scholarly journals Changes in Soluble Factor-Mediated CD8+ Cell-Derived Antiviral Activity in Cynomolgus Macaques Infected with Simian Immunodeficiency Virus SIVmac251: Relationship to Biological Markers of Progression

2006 ◽  
Vol 80 (1) ◽  
pp. 236-245 ◽  
Author(s):  
Vincent Dioszeghy ◽  
Kadija Benlhassan-Chahour ◽  
Benoit Delache ◽  
Nathalie Dereuddre-Bosquet ◽  
Celine Aubenque ◽  
...  

ABSTRACT Cross-sectional studies have shown that the capacity of CD8+ cells from human immunodeficiency virus (HIV)-infected patients and simian immunodeficiency virus (SIV) SIVmac-infected macaques to suppress the replication of human and simian immunodeficiency viruses in vitro depends on the clinical stage of disease, but little is known about changes in this antiviral activity over time in individual HIV-infected patients or SIV-infected macaques. We assessed changes in the soluble factor-mediated noncytolytic antiviral activity of CD8+ cells over time in eight cynomolgus macaques infected with SIVmac251 to determine the pathophysiological role of this activity. CD8+ cell-associated antiviral activity increased rapidly in the first week after viral inoculation and remained detectable during the early phase of infection. The net increase in antiviral activity of CD8+ cells was correlated with plasma viral load throughout the 15 months of follow-up. CD8+ cells gradually lost their antiviral activity over time and acquired virus replication-enhancing capacity. Levels of antiviral activity correlated with CD4+ T-cell counts after viral set point. Concentrations of β-chemokines and interleukin-16 in CD8+ cell supernatants were not correlated with this antiviral activity, and α-defensins were not detected. The soluble factor-mediated antiviral activity of CD8+ cells was neither cytolytic nor restricted to major histocompatibility complex. This longitudinal study strongly suggests that the increase in noncytolytic antiviral activity from baseline and the maintenance of this increase over time in cynomolgus macaques depend on both viral replication and CD4+ T cells.

1999 ◽  
Vol 73 (11) ◽  
pp. 9485-9495 ◽  
Author(s):  
Shane Crotty ◽  
Barbara L. Lohman ◽  
Fabien X.-S. Lü ◽  
ShenBei Tang ◽  
Christopher J. Miller ◽  
...  

ABSTRACT Poliovirus live virus vectors are a candidate recombinant vaccine system. Previous studies using this system showed that a live poliovirus vector expressing a foreign antigen between the structural and nonstructural proteins generates both antibody and cytotoxic T-lymphocyte responses in mice. Here we describe a novel in vitro method of cloning recombinant polioviruses involving a hybrid-PCR approach. We report the construction of recombinant vectors of two different serotypes of poliovirus-expressing simian immunodeficiency virus (SIV) antigens and the intranasal and intravenous inoculations of four adult cynomolgus macaques with these poliovirus vectors expressing the SIV proteins p17 gag and gp41 env . All macaques generated a mucosal anti-SIV immunoglobulin A (IgA) response in rectal secretions. Two of the four macaques generated mucosal antibody responses detectable in vaginal lavages. Strong serum IgG responses lasting for at least 1 year were detected in two of the four monkeys. SIV-specific T-cell lymphoproliferative responses were detected in three of the four monkeys. SIV-specific cytotoxic T lymphocytes were detected in two of the four monkeys. This is the first report of poliovirus-elicited vaginal IgA or cytotoxic T lymphocytes in any naturally infectable primate, including humans. These findings support the concept that a live poliovirus vector is a potentially useful delivery system that elicits humoral, mucosal, and cellular immune responses against exogenous antigens.


2009 ◽  
Vol 84 (5) ◽  
pp. 2304-2317 ◽  
Author(s):  
David O. Willer ◽  
Yongjun Guan ◽  
Mark A. Luscher ◽  
Bing Li ◽  
Rick Pilon ◽  
...  

