Heterogeneity of T Cell Responses to Pandemic pH1N1 Monovalent Vaccine in HIV-Infected Pregnant Women

Abstract We investigated the Th1 protective and regulatory T and B cell (Treg and Breg) responses to pH1N1 monovalent influenza vaccine (IIV1) in HIV-infected pregnant women on combination antiretroviral therapy (cART). Peripheral blood mononuclear cells (PBMCs) from 52 study participants were cryopreserved before and after vaccination and analyzed by flow cytometry. pH1N1-specific Th1, Treg, and Breg responses were measured in PBMCs after in vitro stimulation with pH1N1 and control antigen. The cohort analysis did not detect changes in pH1N1-Th1, Treg, or Breg subsets postvaccination. However, individual analyses distinguished subjects who mounted vigorous Th1 responses postvaccination from others who did not. Postvaccination, high pH1N1-Th1 correlated with high pH1N1-Treg and Breg responses, suggesting that low influenza effector responses did not result from excessive vaccine-induced immune regulation. High postvaccination pH1N1-Th1 responses correlated with baseline high PHA- and pH1N1-IFN-γ ELISpot and circulating CD4+CD39+% and CD8+CD39+% Treg, with low CD8+ cell numbers and CD19+FOXP3+% Breg, but not with CD4+ cell numbers or HIV viral load. These data highlight the heterogeneity of T cell responses to vaccines in HIV-infected individuals on cART. Predictors of robust Th1 responses to IIV include CD8+ cell numbers, T cell functionality, and circulating Breg and Treg

Lack of Marburg virus transmission from experimentally infected to susceptible in-contact Egyptian fruit bats

Egyptian fruit bats (Rousettus aegyptiacus) were inoculated subcutaneously (n = 22) with Marburg virus (MARV). No deaths, overt signs of morbidity, or gross lesions was identified, but microscopic pathological changes were seen in the liver of infected bats. The virus was detected in 15 different tissues and plasma but only sporadically in mucosal swab samples, urine, and fecal samples. Neither seroconversion nor viremia could be demonstrated in any of the in-contact susceptible bats (n = 14) up to 42 days after exposure to infected bats. In bats rechallenged (n = 4) on day 48 after infection, there was no viremia, and the virus could not be isolated from any of the tissues tested. This study confirmed that infection profiles are consistent with MARV replication in a reservoir host but failed to demonstrate MARV transmission through direct physical contact or indirectly via air. Bats develop strong protective immunity after infection with MARV.This work was supported by the National Institute for Communicable Diseases.http://jid.oxfordjournals.orgam2016Paraclinical Science

Between a Rock and a Hard Place: Habitat Selection in Female-Calf Humpback Whale (Megaptera novaeangliae) Pairs on the Hawaiian Breeding Grounds

The Au'au Channel between the islands of Maui and Lanai, Hawaii comprises critical breeding habitat for humpback whales (Megaptera novaeangliae) of the Central North Pacific stock. However, like many regions where marine mega-fauna gather, these waters are also the focus of a flourishing local eco-tourism and whale watching industry. Our aim was to establish current trends in habitat preference in female-calf humpback whale pairs within this region, focusing specifically on the busy, eastern portions of the channel. We used an equally-spaced zigzag transect survey design, compiled our results in a GIS model to identify spatial trends and calculated Neu's Indices to quantify levels of habitat use. Our study revealed that while mysticete female-calf pairs on breeding grounds typically favor shallow, inshore waters, female-calf pairs in the Au'au Channel avoided shallow waters (<20 m) and regions within 2 km of the shoreline. Preferred regions for female-calf pairs comprised water depths between 40–60 m, regions of rugged bottom topography and regions that lay between 4 and 6 km from a small boat harbor (Lahaina Harbor) that fell within the study area. In contrast to other humpback whale breeding grounds, there was only minimal evidence of typical patterns of stratification or segregation according to group composition. A review of habitat use by maternal females across Hawaiian waters indicates that maternal habitat choice varies between localities within the Hawaiian Islands, suggesting that maternal females alter their use of habitat according to locally varying pressures. This ability to respond to varying environments may be the key that allows wildlife species to persist in regions where human activity and critical habitat overlap

Benefits and risks of antiretroviral therapy for perinatal HIV prevention.

CAPRISA, 2016.Abstract available in pdf

Rapid Human Immunodeficiency Virus Decay in Highly Active Antiretroviral Therapy (HAART)-Experienced Children after Starting Mega-HAART

Increasing numbers of patients are treated with mega-highly active antiretroviral therapy (HAART), or multiple-combination antiretroviral therapy, in an attempt to overcome the viral resistance that has contributed to treatment failure. Studies of human immunodeficiency virus (HIV) viral dynamics are used to quantify the potency of a given regimen. While mega-HAART is expected to provide potent therapy, its potency among heavily experienced HIV-infected children who have failed previous treatment is untested. HIV dynamics studies performed in children have provided minimal information on viral dynamics during mega-HAART. The present study estimates first- and second-phase viral dynamics in six children on mega-HAART, following failure of combination therapy. The first phase of viral decay was rapid, relative to rates reported in previous pediatric studies (median δ = 0.778d(−)(1), range = 0.583 to 1.088, half-life 1 [t1(1/2)] = 0.894d), while the second phase revealed results similar to those of previous studies (median μ = 0.026d(−)(1), range = −0.005 to 0.206, t2(1/2) = 9.316d). This indicates that mega-HAART can provide potent therapy among heavily experienced pediatric patients

