HIV Subtypes Distribution and Implication for Antiretroviral Treatment in a Ugandan Population

NAD(+) treatment prevents rotenone-induced apoptosis and necrosis of differentiated PC12 cells

Nicotinamide adenine dinucleotide (NAD(+)) plays critical roles in not only energy metabolism and mitochondrial functions, but also calcium homeostasis and immunological functions. It has been reported that NAD(+) administration can reduce ischemic brain damage. However, the mechanisms underlying the protective effects remain unclear. Because mitochondrial impairments play a key role in the cell death in cerebral ischemia, in this study we tested our hypothesis that NAD(+) can decrease mitochondrial damage-induced cell death using differentiated PC12 cells as a cellular model. We found that NAD(+) can decrease both early-stage and late-stage apoptosis, as well as necrosis of rotenone-treated PC12 cells, as assessed by FACS-based Annexin V/AAD assay. We also found that NAD(+) treatment can restore the intracellular NAD(+) levels of the rotenone-treated cells. Moreover, NAD(+) treatment can prevent rotenone-induced mitochondria depolarization. In summary, our study has provided first direct evidence that NAD(+) treatment can prevent rotenone-induced apoptosis and necrosis. Our study has also indicated that NAD(+) treatment can prevent mitochondrial damage-induced cell death, which may at least partially result from its protective effects on rotenone-induced mitochondrial depolarization. Because both mitochondrial damage and apoptosis play key roles in multiple neurological disorders, our study has highlighted the therapeutic potential of NAD(+) for brain ischemia and other neurological diseases.

Infection with different hiv subtypes is associated with CD4 activation-associated dysfunction and apoptosis

Determination of HIV-1 subtype may be important in the management of HIV-infected individuals, particularly with regard to deciding the CD4 cell count at which to initiate antiretroviral therapy. Non-B subtypes, A and D, are prevalent in Uganda, and individuals infected with subtype D seem to have faster disease progression compared with those infected with subtype A. We examined the level of apoptosis in CD4+ T cells in a study cohort of volunteers infected with subtypes A and D infection. Although the levels of apoptosis in the activated CD4+ cells significantly decreased with viral suppression, CD4+ apoptosis in individuals infected with subtype D were found to be significantly higher compared with those infected with subtype A before antiretroviral treatment. Surface expression of PD-1 on CD4 cells in subtype D was substantially higher compared with that in subtype A (P = 0.03). This difference was not observed in the CD8 population (P > 0.05). Our findings suggest that the infecting HIV subtypes exert an independent influence on the disease outcome in response to antiretroviral treatment.

An 11-Year Surveillance of HIV Type 1 Subtypes in Nagoya, Japan

Abstract To monitor active HIV-1 transmission in Nagoya, Japan, we have been determining the subtypes of HIV-1 infecting therapy-naive individuals who have newly visited the Nagoya Medical Center since 1997. The subtypes were determined by phylogenetic analyses using the base sequences in three regions of the HIV-1 genes including gag p17, pol protease (PR) and reverse transcriptase (RT), and env C2V3. Almost all HIV-1 subtypes from 1997 to 2007 and 93% of all HIV-1 isolates in 2007 were subtype B. HIV-1 subtypes A, C, D, and F have been detected sporadically since 1997, almost all in Africans and South Americans. The first detected circulating recombinant form (CRF ) was CRF01_AE (11-year average annual detection rate, 7.7%). Only two cases of CRF02_AG were detected in 2006. A unique recombinant form (URF ) was first detected in 1998 and the total number of URFs reached 25 by year 2007 (average annual detection rate, 4.7%). Eleven of these 25 were detected from 2000 to 2005 and had subtypes AE/B/AE as determined by base sequencing of the gag p17, pol PR and RT, and env C2V3 genes (average annual detection rate, 3.7%). Unique subtype B has been detected in six cases since 2006. All 17 of these patients were Japanese. Other recombinant HIV-1s have been detected intermittently in eight cases since 1998. During the 11-year surveillance, most HIV-1s in Nagoya, Japan were of subtype B. We expect that subtype B HIV-1 will continue to predominate for the next several years. Active recombination between subtype B and CRF01_AE HIV-1 and its transmission were also shown.

The Distribution and Immune Profile of T Cell Subsets in HIV-Infected Children from Uganda

Abstract T cell activation is an important mechanism in HIV-associated immune depletion. We have previously demonstrated an association between the hyperactivation of CD4(+) and CD8(+) T cells and low CD4 status in HIV-infected Ugandan children. In this study, we explore differences in activation between naive and memory T cells in HIV-infected Ugandan children. A significant correlation between CD4- and CD8-mediated immune activation and CD4 status was observed only in the memory T cells. Antiretroviral (ART) untreated and treated HIV-positive and HIV-negative children displayed similar profiles of activation and distribution within the CD4(+) naive T cells. In contrast, significantly higher immune activation of the memory CD4(+) T cell subset was seen in ART-untreated children when compared to ART-treated or HIV-negative children. ART-mediated viral suppression led to the correction of CD4(+) immune activation to levels seen in uninfected children but did not increase the size of the memory CD4(+) T cell population. High levels of CD8(+) immune activation were also found in both naive and memory cell subsets. Antiretroviral treatment led to the normalization of CD8(+) T cell activation but did not correct the distribution of naive CD8(+) T cells. We also assessed PD-1 expression on CD8(+) T cells as a measure of immune dysfunction. Upregulation of PD-1 was highest in untreated children but persisted in ART-treated children compared to uninfected children. The mechanisms of immunopathogenesis in pediatric HIV infection likely involve distinct contributions from individual naive and memory T cells subsets.