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Objectives: We utilize a large retrospective study cohort derived from electronic medical records to estimate the prevalence of long-term non-progression (LTNP) and determine the factors associated with progression among children infected with HIV in Botswana and Uganda. Methods: Electronic medical records from large tertiary HIV clinical centers in Botswana and Uganda were queried to identify LTNP children 0-18 years enrolled between June 2003 and May 2014 and extract demographic and nutritional parameters. Multivariate subdistribution hazard analyses were used to examine demographic factors and nutritional status in progression in the pre-antiretroviral therapy era. Results: Between the two countries, 14,246 antiretroviral therapy-naïve children infected with HIV were enrolled into clinical care. The overall proportion of LTNP was 6.3% (9.5% in Botswana vs 5.9% in Uganda). The median progression-free survival for the cohort was 6.3 years, although this was lower in Botswana than in Uganda (6.6 vs 8.8 years; P

Abstract Background HIV controllers (HICs) are a rare group of HIV-1-infected individuals able to naturally control viral replication. Several studies have identified the occurrence of HIV dual infections in seropositive individuals leading to disease progression. In HICs, however, dual infections with divergent outcomes in pathogenesis have been described. Case presentation Here, we present a case report of a HIC diagnosed in late 1999 who displayed stable CD4+ T cell levels and low plasmatic viral load across 12 years of follow-up. In early 2013, the patient started to present an increase in viral load, reaching a peak of 10,000 copies/ml in early 2014, followed by an oscillation of viremia at moderate levels in the following years. The genetic diversity of env proviral quasispecies from peripheral blood mononuclear cells (PBMCs) was studied by single genome amplification (SGA) at six timepoints across 2009–2017. Phylogenetic analyses of env sequences from 2009 and 2010 samples showed the presence of a single subtype B variant (called B1). Analyses of sequences from 2011 and after revealed an additional subtype B variant (called B2) and a subsequent dominance shift in the proviral quasispecies frequencies, with the B2 variant becoming the most frequent from 2014 onwards. Latent syphilis related to unprotected sexual intercourse was diagnosed a year before the first detection of B2, evidencing risk behavior and supporting the superinfection hypothesis. Immunologic analyses revealed an increase in CD8+ and CD4+ T cell immune activation following viremia increase and minor T cell subset alterations during follow-up. HIV-specific T cell responses remained low throughout the follow-up period. Conclusions Altogether, these results show that loss of viremia control in the HIC was associated with superinfection. These data alert to the negative consequences of reinfection on HIV pathogenesis, even in patients with a long history of viremia control and an absence of disease progression, reinforcing the need for continued use of adequate prevention strategies.

Abstract Background Abnormally increased immune activation is one of the main pathological features of acquired immunodeficiency syndrome (AIDS). This study aimed to determine whether long-term nonprogression (LTNP) suppresses the upregulation of immune activation and to elucidate the mechanisms whereby the LTNP state is maintained. Methods For this study we selected 4 rhesus macaques(RMs) infected with simian immunodeficiency virus (SIV) that were long-term nonprogressors (LTNP); for comparison we chose 4 healthy RMs that were seronegative for SIV (hereafter referred to as the Control group), and 4 progressing infection (Progressive group) SIV RMs. We observed these animals for 6 months without intervention and explored the immunological and pathological differences among the 3 groups. A series of immune activation and inflammation markers—such as C- C chemokine receptor type 5 (CCR5), beta 2- microglobulin (β2-MG), Human Leukocyte Antigen - antigen D Related (HLA-DR), CD38, the levels of microbial translocation (LPS -binding protein), and MAVS—and histological features were monitored during this period. Results Both SIV RNA and SIV DNA in the plasma and lymph nodes (LNs) of the LTNP group were at significantly lower levels than those of the Progressive group (P

Background: We have previously shown an association of elevated coinhibitory molecule 2B4 expression with iNKT cells alterations in HIV disease. Herein, we show a comparative analysis of 2B4 expression on iNKT cells of HIV long-term nonprogressors (LTNPs) and progressors. Methods: Antiretroviral therapy--naive HIV-seropositive individuals (progressors, n = 16) and LTNPs (n = 10) were recruited for this study. We used multicolor flow cytometry on frozen peripheral blood mononuclear cells to determine iNKT subset frequencies, the levels of coinhibitory 2B4 expression, and intracellular interferon-g (IFN-γ) production. CD1d tetramer was used to characterize iNKT cells. Results: We report significantly lower level of 2B4 expression on bulk LTNPs iNKT cells and on their CD4 subsets compared with HIV progressors. Furthermore, the iNKT cells from LTNPs produced higher amount of IFN-g than HIV progressors as detected by intracellular cytokine staining. Interestingly, the frequency of 2B4+iNKT cells of progressors but not LTNPs significantly correlates with CD4 T-cell count, HIV viral load, and IFN-γ+ production by iNKT cells. Conclusion: Our results suggest that in addition to suppressed HIV replication, diminished 2B4 expression and associated coinhibitory signaling, and substantial production of IFN-γ could contribute to preserved iNKT cell phenotype in LTNPs. [ABSTRACT FROM AUTHOR]

Abstract Background A small proportion of HIV-infected patients remain clinically and/or immunologically stable for years, including elite controllers (ECs) who have undetectable viremia (10 years). However, the mechanism of nonprogression needs to be further resolved. In this study, a transcriptome meta-analysis was performed on nonprogressor and progressor microarray data to identify differential transcriptome pathways and potential biomarkers. Methods Using the INMEX (integrative meta-analysis of expression data) program, we performed the meta-analysis to identify consistently differentially expressed genes (DEGs) in nonprogressors and further performed functional interpretation (gene ontology analysis and pathway analysis) of the DEGs identified in the meta-analysis. Five microarray datasets (81 cases and 98 controls in total), including whole blood, CD4+ and CD8+ T cells, were collected for meta-analysis. Results We determined that nonprogressors have reduced expression of important interferon-stimulated genes (ISGs), CD38, lymphocyte activation gene 3 (LAG-3) in whole blood, CD4+ and CD8+ T cells. Gene ontology (GO) analysis showed a significant enrichment in DEGs that function in the type I interferon signaling pathway. Upregulated pathways, including the PI3K-Akt signaling pathway in whole blood, cytokine–cytokine receptor interaction in CD4+ T cells and the MAPK signaling pathway in CD8+ T cells, were identified in nonprogressors compared with progressors. In each metabolic functional category, the number of downregulated DEGs was more than the upregulated DEGs, and almost all genes were downregulated DEGs in the oxidative phosphorylation (OXPHOS) and tricarboxylic acid (TCA) cycle in the three types of samples. Conclusions Our transcriptomic meta-analysis provides a comprehensive evaluation of the gene expression profiles in major blood types of nonprogressors, providing new insights in the understanding of HIV pathogenesis and developing strategies to delay HIV disease progression.

