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We investigated the effect of combination antiretroviral therapy (cART) on immune recovery, particularly on the percentages of PD-1-positive cells within the major leukocyte subsets. Cryopreserved peripheral blood mononuclear cells and plasma samples collected longitudinally from a subset of 13 children and adolescents (between 9.7 and 18.2 years old) who were enrolled in the International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) P1066 were used for this study. Immunophenotyping by flow cytometry was performed to determine the effect of raltegravir-containing cART regimen on the distribution of leukocyte populations, on the expression of PD-1 on T cell subpopulations, and on the expression of well-established markers of T cell activation (CD38 and HLA-DR) on CD8 T cells. C reactive protein (CRP), lipopolysaccharide (LPS), IL-6, and soluble CD163 were assayed in plasma samples by an enzyme-linked immunosorbent assay. Plasma viral loads were decreased in all subjects (by an average of 2.9 log units). The cART regimen, including raltegravir, induced changes in CD8 T cell subsets, consistent with an effective antiretroviral outcome and improved immunologic status, including increased percentages of CD8 stem cell memory T cells (Tscm). The percentages of CD8 PD-1-positive cells decreased significantly as compared with baseline levels. Among the proinflammatory markers measured in plasma, sCD163 showed a decline that was associated with cART. cART therapy, including raltegravir, over 48 weeks in children is associated with immune restoration, consistent with effective antiretroviral therapy, namely decreased percentages of PD-1 + CD8 + T cells, an increase in CD8 Tscm cells, and decreased levels of sCD163.

Background: The discovery of potent and broadly neutralizing antibodies (bNAbs) against human immunodeficiency virus (HIV) has made passive immunization a potential strategy for the prevention and treatment of HIV infection. We sought to determine whether passive administration of VRC01, a bNAb targeting the HIV CD4-binding site, can safely prevent or delay plasma viral rebound after the discontinuation of antiretroviral therapy (ART)., Methods: We conducted two open-label trials (AIDS Clinical Trials Group [ACTG] A5340 and National Institutes of Health [NIH] 15-I-0140) of the safety, side-effect profile, pharmacokinetic properties, and antiviral activity of VRC01 in persons with HIV infection who were undergoing interruption of ART., Results: A total of 24 participants were enrolled, and one serious alcohol-related adverse event occurred. Viral rebound occurred despite plasma VRC01 concentrations greater than 50 μg per milliliter. The median time to rebound was 4 weeks in the A5340 trial and 5.6 weeks in the NIH trial. Study participants were more likely than historical controls to have viral suppression at week 4 (38% vs. 13%, P=0.04 by a two-sided Fisher's exact test in the A5340 trial; and 80% vs. 13%, P<0.001 by a two-sided Fisher's exact test in the NIH trial) but the difference was not significant at week 8. Analyses of virus populations before ART as well as before and after ART interruption showed that VRC01 exerted pressure on rebounding virus, resulting in restriction of recrudescent viruses and selection for preexisting and emerging antibody neutralization-resistant virus., Conclusions: VRC01 slightly delayed plasma viral rebound in the trial participants, as compared with historical controls, but it did not maintain viral suppression by week 8. In the small number of participants enrolled in these trials, no safety concerns were identified with passive immunization with a single bNAb (VRC01). (Funded by the National Institute of Allergy and Infectious Diseases and others; ACTG A5340 and NIH 15-I-0140 ClinicalTrials.gov numbers, NCT02463227 and NCT02471326 .).

The effects of RU-486, a glucocorticoid antagonist, on HIV infection and replication in depressed and nondepressed women were studied using ex vivo models of HIV infection. RU-486 treatment of cells decreased HIV reverse transcriptase activity of monocyte-derived macrophages in a model of acute infectivity. RU-486 also decreased HIV viral replication in the chronically-infected T-cell line ACH-2, but not in the promonocyte cell line U1. No differences were associated with depression status. Thus, glucocorticoid antagonism may suppress HIV infectivity and replication ex vivo. Studies to determine the role of glucocorticoid antagonists in the host defense against HIV should be performed.

