ELECTRON-MICROSCOPIC OBSERVATION OF A BRAZILIAN HTLV-I ISOLATED

Several studies carried out in Brazil have shown a high incidence of H TLV-I infection among the general population and in different groups, such as blood donors, hemophiliacs, hematological and neurological pat ients. Cases of adult T-cell leukemia/lymphoma as well as tropical spa stic paraparesis/HTLV-I associated myelopathy have already been descri bed. Therefore, it is important to characterize Brazilian HTLV strains using different technical approaches. The purpose of this paper is to characterize and recognize HTLV particles employing routine and immun oelectron microscopy in lymphocyte cocultures. Ultrastructural analysi s showed typical large and small virus particles in close relation wit h the lymphocyte membrane. Immunoelectron microscopy, carried out with HTLV positive sera, allowed the identification of the virus as a type C oncovirus, group HTLV-BLV. The first interaction events between vir us and lymphocyte membrane have also been analysed and structures rela ted to the endocytic route for HTLV entrance were pointed out.