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Title: Modeling the Effects of Morphine on Simian Immunodeficiency Virus Dynamics

Abstract

Complications of HIV-1 infection in individuals who utilize drugs of abuse is a significant problem, because these drugs have been associated with higher virus replication and accelerated disease progression as well as severe neuropathogenesis. To gain further insight it is important to quantify the effects of drugs of abuse on HIV-1 infection dynamics. Here, we develop a mathematical model that incorporates experimentally observed effects of morphine on inducing HIV-1 co-receptor expression. For comparison we also considered viral dynamic models with cytolytic or noncytolytic effector cell responses. Based on the small sample size Akaike information criterion, these models were inferior to the new model based on changes in co-receptor expression. The model with morphine affecting co-receptor expression agrees well with the experimental data from simian immunodeficiency virus infections in morphine-addicted macaques. Our results show that morphine promotes a target cell subpopulation switch from a lower level of susceptibility to a state that is about 2-orders of magnitude higher in susceptibility to SIV infection. As a result, the proportion of target cells with higher susceptibility remains extremely high in morphine conditioning. Such a morphine-induced population switch not only has adverse effects on the replication rate, but also results in a higher steadymore » state viral load and larger CD4 count drops. Moreover, morphine conditioning may pose extra obstacles to controlling viral load during antiretroviral therapy, such as pre-exposure prophylaxis and post infection treatments. In conclusion, this study provides, for the first time, a viral dynamics model, viral dynamics parameters, and related analytical and simulation results for SIV dynamics under drugs of abuse.« less

Authors:
 [1];  [2];  [2];  [3]
  1. Univ. of Missouri-Kansas City (UMKC), MO (United States). Dept. of Mathematics and Statistics; Univ. of Missouri-Kansas City (UMKC), MO (United States). School of Pharmacy, Division of Pharmacology
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. Univ. of Missouri-Kansas City (UMKC), MO (United States). School of Pharmacy, Division of Pharmacology
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE; National Science Foundation (NSF); National Institutes of Health (NIH)
OSTI Identifier:
1345288
Report Number(s):
LA-UR-15-21504
Journal ID: ISSN 1553-7358
Grant/Contract Number:
AC52-06NA25396; KDA-91; DA015013; DMS-1616299; R01-AI028433; R01-OD011095; R01-AI104373
Resource Type:
Journal Article: Published Article
Journal Name:
PLoS Computational Biology (Online)
Additional Journal Information:
Journal Name: PLoS Computational Biology (Online); Journal Volume: 12; Journal Issue: 9; Journal ID: ISSN 1553-7358
Publisher:
Public Library of Science
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; 60 APPLIED LIFE SCIENCES; Biological Science

Citation Formats

Vaidya, Naveen K., Ribeiro, Ruy M., Perelson, Alan S., and Kumar, Anil. Modeling the Effects of Morphine on Simian Immunodeficiency Virus Dynamics. United States: N. p., 2016. Web. doi:10.1371/journal.pcbi.1005127.
Vaidya, Naveen K., Ribeiro, Ruy M., Perelson, Alan S., & Kumar, Anil. Modeling the Effects of Morphine on Simian Immunodeficiency Virus Dynamics. United States. doi:10.1371/journal.pcbi.1005127.
Vaidya, Naveen K., Ribeiro, Ruy M., Perelson, Alan S., and Kumar, Anil. 2016. "Modeling the Effects of Morphine on Simian Immunodeficiency Virus Dynamics". United States. doi:10.1371/journal.pcbi.1005127.
@article{osti_1345288,
title = {Modeling the Effects of Morphine on Simian Immunodeficiency Virus Dynamics},
author = {Vaidya, Naveen K. and Ribeiro, Ruy M. and Perelson, Alan S. and Kumar, Anil},
abstractNote = {Complications of HIV-1 infection in individuals who utilize drugs of abuse is a significant problem, because these drugs have been associated with higher virus replication and accelerated disease progression as well as severe neuropathogenesis. To gain further insight it is important to quantify the effects of drugs of abuse on HIV-1 infection dynamics. Here, we develop a mathematical model that incorporates experimentally observed effects of morphine on inducing HIV-1 co-receptor expression. For comparison we also considered viral dynamic models with cytolytic or noncytolytic effector cell responses. Based on the small sample size Akaike information criterion, these models were inferior to the new model based on changes in co-receptor expression. The model with morphine affecting co-receptor expression agrees well with the experimental data from simian immunodeficiency virus infections in morphine-addicted macaques. Our results show that morphine promotes a target cell subpopulation switch from a lower level of susceptibility to a state that is about 2-orders of magnitude higher in susceptibility to SIV infection. As a result, the proportion of target cells with higher susceptibility remains extremely high in morphine conditioning. Such a morphine-induced population switch not only has adverse effects on the replication rate, but also results in a higher steady state viral load and larger CD4 count drops. Moreover, morphine conditioning may pose extra obstacles to controlling viral load during antiretroviral therapy, such as pre-exposure prophylaxis and post infection treatments. In conclusion, this study provides, for the first time, a viral dynamics model, viral dynamics parameters, and related analytical and simulation results for SIV dynamics under drugs of abuse.},
doi = {10.1371/journal.pcbi.1005127},
journal = {PLoS Computational Biology (Online)},
number = 9,
volume = 12,
place = {United States},
year = 2016,
month = 9
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1371/journal.pcbi.1005127

