Measurement of the mutation rates of animal viruses: influenza A virus and poliovirus type 1.

ABSTRACT We have generated recombinant influenza A viruses belonging to the H1N1 and H3N2 virus subtypes containing an insertion of the 137 C-terminal amino acid residues of the human immunodeficiency virus type 1 (HIV-1) Nef protein into the influenza A virus nonstructural-protein (NS1) reading frame. These viral vectors were found to be genetically stable and capable of growing efficiently in embryonated chicken eggs and tissue culture cells but did not replicate in the murine respiratory tract. Despite the hyperattenuated phenotype of influenza/NS-Nef viruses, a Nef and influenza virus (nucleoprotein)-specific CD8+-T-cell response was detected in spleens and the lymph nodes draining the respiratory tract after a single intranasal immunization of mice. Compared to the primary response, a marked enhancement of the CD8+-T-cell response was detected in the systemic and mucosal compartments, including mouse urogenital tracts, if mice were primed with the H1N1 subtype vector and subsequently boosted with the H3N2 subtype vector. In addition, Nef-specific serum IgG was detected in mice which were immunized twice with the recombinant H1N1 and then boosted with the recombinant H3N2 subtype virus. These findings may contribute to the development of alternative immunization strategies utilizing hyperattenuated live recombinant influenza virus vectors to prevent or control infectious diseases, e.g., HIV-1 infection.

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Synthesis and Evaluation of Some Masked Phosphate Esters of the Anti-Herpesvirus Drug 882C (Netivudine) as Potential Antiviral Agents

Antiviral Chemistry and Chemotherapy ◽

10.1177/095632029800900304 ◽

1998 ◽

Vol 9 (3) ◽

pp. 233-243 ◽

Cited By ~ 5

Author(s):

C McGuigan ◽

A Perry ◽

CJ Yarnold ◽

PW Sutton ◽

D Lowe ◽

...

Keyword(s):

Influenza A Virus ◽

Virus Type ◽

Influenza A ◽

Relative Rate ◽

Antiviral Agents ◽

Phosphate Esters ◽

Lead Target ◽

Immunodeficiency Virus ◽

Simplex Virus

A number of symmetric and asymmetric 5′-phosphate esters of the potent anti-varicellazoster virus (VZV) agent 1–(β-d-arabinofuranosyl)-5-prop-1-ynyluracil (882C; netivudine) were prepared as potential lipophilic, membrane-soluble prodrugs of the bioactive phosphate forms. The compounds were prepared by the base-catalysed coupling of various phosphorochloridates with the free nucleoside analogue. Compounds were fully characterized by a range of spectroscopic and analytical methods and were studied for their inhibition of several viruses in tissue culture. All of the phosphate esters were inactive against human cytomegalovirus, herpes simplex virus type 2, VZV, human immunodeficiency virus type 1 and influenza A virus (EC50 >100 μM) except the 5′-(4–nitrophenyl phenyl) phosphate, which inhibited influenza A virus. The relative rate of esterase-mediated hydrolysis of one of the lead target structures was measured in order to rationalize the poor antiviral action, and data were collected on possible metabolites in support of this analysis. Cell-specific esterases are implicated as key determinants of the antiviral potency of prodrugs of this type.

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Inhibition of Human Immunodeficiency Virus Type 1 Replication prior to Reverse Transcription by Influenza Virus Stimulation

Journal of Virology ◽

10.1128/jvi.74.10.4505-4511.2000 ◽

2000 ◽

Vol 74 (10) ◽

pp. 4505-4511 ◽

Cited By ~ 24

Author(s):

Ligia A. Pinto ◽

Vesna Blazevic ◽

Bruce K. Patterson ◽

C. Mac Trubey ◽

Matthew J. Dolan ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Influenza A Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Reverse Transcription ◽

Influenza A ◽

Immunodeficiency Virus ◽

Anti Hiv ◽

Hiv 1

ABSTRACT It is now recognized that, in addition to drug-mediated therapies against human immunodeficiency virus type 1 (HIV-1), the immune system can exert antiviral effects via CD8+ T-cell-generated anti-HIV factors. This study demonstrates that (i) supernatants from peripheral blood mononuclear cells (PBMC) stimulated with influenza A virus inhibit replication of CCR5- and CXCR4-tropic HIV-1 isolates prior to reverse transcription; (ii) the HIV-suppressive supernatants can be generated by CD4- or CD8-depleted PBMC; (iii) this anti-HIV activity is partially due to alpha interferon (IFN-α), but not to IFN-γ, IFN-β, the β-chemokines MIP-1α, MIP-1β, and RANTES, or interleukin-16; (iv) the anti-HIV activity is generated equally well by PBMC cultured with either infectious or UV-inactivated influenza A virus; and (v) the antiviral activity can be generated by influenza A-stimulated PBMC from HIV-infected individuals. These findings represent a novel mechanism for inhibition of HIV-1 replication that differs from the previously described CD8 anti-HIV factors (MIP-1α, MIP-1β, RANTES, and CD8 antiviral factor).

