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Loy DE, Liu W, Li Y, Learn GH, Plenderleith LJ, Sundararaman SA, Sharp PM, Hahn BH. Out of Africa: origins and evolution of the human malaria parasites Plasmodium falciparum and Plasmodium vivax. Int J Parasitol 2016; 47:87-97. [PMID: 27381764 DOI: 10.1016/j.ijpara.2016.05.008] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 05/25/2016] [Accepted: 05/28/2016] [Indexed: 12/22/2022]
Abstract
Plasmodium falciparum and Plasmodium vivax account for more than 95% of all human malaria infections, and thus pose a serious public health challenge. To control and potentially eliminate these pathogens, it is important to understand their origins and evolutionary history. Until recently, it was widely believed that P. falciparum had co-evolved with humans (and our ancestors) over millions of years, whilst P. vivax was assumed to have emerged in southeastern Asia following the cross-species transmission of a parasite from a macaque. However, the discovery of a multitude of Plasmodium spp. in chimpanzees and gorillas has refuted these theories and instead revealed that both P. falciparum and P. vivax evolved from parasites infecting wild-living African apes. It is now clear that P. falciparum resulted from a recent cross-species transmission of a parasite from a gorilla, whilst P. vivax emerged from an ancestral stock of parasites that infected chimpanzees, gorillas and humans in Africa, until the spread of the protective Duffy-negative mutation eliminated P. vivax from human populations there. Although many questions remain concerning the biology and zoonotic potential of the P. falciparum- and P. vivax-like parasites infecting apes, comparative genomics, coupled with functional parasite and vector studies, are likely to yield new insights into ape Plasmodium transmission and pathogenesis that are relevant to the treatment and prevention of human malaria.
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Cadena C, Stavrou S, Manzoni T, Iyer SS, Bibollet-Ruche F, Zhang W, Hahn BH, Browne EP, Ross SR. The effect of HIV-1 Vif polymorphisms on A3G anti-viral activity in an in vivo mouse model. Retrovirology 2016; 13:45. [PMID: 27363431 PMCID: PMC4929759 DOI: 10.1186/s12977-016-0280-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 06/22/2016] [Indexed: 11/10/2022] Open
Abstract
Humans encode seven APOBEC3 proteins (A-H), with A3G, 3F and 3H as the major factors restricting HIV-1 replication. HIV-1, however, encodes Vif, which counteracts A3 proteins by chaperoning them to the proteasome where they are degraded. Vif polymorphisms found in HIV-1s isolated from infected patients have varying anti-A3G potency when assayed in vitro, but there are few studies demonstrating this in in vivo models. Here, we created Friend murine leukemia viruses encoding vif alleles that were previously shown to differentially neutralize A3G in cell culture or that were originally found in primary HIV-1 isolates. Infection of transgenic mice expressing different levels of human A3G showed that these naturally occurring Vif variants differed in their ability to counteract A3G during in vivo infection, although the effects on viral replication were not identical to those seen in cultured cells. We also found that the polymorphic Vifs that attenuated viral replication reverted to wild type only in A3G transgenic mice. Finally, we found that the level of A3G-mediated deamination was inversely correlated with the level of viral replication. This animal model should be useful for studying the functional significance of naturally occurring vif polymorphisms, as well as viral evolution in the presence of A3G.
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103
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Li H, Wang S, Kong R, Ding W, Lee FH, Parker Z, Kim E, Learn GH, Hahn P, Policicchio B, Brocca-Cofano E, Deleage C, Hao X, Chuang GY, Gorman J, Gardner M, Lewis MG, Hatziioannou T, Santra S, Apetrei C, Pandrea I, Alam SM, Liao HX, Shen X, Tomaras GD, Farzan M, Chertova E, Keele BF, Estes JD, Lifson JD, Doms RW, Montefiori DC, Haynes BF, Sodroski JG, Kwong PD, Hahn BH, Shaw GM. Envelope residue 375 substitutions in simian-human immunodeficiency viruses enhance CD4 binding and replication in rhesus macaques. Proc Natl Acad Sci U S A 2016; 113:E3413-22. [PMID: 27247400 PMCID: PMC4914158 DOI: 10.1073/pnas.1606636113] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Most simian-human immunodeficiency viruses (SHIVs) bearing envelope (Env) glycoproteins from primary HIV-1 strains fail to infect rhesus macaques (RMs). We hypothesized that inefficient Env binding to rhesus CD4 (rhCD4) limits virus entry and replication and could be enhanced by substituting naturally occurring simian immunodeficiency virus Env residues at position 375, which resides at a critical location in the CD4-binding pocket and is under strong positive evolutionary pressure across the broad spectrum of primate lentiviruses. SHIVs containing primary or transmitted/founder HIV-1 subtype A, B, C, or D Envs with genotypic variants at residue 375 were constructed and analyzed in vitro and in vivo. Bulky hydrophobic or basic amino acids substituted for serine-375 enhanced Env affinity for rhCD4, virus entry into cells bearing rhCD4, and virus replication in primary rhCD4 T cells without appreciably affecting antigenicity or antibody-mediated neutralization sensitivity. Twenty-four RMs inoculated with subtype A, B, C, or D SHIVs all became productively infected with different Env375 variants-S, M, Y, H, W, or F-that were differentially selected in different Env backbones. Notably, SHIVs replicated persistently at titers comparable to HIV-1 in humans and elicited autologous neutralizing antibody responses typical of HIV-1. Seven animals succumbed to AIDS. These findings identify Env-rhCD4 binding as a critical determinant for productive SHIV infection in RMs and validate a novel and generalizable strategy for constructing SHIVs with Env glycoproteins of interest, including those that in humans elicit broadly neutralizing antibodies or bind particular Ig germ-line B-cell receptors.
