The Origin, Evolution, and Epidemiology of HIV-1 and HIV-2

2019 ◽  
pp. 15-20
Author(s):  
Jeffrey T. Kirchner
Keyword(s):  
Twentieth Century ◽  
Simian Immunodeficiency Virus ◽  
Early Twentieth Century ◽  
Aids Pandemic ◽  
Immunodeficiency Virus ◽  
Out Of Africa ◽  
Hiv 1

Upon completion of this chapter, the reader should be able to • Explain how HIV evolved from cross-species transmission of strains of simian immunodeficiency virus (SIV) to humans (viral zoonosis), spread out of Africa in the early twentieth century, and ultimately resulted in the global AIDS pandemic...

scholarly journals Characterization and Implementation of a Diverse Simian Immunodeficiency Virus SIVsm Envelope Panel in the Assessment of Neutralizing Antibody Breadth Elicited in Rhesus Macaques by Multimodal Vaccines Expressing the SIVmac239 Envelope

2015 ◽  
Vol 89 (16) ◽  
pp. 8130-8151 ◽  
Author(s):  
Katie M. Kilgore ◽  
Megan K. Murphy ◽  
Samantha L. Burton ◽  
Katherine S. Wetzel ◽  
S. Abigail Smith ◽  
...  
Keyword(s):  
Simian Immunodeficiency Virus ◽  
Nonhuman Primate ◽  
Neutralizing Antibodies ◽  
Rhesus Macaques ◽  
Neutralizing Antibody ◽  
Cd40 Ligand ◽  
Antibody Activity ◽  
Immunodeficiency Virus ◽  
Antibody Profile ◽  
Hiv 1

ABSTRACTAntibodies that can neutralize diverse viral strains are likely to be an important component of a protective human immunodeficiency virus type 1 (HIV-1) vaccine. To this end, preclinical simian immunodeficiency virus (SIV)-based nonhuman primate immunization regimens have been designed to evaluate and enhance antibody-mediated protection. However, these trials often rely on a limited selection of SIV strains with extreme neutralization phenotypes to assess vaccine-elicited antibody activity. To mirror the viral panels used to assess HIV-1 antibody breadth, we created and characterized a novel panel of 14 genetically and phenotypically diverse SIVsm envelope (Env) glycoproteins. To assess the utility of this panel, we characterized the neutralizing activity elicited by four SIVmac239 envelope-expressing DNA/modified vaccinia virus Ankara vector- and protein-based vaccination regimens that included the immunomodulatory adjuvants granulocyte-macrophage colony-stimulating factor, Toll-like receptor (TLR) ligands, and CD40 ligand. The SIVsm Env panel exhibited a spectrum of neutralization sensitivity to SIV-infected plasma pools and monoclonal antibodies, allowing categorization into three tiers. Pooled sera from 91 rhesus macaques immunized in the four trials consistently neutralized only the highly sensitive tier 1a SIVsm Envs, regardless of the immunization regimen. The inability of vaccine-mediated antibodies to neutralize the moderately resistant tier 1b and tier 2 SIVsm Envs defined here suggests that those antibodies were directed toward epitopes that are not accessible on most SIVsm Envs. To achieve a broader and more effective neutralization profile in preclinical vaccine studies that is relevant to known features of HIV-1 neutralization, more emphasis should be placed on optimizing the Env immunogen, as the neutralization profile achieved by the addition of adjuvants does not appear to supersede the neutralizing antibody profile determined by the immunogen.IMPORTANCEMany in the HIV/AIDS vaccine field believe that the ability to elicit broadly neutralizing antibodies capable of blocking genetically diverse HIV-1 variants is a critical component of a protective vaccine. Various SIV-based nonhuman primate vaccine studies have investigated ways to improve antibody-mediated protection against a heterologous SIV challenge, including administering adjuvants that might stimulate a greater neutralization breadth. Using a novel SIV neutralization panel and samples from four rhesus macaque vaccine trials designed for cross comparison, we show that different regimens expressing the same SIV envelope immunogen consistently elicit antibodies that neutralize only the very sensitive tier 1a SIV variants. The results argue that the neutralizing antibody profile elicited by a vaccine is primarily determined by the envelope immunogen and is not substantially broadened by including adjuvants, resulting in the conclusion that the envelope immunogen itself should be the primary consideration in efforts to elicit antibodies with greater neutralization breadth.