ABSTRACT Hyperattenuated simian immunodeficiency virus SIVmac239-derived constructs Δ5-CMV and Δ6-CCI are an effort to render SIV incapable of, in practical terms, both reversion and recombination while maintaining the immune features of SIV as a retrovirus. Primary inoculation of cynomolgus macaques with 108 50% tissue culture infective doses (TCID50) of Δ5-CMV or Δ6-CCI induced low-level humoral and cellular responses detectable in the absence of measureable in vivo replication. The first of three DNA boosts resulted in elevated gamma interferon (IFN-γ) enzyme-linked immunospot (ELISPOT) responses to Gag, Pol, and Env in the Δ5-CMV vaccine group compared to the Δ6-CCI vaccine group (P = 0.001). Weekly intrarectal challenge with a low dose of SIVmac239 followed by a dose escalation was conducted until all animals became infected. The mean peak viral load of the Δ5-CMV-vaccinated animals (3.7 × 105 copies/ml) was ∼1 log unit lower than that of the control animals. More dramatically, the viral load set point of these animals was decreased by 3 log units compared to that of the controls (<50 versus 1.64 × 104 copies/ml; P < 0.0001). Seventy-five percent (6/8) of vaccine recipients controlled virus below 1,000 copies/ml for at least 6 months, with a subset controlling virus and maintaining substantial CD4 T-cell counts for close to 2 years of follow-up. The correlates of protection from SIV disease progression may lie in the rapidity and protective value of immune responses that occur early in primary SIV infection. Prior immunization with hyperattenuated SIVmac239, even if sterilizing immunity is not achieved, may allow a more advantageous host response.


2001 ◽  
Vol 45 (3) ◽  
pp. 976-980 ◽  
Author(s):  
Patrick G. Hoggard ◽  
Judy Lloyd ◽  
Save H. Khoo ◽  
Michael G. Barry ◽  
Louise Dann ◽  
...  

ABSTRACT We sought to determine whether the intracellular activation of zidovudine (ZDV) varied over time and with previous antiretroviral exposure in human immunodeficiency virus-infected individuals and to examine whether there is an association between virological responses and intracellular phosphorylation. A total of 23 patients (12 treatment naı̈ve, 11 previously treated with ZDV) who commenced ZDV as part of dual nucleoside therapy were prospectively monitored for 12 months or until withdrawal from the study. No association was observed between virological responses at 2 weeks and 3 months and ZDV phosphorylation. The mean intracellular concentrations of ZDV mono-, di-, and triphosphates did not change significantly over time or with previous ZDV exposure. The rate of formation of total ZDV phosphates was increased in patients with CD4 counts <100 cells/mm3. Previous reports from in vitro cell culture experiments or cross-sectional cohort studies suggesting alterations of ZDV phosphorylation over time are not confirmed by this longitudinal study.


2007 ◽  
Vol 51 (11) ◽  
pp. 4036-4043 ◽  
Author(s):  
Serge Dandache ◽  
Guy Sévigny ◽  
Jocelyn Yelle ◽  
Brent R. Stranix ◽  
Neil Parkin ◽  
...  

ABSTRACT Despite the success of highly active antiretroviral therapy, the current emergence and spread of drug-resistant variants of human immunodeficiency virus (HIV) stress the need for new inhibitors with distinct properties. We designed, produced, and screened a library of compounds based on an original l-lysine scaffold for their potentials as HIV type 1 (HIV-1) protease inhibitors (PI). One candidate compound, PL-100, emerged as a specific and noncytotoxic PI that exhibited potent inhibition of HIV-1 protease and viral replication in vitro (Ki , ∼36 pM, and 50% effective concentration [EC50], ∼16 nM, respectively). To confirm that PL-100 possessed a favorable resistance profile, we performed a cross-resistance study using a panel of 63 viral strains from PI-experienced patients selected for the presence of primary PI mutations known to confer resistance to multiple PIs now in clinical use. The results showed that PL-100 retained excellent antiviral activity against almost all of these PI-resistant viruses and that its performance in this regard was superior to those of atazanavir, amprenavir, indinavir, lopinavir, nelfinavir, and saquinavir. In almost every case, the increase in the EC50 for PL-100 observed with viruses containing multiple mutations in protease was far less than that obtained with the other drugs tested. These data underscore the potential for PL-100 to be used in the treatment of drug-resistant HIV disease and argue for its further development.


2010 ◽  
Vol 2 (22) ◽  
pp. 22ra18-22ra18 ◽  
Author(s):  
S. L. O'Connor ◽  
J. J. Lhost ◽  
E. A. Becker ◽  
A. M. Detmer ◽  
R. C. Johnson ◽  
...  

1999 ◽  
Vol 73 (5) ◽  
pp. 4443-4446 ◽  
Author(s):  
Donald L. Sodora ◽  
Kristine E. Sheridan ◽  
Preston A. Marx ◽  
Ruth I. Connor

ABSTRACT Rhesus macaques immunized with simian immunodeficiency virus SIVmac239Δnef but not protected from SIVmac251 challenge were studied to determine the genetic and biological characteristics of the breakthrough viruses. Assessment of SIV genetic diversity (env V1-V2) revealed a reduction in the number of viral species in the immunized, unprotected macaques, compared to the number in nonimmunized controls. However, no evidence for selection of a specific V1-V2 genotype was observed, and biologically cloned isolates from the animals with breakthrough virus were similar with respect to replication kinetics and coreceptor use in vitro.


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