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104
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Moody MA, Gao F, Gurley TC, Amos JD, Kumar A, Hora B, Marshall DJ, Whitesides JF, Xia SM, Parks R, Lloyd KE, Hwang KK, Lu X, Bonsignori M, Finzi A, Vandergrift NA, Alam SM, Ferrari G, Shen X, Tomaras GD, Kamanga G, Cohen MS, Sam NE, Kapiga S, Gray ES, Tumba NL, Morris L, Zolla-Pazner S, Gorny MK, Mascola JR, Hahn BH, Shaw GM, Sodroski JG, Liao HX, Montefiori DC, Hraber PT, Korber BT, Haynes BF. Strain-Specific V3 and CD4 Binding Site Autologous HIV-1 Neutralizing Antibodies Select Neutralization-Resistant Viruses. Cell Host Microbe 2016; 18:354-62. [PMID: 26355218 DOI: 10.1016/j.chom.2015.08.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 04/14/2015] [Accepted: 08/14/2015] [Indexed: 11/19/2022]
Abstract
The third variable (V3) loop and the CD4 binding site (CD4bs) of the HIV-1 envelope are frequently targeted by neutralizing antibodies (nAbs) in infected individuals. In chronic infection, HIV-1 escape mutants repopulate the plasma, and V3 and CD4bs nAbs emerge that can neutralize heterologous tier 1 easy-to-neutralize but not tier 2 difficult-to-neutralize HIV-1 isolates. However, neutralization sensitivity of autologous plasma viruses to this type of nAb response has not been studied. We describe the development and evolution in vivo of antibodies distinguished by their target specificity for V3 and CD4bs epitopes on autologous tier 2 viruses but not on heterologous tier 2 viruses. A surprisingly high fraction of autologous circulating viruses was sensitive to these antibodies. These findings demonstrate a role for V3 and CD4bs antibodies in constraining the native envelope trimer in vivo to a neutralization-resistant phenotype, explaining why HIV-1 transmission generally occurs by tier 2 neutralization-resistant viruses.
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105
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Ahuka-Mundeke S, Lunguya-Metila O, Mbenzo-Abokome V, Butel C, Inogwabini BI, Omasombo V, Muyembe-Tamfum JJ, Georgiev AV, Muller MN, Ndjango JBN, Li Y, Delaporte E, Hahn BH, Peeters M, Ayouba A. Genetic diversity of STLV-2 and interspecies transmission of STLV-3 in wild-living bonobos. Virus Evol 2016; 2:vew011. [PMID: 27774304 PMCID: PMC4900509 DOI: 10.1093/ve/vew011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
There are currently four known primate T-cell lymphotropic virus groups (PTLV1-4), each of which comprises closely related simian (STLV) and human (HTLV) viruses. For PTLV-1 and PTLV-3, simian and human viruses are interspersed, suggesting multiple cross-species transmission events; however, for PTLV-2 this is not so clear because HTLV-2 and STLV-2 strains from captive bonobos (Pan paniscus) form two distinct clades. To determine to what extent bonobos are naturally infected with STLV, we screened fecal samples (n = 633) from wild-living bonobos (n = 312) at six different sites in the Democratic Republic of Congo (DRC) for the presence of STLV nucleic acids. STLV infection was detected in 8 of 312 bonobos at four of six field sites, suggesting an overall prevalence of 2.6% (ranging from 0 to 8%). Six samples contained STLV-2, while the two others contained STLV-3, as determined by phylogenetic analysis of partial tax and Long Terminal Repeats (LTR) sequences. The new STLV-2 sequences were highly diverse, but grouped with previously identified STLV-2 strains as a sister clade to HTLV-2. In contrast, the new STLV-3 sequences did not cluster together, but were more closely related to STLVs from sympatric monkey species. These results show for the first time that fecal samples can be used to detect STLV infection in apes. These results also show that wild-living bonobos are endemically infected with STLV-2, but have acquired STLV-3 on at least two occasions most likely by cross-species transmission from monkey species on which they prey. Future studies of bonobos and other non-human primate species in Central Africa are needed to identify the simian precursor of HTLV-2 in humans.
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106
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Apps R, Del Prete GQ, Chatterjee P, Lara A, Brumme ZL, Brockman MA, Neil S, Pickering S, Schneider DK, Piechocka-Trocha A, Walker BD, Thomas R, Shaw GM, Hahn BH, Keele BF, Lifson JD, Carrington M. HIV-1 Vpu Mediates HLA-C Downregulation. Cell Host Microbe 2016; 19:686-95. [PMID: 27173934 PMCID: PMC4904791 DOI: 10.1016/j.chom.2016.04.005] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 03/08/2016] [Accepted: 04/05/2016] [Indexed: 12/31/2022]
Abstract
Many pathogens evade cytotoxic T lymphocytes (CTLs) by downregulating HLA molecules on infected cells, but the loss of HLA can trigger NK cell-mediated lysis. HIV-1 is thought to subvert CTLs while preserving NK cell inhibition by Nef-mediated downregulation of HLA-A and -B but not HLA-C molecules. We find that HLA-C is downregulated by most primary HIV-1 clones, including transmitted founder viruses, in contrast to the laboratory-adapted NL4-3 virus. HLA-C reduction is mediated by viral Vpu and reduces the ability of HLA-C restricted CTLs to suppress viral replication in CD4+ cells in vitro. HLA-A/B are unaffected by Vpu, and primary HIV-1 clones vary in their ability to downregulate HLA-C, possibly in response to whether CTLs or NK cells dominate immune pressure through HLA-C. HIV-2 also suppresses HLA-C expression through distinct mechanisms, underscoring the immune pressure HLA-C exerts on HIV. This viral immune evasion casts new light on the roles of CTLs and NK cells in immune responses against HIV.
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107
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Schoofs T, Klein F, Braunschweig M, Kreider EF, Feldmann A, Nogueira L, Oliveira T, Lorenzi JCC, Parrish EH, Learn GH, West AP, Bjorkman PJ, Schlesinger SJ, Seaman MS, Czartoski J, McElrath MJ, Pfeifer N, Hahn BH, Caskey M, Nussenzweig MC. HIV-1 therapy with monoclonal antibody 3BNC117 elicits host immune responses against HIV-1. Science 2016; 352:997-1001. [PMID: 27199429 DOI: 10.1126/science.aaf0972] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 04/14/2016] [Indexed: 01/07/2023]
Abstract
3BNC117 is a broad and potent neutralizing antibody to HIV-1 that targets the CD4 binding site on the viral envelope spike. When administered passively, this antibody can prevent infection in animal models and suppress viremia in HIV-1-infected individuals. Here we report that HIV-1 immunotherapy with a single injection of 3BNC117 affects host antibody responses in viremic individuals. In comparison to untreated controls that showed little change in their neutralizing activity over a 6-month period, 3BNC117 infusion significantly improved neutralizing responses to heterologous tier 2 viruses in nearly all study participants. We conclude that 3BNC117-mediated immunotherapy enhances host humoral immunity to HIV-1.
