SECRETION OF HETEROCOMPLEXES OF TICK-BORNE ENCEPHALITIS-VIRUS GLYCOPROTEIN-E AND NS1 DURING THE LATE-STAGE OF INFECTION

The heterocomplex of glycoproteins E and NS1 of tick-borne encephaliti s (TBE) virus was isolated from culture fluid of continuous SPEV (porc ine embryo kidney) cells by affinity chromatography on CL4B sepharose with immobilized monoclonal antibodies to TBE virus protein NS1. Compa rison of the TBE E-NS1 heterocomplex from culture fluid and cells show ed the predominance of secreted extracellular form. A similar TBE viru s heterocomplex E-NS1 was revealed in the blood sera of patients with TBE but not in their lymphocytes. Extracellular localization of the E- NS1 complex at the late stage of infection rules out its hypothesized participation in the replication of TBE virus. Virtual absence of the heterocomplex and presence of proteins E and NS1 in high concentration s in the cells makes the nonspecific aggregation of these proteins imp ossible. Evidently, the extracellular heterocomplex E-NS1 may react wi th virusspecific antibodies or with cytotoxic T lymphocytes.