This study investigates the short-term effects of highly active antiretroviral therapy (HAART) on programmed death 1 receptor (PD-1) expression and lymphocyte function. We compared lymphocytes from human immunodeficiency virus (HIV)-infected adults prior to the initiation of HAART with lymphocytes from the same subjects following 2 months of treatment. Short-term HAART resulted in a moderate increase in the expression of PD-1 on both CD4(+) and CD8(+) T cells; yet, there was still a significant reduction in viral load and recovery of CD4(+) T cells. After 2 months of HAART, lymphocytes from the subjects had a reduction in lymphoproliferative responses to phytohemagglutinin (PHA) and an increased response to the Candida recall antigen and the HIV antigen p24 compared to pretreatment lymphocytes. PHA-stimulated peripheral blood mononuclear cells (PBMCs) from samples obtained 2 months after HAART produced higher levels of Th-1 cytokines (gamma interferon [IFN-γ] and tumor necrosis factor alpha[TNF-α]) than the levels observed for samples taken before treatment was initiated. There were no significant changes in the proinflammatory cytokine interleukin-2 (IL-2) or Th-2 cytokines (IL-4, IL-5, and IL-10) in the corresponding samples. Ex vivo PD-1 blockade significantly augmented PHA-induced lymphoproliferation as well as the levels of Th-1 cytokines and to a lesser extent the levels of Th-2 cytokines in PBMC cultures. The ability to downregulate PD-1 expression may be important in enhancing immune recovery in HIV infection.

Functional immunologic assays using cryopreserved peripheral blood mononuclear cells (PBMC) are influenced by blood processing, storage and shipment. The objective of this study was to compare the viability, recovery and ELISPOT results of PBMC stored and shipped in liquid nitrogen (LN/LN) or stored in LN and shipped on dry ice (LN/DI) or stored at -70°C for 3 to 12 weeks and shipped on DI (70/DI 3 to 12); and to assess the effect of donor HIV infection status on the interaction between storage/shipment and the outcome measures. PBMC from 12 HIV-infected and 12 uninfected donors showed that LN/LN conferred higher viability and recovery than LN/DI or 70/DI 3, 6, 9 or 12. LN/DI PBMC had higher viability than any 70/DI PBMC. The PBMC viability and recovery linearly decreased with the duration of storage at -70°C from 3 to 12 weeks. This effect was more pronounced in samples from HIV-infected than uninfected donors. Results of ELISPOT assays using CMV pp65, CEF and Candida albicans antigens were qualitatively and quantitatively similar across LN/LN, LN/DI and 70/DI 3. However, ELISPOT values significantly decreased with the duration of storage at -70°C both in HIV-infected and uninfected donors. ELISPOT results also decreased with PBMC viability <70%., (Copyright © 2010 Elsevier B.V. All rights reserved.)

The accurate measurement of T cell-associated CC chemokine receptor type 5 (CCR5) and CXC chemokine receptor type 4 (CXCR4) expression, including expression of CCR5 and CXCR4 mRNA as an immune measure of immunologic response to highly active antiretroviral therapy (HAART) and newer agents, including entry inhibitors, is essential. Previous studies have reported alterations in lymphocyte cell membrane CCR5 expression that were related to blood collection and cell separation media. Clinical trials often require the transport of specimens to central laboratories for evaluation, resulting in significant time delays between specimen procurement and analysis. This study shows that CCR5 expression on naïve and memory T cells is influenced by blood collection media and specimen age. Peripheral blood collected in Streck Vacutainer tubes containing a cell stabilizer and fixative was found to improve detection of CCR5 expression compared to specimens collected in K2 EDTA anticoagulant. The selection of flow cytometry gating strategies for the identification of naïve and memory T-helper cells can also significantly influence the sensitivity of detection of CCR5 expression. Procedural methods are described that allow for the optimal measurement of naïve and memory T-helper cell CCR5 and CXCR4 expression as well as the quantitation of CCR5 and CXCR4 mRNA.