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108
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Bonsignori M, Zhou T, Sheng Z, Chen L, Gao F, Joyce MG, Ozorowski G, Chuang GY, Schramm CA, Wiehe K, Alam SM, Bradley T, Gladden MA, Hwang KK, Iyengar S, Kumar A, Lu X, Luo K, Mangiapani MC, Parks RJ, Song H, Acharya P, Bailer RT, Cao A, Druz A, Georgiev IS, Kwon YD, Louder MK, Zhang B, Zheng A, Hill BJ, Kong R, Soto C, Mullikin JC, Douek DC, Montefiori DC, Moody MA, Shaw GM, Hahn BH, Kelsoe G, Hraber PT, Korber BT, Boyd SD, Fire AZ, Kepler TB, Shapiro L, Ward AB, Mascola JR, Liao HX, Kwong PD, Haynes BF. Maturation Pathway from Germline to Broad HIV-1 Neutralizer of a CD4-Mimic Antibody. Cell 2016; 165:449-63. [PMID: 26949186 DOI: 10.1016/j.cell.2016.02.022] [Citation(s) in RCA: 241] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 12/11/2015] [Accepted: 02/08/2016] [Indexed: 01/16/2023]
Abstract
Antibodies with ontogenies from VH1-2 or VH1-46-germline genes dominate the broadly neutralizing response against the CD4-binding site (CD4bs) on HIV-1. Here, we define with longitudinal sampling from time-of-infection the development of a VH1-46-derived antibody lineage that matured to neutralize 90% of HIV-1 isolates. Structures of lineage antibodies CH235 (week 41 from time-of-infection, 18% breadth), CH235.9 (week 152, 77%), and CH235.12 (week 323, 90%) demonstrated the maturing epitope to focus on the conformationally invariant portion of the CD4bs. Similarities between CH235 lineage and five unrelated CD4bs lineages in epitope focusing, length-of-time to develop breadth, and extraordinary level of somatic hypermutation suggested commonalities in maturation among all CD4bs antibodies. Fortunately, the required CH235-lineage hypermutation appeared substantially guided by the intrinsic mutability of the VH1-46 gene, which closely resembled VH1-2. We integrated our CH235-lineage findings with a second broadly neutralizing lineage and HIV-1 co-evolution to suggest a vaccination strategy for inducing both lineages.
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109
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Haynes BF, Shaw GM, Korber B, Kelsoe G, Sodroski J, Hahn BH, Borrow P, McMichael AJ. HIV-Host Interactions: Implications for Vaccine Design. Cell Host Microbe 2016; 19:292-303. [PMID: 26922989 DOI: 10.1016/j.chom.2016.02.002] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Development of an effective AIDS vaccine is a global priority. However, the extreme diversity of HIV type 1 (HIV-1), which is a consequence of its propensity to mutate to escape immune responses, along with host factors that prevent the elicitation of protective immune responses, continue to hinder vaccine development. Breakthroughs in understanding of the biology of the transmitted virus, the structure and nature of its envelope trimer, vaccine-induced CD8 T cell control in primates, and host control of broadly neutralizing antibody elicitation have given rise to new vaccine strategies. Despite this promise, emerging data from preclinical trials reinforce the need for additional insight into virus-host biology in order to facilitate the development of a successful vaccine.
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110
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Menger DJ, Omusula P, Wouters K, Oketch C, Carreira AS, Durka M, Derycke JL, Loy DE, Hahn BH, Mukabana WR, Mweresa CK, van Loon JJA, Takken W, Hiscox A. Eave Screening and Push-Pull Tactics to Reduce House Entry by Vectors of Malaria. Am J Trop Med Hyg 2016; 94:868-78. [PMID: 26834195 DOI: 10.4269/ajtmh.15-0632] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 10/31/2015] [Indexed: 11/07/2022] Open
Abstract
Long-lasting insecticidal nets and indoor residual spraying have contributed to a decline in malaria over the last decade, but progress is threatened by the development of physiological and behavioral resistance of mosquitoes against insecticides. Acknowledging the need for alternative vector control tools, we quantified the effects of eave screening in combination with a push-pull system based on the simultaneous use of a repellent (push) and attractant-baited traps (pull). Field experiments in western Kenya showed that eave screening, whether used in combination with an attractant-baited trap or not, was highly effective in reducing house entry by malaria mosquitoes. The magnitude of the effect varied for different mosquito species and between two experiments, but the reduction in house entry was always considerable (between 61% and 99%). The use of outdoor, attractant-baited traps alone did not have a significant impact on mosquito house entry but the high number of mosquitoes trapped outdoors indicates that attractant-baited traps could be used for removal trapping, which would enhance outdoor as well as indoor protection against mosquito bites. As eave screening was effective by itself, addition of a repellent was of limited value. Nevertheless, repellents may play a role in reducing outdoor malaria transmission in the peridomestic area.
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111
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Moeller AH, Foerster S, Wilson ML, Pusey AE, Hahn BH, Ochman H. Social behavior shapes the chimpanzee pan-microbiome. SCIENCE ADVANCES 2016; 2:e1500997. [PMID: 26824072 PMCID: PMC4730854 DOI: 10.1126/sciadv.1500997] [Citation(s) in RCA: 195] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 11/19/2015] [Indexed: 05/21/2023]
Abstract
Animal sociality facilitates the transmission of pathogenic microorganisms among hosts, but the extent to which sociality enables animals' beneficial microbial associations is poorly understood. The question is critical because microbial communities, particularly those in the gut, are key regulators of host health. We show evidence that chimpanzee social interactions propagate microbial diversity in the gut microbiome both within and between host generations. Frequent social interaction promotes species richness within individual microbiomes as well as homogeneity among the gut community memberships of different chimpanzees. Sampling successive generations across multiple chimpanzee families suggests that infants inherited gut microorganisms primarily through social transmission. These results indicate that social behavior generates a pan-microbiome, preserving microbial diversity across evolutionary time scales and contributing to the evolution of host species-specific gut microbial communities.