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  • Complications of HIV-1 infection in individuals who utilize drugs of abuse is a significant problem, because these drugs have been associated with higher virus replication and accelerated disease progression as well as severe neuropathogenesis. To gain further insight it is important to quantify the effects of drugs of abuse on HIV-1 infection dynamics. Here, we develop a mathematical model that incorporates experimentally observed effects of morphine on inducing HIV-1 co-receptor expression. For comparison we also considered viral dynamic models with cytolytic or noncytolytic effector cell responses. Based on the small sample size Akaike information criterion, these models were inferior tomore » the new model based on changes in co-receptor expression. The model with morphine affecting co-receptor expression agrees well with the experimental data from simian immunodeficiency virus infections in morphine-addicted macaques. Our results show that morphine promotes a target cell subpopulation switch from a lower level of susceptibility to a state that is about 2-orders of magnitude higher in susceptibility to SIV infection. As a result, the proportion of target cells with higher susceptibility remains extremely high in morphine conditioning. Such a morphine-induced population switch not only has adverse effects on the replication rate, but also results in a higher steady state viral load and larger CD4 count drops. Moreover, morphine conditioning may pose extra obstacles to controlling viral load during antiretroviral therapy, such as pre-exposure prophylaxis and post infection treatments. In conclusion, this study provides, for the first time, a viral dynamics model, viral dynamics parameters, and related analytical and simulation results for SIV dynamics under drugs of abuse.« less
  • Previous studies from our laboratory have shown that the transmembrane domain (TM) of the Vpu protein of human immunodeficiency virus type 1 (HIV-1) contributes to the pathogenesis of SHIV{sub KU-1bMC33} in macaques and that the TM domain of Vpu could be replaced with the M2 protein viroporin from influenza A virus. Recently, we showed that the replacement of the TM domain of Vpu with that of the M2 protein of influenza A virus resulted in a virus (SHIV{sub M2}) that was sensitive to rimantadine [Hout, D.R., Gomez, M.L., Pacyniak, E., Gomez, L.M., Inbody, S.H., Mulcahy, E.R., Culley, N., Pinson, D.M.,more » Powers, M.F., Wong, S.W., Stephens, E.B., 2006. Substitution of the transmembrane domain of Vpu in simian human immunodeficiency virus (SHIV{sub KU-1bMC33}) with that of M2 of influenza A results in a virus that is sensitive to inhibitors of the M2 ion channel and is pathogenic for pig-tailed macaques. Virology 344, 541-558]. Based on previous studies of the M2 protein which have shown that the His-X-X-X-Trp motif within the M2 is essential to the function of the M2 proton channel, we have constructed a novel SHIV in which the alanine at position 19 of the TM domain was replaced with a histidine residue resulting in the motif His-Ile-Leu-Val-Trp. The SHIV{sub VpuA19H} replicated with similar kinetics as the parental SHIV{sub KU-1bMC33} and pulse-chase analysis revealed that the processing of viral proteins was similar to SHIV{sub KU-1bMC33}. This SHIV{sub VpuA19H} virus was found to be more sensitive to the M2 ion channel blocker rimantadine than SHIV{sub M2}. Electron microscopic examination of SHIV{sub VpuA19H}-infected cells treated with rimantadine revealed an accumulation of viral particles at the cell surface and within intracellular vesicles, which was similar to that previously observed to SHIV{sub M2}-infected cells treated with rimantadine. These data indicate that the Vpu protein of HIV-1 can be converted into a rimantadine-sensitive ion channel with the alteration of one amino acid and provide additional evidence that drugs targeting the Vpu TM/ion channel can be effective anti-HIV-1 drugs.« less