Background: Disease progression monitoring through CD4 counts alone can be inadequate in HIV infection as ongoing immune activation may result in Serious non-AIDS events (SNAEs). SNAEs involve monocyte activation driven chronic inflammation with significant sequelae observed even during HAART. Here, we attempted to delineate functional monocyte based signatures across stages of HIV disease progression.Methods: Participants spanning four cohorts were recruited—pre-ART (PA; 7 years of infection, CD4 > 350 cells/μL, n = 20), individuals on therapy (ART; n = 18) and seronegative controls (SN; n = 15). Immunophenotyping of monocyte subsets and evaluation of expression of HIV-binding receptors—CD4 and CCR5, marker of immune activation- HLA-DR and M2 phenotype—mannose receptor (CD206) was followed by association of monocyte-specific parameters with conventional markers of disease progression such as absolute CD4 count, CD4/CD8 ratio, viral load, and T cell activation.Results: A significant expansion of intermediate monocytes (CD14++CD16+) with a concomitant decline in classical subset (CD14++CD16–) was observed in all infected cohorts compared to seronegative controls. In addition, an expansion of the non-classical subset (CD14+CD16++) was observed in long-term non-progressors. Dysregulation in monocyte subsets associated with CD4 count and CD4/CD8 ratio in PAs but not in LTNPs. We report for the first time that expression of CD206 is most prominent on intermediate monocytes which also have the highest expression of CD4, CCR5, and HLA-DR. Despite preserved CD4 counts, LTNPs had similar immune activation profiles to PAs, as evidenced by elevated HLA-DR expression across monocyte subsets. HLA-DR expression, similar to that in SNs, observed in the ART group indicated partial immune restoration within the monocyte compartment. Increased CD206 expression on monocytes together with frequency of activated CD4+ T lymphocytes (HLA-DR+CD38+) showed significant and positive association with viral load in LTNPs, but not PAs.Conclusion: Our results describe for the first time the presence of monocyte dysregulation involving increased activation in LTNPs, who, in spite of preserved CD4 counts, may remain susceptible to prolonged effects of systemic inflammation and highlight CD206, as a unique non-T correlate of viremia, in viremic non-progression.

Background: Disease progression monitoring through CD4 counts alone can be inadequate in HIV infection as ongoing immune activation may result in Serious non-AIDS events (SNAEs). SNAEs involve monocyte activation driven chronic inflammation with significant sequelae observed even during HAART. Here, we attempted to delineate functional monocyte based signatures across stages of HIV disease progression. Methods: Participants spanning four cohorts were recruited—pre-ART (PA; <7 years of infection; n = 20), long-term non-progressors (LTNP; >7 years of infection, CD4 > 350 cells/μL, n = 20), individuals on therapy (ART; n = 18) and seronegative controls (SN; n = 15). Immunophenotyping of monocyte subsets and evaluation of expression of HIV-binding receptors—CD4 and CCR5, marker of immune activation- HLA-DR and M2 phenotype—mannose receptor (CD206) was followed by association of monocyte-specific parameters with conventional markers of disease progression such as absolute CD4 count, CD4/CD8 ratio, viral load, and T cell activation. Results: A significant expansion of intermediate monocytes (CD14++CD16+) with a concomitant decline in classical subset (CD14++CD16–) was observed in all infected cohorts compared to seronegative controls. In addition, an expansion of the non-classical subset (CD14+CD16++) was observed in long-term non-progressors. Dysregulation in monocyte subsets associated with CD4 count and CD4/CD8 ratio in PAs but not in LTNPs. We report for the first time that expression of CD206 is most prominent on intermediate monocytes which also have the highest expression of CD4, CCR5, and HLA-DR. Despite preserved CD4 counts, LTNPs had similar immune activation profiles to PAs, as evidenced by elevated HLA-DR expression across monocyte subsets. HLA-DR expression, similar to that in SNs, observed in the ART group indicated partial immune restoration within the monocyte compartment. Increased CD206 expression on monocytes together with frequency of activated CD4+ T lymphocytes (HLA-DR+CD38+) showed significant and positive association with viral load in LTNPs, but not PAs. Conclusion: Our results describe for the first time the presence of monocyte dysregulation involving increased activation in LTNPs, who, in spite of preserved CD4 counts, may remain susceptible to prolonged effects of systemic inflammation and highlight CD206, as a unique non-T correlate of viremia, in viremic non-progression. [ABSTRACT FROM AUTHOR]

The polymorphisms in Toll-like receptor (TLR) 7 and 9 genes are shown to influence HIV-1 infection. We studied HIV-1-infected Indian individuals for presence and association of TLR7 and 9 gene polymorphism with different disease outcomes. Genomic DNA from 65 HIV-infected individuals (35 long-term nonprogressors and 30 progressors) and 89 uninfected healthy donors was isolated, amplified, and sequenced for the reported polymorphisms in TLR7 [Gln11Leu (A/T); rs179008] and TLR9 (1635A/G; rs352140) genes. Of these, only the reported TLR9 single-nucleotide polymorphism [SNP; p = .017, odds ratio (OR) = 0.20] and its allele A frequency (p = .038, OR = 0.41) were found to be associated with slow disease progression. Of the new SNPs observed (three TLR7 and two TLR9), the TLR7 rs2074109 G allele showed less likely association with HIV-1 acquisition (p = .019, OR = 0.27). These findings indicate that TLR7 SNP (rs2074109) could be one of the factors for predisposition to HIV-1 and TLR9 1635A/G genotype and allele might have a role in HIV-1 disease progression in Indian population. [ABSTRACT FROM AUTHOR]