scholarly journals Gag-Specific Cellular Immunity DeterminesIn VitroViral Inhibition andIn VivoVirologic Control following Simian Immunodeficiency Virus Challenges of Vaccinated Rhesus Monkeys

2012 ◽  
Vol 86 (18) ◽  
pp. 9583-9589 ◽  
Author(s):  
Kathryn E. Stephenson ◽  
Hualin Li ◽  
Bruce D. Walker ◽  
Nelson L. Michael ◽  
Dan H. Barouch
Keyword(s):  
Simian Immunodeficiency Virus ◽  
Rhesus Monkeys ◽  
Viral Inhibition ◽  
Viral Loads ◽  
Immunodeficiency Virus ◽  
Virologic Control ◽  
Cellular Immune ◽  
Hiv 1

A comprehensive vaccine for human immunodeficiency virus type 1 (HIV-1) would block HIV-1 acquisition as well as durably control viral replication in breakthrough infections. Recent studies have demonstrated that Env is required for a vaccine to protect against acquisition of simian immunodeficiency virus (SIV) in vaccinated rhesus monkeys, but the antigen requirements for virologic control remain unclear. Here, we investigate whether CD8+T lymphocytes from vaccinated rhesus monkeys mediate viral inhibitionin vitroand whether these responses predict virologic control following SIV challenge. We observed that CD8+lymphocytes from 23 vaccinated rhesus monkeys inhibited replication of SIVin vitro. Moreover, the magnitude of inhibition prior to challenge was inversely correlated with set point SIV plasma viral loads after challenge. In addition, CD8 cell-mediated viral inhibition in vaccinated rhesus monkeys correlated significantly with Gag-specific, but not Pol- or Env-specific, CD4+and CD8+T lymphocyte responses. These findings demonstrate thatin vitroviral inhibition following vaccination largely reflects Gag-specific cellular immune responses and correlates within vivovirologic control following infection. These data suggest the importance of including Gag in an HIV-1 vaccine in which virologic control is desired.

scholarly journals The Susceptibility of Primate Lentiviruses to Nucleosides and Vpx during Infection of Dendritic Cells Is Regulated by CA

2015 ◽  
Vol 89 (7) ◽  
pp. 4030-4034 ◽  
Author(s):  
Véronique Barateau ◽  
Xuan-Nhi Nguyen ◽  
Fanny Bourguillault ◽  
Grégory Berger ◽  
Stéphanie Cordeil ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Dendritic Cells ◽  
Simian Immunodeficiency Virus ◽  
Viral Protein ◽  
Immunodeficiency Virus ◽  
Protein X ◽  
Primate Lentiviruses ◽  
Species Specific ◽  
Hiv 1

The block toward human immunodeficiency virus type 1 (HIV-1) infection of dendritic cells (DCs) can be relieved by Vpx (viral protein X), which degrades sterile alpha motif-hydroxylase domain 1 (SAMHD1) or by exogenously added deoxynucleosides (dNs), lending support to the hypothesis that SAMHD1 acts by limiting deoxynucleoside triphosphates (dNTPs). This notion has, however, been questioned. We show that while dNs and Vpx increase the infectivity of HIV-1, only the latter restores the infectivity of a simian immunodeficiency virus of macaques variant, SIVMACΔVpx virus. This distinct behavior seems to map to CA, suggesting that species-specific CA interactors modulate infection of DCs.

scholarly journals Untruths and consequences: the false hypothesis linking CHAT type 1 polio vaccination to the origin of human immunodeficiency virus

2001 ◽  
Vol 356 (1410) ◽  
pp. 815-823 ◽  
Author(s):  
Stanley A. Plotkin
Keyword(s):  
Human Immunodeficiency Virus ◽  
Simian Immunodeficiency Virus ◽  
Kidney Cells ◽  
Epidemiological Analysis ◽  
Polio Vaccination ◽  
Immunodeficiency Virus ◽  
Belgian Congo ◽  
Hiv 1

