Cellular HIV-1 DNA levels in patients receiving antiretroviral therapy strongly correlate with therapy initiation timing but not with therapy duration

<p>Abstract</p> <p>Background</p> <p>Viral reservoir size refers to cellular human immunodeficiency virus-1 (HIV-1) DNA levels in CD4⁺T lymphocytes of peripheral blood obtained from patients with plasma HIV-1-RNA levels (viral load, VL) maintained below the detection limit by antiretroviral therapy (ART). We measured HIV-1 DNA levels in CD4⁺lymphocytes in such patients to investigate their clinical significance.</p> <p>Methods</p> <p>CD4⁺T lymphocytes were isolated from the peripheral blood of 61 patients with a VL maintained at less than 50 copies/ml for at least 4 months by ART and total DNA was purified. HIV-1 DNA was quantified by nested PCR to calculate the copy number per 1 million CD4⁺lymphocytes (relative amount) and the copy number in 1 ml of blood (absolute amount). For statistical analysis, the Spearman rank or Wilcoxon signed-rank test was used, with a significance level of 5%.</p> <p>Results</p> <p>CD4 cell counts at the time of sampling negatively correlated with the relative amount of HIV-1 DNA (median = 33 copies/million CD4⁺lymphocytes; interquartile range [IQR] = 7-123 copies/million CD4⁺lymphocytes), but were not correlated with the absolute amounts (median = 17 copies/ml; IQR = 5-67 copies/ml). Both absolute and relative amounts of HIV-1 DNA were significantly lower in six patients in whom ART was initiated before positive seroconversion than in 55 patients in whom ART was initiated in the chronic phase, as shown by Western blotting. CD4 cell counts before ART introduction were also negatively correlated with both the relative and absolute amounts of HIV-1 DNA. Only the relative amounts of HIV-1 DNA negatively correlated with the duration of VL maintenance below the detection limit, while the absolute amounts were not significantly correlated with this period.</p> <p>Conclusions</p> <p>The amounts of cellular HIV-1 DNA in patients with VLs maintained below the detection limit by the introduction of ART correlated with the timing of ART initiation but not with the duration of ART. In addition, CD4⁺T lymphocytes, which were newly generated by ART, diluted latently infected cells, indicating that measurements of the relative amounts of cellular HIV-1 DNA might be underestimated.</p

Cloning of a Novel Gene for Quinolone Resistance from a Transferable Plasmid in Shigella flexneri 2b

A novel gene for quinolone resistance was cloned from a transferable plasmid carried by a clinical isolate of Shigella flexneri 2b that was resistant to fluoroquinolones. The plasmid conferred low-level resistance to quinolones on Escherichia coli HB101. The protein encoded by the gene showed 59% amino acid identity with Qnr

HIV-1 drug-resistance surveillance among treatment-experienced and -naïve patients after the implementation of antiretroviral therapy in Ghana.

BACKGROUND: Limited HIV-1 drug-resistance surveillance has been carried out in Ghana since the implementation of antiretroviral therapy (ART). This study sought to provide data on the profile of HIV-1 drug resistance in ART-experienced and newly diagnosed individuals in Ghana. METHODS: Samples were collected from 101 HIV-1-infected patients (32 ART-experienced cases with virological failure and 69 newly diagnosed ART-naïve cases, including 11 children), in Koforidua, Eastern region of Ghana, from February 2009 to January 2010. The pol gene sequences were analyzed by in-house HIV-1 drug-resistance testing. RESULTS: The most prevalent HIV-1 subtype was CRF02_AG (66.3%, 67/101) followed by unique recombinant forms (25.7%, 26/101). Among 31 ART-experienced adults, 22 (71.0%) possessed at least one drug-resistance mutation, and 14 (45.2%) had two-class-resistance to nucleoside and non-nucleoside reverse-transcriptase inhibitors used in their first ART regimen. Importantly, the number of accumulated mutations clearly correlated with the duration of ART. The most prevalent mutation was lamivudine-resistance M184V (n = 12, 38.7%) followed by efavirenz/nevirapine-resistance K103N (n = 9, 29.0%), and zidovudine/stavudine-resistance T215Y/F (n = 6, 19.4%). Within the viral protease, the major nelfinavir-resistance mutation L90M was found in one case. No transmitted HIV-1 drug-resistance mutation was found in 59 ART-naïve adults, but K103N and G190S mutations were observed in one ART-naïve child. CONCLUSIONS: Despite expanding accessibility to ART in Eastern Ghana, the prevalence of transmitted HIV-1 drug resistance presently appears to be low. As ART provision with limited options is scaled up nationwide in Ghana, careful monitoring of transmitted HIV-1 drug resistance is necessary