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112
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Li H, Stoddard MB, Wang S, Giorgi EE, Blair LM, Learn GH, Hahn BH, Alter HJ, Busch MP, Fierer DS, Ribeiro RM, Perelson AS, Bhattacharya T, Shaw GM. Single-Genome Sequencing of Hepatitis C Virus in Donor-Recipient Pairs Distinguishes Modes and Models of Virus Transmission and Early Diversification. J Virol 2016; 90:152-66. [PMID: 26468546 PMCID: PMC4702571 DOI: 10.1128/jvi.02156-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 10/02/2015] [Indexed: 01/06/2023] Open
Abstract
UNLABELLED Despite the recent development of highly effective anti-hepatitis C virus (HCV) drugs, the global burden of this pathogen remains immense. Control or eradication of HCV will likely require the broad application of antiviral drugs and development of an effective vaccine. A precise molecular identification of transmitted/founder (T/F) HCV genomes that lead to productive clinical infection could play a critical role in vaccine research, as it has for HIV-1. However, the replication schema of these two RNA viruses differ substantially, as do viral responses to innate and adaptive host defenses. These differences raise questions as to the certainty of T/F HCV genome inferences, particularly in cases where multiple closely related sequence lineages have been observed. To clarify these issues and distinguish between competing models of early HCV diversification, we examined seven cases of acute HCV infection in humans and chimpanzees, including three examples of virus transmission between linked donors and recipients. Using single-genome sequencing (SGS) of plasma vRNA, we found that inferred T/F sequences in recipients were identical to viral sequences in their respective donors. Early in infection, HCV genomes generally evolved according to a simple model of random evolution where the coalescent corresponded to the T/F sequence. Closely related sequence lineages could be explained by high multiplicity infection from a donor whose viral sequences had undergone a pretransmission bottleneck due to treatment, immune selection, or recent infection. These findings validate SGS, together with mathematical modeling and phylogenetic analysis, as a novel strategy to infer T/F HCV genome sequences. IMPORTANCE Despite the recent development of highly effective, interferon-sparing anti-hepatitis C virus (HCV) drugs, the global burden of this pathogen remains immense. Control or eradication of HCV will likely require the broad application of antiviral drugs and the development of an effective vaccine, which could be facilitated by a precise molecular identification of transmitted/founder (T/F) viral genomes and their progeny. We used single-genome sequencing to show that inferred HCV T/F sequences in recipients were identical to viral sequences in their respective donors and that viral genomes generally evolved early in infection according to a simple model of random sequence evolution. Altogether, the findings validate T/F genome inferences and illustrate how T/F sequence identification can illuminate studies of HCV transmission, immunopathogenesis, drug resistance development, and vaccine protection, including sieving effects on breakthrough virus strains.
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113
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Barbian HJ, Li Y, Ramirez M, Klase Z, Lipende I, Mjungu D, Moeller AH, Wilson ML, Pusey AE, Lonsdorf EV, Bushman FD, Hahn BH. Destabilization of the gut microbiome marks the end-stage of simian immunodeficiency virus infection in wild chimpanzees. Am J Primatol 2015; 80. [PMID: 26676710 DOI: 10.1002/ajp.22515] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 10/20/2015] [Accepted: 12/01/2015] [Indexed: 12/17/2022]
Abstract
Enteric dysbiosis is a characteristic feature of progressive human immunodeficiency virus type 1 (HIV-1) infection but has not been observed in simian immunodeficiency virus (SIVmac)-infected macaques, including in animals with end-stage disease. This has raised questions concerning the mechanisms underlying the HIV-1 associated enteropathy, with factors other than virus infection, such as lifestyle and antibiotic use, implicated as playing possible causal roles. Simian immunodeficiency virus of chimpanzees (SIVcpz) is also associated with increased mortality in wild-living communities, and like HIV-1 and SIVmac, can cause CD4+ T cell depletion and immunodeficiency in infected individuals. Given the central role of the intestinal microbiome in mammalian health, we asked whether gut microbial constituents could be identified that are indicative of SIVcpz status and/or disease progression. Here, we characterized the gut microbiome of SIVcpz-infected and -uninfected chimpanzees in Gombe National Park, Tanzania. Subjecting a small number of fecal samples (N = 9) to metagenomic (shotgun) sequencing, we found bacteria of the family Prevotellaceae to be enriched in SIVcpz-infected chimpanzees. However, 16S rRNA gene sequencing of a larger number of samples (N = 123) failed to show significant differences in both the composition and diversity (alpha and beta) of gut bacterial communities between infected (N = 24) and uninfected (N = 26) chimpanzees. Similarly, chimpanzee stool-associated circular virus (Chi-SCV) and chimpanzee adenovirus (ChAdV) identified by metagenomic sequencing were neither more prevalent nor more abundant in SIVcpz-infected individuals. However, fecal samples collected from SIVcpz-infected chimpanzees within 5 months before their AIDS-related death exhibited significant compositional changes in their gut bacteriome. These data indicate that SIVcpz-infected chimpanzees retain a stable gut microbiome throughout much of their natural infection course, with a significant destabilization of bacterial (but not viral) communities observed only in individuals with known immunodeficiency within the last several months before their death. Am. J. Primatol. 80:e22515, 2018. © 2015 Wiley Periodicals, Inc.
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Richard J, Veillette M, Ding S, Zoubchenok D, Alsahafi N, Coutu M, Brassard N, Park J, Courter JR, Melillo B, Smith AB, Shaw GM, Hahn BH, Sodroski J, Kaufmann DE, Finzi A. Small CD4 Mimetics Prevent HIV-1 Uninfected Bystander CD4 + T Cell Killing Mediated by Antibody-dependent Cell-mediated Cytotoxicity. EBioMedicine 2015; 3:122-134. [PMID: 26870823 PMCID: PMC4739418 DOI: 10.1016/j.ebiom.2015.12.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 12/07/2015] [Accepted: 12/08/2015] [Indexed: 02/06/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) infection causes a progressive depletion of CD4 + T cells. Despite its importance for HIV-1 pathogenesis, the precise mechanisms underlying CD4 + T-cell depletion remain incompletely understood. Here we make the surprising observation that antibody-dependent cell-mediated cytotoxicity (ADCC) mediates the death of uninfected bystander CD4 + T cells in cultures of HIV-1-infected cells. While HIV-1-infected cells are protected from ADCC by the action of the viral Vpu and Nef proteins, uninfected bystander CD4 + T cells bind gp120 shed from productively infected cells and are efficiently recognized by ADCC-mediating antibodies. Thus, gp120 shedding represents a viral mechanism to divert ADCC responses towards uninfected bystander CD4 + T cells. Importantly, CD4-mimetic molecules redirect ADCC responses from uninfected bystander cells to HIV-1-infected cells; therefore, CD4-mimetic compounds might have therapeutic utility in new strategies aimed at specifically eliminating HIV-1-infected cells. Gp120 shed from productively-infected cells binds to bystander CD4 + T cells. Gp120-coated bystander cells are highly sensitivity to ADCC responses mediated by CD4-induced antibodies. Small-molecule CD4-mimetics redirect CD4-induced antibodies to HIV-1-infected cells.
