Molecular cloning of a unique human T-cell leukemia virus (HTLV-IIMo)

Human T-cell leukemia virus IIMo (HTLV-IIMo) is a human retrovirus isolated from a patient with a T-cell hairy cell leukemia. This virus has been shown to have core protein (gag) antigens similar to, but distinct from, those of all known isolates of the prototype human T-cell leukemia virus (HTLV-I). We have used a subgenomic clone of the HTLV-I env-pX region to detect and characterize HTLV-IIMo proviral sequences by performing Southern blot hybridization under conditions of low stringency. Using the HTLV-I probe, we cloned a partial integrated HTLV-IIMo provirus from a genomic library of the producer Mo cell line. These sequences could be characterized by low stringency hybridization with different subgenomic clones of HTLV-I. An HTLV-IIMo-specific subclone was made by isolating a 3.6-kilobase BamHI fragment of the partial provirus. This was used to clone two full-length integrated viral genomes. Using the HTLV-IIMo viral probe, we also showed by hybridization under stringent conditions to DNA and RNA of various infected and uninfected cell lines that these HTLV-IIMo sequences are unique.