  • Viral vectors available for gene therapy are either inefficient or suffer from safety concerns for human applications. Foamy viruses are non-pathogenic retroviruses that offer several unique opportunities for gene transfer in various cell types from different species. In this report, we describe the use of simian foamy virus type 1 (SFV-1) vector to examine the efficacy of therapeutic genes. Hairpin short-interfering RNA (siRNA) that targets the simian immunodeficiency virus (SIV) rev/env was placed under the control of the PolIII U6 snRNA promoter for expression and screened for silencing target genes using cognate target-reporter fusions. We have identified an effective siRNAmore » (designated R2) which reduces the rev and env gene expression by 89% and 95%, respectively. Using the simian foamy virus type 1 (SFV-1) based vector, we delivered the PolIII expressed R2 siRNA into cultured cells and challenged with SIV. The results show that the R2 siRNA is a potent inhibitor of SIV replication as determined by p27 expression and reverse transcriptase assays. Vectors based on a non-pathogenic SFV-1 vector may provide a safe and efficient alternative to currently available vectors, and the SIV model will help devise protocols for effective anti-HIV gene therapy.« less
  • The Vpu protein of human immunodeficiency virus type 1 has been shown to shunt the CD4 receptor molecule to the proteasome for degradation and to enhance virus release from infected cells. The exact mechanism by which the Vpu protein enhances virus release is currently unknown but some investigators have shown that this function is associated with the transmembrane domain and potential ion channel properties. In this study, we determined if the transmembrane domain of Vpu could be functionally substituted with that of the prototypical viroporin, the M2 protein of influenza A virus. We constructed chimeric vpu gene in which themore » transmembrane domain of Vpu was replaced with that of the M2 protein of influenza. This chimeric vpu gene was substituted for the vpu gene in the genome of a pathogenic simian human immunodeficiency virus, SHIV{sub KU-1bMC33}. The resulting virus, SHIV{sub M2}, synthesized a Vpu protein that had a slightly different M{sub r} compared to the parental SHIV{sub KU-1bMC33}, reflecting the different sizes of the two Vpu proteins. The SHIV{sub M2} was shown to replicate with slightly reduced kinetics when compared to the parental SHIV{sub KU-1bMC33} but electron microscopy revealed that the site of maturation was similar to the parental virus SHIV{sub KU1bMC33}. We show that the replication and spread of SHIV{sub M2} could be blocked with the antiviral drug rimantadine, which is known to target the M2 ion channel. Our results indicate a dose dependent inhibition of SHIV{sub M2} with 100 {mu}M rimantadine resulting in a >95% decrease in p27 released into the culture medium. Rimantadine did not affect the replication of the parental SHIV{sub KU-1bMC33}. Examination of SHIV{sub M2}-infected cells treated with 50 {mu}M rimantadine revealed numerous viral particles associated with the cell plasma membrane and within intracytoplasmic vesicles, which is similar to HIV-1 mutants lacking a functional vpu. To determine if SHIV{sub M2} was as pathogenic as the parental SHIV{sub KU-1bMC33} virus, two pig-tailed macaques were inoculated and followed for up to 8 months. Both pig-tailed macaques developed severe CD4{sup +} T cell loss within 1 month of inoculation, high viral loads, and histological lesions consistent with lymphoid depletion similar to the parental SHIV{sub KU-1bMC33}. Taken together, these results indicate for the first time that the TM domain of the Vpu protein can be functionally substituted with the TM of M2 of influenza A virus, and shows that compounds that target the TM domain of Vpu protein of HIV-1 could serve as novel anti-HIV-1 drugs.« less
  • The immunogenicity and protective capacity of replication-defective herpes simplex virus (HSV) vector-based vaccines were examined in rhesus macaques. Three macaques were inoculated with recombinant HSV vectors expressing Gag, Env, and a Tat-Rev-Nef fusion protein of simian immunodeficiency virus (SIV). Three other macaques were primed with recombinant DNA vectors expressing Gag, Env, and a Pol-Tat-Nef-Vif fusion protein prior to boosting with the HSV vectors. Robust anti-Gag and anti-Env cellular responses were detected in all six macaques. Following intravenous challenge with wild-type, cloned SIV239, peak and 12-week plasma viremia levels were significantly lower in vaccinated compared to control macaques. Plasma SIV RNAmore » in vaccinated macaques was inversely correlated with anti-Rev ELISPOT responses on the day of challenge (P value < 0.05), anti-Tat ELISPOT responses at 2 weeks post challenge (P value < 0.05) and peak neutralizing antibody titers pre-challenge (P value 0.06). These findings support continued study of recombinant herpesviruses as a vaccine approach for AIDS.« less