Lymphocyte subsets of long-term non-progressor (LPNT) HIV-infected children is a less studied aspect of HIV infection. Evaluation of different lymphocyte subsets was done in HIV-infected children ≥8 years of age. Subjects were divided in two groups—group 1 (LTNP), treatment-naive with CD4 ≥ 500 cells/μL (n = 20); group 2, non-long-term non-progressor (nLTNPs) receiving antiretroviral therapy (ART) with CD4 count ≤500 on at least one occasion (n = 21). Group 3 comprised age-, sex-matched healthy controls (HCs, n = 20). Lymphocyte subsets were acquired with a flow cytometer (Navios; Beckman Coulter), and data were analyzed using Kaluza flow analysis software. The mean ages were 12.1 (±2.4 SD) and 12.5 (±2.7) years with mean duration of follow-up of 6.8 (±3.4) and 5.6 (±1.95) years in LTNP and nLTNP subjects, respectively. The mean duration of ART was 5.17 years for group 2. Absolute count and percentage of CD4+ T cells was lower in nLTNPs than in LTNPs. Cytotoxic T cells were high in both HIV-infected groups compared with HCs. Natural killer (NK) cells were found to be significantly lower in LTNP and nLTNP groups compared with HCs (p ≤ .000003 and p ≤ .00003, respectively). Naïve B cells were more in HIV-infected individuals than in HCs. NK cells were significantly lower in LTNP and nLTNP groups. Immune reconstitution was comparable in children initiated with ART early versus long-term HIV-infected children receiving no ART. [ABSTRACT FROM AUTHOR]

There is a rare group of HIV-1-infected individuals who show permanent control of clinical progression for over 10 years, maintain CD4+ cells >500 μl and have undetectable viral loads; they are designated long-term non-progressors elite controllers (LTNPs ECs). Multiple studies have demonstrated the necessary contribution of at least two of host, immune and viral factors to the LTNP phenotype. This group of individuals is not homogenous because of the different involvement of these factors. We will review the role of each of these and their combinations to the LTNP EC phenotype. LTNP EC individuals offer an opportunity for the investigation into the mechanisms for the spontaneous control of HIV infection. [ABSTRACT FROM AUTHOR]

Abstract Progressive HIV infection is marked with reduced frequency and impaired function of Th17 cells. Since T-cell functional responses are regulated by various inhibitory receptors; we examined the expression profile of CTLA-4, PD-1, Tim-3 and apoptotic marker: Caspase-3 on virus-specific Th17 cells from HIV-infected Long-Term Non-Progressors (LTNPs), chronic disease progressors and HIV-uninfected healthy controls (HC) using flowcytometry. Real-time PCR was done to analyze the mRNA expression of Th17 and Treg specific genes. LTNPs showed higher frequencies of HIV-specific Th17 cells; higher mRNA expression of IL-17, IL-22 while lower expression of IL-10; along with lower Caspase-3 expression than the progressors. Among inhibitory receptors, expression of CTLA-4 was 27 and 8 fold; PD-1 was 8 and 6 fold while Tim-3 was 7 and 6 fold higher in progressors and LTNPs respectively than HC. Among HIV-infected patients, LTNPs had 3-fold lower expression of CTLA-4 on HIV-specific Th17 cells than progressors ( p = 0.06). Caspase-3+ve Th17 cells were associated with HIV-specific Th17 cells expressing CTLA-4 ( r = 0.66; p < 0.0001), PD-1 ( r = 0.40; p = 0.02) and Tim-3 ( r = 0.35; p = 0.04). To conclude, virus-specific Th17 cells from LTNP maintained IL-17 production, expressed low levels of CTLA-4 and reduced apoptosis. The study suggests that such functional competence of Th17 cells could be one of the factors in maintenance of non-progressive HIV infection. [ABSTRACT FROM AUTHOR]

The exposure to CCR5 (CC chemokine receptor 5) specific natural antibodies in vitro produces a Class B β-arrestin2-dependent CCR5 retention with the aid of ERK1, due to the formation of a CCR5 signalosome, which remains stable for at least 48 h. Considering that β-arrestins and MAPKs are receptive to environmental signals, their signal complexes could be one of the key junction for GPCRs internalization related signal transduction. Here, we demonstrate that, in T cells, the phosphorylation status of either CCR5 receptor or ERK1 protein is necessary to drive the internalized receptor into the early endosomes, forming the CCR5 signalosome. In particular, our data show that β-arrestin2/ERK1 complex is a relevant transducer in the CCR5 signaling pathway. Understanding the mechanism of CCR5 regulation is essential for many inflammatory disorders, tumorigenesis and viral infection such as HIV. [ABSTRACT FROM AUTHOR]

Background:The influenza-specific antibodies mediating antibody-dependent cellular cytotoxicity (ADCC) may be important in protection against influenza. However, it is not known whether immunocompromised individuals such as HIV-infected persons who have never been vaccinated with influenza vaccine have such a response. Methods:The anti-influenza ADCC responses were investigated in plasma samples from 50 HIV positive persons [25 long-term nonprogressors (LTNPs) and 25 progressors] and from 20 HIV-uninfected healthy individuals. None of the participants had received influenza vaccine. Results:The frequencies and the magnitude of ADCC responses against two influenza A virus strains (pH1N1-A/California/7/2009 and H3N2-A/Brisbane/10/2007) were comparable in HIV-infected individuals and in healthy controls (p > .05). However, the magnitude of the ADCC response was slightly higher in LTNPs than in progressors (p = .025). The level of ADCC antibodies against pH1N1 and H3N2 correlated significantly indicating the cross-reactive nature of these antibodies (p < .0001). Additionally, the level of these ADCC antibodies was significantly associated with antibodies against the highly pathogenic avian influenza H5N1 virus (H5N1-A/Chicken/India/NIV/33487/2007). Conclusion:This is the first report of anti-influenza ADCC antibodies in HIV-infected Indian individuals. Identification of cross-reactive ADCC epitopes in HIV-infected individuals could improve the design of influenza vaccine for immunocompromised individuals. [ABSTRACT FROM AUTHOR]