The hallmark of human immunodeficiency virus type 1 (HIV-1) infection is the progressive depletion of CD4 + T cells. Using cultures of HIV-1-infected cells, we observed that a part of the machinery that the virus uses to infect cells (gp120) binds to uninfected cells. Antibodies elicited during the course of the infection against the gp120 can recognize uninfected cells and redirect an immune response to them that results in their elimination. Importantly, this phenomenon can be blocked with a small CD4-mimetic compound that abrogates the binding of gp120 to uninfected cells and redirects the immune system to infected cells.
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115
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Langer SM, Hopfensperger K, Iyer SS, Kreider EF, Learn GH, Lee LH, Hahn BH, Sauter D. A Naturally Occurring rev1-vpu Fusion Gene Does Not Confer a Fitness Advantage to HIV-1. PLoS One 2015; 10:e0142118. [PMID: 26554585 PMCID: PMC4640844 DOI: 10.1371/journal.pone.0142118] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 10/16/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Pandemic strains of HIV-1 (group M) encode a total of nine structural (gag, pol, env), regulatory (rev, tat) and accessory (vif, vpr, vpu, nef) genes. However, some subtype A and C viruses exhibit an unusual gene arrangement in which the first exon of rev (rev1) and the vpu gene are placed in the same open reading frame. Although this rev1-vpu gene fusion is present in a considerable fraction of HIV-1 strains, its functional significance is unknown. RESULTS Examining infectious molecular clones (IMCs) of HIV-1 that encode the rev1-vpu polymorphism, we show that a fusion protein is expressed in infected cells. Due to the splicing pattern of viral mRNA, however, these same IMCs also express a regular Vpu protein, which is produced at much higher levels. To investigate the function of the fusion gene, we characterized isogenic IMC pairs differing only in their ability to express a Rev1-Vpu protein. Analysis in transfected HEK293T and infected CD4+ T cells showed that all of these viruses were equally active in known Vpu functions, such as down-modulation of CD4 or counteraction of tetherin. Furthermore, the polymorphism did not affect Vpu-mediated inhibition of NF-кB activation or Rev-dependent nuclear export of incompletely spliced viral mRNAs. There was also no evidence for enhanced replication of Rev1-Vpu expressing viruses in primary PBMCs or ex vivo infected human lymphoid tissues. Finally, the frequency of HIV-1 quasispecies members that encoded a rev1-vpu fusion gene did not change in HIV-1 infected individuals over time. CONCLUSIONS Expression of a rev1-vpu fusion gene does not affect regular Rev and Vpu functions or alter HIV-1 replication in primary target cells. Since there is no evidence for increased replication fitness of rev1-vpu encoding viruses, this polymorphism likely emerged in the context of other mutations within and/or outside the rev1-vpu intergenic region, and may have a neutral phenotype.
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Larremore DB, Sundararaman SA, Liu W, Proto WR, Clauset A, Loy DE, Speede S, Plenderleith LJ, Sharp PM, Hahn BH, Rayner JC, Buckee CO. Ape parasite origins of human malaria virulence genes. Nat Commun 2015; 6:8368. [PMID: 26456841 PMCID: PMC4633637 DOI: 10.1038/ncomms9368] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 08/14/2015] [Indexed: 12/22/2022] Open
Abstract
Antigens encoded by the var gene family are major virulence factors of the human malaria parasite Plasmodium falciparum, exhibiting enormous intra- and interstrain diversity. Here we use network analysis to show that var architecture and mosaicism are conserved at multiple levels across the Laverania subgenus, based on var-like sequences from eight single-species and three multi-species Plasmodium infections of wild-living or sanctuary African apes. Using select whole-genome amplification, we also find evidence of multi-domain var structure and synteny in Plasmodium gaboni, one of the ape Laverania species most distantly related to P. falciparum, as well as a new class of Duffy-binding-like domains. These findings indicate that the modular genetic architecture and sequence diversity underlying var-mediated host-parasite interactions evolved before the radiation of the Laverania subgenus, long before the emergence of P. falciparum. Antigens encoded by var genes are major virulence factors of the human malaria parasite Plasmodium falciparum. Here, Larremore et al. identify var-like genes in distantly related Plasmodium species infecting African apes, indicating that these genes already existed in an ancestral ape parasite many millions of years ago.
