Discovery of a new human T-cell lymphotropic virus (HTLV-3) in Central Africa

Human T-cell Leukemia virus type 1 (HTLV-1) and type 2 (HTLV-2) are pathogenic retroviruses that infect humans and cause severe hematological and neurological diseases. Both viruses have simian counterparts (STLV-1 and STLV-2). STLV-3 belongs to a third group of lymphotropic viruses which infect numerous African monkeys species. Among 240 Cameroonian plasma tested for the presence of HTLV-1 and/or HTLV-2 antibodies, 48 scored positive by immunofluorescence. Among those, 27 had indeterminate western-blot pattern. PCR amplification of pol and tax regions, using HTLV-1, -2 and STLV-3 highly conserved primers, demonstrated the presence of a new human retrovirus in one DNA sample. tax (180 bp) and pol (318 bp) phylogenetic analyses demonstrated the strong relationships between the novel human strain (Pyl43) and STLV-3 isolates from Cameroon. The virus, that we tentatively named HTLV-3, originated from a 62 years old Bakola Pygmy living in a remote settlement in the rain forest of Southern Cameroon. The plasma was reactive on MT2 cells but was negative on C19 cells. The HTLV 2.4 western-blot exhibited a strong reactivity to p19 and a faint one to MTA-1. On the INNO-LIA strip, it reacted faintly with the generic p19 (I/II), but strongly to the generic gp46 (I/II) and to the specific HTLV-2 gp46. The molecular relationships between Pyl43 and STLV-3 are thus not paralleled by the serological results, as most of the STLV-3 infected monkeys have an "HTLV-2 like" WB pattern. In the context of the multiple interspecies transmissions which occurred in the past, and led to the present-day distribution of the PTLV-1, it is thus very tempting to speculate that this newly discovered human retrovirus HTLV-3 might be widespread, at least in the African continent

Novel Human Herpesvirus 8 Subtype D Strains in Vanuatu, Melanesia

We show human herpesvirus 8 with diverse molecular subtype D variants to be highly endemic among the Ni-Vanuatu population. Most K1 genes were nearly identical to Polynesian strains, although a few clustered with Australian or Taiwanese strains. These results suggest diverse origins of the Ni-Vanuatu population and raise questions about the ancient human population movements in Melanesia

Novel γ-2-Herpesvirus of the Rhadinovirus 2 Lineage in Gibbons

We obtained 475 nucleotides of the DNA polymerase gene of a novel human herpesvirus 8 homolog sequence in a gibbon. The finding of this new gibbon virus, which clusters with a related chimpanzee virus in the rhadinovirus 2 genogroup, suggests the existence of a novel γ-2-herpesvirus in humans

Herpèsvirus Humain 8 (épidémiologie moléculaire et analyse de la clonalité virale et cellulaire des pathologies associés)

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Vibration of effects from diverse inclusion/exclusion criteria and analytical choices 9216 different ways to perform an indirect comparison meta-analysis

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Human T-Cell Lymphotropic Virus Type 3: Complete Nucleotide Sequence and Characterization of the Human Tax3 Protein

We and others have recently uncovered the existence of human T-cell lymphotropic virus type 3 (HTLV-3), the third member of the HTLV family. We have now sequenced the full-length HTLV-3(Pyl43) provirus. As expected, HTLV-3(Pyl43) contains open reading frames corresponding to the gag, pol, env, tax, and rex genes. Interestingly, its long terminal repeat (LTR) includes only two Tax-responsive elements, as is the case for type 3 simian T-cell lymphotropic viruses (STLV-3). Phylogenetic analyses reveal that HTLV-3(Pyl43) is closely related to central African STLV-3. Unexpectedly, the proximal pX region of HTLV-3(Pyl43) lacks 366 bp compared to its STLV-3 counterpart. Because of this deletion, the previously described RorfII sequence is lacking. At the amino acid level, Tax3(Pyl43) displays strong similarities with HTLV-1 Tax, including the sequence of a PDZ class I binding motif. In transient-transfection assays, Tax3(Pyl43) activates the transcriptions from HTLV-3, HTLV-1, and HTLV-2 LTRs. Mutational analysis indicates that two functional domains (M22 and M47) important for transactivation through the CREB/ATF or NF-κB pathway are similar but not identical in Tax1 and Tax3(Pyl43). We also show that Tax3(Pyl43) transactivates the human interleukin-8 and Bcl-X(L) promoters through the induction of the NF-κB pathway. On the other hand, Tax3(Pyl43) represses the transcriptional activity of the p53 tumor suppressor protein as well as the c-Myb promoter. Altogether, these results demonstrate that although HTLV-3 and HTLV-1 have only 60% identity, Tax3(Pyl43) is functionally closely related to the transforming protein Tax1 and suggest that HTLV-3, like HTLV-1, might be pathogenic in vivo

Extracavitary tumor after primary effusion lymphoma: relapse or second distinct lymphoma?

International audienceHHV-8-associated solid lymphomas which develop in extracavitary sites during the course of primary effusion lymphoma (PEL) could represent the relapse of original PEL tumors in different anatomical sites, or newly occurring distinct HHV-8-associated lymphomas, such as multicentric Castleman disease-related microlymphomas. HHV-8 episome clonality might help identify which event takes place

Cutaneous disseminated endemic Kaposi's sarcoma in a Polynesian man infected with a new divergent human herpesvirus 8 subtype D

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