Background: Natural killer T (NKT) cells act as a bridge between innate and adaptive immune responses. Limited information is available regarding the role of NKT cells in the HIV disease progression especially HIV-1 C infection. Methodology: NKT cells were characterized for their frequency and the activation, aging, exhaustion status, and their proliferation ability in 32 long-term nonprogressors (LTNPs), 40 progressors, 18 patients before and after suppressive combination antiretroviral therapy (cART) along with 35 HIV-1-negative subjects using multicolor flow cytometry. Results: The frequencies of total NKT cells and their subpopulation were significantly higher in LTNPs as compared with those obtained in progressors (P < 0.0001) and were significantly associated with higher CD4 counts and with lower plasma viral loads. The percentage of activated, aged, and exhausted NKT cells were significantly lower in LTNPs as compared with the progressors and inversely correlated with CD4 count and positively with plasma viral loads. The NKT cells from the LTNPs showed higher proliferation ability. The frequency and proliferation ability of the NKT cells were partially restored after 12 months of suppressive cART but still lower than the levels in LTNPs. The degree of restoration after cART was similar in both CD4+ and CD42 NKT cells. Conclusion: The findings demonstrate significant association of preserved NKT cells with the nonprogressive HIV infection and also showed that exhausted NKT cells are associated with disease progression. Further characterization of their functionality and assessment of sustenance in HIV infection will help to understand the HIV pathogenesis and to develop immune therapies. [ABSTRACT FROM AUTHOR]

Background. Thymic function has been mainly analyzed with surrogate peripheral markers affected by peripheral T-cell expansion, making it difficult to assess the role of thymic failure in human immunodeficiency virus (HIV) disease progression. The assay of signal-joint/DβJβ T-cell rearrangement excision circles (sj/β-TREC ratio) overcomes this limitation but has only been assayed in small cohorts. Thus, the aim of this study was to determine the role of thymic function, measured by the sj/β-TREC ratio, on CD4 T-cell maintenance in prospective HIV cohorts that include patients with a wide age range and different immunological phenotypes. Methods. Seven hundred seventy-four patients including typical progressors, long-term nonprogressors (LTNPs), and vertically HIV-infected subjects were analyzed. Thymic function was quantified in peripheral blood samples using the sj/β-TREC ratio. Associations between thymic function and CD4 T-cell dynamics and combination antiretroviral therapy (cART) onset were analyzed using linear, logistic, and Cox proportional hazard models. Results. Thymic function failure (sj/β-TREC ratio <10) was independently associated with HIV progression. In agreement, patients with distinctive high CD4 T-cell levels and low progression rates (vertically HIV-infected patients and LTNPs, including HIV controllers) had significantly higher thymic function levels whereas patients with thymic function failure had lower CD4 T-cell levels, lower nadir, and faster CD4 T-cell decay. Conclusions. This work establishes the relevance of thymic function, measured by sj/β-TREC ratio, in HIV disease progression by analyzing a large number of patients in 3 cohorts with different HIV disease progression phenotypes. These results support and help to understand the mechanisms underlying the rationale of early cART onset. [ABSTRACT FROM AUTHOR]

Identification of broadly neutralizing antibodies (NAbs) generated during the course of HIV-1 infection is essential for effective HIV-1 vaccine design. The magnitude and breadth of neutralizing activity in the sera from 46 antiretroviral treatment-naive HIV-1 clade C-infected individuals was measured in a single round infection assay using TZM-bl cells and multisubtype panel of env-pseudotyped viruses. Higher levels of NAb response (NAb titer 500 to >40 000) were measured in these patients against tier 1 and tier 2 viruses. The average magnitude of the NAb responses of chronically infected individuals against heterologous viruses was consistently higher than the response observed from individuals with long-term nonprogressor ( P = .086). To conclude, high titers of HIV-1 cross-neutralizing activity were observed in the sera from a subset of HIV-1-infected individuals in Chennai, India. Additional studies of the epitopes recognized by these antibodies may facilitate the discovery of an effective vaccine immunogen. [ABSTRACT FROM AUTHOR]

HIV-specific antibody-dependent cell cytotoxicity (ADCC) is likely to be important in governing protection from human immunodeficiency virus (HIV) and slowing disease progression. Little is known about the ADCC responses to HIV-1 subtype C. We characterized ADCC responses in HIV-1 subtype C-infected Indian subjects with slow disease progression and identified the dominant antigenic regions recognized by these antibodies. ADCC responses were measured in plasma from 34 long-term non-progressors (LTNPs), who were asymptomatic and maintained CD4 count above 500 cells/mm3 for the last 7 years in the absence of antiretroviral therapy (ART), and 58 ART naïve progressors with CD4 count <500 cells/mm3 against overlapping HIV-1 peptides using a flow cytometry-based antibody-dependent natural killer (NK) cell activation assay. The assay measured CD107a expression on NK cells as a marker of antibody-dependent NK cell activation and IFN-γ secretion by NK cells upon activation. The ADCC epitopes were mapped using the matrix of overlapping peptides. Indian LTNPs showed higher and broader ADCC responses compared to the progressors. The Env-C and Tat-specific ADCC responses were associated with lower plasma viral load, whereas the Env-C responses were also associated with higher CD4 counts. Five of 10 LTNP responders targeted epitopes in the V3 region (amino acids 288-330) of Env-C. Additionally, three Tat regions were targeted by ADCC antibodies from LTNPs. ADCC responses were associated with slow HIV progression in Indian subtype C-infected cohort. The frequently recognized peptides from the V3 loop of Env and the novel epitopes from Tat by the LTNPs warrants further study to understand the role of ADCC responses to these regions in control and prevention of HIV-1 infection. [ABSTRACT FROM AUTHOR]

Background: HIV-infected long-term non-progressor (LTNP) subjects can prevent viral replication and may harbor useful information for the development of both antibody and active vaccination treatments. In this study we used LTNP sera to examine the epitopes presented to the gp160 protein, and from this procedure we hope to elucidate potential biomarkers pertaining to the level of resistance a patient may have in developing AIDS after infection with HIV. We used five clinical sera samples from LTNP patients to identify common epitopes by ELISA; peptides with high binding to sera were selected and analyzed for conservation among HIV clades. Antibodies were generated against one identified epitope using a chimeric peptide in BALB/c mice, and both the sera from these mice and LTNP sera were tested for viral inhibition capabilities. Results: A monoclonal antibody, CL3, against one identified epitope was used to compare these epitopes neutralizing capability. LTNP sera was also studied to determine chemokine/cytokine changes in these patients. The sera from LTNP patients 2, 3, 4, and 5 were identified as having the highest titers, and also significantly inhibited syncytia formation in vitro. Finally, the protein cytokine array demonstrated that I-309 and IGFBP-1 decreased in LTNPs, but levels of TIMP-1 and NAP-2 increased significantly. Conclusions: Our results indicate that the use of LTNP samples may be a useful for identifying further anti-viral epitopes, and may be a possible predictor for determining if patients show higher resistances of converting the HIV infection to AIDS. [ABSTRACT FROM AUTHOR]