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Etienne L, Bibollet-Ruche F, Sudmant PH, Wu LI, Hahn BH, Emerman M. The Role of the Antiviral APOBEC3 Gene Family in Protecting Chimpanzees against Lentiviruses from Monkeys. PLoS Pathog 2015; 11:e1005149. [PMID: 26394054 PMCID: PMC4578921 DOI: 10.1371/journal.ppat.1005149] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 08/13/2015] [Indexed: 02/07/2023] Open
Abstract
Cross-species transmissions of viruses from animals to humans are at the origin of major human pathogenic viruses. While the role of ecological and epidemiological factors in the emergence of new pathogens is well documented, the importance of host factors is often unknown. Chimpanzees are the closest relatives of humans and the animal reservoir at the origin of the human AIDS pandemic. However, despite being regularly exposed to monkey lentiviruses through hunting, chimpanzees are naturally infected by only a single simian immunodeficiency virus, SIVcpz. Here, we asked why chimpanzees appear to be protected against the successful emergence of other SIVs. In particular, we investigated the role of the chimpanzee APOBEC3 genes in providing a barrier to infection by most monkey lentiviruses. We found that most SIV Vifs, including Vif from SIVwrc infecting western-red colobus, the chimpanzee’s main monkey prey in West Africa, could not antagonize chimpanzee APOBEC3G. Moreover, chimpanzee APOBEC3D, as well as APOBEC3F and APOBEC3H, provided additional protection against SIV Vif antagonism. Consequently, lentiviral replication in primary chimpanzee CD4+ T cells was dependent on the presence of a lentiviral vif gene that could antagonize chimpanzee APOBEC3s. Finally, by identifying and functionally characterizing several APOBEC3 gene polymorphisms in both common chimpanzees and bonobos, we found that these ape populations encode APOBEC3 proteins that are uniformly resistant to antagonism by monkey lentiviruses. Many human pathogens are of zoonotic origin, meaning they originated in animals. This includes HIV-1, the cause of the human AIDS pandemic, which is the result of cross-species transmissions of lentiviruses from chimpanzees and gorillas. However, little is known about the host factors that provide natural protection against viral emergence in a new species. Chimpanzees, which are humans’ closest relatives, harbor only a single lentiviral lineage, despite their frequent exposure to lentiviruses that infect monkeys on which they prey. Here, we investigate the capacity of the accessory protein Vif from different primate lentiviruses to antagonize the APOBEC3 antiviral gene family found in chimpanzees. We found that the Vif protein from most monkey lentiviruses was not able to antagonize chimpanzee APOBEC3G. Furthermore, other APOBEC3 proteins from chimpanzees were also resistant to Vif antagonism. Finally, we showed that, despite polymorphism in the APOBEC3 genes, common chimpanzee and bonobo populations are uniformly resistant to monkey lentiviral Vif antagonism. Our results are consistent with the hypothesis that the host APOBEC3 antiviral proteins protect chimpanzees against many HIV-related viruses commonly found in monkeys.
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Wroblewski EE, Norman PJ, Guethlein LA, Rudicell RS, Ramirez MA, Li Y, Hahn BH, Pusey AE, Parham P. Signature Patterns of MHC Diversity in Three Gombe Communities of Wild Chimpanzees Reflect Fitness in Reproduction and Immune Defense against SIVcpz. PLoS Biol 2015; 13:e1002144. [PMID: 26020813 PMCID: PMC4447270 DOI: 10.1371/journal.pbio.1002144] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 04/02/2015] [Indexed: 11/19/2022] Open
Abstract
Major histocompatibility complex (MHC) class I molecules determine immune responses to viral infections. These polymorphic cell-surface glycoproteins bind peptide antigens, forming ligands for cytotoxic T and natural killer cell receptors. Under pressure from rapidly evolving viruses, hominoid MHC class I molecules also evolve rapidly, becoming diverse and species-specific. Little is known of the impact of infectious disease epidemics on MHC class I variant distributions in human populations, a context in which the chimpanzee is the superior animal model. Population dynamics of the chimpanzees inhabiting Gombe National Park, Tanzania have been studied for over 50 years. This population is infected with SIVcpz, the precursor of human HIV-1. Because HLA-B is the most polymorphic human MHC class I molecule and correlates strongly with HIV-1 progression, we determined sequences for its ortholog, Patr-B, in 125 Gombe chimpanzees. Eleven Patr-B variants were defined, as were their frequencies in Gombe's three communities, changes in frequency with time, and effect of SIVcpz infection. The growing populations of the northern and central communities, where SIVcpz is less prevalent, have stable distributions comprising a majority of low-frequency Patr-B variants and a few high-frequency variants. Driving the latter to high frequency has been the fecundity of immigrants to the northern community, whereas in the central community, it has been the fecundity of socially dominant individuals. In the declining population of the southern community, where greater SIVcpz prevalence is associated with mortality and emigration, Patr-B variant distributions have been changing. Enriched in this community are Patr-B variants that engage with natural killer cell receptors. Elevated among SIVcpz-infected chimpanzees, the Patr-B*06:03 variant has striking structural and functional similarities to HLA-B*57, the human allotype most strongly associated with delayed HIV-1 progression. Like HLA-B*57, Patr-B*06:03 correlates with reduced viral load, as assessed by detection of SIVcpz RNA in feces.
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Cohn LB, Silva IT, Oliveira TY, Rosales RA, Parrish EH, Learn GH, Hahn BH, Czartoski JL, McElrath MJ, Lehmann C, Klein F, Caskey M, Walker BD, Siliciano JD, Siliciano RF, Jankovic M, Nussenzweig MC. HIV-1 integration landscape during latent and active infection. Cell 2015; 160:420-32. [PMID: 25635456 DOI: 10.1016/j.cell.2015.01.020] [Citation(s) in RCA: 345] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 12/18/2014] [Accepted: 01/12/2015] [Indexed: 11/15/2022]
Abstract
The barrier to curing HIV-1 is thought to reside primarily in CD4(+) T cells containing silent proviruses. To characterize these latently infected cells, we studied the integration profile of HIV-1 in viremic progressors, individuals receiving antiretroviral therapy, and viremic controllers. Clonally expanded T cells represented the majority of all integrations and increased during therapy. However, none of the 75 expanded T cell clones assayed contained intact virus. In contrast, the cells bearing single integration events decreased in frequency over time on therapy, and the surviving cells were enriched for HIV-1 integration in silent regions of the genome. Finally, there was a strong preference for integration into, or in close proximity to, Alu repeats, which were also enriched in local hotspots for integration. The data indicate that dividing clonally expanded T cells contain defective proviruses and that the replication-competent reservoir is primarily found in CD4(+) T cells that remain relatively quiescent.