A book published in 1999 hypothesized that the scientists who worked with the CHAT type 1 attenuated polio strain tested in the former Belgian Congo in the late 1950s had covertly prepared the vaccine in chimpanzee kidney cells contaminated with a simian immunodeficiency virus, which evolved into HIV–1 group M. This paper summarizes the results of the investigation conducted by the author to determine the legitimacy of the accusation. Testimony by eyewitnesses, documents of the time, epidemiological analysis, and ancillary phylogenetic, virologic and PCR data all concur to reject the hypothesis as false and without factual foundation.

scholarly journals Cell Type-Dependent Escape of Capsid Inhibitors by Simian Immunodeficiency Virus SIVcpz

2020 ◽  
Vol 94 (23) ◽  
Author(s):  
Augustin Penda Twizerimana ◽  
Rachel Scheck ◽  
Daniel Becker ◽  
Zeli Zhang ◽  
Marianne Wammers ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Simian Immunodeficiency Virus ◽  
Pan Troglodytes ◽  
Hela Cells ◽  
Cyclophilin A ◽  
Human Pbmcs ◽  
Cell Type ◽  
Content Type ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Pandemic human immunodeficiency virus type 1 (HIV-1) is the result of the zoonotic transmission of simian immunodeficiency virus (SIV) from the chimpanzee subspecies Pan troglodytes troglodytes (SIVcpzPtt). The related subspecies Pan troglodytes schweinfurthii is the host of a similar virus, SIVcpzPts, which did not spread to humans. We tested these viruses with small-molecule capsid inhibitors (PF57, PF74, and GS-CA1) that interact with a binding groove in the capsid that is also used by CPSF6. While HIV-1 was sensitive to capsid inhibitors in cell lines, human macrophages, and peripheral blood mononuclear cells (PBMCs), SIVcpzPtt was resistant in rhesus FRhL-2 cells and human PBMCs but was sensitive to PF74 in human HOS and HeLa cells. SIVcpzPts was insensitive to PF74 in FRhL-2 cells, HeLa cells, PBMCs, and macrophages but was inhibited by PF74 in HOS cells. A truncated version of CPSF6 (CPSF6-358) inhibited SIVcpzPtt and HIV-1, while in contrast, SIVcpzPts was resistant to CPSF6-358. Homology modeling of HIV-1, SIVcpzPtt, and SIVcpzPts capsids and binding energy estimates suggest that these three viruses bind similarly to the host proteins cyclophilin A (CYPA) and CPSF6 as well as the capsid inhibitor PF74. Cyclosporine treatment, mutation of the CYPA-binding loop in the capsid, or CYPA knockout eliminated the resistance of SIVcpzPts to PF74 in HeLa cells. These experiments revealed that the antiviral capacity of PF74 is controlled by CYPA in a virus- and cell type-specific manner. Our data indicate that SIVcpz viruses can use infection pathways that escape the antiviral activity of PF74. We further suggest that the antiviral activity of PF74 capsid inhibitors depends on cellular cofactors. IMPORTANCE HIV-1 originated from SIVcpzPtt but not from the related virus SIVcpzPts, and thus, it is important to describe molecular infection by SIVcpzPts in human cells to understand the zoonosis of SIVs. Pharmacological HIV-1 capsid inhibitors (e.g., PF74) bind a capsid groove that is also a binding site for the cellular protein CPSF6. SIVcpzPts was resistant to PF74 in HeLa cells but sensitive in HOS cells, thus indicating cell line-specific resistance. Both SIVcpz viruses showed resistance to PF74 in human PBMCs. Modulating the presence of cyclophilin A or its binding to capsid in HeLa cells overcame SIVcpzPts resistance to PF74. These results indicate that early cytoplasmic infection events of SIVcpzPts may differ between cell types and affect, in an unknown manner, the antiviral activity of capsid inhibitors. Thus, capsid inhibitors depend on the activity or interaction of currently uncharacterized cellular factors.

scholarly journals Characterization of Simian Immunodeficiency Virus SIVSM/Human Immunodeficiency Virus Type 2 Vpx Function in Human Myeloid Cells