Introduction HIV‐1‐associated CD4+ T‐cell depletion is a consequence of uninfected cell death. Nef is one of the viral factors that trigger apoptosis on bystander cells, though the plasma Nef levels do not correlate with Th lymphocytes counts. The aim of our study was to evaluate whether anti‐Nef antibodies were involved in paediatric AIDS development and whether they can prevent the CD4+ T‐cell depletion in vertically infected children. Methods Two hundred and seventy three HIV‐1 vertically infected children seen at Garrahan Paediatric Hospital were randomly included in the study, adding 13 selected cases: seven LTNP (long‐term non‐progressors) and six RP (rapid progressors) children (ntotal=286). Specific anti‐HIV‐1‐Nef antibodies were titrated by indirect ELISA and compared between groups. The plasma blocking effect on Nef‐dependent cytotoxicity was evaluated in Jurkat cells using recombinant Nef as apoptotic stimulus and patient plasmas as blockers, measuring the apoptotic levels using Annexin‐V stain and flow cytometry. Results Only 63.4% of the patients had specific anti‐Nef antibodies, and the levels of anti‐Nef antibodies found in the selected LTNPs plasmas were always significantly higher (p=1.55×10−4) than those in RPs or general HIV‐1+ paediatric populations. The LTNPs’ plasma had a strong inhibitory effect on Nef‐dependent cytotoxicity even at high dilutions, while RP plasmas had little or no effect on Nef‐induced apoptosis. Discussion and conclusions High anti‐Nef antibody levels are associated and predict slow or non‐progression to AIDS in vertically HIV‐1‐infected children. They could be an efficient tool in preventing Nef‐associated bystander effect, preserving CD4+ T‐cells and the immune function in the context of paediatric HIV‐1 infection.

Complex mechanisms underlying the maintenance of fully functional, proliferative, HIV-1-specific T-cell responses involve processes from early T-cell development through to the final stages of T-cell differentiation and antigen recognition. Virus-specific proliferative CD4 and CD8 T-cell responses, important for the control of infection, are observed in some HIV-1+ patients during early stages of disease, and are maintained in long-term nonprogressing subjects. In the vast majority of HIV-1+ patients, full immune functionality is lost when proliferative HIV-1-specific T-cell responses undergo a variable progressive decline throughout the course of chronic infection. This appears irreparable despite administration of potent combination antiretroviral therapy, which to date is non-curative, necessitating life-long administration and the development of effective, novel, therapeutic interventions. While a sterilising cure, involving clearance of virus from the host, remains a primary aim, a functional cure may be a more feasible goal with considerable impact on worldwide HIV-1 infection. Such an approach would enable long-term co-existence of host and virus in the absence of toxic and costly drugs. Effective immune homeostasis coupled with a balanced response appropriately targeting conserved viral antigens, in a manner that avoids hyperactivation and exhaustion, may prove to be the strongest correlate of durable viral control. This review describes novel concepts underlying full immune functionality in the context of HIV-1 infection, which may be utilised in future strategies designed to improve upon existing therapy. The aim will be to induce long-term nonprogressor or elite controller status in every infected host, through immune-mediated control of viraemia and reduction of viral reservoirs, leading to lower HIV-1 transmission rates.

Low-temperature nitrogen plasma ( LTNP) was used to wither green tea leaf to study its effect on the polyphenol content. Using a dielectric barrier discharge chamber to provide the LTNP environment, green tea leaf was withered at various withering times. Made tea samples indicated that LTNP had an effect on polyphenol content. The highest polyphenol content of 78.56 mg g−1 in made tea was attained in 1 h after which it showed a decreasing trend with increasing retention time. For comparison purposes, green tea leaf was also withered in nonplasma environments. Highest polyphenol content of 133.4 mg g−1 in made tea was attained in a sample withered anaerobically in nitrogen gas at room temperature and atmospheric pressure for 18 h. In another sample, green tea leaf was directly macerated and dried without withering and fermenting and had polyphenol content of 101.91 mg g−1 in made tea. These contents were compared with green tea 4, purple tea and oolong tea that are currently manufactured in Kenya. [ABSTRACT FROM AUTHOR]

[Display omitted] • HIV-specific T cell responses in Viremic Non Progressors are mainly non-cytolytic. • These are enriched for MIP-1β production and reduced degranulation ability. • Cytolytic potential is limited to polyfunctional effector (CD4+ and CD8+) T cells. • Preserved CD4+ Central memory T cells retain Gag specific IFN-γ production. This study reports on HIV-specific T cell responses in HIV-1 infected Viremic Non-Progressors (VNPs), a rare group of people living with HIV that exhibit asymptomatic infection over several years accompanied by stable CD4+ T cell counts in spite of ongoing viral replication. We attempted to identify key virus-specific functional attributes that could underlie the apparently paradoxical virus-host equilibrium observed in VNPs. Our results revealed modulation of HIV-specific CD4+ and CD8+ effector T cell responses in VNPs towards a dominant non-cytolytic profile with concomitantly diminished degranulation (CD107a+) ability. Further, the HIV specific CD8+ effector T cell response was primarily enriched for MIP-1β producing cells. As expected, concordant with better viral suppression, VCs exhibit a robust cytolytic T cell response. Interestingly, PuPs shared features common to both these responses but did not exhibit a CD4+ central memory IFN-γ producing Gag-specific response that was shared by both non-progressor (VC and VNP) groups, suggesting CD4 helper response is critical for non-progression. Our study also revealed that cytolytic response in VNPs is primarily limited to polyfunctional cells while both monofunctional and polyfunctional cells significantly contribute to cytolytic responses in VCs. To further understand mechanisms underlying the unique HIV-specific effector T cell response described here in VNPs we also evaluated and demonstrated a possible role for altered gut homing in these individuals. Our findings inform immunotherapeutic interventions to achieve functional cures in the context of ART resistance and serious non AIDS events. [ABSTRACT FROM AUTHOR]

