Frequent and Recent Human Acquisition of Simian Foamy Viruses Through Apes' Bites in Central Africa

Human infection by simian foamy viruses (SFV) can be acquired by persons occupationally exposed to non-human primates (NHP) or in natural settings. This study aimed at getting better knowledge on SFV transmission dynamics, risk factors for such a zoonotic infection and, searching for intra-familial dissemination and the level of peripheral blood (pro)viral loads in infected individuals. We studied 1,321 people from the general adult population (mean age 49 yrs, 640 women and 681 men) and 198 individuals, mostly men, all of whom had encountered a NHP with a resulting bite or scratch. All of these, either Pygmies (436) or Bantus (1085) live in villages in South Cameroon. A specific SFV Western blot was used and two nested PCRs (polymerase, and LTR) were done on all the positive/borderline samples by serology. In the general population, 2/1,321 (0.2%) persons were found to be infected. In the second group, 37/198 (18.6%) persons were SFV positive. They were mostly infected by apes (37/39) FV (mainly gorilla). Infection by monkey FV was less frequent (2/39). The viral origin of the amplified sequences matched with the history reported by the hunters, most of which (83%) are aged 20 to 40 years and acquired the infection during the last twenty years. The (pro)viral load in 33 individuals infected by a gorilla FV was quite low (<1 to 145 copies per 105 cells) in the peripheral blood leucocytes. Of the 30 wives and 12 children from families of FV infected persons, only one woman was seropositive in WB without subsequent viral DNA amplification. We demonstrate a high level of recent transmission of SFVs to humans in natural settings specifically following severe gorilla bites during hunting activities. The virus was found to persist over several years, with low SFV loads in infected persons. Secondary transmission remains an open question

IL-17: good fear no tears

International audienceCytokines are well-known mediators of the immune response, but, recently, pleiotropic roles in the central nervous system have started to be uncovered. It is now shown that IL-17 directly modulates fear behavior in mice

Caractérisation génétique, moléculaire et immunologique de l'infection zoonotique par le virus Foamy in vitro et in vivo (étude de la transmission rétrovirale inter-espèces)

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

A new sensitive indicator cell line reveals cross-transactivation of the viral LTR by gorilla and chimpanzee simian foamy viruses

International audienceThe majority of currently identified simian foamy virus (SFV)-infected Cameroonian and Gabonese individuals harbor SFV from the gorilla lineage. We constructed an indicator cell line for the quantification of gorilla SFVs, in which the U3 sequence of a gorilla SFV directs the expression of the β-galactosidase protein. The gorilla foamy virus activated β-galactosidase (GFAB) cells efficiently quantified two zoonotic primary gorilla isolates and SFVs from three chimpanzee subspecies. Primary gorilla SFVs replicated more slowly and at lower levels than primary chimpanzee SFVs. Analysis of previously described motifs of Tas proteins and U3 LTRs involved in viral gene synthesis revealed conservation of such motifs in Tas proteins from gorilla and chimpanzee SFVs, but little sequence homology in the LTR regions previously shown to interact with viral and cellular factors

A new sensitive indicator cell line reveals cross-transactivation of the viral LTR by gorilla and chimpanzee simian foamy viruses

International audienceThe majority of currently identified simian foamy virus (SFV)-infected Cameroonian and Gabonese individuals harbor SFV from the gorilla lineage. We constructed an indicator cell line for the quantification of gorilla SFVs, in which the U3 sequence of a gorilla SFV directs the expression of the β-galactosidase protein. The gorilla foamy virus activated β-galactosidase (GFAB) cells efficiently quantified two zoonotic primary gorilla isolates and SFVs from three chimpanzee subspecies. Primary gorilla SFVs replicated more slowly and at lower levels than primary chimpanzee SFVs. Analysis of previously described motifs of Tas proteins and U3 LTRs involved in viral gene synthesis revealed conservation of such motifs in Tas proteins from gorilla and chimpanzee SFVs, but little sequence homology in the LTR regions previously shown to interact with viral and cellular factors

Latency, tropism and genetic variation of Simian Foamy Virus in blood and saliva from infected Humans

International audienceSimian foamy viruses (SFV) are widespread retroviruses among non-human primates (NHP). SFV actively replicate in the oral cavity of NHP and can be transmitted to humans through NHP bites, in whom they establish a persistent infection. We aimed to study three major properties of these zoonotic retroviruses: replicative status, tropism and variability. In 14 hunters from Cameroon previously shown to be infected with a gorilla SFV strain, viral DNA could be detected by quantitative polymerase chain reaction in most samples of peripheral blood mononuclear cells (PBMCs) and saliva. The SFV DNA levels were 7.1±6.0 SFV DNA copies/105 cells in PBMCs and 2.4±4.3 SFV DNA copies/105 cells in saliva. In contrast, no SFV RNA was detected by qRT-PCR in either PBMCs or saliva. PBMCs populations (T4, T8, B, NK lymphocytes and monocytes) were sorted with magnetic beads before quantification of SFV DNA. Our preliminary results showed the presence of SFV DNA in all PBMCs populations at different levels. We finally assessed the viral diversity in vivo. Although intra-individual SFV genetic variation was low (<0,5%) we detected some viral diversity in 3 out of 9 individuals. In one subject, genetic variation might be associated with coinfection with 2 SFV strains, while in the two other subjects, variations seemed to derive from APOBEC3 editing with a high rate of G-to-A substitutions. Our study demonstrates that SFV infection is mostly latent in PBMCs and in saliva. Such a scenario may explain the putative lack of secondary human-to-human transmissions of SFV

Epidemiological and “classical” biological features of SFV infected humans in contact group and general population.

<p>Pop: population. Loc: location. Cont: contact. Samp: sampling. SFV: Simian Foamy Virus. LTR: Long Terminal Repeat. Gor: Gorilla. Cpz: Chimpanzee. Cerco: <i>Cercopithecus</i>/ Ind: Indeterminate/ +: Positive/ −: Negative/ ND: Not determined for Chimpanzees and small monkeys infected individuals. Wound severity: 1 = low, 2 = medium, 3 = high.</p><p>◊: sampled twice and tested two times for serology and PCR/.</p><p>‡: family members also tested (spouse and/or children).</p><p>Δ: LTR was sequenced and blasted. In all cases, correspondence was found with the history.</p><p>Φ: (pro)viral loads are reported per 10⁵ cells.</p><p>Ψ: No Integrase sequence obtained.</p