2008 ◽  
Vol 82 (24) ◽  
pp. 12335-12345 ◽  
Author(s):  
Caroline Goujon ◽  
Vanessa Arfi ◽  
Thomas Pertel ◽  
Jeremy Luban ◽  
Julia Lienard ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Simian Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Intracellular Localization ◽  
Lymphoid Cells ◽  
Viral Dna ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 2 (HIV-2)/simian immunodeficiency virus SIVSM Vpx is incorporated into virion particles and is thus present during the early steps of infection, when it has been reported to influence the nuclear import of viral DNA. We recently reported that Vpx promoted the accumulation of full-length viral DNA following the infection of human monocyte-derived dendritic cells (DCs). This positive effect was exerted following the infection of DCs with cognate viruses and with retroviruses as divergent as HIV-1, feline immunodeficiency virus, and even murine leukemia virus, leading us to suggest that Vpx counteracted an antiviral restriction present in DCs. Here, we show that Vpx is required, albeit to a different extent, for the infection of all myeloid but not of lymphoid cells, including monocytes, macrophages, and monocytoid THP-1 cells that had been induced to differentiate with phorbol esters. The intracellular localization of Vpx was highly heterogeneous and cell type dependent, since Vpx localized differently in HeLa cells and DCs. Despite these differences, no clear correlation between the functionality of Vpx and its intracellular localization could be drawn. As a first insight into its function, we determined that SIVSM/HIV-2 and SIVRCM Vpx proteins interact with the DCAF1 adaptor of the Cul4-based E3 ubiquitin ligase complex recently described to associate with HIV-1 Vpr and HIV-2 Vpx. However, the functionality of Vpx proteins in the infection of DCs did not strictly correlate with DCAF1 binding, and knockdown experiments failed to reveal a functional role for this association in differentiated THP-1 cells. Lastly, when transferred in the context of a replication-competent viral clone, Vpx was required for replication in DCs.

scholarly journals Cholesterol Depletion of Human Immunodeficiency Virus Type 1 and Simian Immunodeficiency Virus with β-Cyclodextrin Inactivates and Permeabilizes the Virions: Evidence for Virion-Associated Lipid Rafts

2003 ◽  
Vol 77 (15) ◽  
pp. 8237-8248 ◽  
Author(s):  
David R. M. Graham ◽  
Elena Chertova ◽  
Joanne M. Hilburn ◽  
Larry O. Arthur ◽  
James E. K. Hildreth
Keyword(s):  
Human Immunodeficiency Virus ◽  
Lipid Rafts ◽  
Simian Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Viral Rna ◽  
Host Proteins ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Recent evidence suggests that human immunodeficiency virus type 1 (HIV-1) particles assemble and bud selectively through areas in the plasma membrane of cells that are highly enriched with glycosylphosphatidylinositol-anchored proteins and cholesterol, called lipid rafts. Since cholesterol is required to maintain lipid raft structure and function, we proposed that virion-associated cholesterol removal with the compound 2-hydroxy-propyl-β-cyclodextrin (β-CD) might be disruptive to HIV-1 and simian immunodeficiency virus (SIV). We examined the effect of β-CD on the structure and infectivity of cell-free virions. We found that β-CD inactivated HIV-1 and SIV in a dose-dependent manner and permeabilized the viral membranes, resulting in the loss of mature Gag proteins (capsid, matrix, nucleocapsid, p1, and p6) without loss of the envelope glycoproteins. SIV also lost reverse transcriptase (RT), integrase (IN), and viral RNA. IN appeared to be only slightly diminished in HIV-1, and viral RNA, RT, matrix, and nucleocapsid proteins were retained in HIV-1 but to a much lesser degree. Host proteins located internally in the virus (actin, moesin, and ezrin) and membrane-associated host proteins (major histocompatibility complex classes I and II) remained associated with the treated virions. Electron microscopy revealed that under conditions that permeabilized the viruses, holes were present in the viral membranes and the viral core structure was perturbed. These data provide evidence that an intact viral membrane is required to maintain mature virion core integrity. Since the viruses were not fixed before β-CD treatment and intact virion particles were recovered, the data suggest that virions may possess a protein scaffold that can maintain overall structure despite disruptions in membrane integrity.

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