The sensitivity and specificity of 3 rapid HIV antibody tests were assessed at 5 clinical trial sites in Africa and 1 site in the United States using a minimum of 100 HIV antibody positive samples and 100 HIV antibody negative samples at each site. The overall sensitivity and specificity for the OraSure OraQuick, Abbott Determine, and Trinity Unigold tests were 99.3%, 99.8%, and 98.5%, respectively, and 99.3%, 99.4%, and 99.5%, respectively. There were no instances at any site in which false-negative or false-positive results were obtained for the same sample on more than 1 rapid test kit. The results of this study provide assurance that for these diverse sites in Africa, the accuracy of these kits is quite good. Given the excellent accuracy, relatively fast turnaround time, and minimal infrastructure required, these rapid tests for HIV antibody provide a very attractive and accurate testing format.

The B7-CD28 immunoglobulin superfamily of costimulatory and coinhibitory ligands and their cell receptors play a critical role in modulating immune responses. Imbalances in these immune regulatory signals occur in pathological conditions characterized by chronic antigenic stimulation. Clinical studies often rely on the use of cryopreserved peripheral blood mononuclear cells (PBMC) to evaluate cellular immune responses. The impact of cryopreservation on these coinhibitory ligands and their cell receptors is unknown. In our studies, cryopreservation significantly reduced the expression of both PD-1 and PD-L1 on PBMC-derived CD3+/CD8+ T cells and CD45+/CD14+ monocytes obtained from adult control subjects. Blockade of PD-1, PD-L1, and PD-L2 using both freshly isolated and cryopreserved PBMC led to higher levels of phytohemagglutinin (PHA) and Candida-induced gamma interferon (IFN-gamma), interleukin-2 (IL-2), and tumor necrosis factor alpha (TNF-alpha) with no effect on IL-10 production. Coinhibitory signaling blockade of freshly isolated, PHA-stimulated PBMC from normal adult controls and human immunodeficiency virus (HIV)-infected subjects led to increased production of IL-4 and IL-5. Candida-stimulated PBMC preferentially induced IFN-gamma and TNF-alpha production, with reduced production of IL-2 and IL-10. This is in contrast to high levels of IFN-gamma, IL-2, and TNF-alpha production with PHA-stimulated cells. The effects of coinhibitory blockade on PHA and Candida-induced lymphoproliferation were varied, with freshly isolated PBMC from adult control subjects and HIV-infected patients yielding higher levels of lymphoproliferation in response to PD-1/PD-L1 blockade. Immune function studies employing cryopreserved cells may lead to increased T-cell effector cytolytic and regulatory immune responses.

Substance P (SP) is a member of the tachykinin family and has an important role in immune responses. SP is detectable in plasma in a free and bound state. Simple modification of a commercially available SP enzyme-linked immunosorbent assay allows the dissociation and capture of plasma SP without solid-phase extraction.

The pharmacokinetics of abacavir and its metabolites were investigated in 30 human immunodeficiency virus (HIV)-infected adolescents and young adults 13-25 years of age, equally divided into two groups: <18 years of age and >or=18 years of age. All the subjects received the recommended adult dose of 300 mg twice daily. The area under the plasma concentration-time curve (AUC) and half-life of abacavir did not differ significantly between the age groups or by gender or race, and there were only modest associations of age with apparent abacavir clearance and with volume of distribution. There were no significant correlations of carboxylate or glucuronide metabolite levels with age or gender, although glucuronide AUC was higher in Hispanic subjects than in African-American subjects. Zidovudine and lamivudine concentration profiles were also similar in the two age groups. A novel aspect of the study included an assessment of intracellular carbovir, zidovudine, and lamivudine triphosphate levels, and these were found to be similar in the two age-based groups. Overall, these findings suggest that current recommendations relating to adult dosages are appropriate for adolescents and young adults.