HIV-infected controllers control viral replication and maintain normal CD4 T cell counts. Long-term nonprogressors (LTNPs) also maintain normal CD4 T cell counts but have ongoing viral replication. We hypothesized that immunoregulatory mechanisms are involved in preserved CD4 T cell counts in controllers and in LTNPs.Twenty HIV-infected viremic controllers, 5 elite controllers (ECs), and 14 LTNPs were included in this cross-sectional study. For comparison, 25 progressors and 34 healthy controls were included. Regulatory T cells (Tregs), Treg subpopulations, CD161+Th17 cells, and CD3+CD8+CD161highTc17 cells in peripheral blood were measured using flow cytometry. Tregs in lymphoid tissue were determined in tonsil biopsies and evaluated using immunolabeling. The production of transforming growth factor beta (TGF-β), interleukin (IL)-10, and IL-17 upon stimulation with phytohemagglutinin in peripheral blood was determined by Luminex.All groups of HIV-infected patients displayed similar percentages of Tregs in both peripheral blood and lymphoid tissue. However, a larger percentage of Tregs in ECs and LTNPs were activated compared with that in controls, progressors, and viremic controllers. Further, ECs as the only group of HIV-infected patients, displayed elevated percentages of CD161+Th17 cells, preserved CD3+CD8+CD161highTc17 cells, and preserved IL-10 production.Overall, Treg percentage was similar in both blood and lymphoid tissue in all groups of patients and controls. However, both ECs and LTNPs displayed a large proportion of activated Tregs suggesting immunoregulatory mechanisms to be involved in preserving CD4 T cell counts in HIV-infected nonprogressors. [ABSTRACT FROM AUTHOR]

Introduction: HIV‐1‐associated CD4+ T‐cell depletion is a consequence of uninfected cell death. Nef is one of the viral factors that trigger apoptosis on bystander cells, though the plasma Nef levels do not correlate with Th lymphocytes counts. The aim of our study was to evaluate whether anti‐Nef antibodies were involved in paediatric AIDS development and whether they can prevent the CD4+ T‐cell depletion in vertically infected children. Methods: Two hundred and seventy three HIV‐1 vertically infected children seen at Garrahan Paediatric Hospital were randomly included in the study, adding 13 selected cases: seven LTNP (long‐term non‐progressors) and six RP (rapid progressors) children (ntotal=286). Specific anti‐HIV‐1‐Nef antibodies were titrated by indirect ELISA and compared between groups. The plasma blocking effect on Nef‐dependent cytotoxicity was evaluated in Jurkat cells using recombinant Nef as apoptotic stimulus and patient plasmas as blockers, measuring the apoptotic levels using Annexin‐V stain and flow cytometry. Results: Only 63.4% of the patients had specific anti‐Nef antibodies, and the levels of anti‐Nef antibodies found in the selected LTNPs plasmas were always significantly higher (p=1.55×10−4) than those in RPs or general HIV‐1+ paediatric populations. The LTNPs’ plasma had a strong inhibitory effect on Nef‐dependent cytotoxicity even at high dilutions, while RP plasmas had little or no effect on Nef‐induced apoptosis. Discussion and conclusions: High anti‐Nef antibody levels are associated and predict slow or non‐progression to AIDS in vertically HIV‐1‐infected children. They could be an efficient tool in preventing Nef‐associated bystander effect, preserving CD4+ T‐cells and the immune function in the context of paediatric HIV‐1 infection. [ABSTRACT FROM AUTHOR]

Human immunodeficiency virus type 1 (HIV-1) dual infection (DI) in long-term nonprogressor-elite controller patients (LTNP-EC) has been described only in sporadic cases and then, consequences in disease progression are not clearly established. To fill-up this limited knowledge, we analyzed, for the first time, the prevalence, host genetic polymorphisms, and clinical consequences of HIV-1 DI in a group of LTNP-EC.For DI detection, nucleotide sequences in env gene from viruses from 20 LTNP-EC were analyzed by maximum likelihood. Epidemiological and clinical parameters and host factors of patients were also studied.DI was detected in 4 (20%) of the 20 LTNP-EC, of which 3 maintained the elite controller status. CD4+ T-cell counts were not different between single and DI patients although higher CD8+ T-cell counts were observed in DI patients, and, consequently, the CD4+/CD8+ ratios were lower in LTNP-EC DI patients.Prevalence of HIV-1 DIs in LTNP-EC is similar to other groups of HIV-1 patients; in addition, DI was not associated with loss of disease control in the patients. These DI LTNP-EC patients showed, in comparison with single infected patients, higher numbers of CD8+ T cells and lower CD4+/CD8+ ratios. [ABSTRACT FROM AUTHOR]

Natural killer (NK) cells are important effectors of the innate immune system that help control viral infections and tumorigenesis. However, the relationship between NK cell function and HIV disease progression remains poorly defined. In this study, we examined the function of NK cells in Chinese patients who were HIV-infected but treatment-naïve. These individuals include primary HIV-infected patients (PHIs), typical progressors (TPs), and long-term nonprogressors (LTNPs). We observed an increase of CD56 dim NK cells in PHIs, but the production of interferon-gamma (IFN-γ) and CD107a expression in PHIs were not altered compared with normal control subjects (NCs). However, the NK cells from LTNPs exhibited increased activities in IFN-γ production, CD107a expression and granzyme B change after K562 stimulation compared with NCs. Furthermore, the percentage of IFN-γ +CD107a − NK cells in LTNPs was higher than that in TPs, PHIs and NCs; levels of IFN-γ production in LTNP NK cells exhibited an inverse correlation with viral loads. Similar correlations, however, were not observed in the PHI and TP groups. Taken together, these data demonstrate that enhanced NK cell function may contribute to the control of HIV infection, and increased IFN-γ secretion may be associated with delayed disease progression. [ABSTRACT FROM AUTHOR]

Abstract: HIV infection is characterized by a chronic inflammatory state. Recently, it has been shown that mitochondrial DNA (mtDNA) released from damaged or dead cells can bind Toll like receptor-9 (TLR9), an intracellular receptor that responds to bacterial or viral DNA molecules. The activation of TLR9 present within monocytes or neutrophils results in a potent inflammatory reaction, with the production of proinflammatory cytokines. We measured plasma levels of mtDNA in different groups of HIV+ patients, i.e., those experiencing an acute HIV infection (AHI), long term non progressors (LTNP), late presenters (LP) taking antiretroviral therapy for the first time, and healthy controls. We found that in AHI and LP mtDNA plasma levels were significantly higher than in healthy individuals or in LTNP. Plasma mtDNA levels were not correlated to peripheral blood CD4+ T cell count, nor to markers of immune activation, but had a significant correlation with plasma viral load, revealing a possible role for mtDNA in inflammation, or as a biomarker of virus-induced damage. [Copyright &y& Elsevier]

