The complex of flavivirus envelope polypeptide with meningococcal proteosomes elicits formation of virus-neutralizing antibodies.

Polypeptide E of tick-borne encephalitis virus was isolated in sucrose density gradient and mixed with equal weight portion of meningococcal proteosomes in the presence of N-dodecyl-N,N-dimethylglycine. Mutual complexing of viral and bacterial molecules occurred after removal of detergent by dialysis. Complexed particles appeared in the electron microscope as 40-50 microns thick short-rod structures covered on their surface with both, delicate poppy-like grains, or envelope subunit-like clustered molecules. Even when applied without adjuvant, the complex of tick-borne encephalitis virus polypeptide E with meningococcal proteosomes elicited in mice a marked antiviral as well as antibacterial humoral response.