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Barbian HJ, Decker JM, Bibollet-Ruche F, Galimidi RP, West AP, Learn GH, Parrish NF, Iyer SS, Li Y, Pace CS, Song R, Huang Y, Denny TN, Mouquet H, Martin L, Acharya P, Zhang B, Kwong PD, Mascola JR, Verrips CT, Strokappe NM, Rutten L, McCoy LE, Weiss RA, Brown CS, Jackson R, Silvestri G, Connors M, Burton DR, Shaw GM, Nussenzweig MC, Bjorkman PJ, Ho DD, Farzan M, Hahn BH. Neutralization properties of simian immunodeficiency viruses infecting chimpanzees and gorillas. mBio 2015; 6:e00296-15. [PMID: 25900654 PMCID: PMC4453581 DOI: 10.1128/mbio.00296-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 03/19/2015] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED Broadly cross-reactive neutralizing antibodies (bNabs) represent powerful tools to combat human immunodeficiency virus type 1 (HIV-1) infection. Here, we examined whether HIV-1-specific bNabs are capable of cross-neutralizing distantly related simian immunodeficiency viruses (SIVs) infecting central (Pan troglodytes troglodytes) (SIVcpzPtt) and eastern (Pan troglodytes schweinfurthii) (SIVcpzPts) chimpanzees (n = 11) as well as western gorillas (Gorilla gorilla gorilla) (SIVgor) (n = 1). We found that bNabs directed against the CD4 binding site (n = 10), peptidoglycans at the base of variable loop 3 (V3) (n = 5), and epitopes at the interface of surface (gp120) and membrane-bound (gp41) envelope glycoproteins (n = 5) failed to neutralize SIVcpz and SIVgor strains. In addition, apex V2-directed bNabs (n = 3) as well as llama-derived (heavy chain only) antibodies (n = 6) recognizing both the CD4 binding site and gp41 epitopes were either completely inactive or neutralized only a fraction of SIVcpzPtt strains. In contrast, one antibody targeting the membrane-proximal external region (MPER) of gp41 (10E8), functional CD4 and CCR5 receptor mimetics (eCD4-Ig, eCD4-Ig(mim2), CD4-218.3-E51, and CD4-218.3-E51-mim2), as well as mono- and bispecific anti-human CD4 (iMab and LM52) and CCR5 (PRO140, PRO140-10E8) receptor antibodies neutralized >90% of SIVcpz and SIVgor strains with low-nanomolar (0.13 to 8.4 nM) potency. Importantly, the latter antibodies blocked virus entry not only in TZM-bl cells but also in Cf2Th cells expressing chimpanzee CD4 and CCR5 and neutralized SIVcpz in chimpanzee CD4(+) T cells, with 50% inhibitory concentrations (IC50s) ranging from 3.6 to 40.5 nM. These findings provide new insight into the protective capacity of anti-HIV-1 bNabs and identify candidates for further development to combat SIVcpz infection. IMPORTANCE SIVcpz is widespread in wild-living chimpanzees and can cause AIDS-like immunopathology and clinical disease. HIV-1 infection of humans can be controlled by antiretroviral therapy; however, treatment of wild-living African apes with current drug regimens is not feasible. Nonetheless, it may be possible to curb the spread of SIVcpz in select ape communities using vectored immunoprophylaxis and/or therapy. Here, we show that antibodies and antibody-like inhibitors developed to combat HIV-1 infection in humans are capable of neutralizing genetically diverse SIVcpz and SIVgor strains with considerable breadth and potency, including in primary chimpanzee CD4(+) T cells. These reagents provide an important first step toward translating intervention strategies currently developed to treat and prevent AIDS in humans to SIV-infected apes.
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Busula AO, Takken W, Loy DE, Hahn BH, Mukabana WR, Verhulst NO. Mosquito host preferences affect their response to synthetic and natural odour blends. Malar J 2015; 14:133. [PMID: 25889954 PMCID: PMC4381365 DOI: 10.1186/s12936-015-0635-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 03/01/2015] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND The anthropophilic malaria mosquito Anopheles gambiae sensu stricto (hereafter termed Anopheles gambiae) primarily takes blood meals from humans, whereas its close sibling Anopheles arabiensis is more opportunistic. Previous studies have identified several compounds that play a critical role in the odour-mediated behaviour of An. gambiae. This study determined the effect of natural and synthetic odour blends on mosquitoes with different host preferences to better understand the host-seeking behaviour of mosquitoes and the potential of synthetic odour blends for standardized monitoring. METHODS Odour blends were initially tested for their attractiveness to An. gambiae and An. arabiensis in a semi-field system with MM-X traps baited with natural and synthetic odours. Natural host odours were collected from humans, cows and chickens. The synthetic odour blends consisted of three or five previously identified compounds released with carbon dioxide. These studies were continued under natural conditions where odour blends were tested outdoors to determine their effect on species with different host preferences. RESULTS In the semi-field experiments, human odour attracted significantly higher numbers of both mosquito species. However, An. arabiensis was also attracted to cow and chicken odours, which confirms its opportunistic behaviour. A five-component synthetic blend was highly attractive to both mosquito species. In the field, the synthetic odour blend caught significantly more An. funestus than traps baited with human odour, while no difference was found for An. arabiensis. Catches of An. arabiensis and Culex spp. contained large numbers of blood-fed mosquitoes, mostly from cows, which indicates that these mosquitoes had fed outdoors. CONCLUSIONS Different odour baits elicit varying responses among mosquito species. Synthetic odour blends are highly effective for trapping mosquitoes; however, not all mosquitoes respond equally to the same odour blend. Combining fermenting molasses with synthetic blends in a trap represents the most effective tool to catch blood-fed mosquitoes outside houses, which is essential for understanding outdoor malaria transmission.
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Gardner MR, Kattenhorn LM, Kondur HR, von Schaewen M, Dorfman T, Chiang JJ, Haworth KG, Decker JM, Alpert MD, Bailey CC, Neale ES, Fellinger CH, Joshi VR, Fuchs SP, Martinez-Navio JM, Quinlan BD, Yao AY, Mouquet H, Gorman J, Zhang B, Poignard P, Nussenzweig MC, Burton DR, Kwong PD, Piatak M, Lifson JD, Gao G, Desrosiers RC, Evans DT, Hahn BH, Ploss A, Cannon PM, Seaman MS, Farzan M. AAV-expressed eCD4-Ig provides durable protection from multiple SHIV challenges. Nature 2015; 519:87-91. [PMID: 25707797 PMCID: PMC4352131 DOI: 10.1038/nature14264] [Citation(s) in RCA: 238] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Accepted: 01/27/2015] [Indexed: 12/25/2022]
Abstract
Long-term in vivo expression of a broad and potent entry inhibitor could circumvent the need for a conventional vaccine for HIV-1. Adeno-associated virus (AAV) vectors can stably express HIV-1 broadly neutralizing antibodies (bNAbs). However, even the best bNAbs neutralize 10-50% of HIV-1 isolates inefficiently (80% inhibitory concentration (IC80) > 5 μg ml(-1)), suggesting that high concentrations of these antibodies would be necessary to achieve general protection. Here we show that eCD4-Ig, a fusion of CD4-Ig with a small CCR5-mimetic sulfopeptide, binds avidly and cooperatively to the HIV-1 envelope glycoprotein (Env) and is more potent than the best bNAbs (geometric mean half-maximum inhibitory concentration (IC50) < 0.05 μg ml(-1)). Because eCD4-Ig binds only conserved regions of Env, it is also much broader than any bNAb. For example, eCD4-Ig efficiently neutralized 100% of a diverse panel of neutralization-resistant HIV-1, HIV-2 and simian immunodeficiency virus isolates, including a comprehensive set of isolates resistant to the CD4-binding site bNAbs VRC01, NIH45-46 and 3BNC117. Rhesus macaques inoculated with an AAV vector stably expressed 17-77 μg ml(-1) of fully functional rhesus eCD4-Ig for more than 40 weeks, and these macaques were protected from several infectious challenges with SHIV-AD8. Rhesus eCD4-Ig was also markedly less immunogenic than rhesus forms of four well-characterized bNAbs. Our data suggest that AAV-delivered eCD4-Ig can function like an effective HIV-1 vaccine.
