[Isolation of a cellular receptor for tick-borne encephalitis virus using anti-idiotypic antibodies].

Cell surface receptors for tick-borne encephalitis (TBE) virus are proposed to be identified by affinity chromatography with polyclonal antiidiotypic antibodies (AIA) as antireceptor antibodies. A single affinity chromatography procedure permitted us to obtain 33-150 times purified cell surface receptor from human embryonic renal cell membranes. Four polypeptides with molecular weight 43, 67, 110, and 210 kD were detected in highly purified fractions of TBE virus cell surface receptor. Antireceptor antibodies reacted in immunoblotting only with the 67 kD polypeptide. The molecular weight of protein p67 suggests that it is the nonintegrin laminin receptor. Monoclonal antibodies 8E3 to beta 1-chain of human integrin and M-KID2 to alpha 3 beta 1-integrin reacted in enzyme immunoassay and spot analysis with purified cell surface receptor for TBE virus. The molecular weight of beta 1-chain of human integrin is 110 kD. Probably, the 210 kD polypeptide is an alpha 3-chain of human integrin. Laminin serves as the ligand for alpha 3 beta 1-integrin and laminin receptor, which can be the structural basis for joint isolation of these molecules from lysates of RH cell membranes in a column with immobilized antireceptor antibodies. The role of p43 protein is not clear. Identification of two laminin-binding protein molecules by means of antireceptor antibodies permits us to propose that laminin-binding sites of human alpha 3 beta 1-integrin and laminin receptor can ensure the receptor interactions between TBE virions and RH cells.