Background: Natural killer (NK) cells play an important role in innate immunity and are involved in the host defense against human immunodeficiency virus (HIV) infection. This study examines the potential role of three underlying regulatory systems that have been under investigation in central nervous system research as well as immune and viral research: serotonin, neurokinin, and glucocorticoid systems., Methods: Fifty-one HIV-seropositive subjects were recruited to achieve a representative sample of depressed and nondepressed women. The effects of a selective serotonin reuptake inhibitor (SSRI), a substance P (SP) antagonist, and a glucocorticoid antagonist on NK cell function were assessed in a series of ex vivo experiments of peripheral blood mononuclear cells from each HIV-seropositive subject., Results: Natural killer cell cytolytic activity was significantly increased by the SSRI citalopram and by the substance P antagonist CP-96345 relative to control conditions; the glucocorticoid antagonist, RU486, showed no effect on NK cytotoxicity. Our results suggest that the effects of the three agents did not differ as a function of depression., Conclusions: Our findings provide evidence that NK cell function in HIV infection may be enhanced by serotonin reuptake inhibition and by substance P antagonism. It remains to be determined if HIV-related impairment in not only NK cytolytic activity but also NK noncytolytic activity can be improved by an SSRI or an SP antagonist. Clinical studies are warranted to address these questions and the potential roles of serotonergic agents and SP antagonists in improving NK cell immunity, delaying HIV disease progression, and extending survival with HIV infection.

The undecapeptide substance P (SP) is a member of the tachykinin family of neurotransmitters, which has a pivotal role in the regulation of inflammatory and immune responses. One of the major barriers to the study of the in vivo role of SP in a number of immune disorders is the accurate measurement of SP in fluids. This is reflected in the variability of reported SP levels in serum and plasma of humans in both healthy and diseased states. This study was initiated in order to identify sources of variability by the comparative evaluation of the influences of sample preparation and analytical detection methods on the measurement of SP in plasma. The results indicate that sample preparation (peptide extraction versus no extraction) and the choice of analytical method for SP quantitation may yield significantly different values and may contribute to the variability in SP values reported in the literature. These results further emphasize the need for careful consideration in the selection of methods for SP quantitation, as well as caution in the interpretation and comparison of data reported in the literature.

This is the first report of natural killer cell enumeration and function in HIV-infected and high-risk uninfected adolescents. We examined the association of demographic characteristics of this cohort with three outcomes: CD16+ cell absolute count, lytic units per peripheral blood mononuclear cell (PBMC), and lytic units per natural killer (NK) cell. We also examined the association of CD4, CD38, and antiretroviral therapy (ART) use with these outcomes in the subset of HIV-infected adolescents. Adolescents participating in an on-going longitudinal study (the REACH study) were sampled for CD16+ cell count and NK function. This cross-sectional analysis was performed on 412 subjects with NK cell data available. HIV-positive males had higher numbers of CD3-/CD16+/CD56+ NK cells than HIV-positive females. However, for the HIV-negative subjects, we did not observe a gender-related effect for absolute NK cell numbers. Gender, however, was a significant covariate for the analysis, using lytic units per PBMC as the unit of measurement, with males showing higher values than females. Age was not a predictive covariate for any of the three assessments of NK cell number and function examined. Our observations concerning the HIV-positive individuals indicate that reduced CD4+ T cell counts were associated with decreased circulating CD3-/CD16+/CD56+ NK cells. We also observed an association between elevation of CD8+/CD38+/DR+ lymphocytes and lower NK lytic units per PBMC. The results of our multivariate models indicate that there is a reduced number of NK cells and reduced lytic units per PBMC in patients receiving single or multidrug antiretroviral therapy. There are changes in circulating NK cell number and function in HIV-infected adolescents, in comparison with high-risk HIV-negative adolescents. The data suggest that these changes may occur early in the course of HIV disease but that quantitative changes continue to occur with advancing depletion of the CD4+ T cell pool.

