Detection, Cloning, Molecular Characterization and Phylogenic Analyses of a New Primate T-Cell Lymphotropic Virus Type I in Olive Baboon

Abstract

Infection with Human T-cell Lymphotropic Virus Type I (HTLV-I) is a global health problem, affecting 10 to 20<br />million people around the world, including north-east of Iran. It has been recognized to be the etiologic agent of adult T-cell Leukemia and HTLV-I-associated Myelopathy. In both cases, the HTLV-I transactivator<br />protein (Tax), plays crucial role. Monkeys are suitable host for a related virus called STLV, which together<br />with HTLV are called Primate T-cell Lymphotropic Viruses (PTLVs). Primates are the only known hosts, in<br />addition to human, to be able to develop malignant changes in the natural course of infection with PTLV-I<br />and therefore, could be a valuable animal model for studies on this virus. In the present study, we report<br />PCR-based detection and cloning of 1.8 kb pX region of a new PTLV in olive baboon (Papio anubis).<br />Sequence alignments and phylogenic studies on nucleotide sequence of this region and amino acids of<br />conceptually translated Tax protein showed that monkeys are infected with a PTLV much closer to HTLV-I<br />sub-types a and b, rather than STLV-I. Moreover, analyses of its Tax protein suggest that it might have<br />the same function as HTLV-I Tax proteins. Results of our study indicate the possibility of exploiting these<br />baboons as an animal model of choice for evaluating a tax-based DNA vaccine to decrease the viral load of<br />HTLV-I in carriers , in order to prevent the outcomes, as well as they may be utilized for other HTLV-I physiopathologic or therapeutic studies.