The endothelium participates in haemostasis, inflammation, blood pressure regulation and other physiological systems. Consequently, endothelial dysfunction has been related to hypertension, thrombosis and atherosclerosis. Both von Willebrand factor (vWF) and tissue-type plasminogen activator (t-PA) are synthesized by the endothelium and their plasma levels increased during endothelium activation or injury. So far, they are well-known markers of endothelial cell function. Many circumstances activate or damage the endothelium, such as viruses, bacterium and inflammation. Circulating vWF and t-PA were studied in 92 unselected human immunodeficiency virus-1 (HIV-1)-infected patients [27 patients with and 65 patients without acquired immunodeficiency syndrome (AIDS)] and correlated with plasma levels of pro-inflammatory cytokines (tumour necrosis factor-alpha, interleukin-6), viral load, CD4 T-cell count and infectious status. HIV-1-infected patients had significantly higher plasma levels of vWF (152 versus 90%), tumour necrosis factor-alpha (31.3 versus 9.0 pg/ml) and interleukin-6 (3.5 versus 1.9 pg/ml) but not t-PA (5.9 versus 4.2 ng/ml) than the control group. These two endothelial markers correlated significantly with viral load and interleukin-6 levels in HIV-1-infected patients. The highest levels of vWF and t-PA were found in patients with AIDS. In conclusion, endothelial cell perturbation is present in HIV infection and may be a consequence of different mechanisms such as viral load, cytokines and advanced diseases.
BackgroundCytotoxic T-Lymphocyte (CTL) response drives the evolution of HIV-1 at a host-level by selecting HLA-restricted escape mutations. Dissecting the dynamics of these escape mutations at a population-level would help to understand how HLA-mediated selection drives the evolution of HIV-1.Methodology/Principal FindingsWe undertook a study of the dynamics of HIV-1 CTL-escape mutations by analyzing through statistical approaches and phylogenetic methods the viral gene gag sequenced in plasma samples collected between the years 1987 and 2006 from 302 drug-naïve HIV-positive patients. By applying logistic regression models and after performing correction for multiple test, we identified 22 potential CTL-escape mutations (p-value<0.05; q-value<0.2); 10 of these associations were confirmed in samples biologically independent by a Bayesian Markov Chain Monte-Carlo method. Analyzing their prevalence back in time we found that escape mutations that are the consensus residue in samples collected after 2003 have actually significantly increased in time in one of either B or F subtype until becoming the most frequent residue, while dominating the other viral subtype. Their estimated prevalence in the viral subtype they did not dominate was lower than 30% for the majority of samples collected at the end of the 80's. In addition, when screening the entire viral region, we found that the 75% of positions significantly changing in time (p<0.05) were located within known CTL epitopes.ConclusionsAcross HIV Gag protein, the rise of polymorphisms from independent origin during the last twenty years of epidemic in our setting was related to an association with an HLA allele. The fact that these mutations accumulated in one of either B or F subtypes have also dominated the other subtype shows how this selection might be causing a convergence of viral subtypes to variants which are more likely to evade the immune response of the population where they circulate.
Here we present a survey including 52 drug-naive recently HIV-1-infected subjects from Buenos Aires City and province (79%) and 3 other regions in Argentina (21%). Recent infections were established from previous negative serology (32/52), indeterminate Western blot (12/52), or acute retroviral syndrome after high-risk HIV exposure (8/52) within 9 months before genotyping (median time, 4.2 months). Genotyping was performed from plasma by sequencing both protease and reverse transcriptase. Phylogenetic analysis combined with bootscanning resulted in 21 subtype B sequences and 31 B/F recombinants (RecBF). On protease, minor resistance-related mutations were found in both subtype B and RecBF with low frequencies. The substitution L89M, recently suggested as a resistance-related mutation in some subtype F viruses, was observed in 1 RecBF. On reverse transcriptase, major resistance-related mutations were found in 4 of 52 (7.7%) patients from different health centers: M41L (subtype B) and K103N+/-P225H (1 RecBF and 2 subtype B). The greater than 5% resistance threshold found indicates a need for sentinel resistance surveillances calling for an update in the current resistance testing guidelines in Argentina.
Background: Cytotoxic T-Lymphocyte (CTL) response drives the evolution of HIV-1 at a host-level by selecting HLArestricted escape mutations. Dissecting the dynamics of these escape mutations at a population-level would help to understand how HLA-mediated selection drives the evolution of HIV-1. Methodology/Principal Findings:We undertook a study of the dynamics of HIV-1 CTL-escape mutations by analyzing through statistical approaches and phylogenetic methods the viral gene gag sequenced in plasma samples collected between the years 1987 and 2006 from 302 drug-naı ¨ve HIV-positive patients. By applying logistic regression models and after performing correction for multiple test, we identified 22 potential CTL-escape mutations (p-value,0.05; q-value,0.2); 10 of these associations were confirmed in samples biologically independent by a Bayesian Markov Chain Monte-Carlo method. Analyzing their prevalence back in time we found that escape mutations that are the consensus residue in samples collected after 2003 have actually significantly increased in time in one of either B or F subtype until becoming the most frequent residue, while dominating the other viral subtype. Their estimated prevalence in the viral subtype they did not dominate was lower than 30% for the majority of samples collected at the end of the 80's. In addition, when screening the entire viral region, we found that the 75% of positions significantly changing in time (p,0.05) were located within known CTL epitopes.Conclusions: Across HIV Gag protein, the rise of polymorphisms from independent origin during the last twenty years of epidemic in our setting was related to an association with an HLA allele. The fact that these mutations accumulated in one of either B or F subtypes have also dominated the other subtype shows how this selection might be causing a convergence of viral subtypes to variants which are more likely to evade the immune response of the population where they circulate.
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