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Sauter D, Hotter D, Van Driessche B, Stürzel CM, Kluge SF, Wildum S, Yu H, Baumann B, Wirth T, Plantier JC, Leoz M, Hahn BH, Van Lint C, Kirchhoff F. Differential regulation of NF-κB-mediated proviral and antiviral host gene expression by primate lentiviral Nef and Vpu proteins. Cell Rep 2015; 10:586-99. [PMID: 25620704 PMCID: PMC4682570 DOI: 10.1016/j.celrep.2014.12.047] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 11/28/2014] [Accepted: 12/19/2014] [Indexed: 02/06/2023] Open
Abstract
NF-κB is essential for effective transcription of primate lentiviral genomes and also activates antiviral host genes. Here, we show that the early protein Nef of most primate lentiviruses enhances NF-κB activation. In contrast, the late protein Vpu of HIV-1 and its simian precursors inhibits activation of NF-κB, even in the presence of Nef. Although this effect of Vpu did not correlate with its ability to interact with β-TrCP, it involved the stabilization of IκB and reduced nuclear translocation of p65. Interestingly, however, Vpu did not affect casein kinase II-mediated phosphorylation of p65. Lack of Vpu was associated with increased NF-κB activation and induction of interferon and interferon-stimulated genes (ISGs) in HIV-1-infected T cells. Thus, HIV-1 and its simian precursors employ Nef to boost NF-κB activation early during the viral life cycle to initiate proviral transcription, while Vpu is used to downmodulate NF-κB-dependent expression of ISGs at later stages.
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Moeller AH, Peeters M, Ayouba A, Ngole EM, Esteban A, Hahn BH, Ochman H. Stability of the gorilla microbiome despite simian immunodeficiency virus infection. Mol Ecol 2015; 24:690-7. [PMID: 25545295 DOI: 10.1111/mec.13057] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 12/17/2014] [Accepted: 12/19/2014] [Indexed: 01/04/2023]
Abstract
Simian immunodeficiency viruses (SIVs) have been discovered in over 45 primate species; however, the pathogenic potential of most SIV strains remains unknown due to difficulties inherent in observing wild populations. Because those SIV infections that are pathogenic have been shown to induce changes in the host's gut microbiome, monitoring the microbiota present in faecal samples can provide a noninvasive means for studying the effects of SIV infection on the health of wild-living primates. Here, we examine the effects of SIVgor, a close relative of SIVcpz of chimpanzees and HIV-1 of humans, on the gut bacterial communities residing within wild gorillas, revealing that gorilla gut microbiomes are exceptionally robust to SIV infection. In contrast to the microbiomes of HIV-1-infected humans and SIVcpz-infected chimpanzees, SIVgor-infected gorilla microbiomes exhibit neither rises in the frequencies of opportunistic pathogens nor elevated rates of microbial turnover within individual hosts. Regardless of SIV infection status, gorilla microbiomes assort into enterotypes, one of which is compositionally analogous to those identified in humans and chimpanzees. The other gorilla enterotype appears specialized for a leaf-based diet and is enriched in environmentally derived bacterial genera. We hypothesize that the acquisition of this gorilla-specific enterotype was enabled by lowered immune system control over the composition of the microbiome. Our results indicate differences between the pathology of SIVgor and SIVcpz/HIV-1 infections, demonstrating the utility of investigating host microbial ecology as a means for studying disease in wild primates of high conservation priority.
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Asmal M, Luedemann C, Lavine CL, Mach LV, Balachandran H, Brinkley C, Denny TN, Lewis MG, Anderson H, Pal R, Sok D, Le K, Pauthner M, Hahn BH, Shaw GM, Seaman MS, Letvin NL, Burton DR, Sodroski JG, Haynes BF, Santra S. Infection of monkeys by simian-human immunodeficiency viruses with transmitted/founder clade C HIV-1 envelopes. Virology 2015; 475:37-45. [PMID: 25462344 PMCID: PMC4280322 DOI: 10.1016/j.virol.2014.10.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 10/27/2014] [Indexed: 10/24/2022]
Abstract
Simian-human immunodeficiency viruses (SHIVs) that mirror natural transmitted/founder (T/F) viruses in man are needed for evaluation of HIV-1 vaccine candidates in nonhuman primates. Currently available SHIVs contain HIV-1 env genes from chronically-infected individuals and do not reflect the characteristics of biologically relevant HIV-1 strains that mediate human transmission. We chose to develop clade C SHIVs, as clade C is the major infecting subtype of HIV-1 in the world. We constructed 10 clade C SHIVs expressing Env proteins from T/F viruses. Three of these ten clade C SHIVs (SHIV KB9 C3, SHIV KB9 C4 and SHIV KB9 C5) replicated in naïve rhesus monkeys. These three SHIVs are mucosally transmissible and are neutralized by sCD4 and several HIV-1 broadly neutralizing antibodies. However, like natural T/F viruses, they exhibit low Env reactivity and a Tier 2 neutralization sensitivity. Of note, none of the clade C T/F SHIVs elicited detectable autologous neutralizing antibodies in the infected monkeys, even though antibodies that neutralized a heterologous Tier 1 HIV-1 were generated. Challenge with these three new clade C SHIVs will provide biologically relevant tests for vaccine protection in rhesus macaques.
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