Species Association of Hepatitis B Virus (HBV) in Non-Human Apes; Evidence for Recombination between Gorilla and Chimpanzee Variants

Hepatitis B virus (HBV) infections are widely distributed in humans, infecting approximately one third of the world's population. HBV variants have also been detected and genetically characterised from Old World apes; Gorilla gorilla (gorilla), Pan troglodytes (chimpanzee), Pongo pygmaeus (orang-utan), Nomascus nastusus and Hylobates pileatus (gibbons) and from the New World monkey, Lagothrix lagotricha (woolly monkey). To investigate species-specificity and potential for cross species transmission of HBV between sympatric species of apes (such as gorillas and chimpanzees in Central Africa) or between humans and chimpanzees or gorillas, variants of HBV infecting captive wild-born non-human primates were genetically characterised. 9 of 62 chimpanzees (11.3%) and two from 11 gorillas (18%) were HBV-infected (15% combined frequency), while other Old world monkey species were negative. Complete genome sequences were obtained from six of the infected chimpanzee and both gorillas; those from P. t .ellioti grouped with previously characterised variants from this subspecies. However, variants recovered from P. t. troglodytes HBV variants also grouped within this clade, indicative of transmission between sub-species, forming a paraphyletic clade. The two gorilla viruses were phylogenetically distinct from chimpanzee and human variants although one showed evidence for a recombination event with a P.t.e.-derived HBV variant in the partial X and core gene region. Both of these observations provide evidence for circulation of HBV between different species and sub-species of non-human primates, a conclusion that differs from the hypothesis if of strict host specificity of HBV genotypes

Characterization of a new simian immunodeficiency virus strain in a naturally infected Pan troglodytes troglodytes chimpanzee with AIDS related symptoms

<p>Abstract</p> <p>Background</p> <p>Data on the evolution of natural SIV infection in chimpanzees (SIVcpz) and on the impact of SIV on local ape populations are only available for Eastern African chimpanzee subspecies (<it>Pan troglodytes schweinfurthii</it>), and no data exist for Central chimpanzees (<it>Pan troglodytes troglodytes</it>), the natural reservoir of the ancestors of HIV-1 in humans. Here, we report a case of naturally-acquired SIVcpz infection in a <it>P.t.troglodytes </it>chimpanzee with clinical and biological data and analysis of viral evolution over the course of infection.</p> <p>Results</p> <p>A male chimpanzee (Cam155), 1.5 years, was seized in southern Cameroon in November 2003 and screened SIV positive during quarantine. Clinical follow-up and biological analyses have been performed for 7 years and showed a significant decline of CD4 counts (1,380 cells/mm³in 2004 vs 287 in 2009), a severe thrombocytopenia (130,000 cells/mm³in 2004 vs 5,000 cells/mm³in 2009), a weight loss of 21.8% from August 2009 to January 2010 (16 to 12.5 kg) and frequent periods of infections with diverse pathogens.</p> <p>DNA from PBMC, leftover from clinical follow-up samples collected in 2004 and 2009, was used to amplify overlapping fragments and sequence two full-length SIVcpz<it>Ptt</it>-Cam155 genomes. SIVcpz<it>Ptt</it>-Cam155 was phylogenetically related to other SIVcpz<it>Ptt </it>from Cameroon (SIVcpz<it>Ptt</it>-Cam13) and Gabon (SIVcpz<it>Ptt</it>-Gab1). Ten molecular clones 5 years apart, spanning the V1V4 gp120 <it>env </it>region (1,100 bp), were obtained. Analyses of the <it>env </it>region showed positive selection (dN-dS >0), intra-host length variation and extensive amino acid diversity between clones, greater in 2009. Over 5 years, N-glycosylation site frequency significantly increased (p < 0.0001).</p> <p>Conclusions</p> <p>Here, we describe for the first time the clinical history and viral evolution of a naturally SIV infected <it>P.t.troglodytes </it>chimpanzee. The findings show an increasing viral diversity over time and suggest clinical progression to an AIDS-like disease, showing that SIVcpz can be pathogenic in its host, as previously described in <it>P.t.schweinfurthii</it>. Although studying the impact of SIV infection in wild apes is difficult, efforts should be made to better characterize the pathogenicity of the ancestors of HIV-1 in their natural host and to find out whether SIV infection also plays a role in ape population decline.</p

Specimen isolation data.