In HIV-positive individuals, complex multifactorial mechanisms control viral infection. In addition to viral and immunological factors, the host genetic background also plays an important role. Our objective was to evaluate how various genetic factors associated with delayed AIDS onset.Thirty HIV+ long-term nonprogressors (LTNPs) and 30 known progressors were analyzed. Host genes were analyzed in peripheral blood mononuclear cells DNA: CCR5 and HLA were polymerase chain reaction typed. HLA-C5′, HCP5 polymorphisms, and CCL3L1 copy number were determined using real-time polymerase chain reaction.The CCL3L1high-copy-CCR5 deletion genetic risk groups was overrepresented in LTNPs. However, separately, neither CCL3L1 nor CCR5 were significantly associated with clinical outcome. HLA seemed as a strong nonprogression determinant, mainly HLA-B and the less-studied HLA-C. HLA-Cw0102 and HLA-C5′ had an impact on LTNP phenotype along with HLA-B5701 and B2705. The presence of allele combinations like HLA- B∗5701-Cw0602, HLA-B∗2705-Cw0102, or HLA-B∗3801-Cw1203 had the strongest effect in non-progression. As for HCP5, no independent effect was observed. The studied factors had additive effects, and although the number of patients was small, it seemed that carrying a high number of protective alleles associated with progression delay.We showed the additive load of protective host factors was predictive of nonprogression, and that HLA-associated factors were predominant in this global effect. [ABSTRACT FROM AUTHOR]

Abstract: The course of HIV-1 infection shows a variety of clinical phenotypes with an important involvement of host factors. We compare host gene expression patterns in CD3+ T cells from two of these phenotypes: long-term non-progressor patients (LTNP) and matched control patients with standard HIV disease progression. Array analysis revealed over-expression of 322 genes in progressors and 136 in LTNP. Up-regulated genes in progressors were mainly implicated in the regulation of DNA replication, cell cycle and DNA damage stimulus and mostly localized into cellular organelles. In contrast, most up-regulated genes in LTNP were located at the plasmatic membrane and involved in cytokine–cytokine receptor interaction, negative control of apoptosis or regulation of actin cytoskeleton. Regarding gene interactions, a higher number of viral genes interacting with cellular factors were seen in progressors. Our study offers new comparative insights related to disease status and can distinguish differentiated patterns of gene expression among clinical phenotypes. [Copyright &y& Elsevier]

Background We hypothesized that there may be a correlation between the interleukin-7 (IL-7)/IL-7 receptor (IL-7R) regulatory system and parameters of T-cell homeostasis in HIV-infected long-term nonprogressors (LTNPs) as compared with patients with disease progression. Methods The possibility of a correlation between T-cell homeostatic parameters and IL-7/IL-7R was investigated in 22 LTNPs (CD4 count ≥500 cells/μL for >10 years) vs. HIV-positive patients at different disease stages [12 early: CD4 count ≥400 cells/μL; 15 late (AIDS-presenters): CD4 count ≤150 cells/μL]. Results Compared with early-stage HIV-positive patients, LTNPs displayed a higher circulating IL-7 concentration ( P=0.05), which was positively associated with higher IL-7Rα expression and a higher T-cell receptor excision circle (TREC) content specifically within CD4 cells ( P<0.05). Compared with late-stage disease patients, early-stage disease patients displayed a lower IL-7 concentration ( P<0.01) and higher percentages of IL-7Rα+ CD4 and CD8 cells ( P=0.05). IL-7 was positively correlated with the percentage of TREC+ CD4 cells ( P<0.01), which translated into a higher percentage of naïve CD4 cells in early-stage disease patients than in late-stage disease patients; however, the CD4 cells in early-stage disease patients were less enriched in recent thymic emigrants (RTEs) compared with LTNPs ( P<0.05). In late-stage AIDS-developing patients, substantially increased IL-7 was correlated with a decreased percentage of IL-7Rα+ CD4 cells ( P=0.01), which resulted in these patients having a significantly lower percentage of naïve T cells ( P<0.01) and a significantly lower content of TREC ( P<0.01) than the other patients. Conclusions The maintenance of high CD4 cell counts in LTNPs was associated with a specific IL-7/IL-7R pattern characterized by increased IL-7 and highest IL-7Rα-expressing CD4 cells relative to other patients. Compared with patients with late-stage disease, LTNPs displayed a phenotypically naïve, less activated CD4 cell pool highly enriched in RTEs, suggesting the existence of a compensatory IL-7-mediated pathway specifically sustaining peripheral CD4 counts. [ABSTRACT FROM AUTHOR]

NAb have been considered to be an important component of a protective immune response to HIV-1, yet the relationship between the capacity of HIV-1 NAb, the conserved neutralization epitopes and disease progression has been unclear. To gain a better understanding of the protective roles that NAb and conserved neutralization epitopes could play in LTNP, twenty-eight HIV-1-infected subjects were investigated by evaluation of the concentrations of HIV-1 NAb and conserved neutralization epitopes, using single-round PBMC neutralization assay and sequencing. Our study revealed that the concentration of NAb in LTNP was significantly higher than that in subjects with asymptomatic HIV ( P < 0.05) and AIDS ( P < 0.01). No amino acids substitutions were found in the conserved epitopes of the HIV-1 gp120 region in LTNP, whereas the viruses circulating both in persons with asymptomatic HIV and those with AIDS had amino acid substitutions in their conserved neutralization epitopes. This study suggests that high levels of NAb and stable epitopes in gp120 could play a crucial role in protection against disease progression. [ABSTRACT FROM AUTHOR]

Abstract: Although cryopreservation of peripheral blood mononuclear cells (PBMC) is a commonly used technique, the degree to which it affects subsequent functional studies has not been well defined. Here we demonstrate that long-term cryopreservation has detrimental effects on T cell IFN-γ responses in human immunodeficiency virus (HIV) infected individuals. Long-term cryopreservation caused marked decreases in CD4+ T cell responses to whole proteins (HIV p55 and cytomegalovirus (CMV) lysate) and HIV peptides, and more limited decreases in CD8+ T cell responses to whole proteins. These losses were more apparent in cells stored for greater than one year compared to less than six months. CD8+ T cell responses to peptides and peptide pools were well preserved. Loss of both CD4+ and CD8+ T cell responses to CMV peptide pools were minimal in HIV-negative individuals. Addition of exogenous antigen presenting cells (APC) did not restore CD4+ T cell responses to peptide stimulation and partially restored T cell IFN-γ responses to p55 protein. Overnight resting of thawed cells did not restore T cell IFN-γ responses to peptide or whole protein stimulation. A selective loss of phenotypically defined effector cells did not explain the decrement of responses, although cryopreservation did increase CD4+ T cell apoptosis, possibly contributing to the loss of responses. These data suggest that the impact of cryopreservation should be carefully considered in future vaccine and pathogenesis studies. In HIV-infected individuals short-term cryopreservation may be acceptable for measuring CD4+ and CD8+ T cell responses. Long-term cryopreservation, however, may lead to the loss of CD4+ T cell responses and mild skewing of T cell phenotypic marker expression. [Copyright &y& Elsevier]