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Effect of Adenovirus Type 1 and Influenza a Virus onStreptococcus PneumoniaeNasopharyngeal Colonization and Otitis Media in the Chinchilla

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348940010901106 ◽

2000 ◽

Vol 109 (11) ◽

pp. 1021-1027 ◽

Cited By ~ 36

Author(s):

Hua Hua Tong ◽

Gregory M. Kosunick ◽

Lisa M. Fisher ◽

Thomas F. DeMaria

Keyword(s):

Otitis Media ◽

Influenza A Virus ◽

Influenza A ◽

Adenovirus Type

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Stoichiometry of Envelope Glycoprotein Trimers in the Entry of Human Immunodeficiency Virus Type 1

Journal of Virology ◽

10.1128/jvi.79.19.12132-12147.2005 ◽

2005 ◽

Vol 79 (19) ◽

pp. 12132-12147 ◽

Cited By ~ 125

Author(s):

Xinzhen Yang ◽

Svetla Kurteva ◽

Xinping Ren ◽

Sandra Lee ◽

Joseph Sodroski

Keyword(s):

Human Immunodeficiency Virus ◽

Membrane Fusion ◽

Influenza A Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Influenza A ◽

Virus Entry ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) envelope glycoproteins (Envs) function as a trimer, mediating virus entry by promoting the fusion of the viral and target cell membranes. HIV-1 Env trimers induce membrane fusion through a pH-independent pathway driven by the interaction between an Env trimer and its cellular receptors, CD4 and CCR5/CXCR4. We studied viruses with mixed heterotrimers of wild-type and dominant-negative Envs to determine the number (T) of Env trimers required for HIV-1 entry. To our surprise, we found that a single Env trimer is capable of supporting HIV-1 entry; i.e., T = 1. A similar approach was applied to investigate the entry stoichiometry of envelope glycoproteins from amphotropic murine leukemia virus (A-MLV), avian sarcoma/leukosis virus type A (ASLV-A), and influenza A virus. When pseudotyped on HIV-1 virions, the A-MLV and ASLV-A Envs also exhibit a T = 1 entry stoichiometry. In contrast, eight to nine influenza A virus hemagglutinin trimers function cooperatively to achieve membrane fusion and virus entry, using a pH-dependent pathway. The different entry requirements for cooperativity among Env trimers for retroviruses and influenza A virus may influence viral strategies for replication and evasion of the immune system.

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The mutation rates and mutational bias of influenza A virus

10.1101/110197 ◽

2017 ◽

Cited By ~ 4

Author(s):

Matthew D. Pauly ◽

Megan Procario ◽

Adam S. Lauring

Keyword(s):

Influenza Virus ◽

Influenza A Virus ◽

Mutation Rate ◽

Influenza A ◽

Rapid Evolution ◽

Viral Fitness ◽

High Mutation Rate ◽

Mutation Rates ◽

Mutational Bias ◽

Neutral Mutations

AbstractInfluenza virus has a high mutation rate, and this low replicative fidelity contributes to its capacity for rapid evolution. Clonal sequencing and fluctuation tests have suggested that the mutation rate of influenza A virus is 7.1 × 10−6− 4.5 × 10−5substitutions per nucleotide per cell infection cycle and 2.7 × 10−6− 3.0 × 10−5substitutions per nucleotide per strand copied (s/n/r). However, sequencing assays are biased toward mutations with minimal impacts on viral fitness and fluctuation tests typically investigate only a subset of the twelve mutational classes. We developed a fluctuation test based on reversion to fluorescence in a set of virally encoded mutant green fluorescent proteins. This method allowed us to measure the rates of selectively neutral mutations representative of all 12 mutational classes in the context of an unstructured RNA. We measured an overall mutation rate of 1.8 × 10−4s/n/r for PR8 (H1N1) and 2.5 × 10−4s/n/r for Hong Kong 2014 (H3N2). The replication mode was linear. The mutation rates of these divergent strains are significantly higher than previous estimates and suggest that each replicated genome will have an average of 2-3 mutations. The viral mutational spectrum is heavily biased toward A to G and U to C transitions, resulting in a transition to transversion bias of 2.7 and 3.6 for the two strains. These mutation rates were relatively constant over a range of physiological temperatures. Our high-resolution analysis of influenza virus mutation rates will enable more refined models of its molecular evolution.SignificanceThe rapid evolution of influenza virus is a major problem in public health. A key factor driving this rapid evolution is the virus’ very high mutation rate. We developed a new method for measuring the rates of all 12 mutational classes in influenza virus, which eliminates some of the biases of existing assays. We find that the influenza virus mutation rate is much higher than previously reported and is consistent across two distinct strains and a range of temperatures. Our data suggest that influenza viruses replicate at their maximally tolerable mutation rates, highlighting both the virus’ evolutionary potential and its significant constraints.

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