<p>Specimen isolation data.</p

Tree Order Scan of HBV sequences.

<p><b>Figure 2(a)</b>. TreeOrder Scan of HBV sequences, indicating positions of individual sequences (y axis) in Phylogenetic trees generated from sequential 250-base sequence fragments, incrementing by 50 bases. Changes in sequence order as a result of changes in phylogeny at the 70% bootstrap level are shown. Sequences are colour coded by genotype and host species, as indicated by the labels in left and right margin: genotype A, purple; B, light blue; C, wine; D, emerald; E, royal blue; F, orange; G, pale green; H, navy; Gorilla, blue (Gor); Chimpanzee, green (Pan); and Woolly monkey (WM-out-group on line 1), red. For comparison the Tree Order Scan has been aligned with scale genome of HBV (top panel). Recombinant sequences are highlighted as by dashed lines; black gorilla/<i>P.t.e</i> ECO50003LIP3, green FJ798099 <i>P.t.e/P.t.t</i>, pink FJ798098 <i>P.t.e/P.t.t</i>, orange AB046525 <i>P.t.t</i> and purple AF498266 <i>P.t.s </i><b>2(b).</b> Tree Order Scan of HBV sequences, indicating positions of individual sequences (y axis) in phylogenetic trees generated from sequential 250-base sequence fragments, incrementing by 50 bases. Changes in sequence order as a result of changes in phylogeny at the 70% bootstrap level are shown. Sequences are colour coded by host species and sub-species of chimpanzee, as indicated by the labels in left and right margin: <i>Gorilla gorilla</i>, blue (Gor); <i>Pan troglodytes troglodytes</i>, yellow (<i>Ptt</i>); <i>Pan troglodytes ellioti</i>, green (<i>Pte</i>); <i>Pan troglodytes verus</i>, purple (<i>Ptv</i>); <i>Pan troglodytes schweinfurthii</i>, violet (<i>Pts</i>); and <i>Hylobates pileatus</i> (<i>Hyl</i>) (out-group-line 1-GII), red. For comparison the Tree Order Scan has been aligned with scale genome of HBV (top panel). Recombinant sequences are highlighted as by dashed lines; black gorilla/<i>P.t.e</i> ECO50003LIP3, green FJ798099 <i>P.t.e/P.t.t</i>, brown FJ798098 <i>P.t.e/P.t.t</i>, orange AB046525 <i>P.t.t</i> and blue AF498266 <i>P.t.s.</i></p

Grouping Scan analysis.

<p>Sequence fragments of 250 bases incrementing by 100 bases with 100 bootstrap replicates, were used to compare and analyse (a) <i>P.t.troglodytes/P.t.ellioti</i> recombinant FJ98098.1 (b) <i>P.t.ellioti/P.t.troglodytes</i> recombinant FJ98099.1 (c) <i>P.t.schweinfurthii</i> isolate A498266; (d) <i>P.t.troglodytes</i> AM117396 (e) <i>P.t.troglodytes</i> recombinant AB046525 (f) study recombinant <i>Gorilla gorilla</i> HBV sequence (ECO50003); to sequence groups from <i>Gorilla gorilla</i> (red), <i>Pan troglodytes ellioti</i> (blue), <i>Pan troglodytes troglodytes</i> (green), <i>Pan troglodytes verus</i> (yellow), <i>Pan troglodytes schweinfurthii</i> (purple) and human genotype HBV/C (light blue) with respect to A498266. Values >0.5 indicate clustering within the indicated group.</p