cell substrates. The clones also responded to the rabies virus strains Evelyn-Rokitnicki-Abelseth (ERA) and challenge virus standard (CVS), but not to the rabies virus-related Mokola and Duvenhage-6 virus strains. Proliferative responses of T cell clones required rabies virus antigen to be presented by autologous antigen-presenting cells in association with HLA class II molecules. When cultured with rabies virus antigen, but in the absence of growth factors, some of the T cell clones provided help for an antibody response of rabies virus immune B lymphocytes. Analysis of culture supernatant fluids showed that at least a part of this antibody response was directed against neutralizing antibody-inducing determinants of the viral glycoprotein.