Impact of Nucleoside Reverse Transcriptase Inhibitors on Mitochondria in Human Immunodeficiency Virus Type 1-Infected Children Receiving Highly Active Antiretroviral Therapy▿

Mitochondrial toxicity induced by nucleoside reverse transcriptase inhibitors (NRTIs) has been reported to be responsible for various adverse effects. The relative impact of NRTIs on the mitochondria of human immunodeficiency virus (HIV) type 1 (HIV-1)-infected children receiving highly active antiretroviral therapy (HAART) is unknown. Mitochondrial DNA (mtDNA) levels were quantified longitudinally from peripheral blood mononuclear cells (PBMCs) in 31 HIV-1-infected children from Pediatric AIDS Clinical Trial Group Study 382 who were receiving HAART, including nelfinavir, efavirenz, and different NRTIs, and who had had undetectable plasma HIV-1 RNA levels for >2 years. The median mtDNA levels in PBMCs increased from 137 copies/cell at the baseline to 179 copies/cell at week 48 (P = 0.01) and 198 copies/cell at week 104 (P < 0.001). Before the initiation of HAART, children who received regimens containing didanosine had mtDNA levels persistently lower than those in children not receiving didanosine (106 versus 140 copies/cell; P = 0.008). During HAART, the median increase in the mtDNA level from the baseline to week 104 was the lowest in children who received regimens containing didanosine (+26 copies/cell) compared to those in children who received other regimens (+79 copies/cell) (P = 0.02). A multivariate analysis also demonstrated that didanosine, as part of HAART, was the only NRTI associated with the change in mtDNA levels (P = 0.007). Children receiving didanosine-containing antiretroviral regimens have the lowest mtDNA levels in PBMCs and may be at greater risk for long-term adverse effects due to mitochondrial toxicity. This may be of particular importance in resource-limited countries where didanosine is widely used for the treatment of HIV-infected children

Intrapatient Variability of Efavirenz Concentrations as a Predictor of Virologic Response to Antiretroviral Therapy

Intrapatient variability of drug concentrations over time has not been evaluated as a predictor of drug response but may provide information on the onset and maintenance of response and a patient's adherence to therapy. Our objective was to develop a pharmacologically based measure of intrapatient variability of concentrations and investigate its association with a patient's response to antiretroviral therapy. Efavirenz concentrations were obtained for 50 children enrolled in Pediatric AIDS Clinical Trials Group study 382, a concentration-controlled trial of efavirenz plus nelfinavir and at least one nucleoside reverse transcriptase inhibitor. Efavirenz pharmacokinetic parameters were determined from 24-h concentration-time profiles at weeks 2 and 6 and used to predict trough concentrations obtained during 1 year of therapy. A concentration predictability score, defined as the fraction of measured trough concentrations that fell within a ±50% range of the predicted concentration, was used to place subjects into high and low concentration predictability groups. Relationships between this score and human immunodeficiency virus RNA levels in plasma were investigated. Eight of 33 children (24%) in the high-predictability group experienced viral rebound, compared with 9 of 17 children (53%) in the low-predictability group (P = 0.042). Children with low predictability scores exhibited a significantly shorter time to their first viral rebounds and were significantly more likely to experience viral rebound; the latter finding persisted after adjustment for baseline viral load and efavirenz exposure at week 6. This novel method for the quantitation of intrapatient concentration variability was independently predictive of virologic rebound. This measure may allow interventions to minimize therapeutic failure and is applicable to other drugs

Killer Cell Immunoglobulin-Like Receptor Alleles Alter HIV Disease in Children

Background: HLA class I molecules are ligands for killer cell immunoglobin like receptors (KIR) that control the antiviral response of natural killer (NK) cells. However, the effects of KIR and HLA (KIR/HLA) alleles on HIV disease of children have not been studied. Methods: 993 antiretroviral naïve children with symptomatic HIV infection from PACTG protocols P152 and P300 were genotyped for KIR and HLA alleles using the Luminex platform. Linear regression was used to test the association between genotypes and baseline pre-ART HIV RNA, CD4+ lymphocyte count, and cognitive score, adjusting for age, race/ethnicity and study. The interaction between genetic markers and age was investigated. To account for multiple testing the false discovery rate (FDR) was controlled at 0.05. Results: Children with the KIR2DS4*ALL FULL LENGTH (KIR2DS4*AFL) allele had higher CD4+ lymphocyte counts. Among children ≤2 years of age, the KIR2DS4*AFL was associated with lower plasma HIV RNA and higher cognitive index scores. KIR Cent2DS3/5_1 had lower CD4+ lymphocyte counts in children ≤2 years of age, while the presence of Tel1, Tel2DS4_2, Tel2DS4_4, Tel8, Tel2DS4_6 had higher CD4+ lymphocyte counts in all children. Presence of Cent2, Cent4 and Cent8 was associated with increased HIV RNA load in children ≤2 years. Presence of KIR3DL1+Bw4 was associated with higher CD4+ lymphocyte counts in all children. Among children >2 years old, KIR3DS1+Bw4-80I was associated with higher plasma HIV RNA, and Bw6/Bw6 was associated with lower plasma HIV RNA compared to children with KIR3DS1+Bw4-80I. Conclusions: Presented data show for the first time that specific KIR alleles independently or combined with HLA ligands are associated with HIV RNA and CD4+ lymphocyte counts in infected, antiretroviral naive children; and many of these effect estimates appear to be age dependent. These data support a role for specific KIR alleles in HIV pathogenesis in children