The carboxyl-terminus of human immunodeficiency virus type 2 circulating recombinant form 01_AB capsid protein affects sensitivity to human TRIM5α.

Human immunodeficiency virus (HIV) type 2 shows limited geographical distribution compared with HIV type 1. Although 8 genetic groups of HIV type 2 (HIV-2) have been described, recombinant viruses between these groups are rarely observed. Recently, three HIV-2 patients in Japan were described with rapidly progressive, acquired immunodeficiency. These patients were infected with an A/B inter-group recombinant designated CRF01_AB. Here, we characterize the capsid protein (CA) encoded by the viruses from these patients. HIV-2 CRF01_AB CA showed unique amino acid sequence almost equally distinct from group A and group B viruses. Notably, HIV-2 CRF01_AB CA showed potent resistance to human TRIM5α. In addition to the previously identified amino acid position 119 in the N-terminal domain of CA, we found that HIV-2 CRF01_AB-specific amino acid substitutions in the C-terminal domain also were necessary for resistance to human TRIM5α. These results indicate that retroviruses can evade TRIM5α by substitution at residues within the C-terminal domain of CA

ガーナ ホクブ ノ エイズ チリョウ セイジン カンジャ ニ オケル HIV-1 クミカエ ト ヤクザイ タイセイ

熊本大

List of primers used in HIV-1 genotypic drug-resistance testing.

<p>bp, base pairs; PCR, polymerase chain reaction; and RT-PCR, reverse transcription and polymerase chain reaction.</p>a<p>Amplicon positions in the reference HIV-1 HXB2 sequence are represented.</p

HIV-1 drug-resistance mutations in patients <15 years old (<i>n</i> = 11)^a.

<p>ART, antiretroviral therapy; d4T, stavudine; EFV, efavirenz; NNRTI, non-nucleoside reverse-transcriptase inhibitor; NRTI, nucleoside reverse-transcriptase inhibitor; and 3TC, lamivudine.</p>a<p>HIV-1 drug-resistance mutations were detected according to the latest definition of the International AIDS Society-USA panel <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071972#pone.0071972-Johnson1" target="_blank">[10]</a>. For ART-naïve patients, transmitted drug-resistance (shown in bold and underlined) was detected according to the latest definition of the WHO drug-resistance surveillance <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071972#pone.0071972-Bennett1" target="_blank">[11]</a>.</p

Frequency of HIV-1 drug-resistance mutations in ART-experienced and -naïve adult patients (≧15 years old) (<i>n</i> = 90)^a.

<p>ART, antiretroviral therapy; NNRTI, non-nucleoside reverse-transcriptase inhibitor; NRTI, nucleoside reverse-transcriptase inhibitor; PI, protease inhibitor; and TAMs, thymidine analog-associated mutations.</p>a<p>HIV-1 drug-resistance mutations were detected according to the latest definition of the International AIDS Society-USA panel <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071972#pone.0071972-Johnson1" target="_blank">[10]</a>. For ART-naïve patients, transmitted drug resistance was defined according to the latest definition of the WHO drug-resistance surveillance <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071972#pone.0071972-Bennett1" target="_blank">[11]</a>.</p