Genome-wide analyses of HTLV-1aD strains from Cape Verde, Africa

Abstract

We characterised and reported the first full-length genomes of Human T-cell Lymphotropic Virus Type 1 subgroup HTLV-1aD (CV21 and CV79). This subgroup is one of the major determinants of HTLV-1 infections in North and West Africa, and recombinant strains involving this subgroup have been recently demonstrated. The CV21 and CV79 strains from Cape Verde/Africa were characterised as pure HTLV-1aD genomes, comparative analyses including HTLV-1 subtypes and subgroups revealed HTLV-1aD signatures in the envelope, pol, and pX regions. These genomes provide original information that will contribute to further studies on HTLV-1a epidemiology and evolution.

Phylogenetic dating analysis of HTLV-1 from Chile suggests transmissions events related to ancient migrations and contemporary expansion

“…The origin of HTLV-1 in the Americas was initially believed to be exclusively due to the Africa slave trade (Gessain et al, 1985), but several studies have shown phylogenetic evidence that HTLV-1 arrived in the Americas from another source too: via ancestral migration of humans infected with HTLV across the Bering Strait (Amoussa et al, 2017;Zanella et al, 2016;Neva et al, 1998;Salemi et al, 2000). These results suggest that both events occurred during the introduction of HTLV-1aA into Chile during expansion of the Amerindian people and European colonization of South America.…”

“…Regarding the samples, the procedures of DNA extraction from the blood samples and PCR amplification of LTR were performed according to previously described protocols (Zanella et al, 2016). This amplicon was then sequenced by the Sanger method in Macrogen Inc. (https://dna.macrogen.com) and the LTR sequence Chi_Ara was subsequently registered in the GenBank under the accession number MT434683.…”

Re-emergence of human T-lymphotropic viruses in West Africa

“…Full length genome characterization of the identified HTLV-1 isolates revealed them to belong to the HTLV-1aD subgroup. 66 No other study is available on HTLV presence and/or prevalence in the Cabo Verdean population.…”