Objective: To test the efficacy of vaccination with the Towne live attenuated cytomegalovirus vaccine., Design: A double-blind, randomized, placebo-controlled trial in candidates for renal transplantation. The cytomegalovirus serologic status of both recipients and donors were determined, and the recipients were followed for periods of 6 months to 7 years after transplant., Setting: A university transplant center., Patients: The analyses were made on 237 patients who were given either vaccine or placebo, received renal transplants, and were followed for at least 6 months., Intervention: Subcutaneous inoculation with Towne live attenuated virus or with placebo., Main Outcome Measures: The presence of cytomegalovirus infection was defined by virus isolation and antibody tests. If infection occurred, a prearranged scoring system for cytomegalovirus disease was used to objectify disease severity., Results: The vaccine was well tolerated, and there were no discernible long-term adverse effects. Recipients who were originally seropositive did not clearly benefit from vaccination. Protective efficacy was analyzed in the group at highest risk for cytomegalovirus disease; recipients who were seronegative at the time of vaccination and who received a kidney from a seropositive donor. Compared with placebo recipients, vaccinated patients in this group had significantly less severe cytomegalovirus disease, with a significant reduction in disease scores (P = 0.03) and 85% decrease in the most severe disease (95% CI, 35% to 96%), although infection rates were similar. Graft survival at 36 months was improved in vaccinated recipients of cadaver kidneys (8 of 16) compared with unvaccinated recipients (4 of 16) (P = 0.04)., Conclusions: Previous vaccination of seronegative renal transplant recipients with live cytomegalovirus results in reduction of disease severity mimicking the action of naturally derived immunity.

An automated fluorescent immunoassay system (FIAX) was compared with complement fixation (CF) for measuring antibodies to cytomegalovirus (CMV) and herpes simplex virus (HSV) in clinical specimens. Compared with CF the specificity of FIAX (ability to detect a negative titer) was 95% for CMV and 92% for HSV. The sensitivity of FIAX (ability to detect a positive titer) was 98% for CMV and 95% for HSV. When paired samples were tested for significant titer rises, the concordance of the two assays for CMV was 96% and for HSV 80%. The FIAX assay was found to be reproducible when sera were tested within the same laboratory and in two different laboratories. The assay is fast, simple to perform, and not affected by anticomplementary activity. It is seen as a useful alternative to CF testing in a clinical virology laboratory.

To determine the extent to which pretransplant immunity resulting from natural infection protects against cytomegalovirus (CMV) disease, we analyzed CMV serology on 153 kidney donor and recipient pairs and followed transplant patients to determine incidence and severity of CMV disease. The overall incidence of CMV disease was 22%. Significant differences occurred in CMV disease incidence and severity, depending on the immune status of the kidney donor and recipient. Among recipients of kidneys from seropositive donors, immunity offered significant protection from CMV disease, reducing its incidence from 61% in nonimmune to 24% in immune patients (P less than 0.01). Pretransplant immune patients also had fever CMV-related complications. Among recipients of kidneys from seronegative donors, pretransplant immunity conferred a significant risk of CMV disease; immune patients had a 20% incidence of CMV disease compared with 2% in nonimmune patients (P less than 0.02). Disease was generally mild in all patients receiving kidneys from CMV infection had a 3-fold higher incidence of CMV disease than patients with reactivation infection (P less than 0.01). The incidence of CMV disease was similar in immune patients, whether they received a kidney from a seropositive or a seronegative donor. However, an important observation was that disease was significantly more severe in immune patients receiving a kidney from a seropositive donor (P less than 0.05). This indicates that if kidneys from seropositive donors are selected for use only in seropositive recipients, this places the immune patient at a higher risk for severe CMV disease. We conclude that pretransplant immunity offers a significant advantage to patients receiving kidneys from seropositive donors.