Abstract: Short, unique, in-frame deletions were consistently detected within p6gag sequences obtained over time from three of eight HIV-1-infected long-term nonprogressors (Alexander, L., Weiskopf, E., Greenough, T.C., Gaddis, N.C., Auerbach, M.R., Malim, M.H., O''Brien, S.J., Walker, B.D., Sullivan, J.L., Desrosiers, R.C., 2000. Unusual polymorphisms in Human Immunodeficiency Virus Type 1 associated with nonprogressive infection. J. Virol. 74, 4361–4376). Using PCR mutagenesis, we created 11 mutant forms of SIV239 and 8 mutant forms of HIV-1 NL4-3 with serial 2 amino acid deletions within p6gag downstream of the PTAP late domain. Nine of the 11 SIV239 mutants assembled and released virion particles similar to wild-type, displayed wild-type infectivity, and replicated similar to wild-type SIV239 in cultured cells. Two of the 11 SIV239 mutants, both involving D at position 21, were grossly defective for intracellular gag accumulation and did not replicate detectably in cultured cells. Similar to the 9 SIV239 mutants, 7 of the 8 HIV-1 mutants replicated well in cultured cells. Only the mutant deleted of ES at positions 19 and 20, immediately adjacent to the PTAP sequence, was markedly impaired in its replicative capacity. These results demonstrate an overall high tolerance of SIV and HIV to two amino acid deletions within p6gag downstream of the late domain. [Copyright &y& Elsevier]

Background: HIV controllers (HICs) are a rare group of HIV-1-infected individuals able to naturally control viral replication. Several studies have identified the occurrence of HIV dual infections in seropositive individuals leading to disease progression. In HICs, however, dual infections with divergent outcomes in pathogenesis have been described.Case Presentation: Here, we present a case report of a HIC diagnosed in late 1999 who displayed stable CD4+ T cell levels and low plasmatic viral load across 12 years of follow-up. In early 2013, the patient started to present an increase in viral load, reaching a peak of 10,000 copies/ml in early 2014, followed by an oscillation of viremia at moderate levels in the following years. The genetic diversity of env proviral quasispecies from peripheral blood mononuclear cells (PBMCs) was studied by single genome amplification (SGA) at six timepoints across 2009-2017. Phylogenetic analyses of env sequences from 2009 and 2010 samples showed the presence of a single subtype B variant (called B1). Analyses of sequences from 2011 and after revealed an additional subtype B variant (called B2) and a subsequent dominance shift in the proviral quasispecies frequencies, with the B2 variant becoming the most frequent from 2014 onwards. Latent syphilis related to unprotected sexual intercourse was diagnosed a year before the first detection of B2, evidencing risk behavior and supporting the superinfection hypothesis. Immunologic analyses revealed an increase in CD8+ and CD4+ T cell immune activation following viremia increase and minor T cell subset alterations during follow-up. HIV-specific T cell responses remained low throughout the follow-up period.Conclusions: Altogether, these results show that loss of viremia control in the HIC was associated with superinfection. These data alert to the negative consequences of reinfection on HIV pathogenesis, even in patients with a long history of viremia control and an absence of disease progression, reinforcing the need for continued use of adequate prevention strategies. [ABSTRACT FROM AUTHOR]

Background: Abnormally increased immune activation is one of the main pathological features of acquired immunodeficiency syndrome (AIDS). This study aimed to determine whether long-term nonprogression (LTNP) suppresses the upregulation of immune activation and to elucidate the mechanisms whereby the LTNP state is maintained. Methods: For this study we selected 4 rhesus macaques(RMs) infected with simian immunodeficiency virus (SIV) that were long-term nonprogressors (LTNP); for comparison we chose 4 healthy RMs that were seronegative for SIV (hereafter referred to as the Control group), and 4 progressing infection (Progressive group) SIV RMs. We observed these animals for 6 months without intervention and explored the immunological and pathological differences among the 3 groups. A series of immune activation and inflammation markers—such as C- C chemokine receptor type 5 (CCR5), beta 2- microglobulin (β2-MG), Human Leukocyte Antigen - antigen D Related (HLA-DR), CD38, the levels of microbial translocation (LPS -binding protein), and MAVS—and histological features were monitored during this period. Results: Both SIV RNA and SIV DNA in the plasma and lymph nodes (LNs) of the LTNP group were at significantly lower levels than those of the Progressive group (P < 0.05). The CD4/CD8 ratio and CD4 cell count and proportion in the LTNP group were between those of the Progressive and Control groups (P < 0.05): that is, they were higher than in the Progressive group and lower than in the Control group. The LTNP macaques manifested slow progression and decreased immune activation and inflammation; they also had lower levels of CCR5, LPS-binding protein, and β2-MG than the Progressive RMs (P < 0.05). Activation of LTNP in both CD4+ and CD8+ T cells was significantly lower than in the Progressive group and closer to that in the Control group. The histological features of the LTNP macaques were also closer to those of the Control group, even though they had been infected with SIV 4 years earlier. These data point to low viral replication in the LTNP macaques but it is not static. The expression of MAVS in peripheral blood and LNs was lower in the LTNP group than that in the Progressive group (P < 0.01), and MAVS was positively correlated with SIV DNA in LNs (P < 0.05). This may reflect the low activation of T lymphocytes. It was speculated that MAVS may be the link between innate and acquired antiviral immunity in SIV infection. Conclusions: The LTNP RMs in our study were in a relatively stable state of low activation and inflammation, some biological progression with no disease events. This may have been associated with their low levels of the mitochondrial antiviral signaling protein (MAVS). [ABSTRACT FROM AUTHOR]