Highly active antiretroviral therapy (HAART) suppresses HIV-1 replication but cannot eliminate the virus because HIV-1 establishes latent infection. Interruption of HAART leads to a rapid rebound of ...viremia, so life-long treatment is required. Efforts to purge the latent reservoir have focused on reactivating latent proviruses without inducing global T cell activation. However, the killing of the infected cells after virus reactivation, which is essential for elimination of the reservoir, has not been assessed. Here we show that after reversal of latency in an in vitro model, infected resting CD4+ T cells survived despite viral cytopathic effects, even in the presence of autologous cytolytic T lymphocytes (CTLs) from most patients on HAART. Antigen-specific stimulation of patient CTLs led to efficient killing of infected cells. These results demonstrate that stimulating HIV-1-specific CTLs prior to reactivating latent HIV-1 may be essential for successful eradication efforts and should be considered in future clinical trials.
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► Resting CD4+ T cells latently infected with HIV-1 do not die after virus reactivation ► Viral CPEs or patient CTLs do not cause death of HIV-1-infected resting CD4+ T cells ► Stimulated patient CTLs kill infected resting CD4+ T cells after reversal of latency ► Autologous viruses recovered from latent reservoir do not escape from patient CTLs
The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic was first reported in Wuhan, China in December 2019, moved across the globe at an unprecedented speed, and is having a ...profound and yet still unfolding health and socioeconomic impacts. SARS-CoV-2, a β-coronavirus, is a highly contagious respiratory pathogen that causes a disease that has been termed the 2019 coronavirus disease (COVID-19). Clinical experience thus far indicates that COVID-19 is highly heterogeneous, ranging from being asymptomatic and mild to severe and causing death. Host factors including age, sex, and comorbid conditions are key determinants of disease severity and progression. Aging itself is a prominent risk factor for severe disease and death from COVID-19. We hypothesize that age-related decline and dysregulation of immune function, i.e., immunosenescence and inflammaging play a major role in contributing to heightened vulnerability to severe COVID-19 outcomes in older adults. Much remains to be learned about the immune responses to SARS-CoV-2 infection. We need to begin partitioning all immunological outcome data by age to better understand disease heterogeneity and aging. Such knowledge is critical not only for understanding of COVID-19 pathogenesis but also for COVID-19 vaccine development.
OBJECTIVES:To investigate the impact of HAART-induced HIV suppression on levels of 24 serological biomarkers of inflammation and immune activation.
DESIGN:A prospective cohort study.
...METHODS:Biomarkers were measured with multiplex assays in centralized laboratories using stored serum samples contributed by 1697 men during 8903 person-visits in the Multicenter AIDS Cohort Study (MACS) from 1984 to 2009. Using generalized gamma models, we compared biomarker values across three groups, adjusting for possible confoundersHIV-uninfected (NEG); HIV-positive, HAART-naive (NAI); and HAART-exposed with HIV RNA suppressed to less than 50 copies/ml plasma (SUP). We also estimated changes in biomarker levels associated with duration of HIV suppression, using splined generalized gamma regression with a knot at 1 year.
RESULTS:Most biomarkers were relatively normalized in the SUP group relative to the NAI group; however, 12 biomarkers in the SUP group were distinct (P < 0.002) from NEG valuesCXCL10, C-reactive protein (CRP), sCD14, sTNFR2, tumour necrosis factor-alpha (TNF-α), sCD27, sGP130, interleukin (IL)-8, CCL13, BAFF, GM-CSF and IL-12p70. Thirteen biomarkers exhibited significant changes in the first year after viral suppression, but none changed significantly after that time.
CONCLUSION:Biomarkers of inflammation and immune activation moved towards HIV-negative levels within the first year after HAART-induced HIV suppression. Although several markers of T-cell activation returned to levels present in HIV-negative men, residual immune activation, particularly monocyte/macrophage activation, was present. This residual immune activation may represent a therapeutic target to improve the prognosis of HIV-infected individuals receiving HAART.
A stable latent reservoir for HIV-1 in resting CD4
T cells is the principal barrier to a cure
. Curative strategies that target the reservoir are being tested
and require accurate, scalable reservoir ...assays. The reservoir was defined with quantitative viral outgrowth assays for cells that release infectious virus after one round of T cell activation
. However, these quantitative outgrowth assays and newer assays for cells that produce viral RNA after activation
may underestimate the reservoir size because one round of activation does not induce all proviruses
. Many studies rely on simple assays based on polymerase chain reaction to detect proviral DNA regardless of transcriptional status, but the clinical relevance of these assays is unclear, as the vast majority of proviruses are defective
. Here we describe a more accurate method of measuring the HIV-1 reservoir that separately quantifies intact and defective proviruses. We show that the dynamics of cells that carry intact and defective proviruses are different in vitro and in vivo. These findings have implications for targeting the intact proviruses that are a barrier to curing HIV infection.
Despite antiretroviral therapy (ART), human immunodeficiency virus (HIV)-1 persists in a stable latent reservoir, primarily in resting memory CD4(+) T cells. This reservoir presents a major barrier ...to the cure of HIV-1 infection. To purge the reservoir, pharmacological reactivation of latent HIV-1 has been proposed and tested both in vitro and in vivo. A key remaining question is whether virus-specific immune mechanisms, including cytotoxic T lymphocytes (CTLs), can clear infected cells in ART-treated patients after latency is reversed. Here we show that there is a striking all or none pattern for CTL escape mutations in HIV-1 Gag epitopes. Unless ART is started early, the vast majority (>98%) of latent viruses carry CTL escape mutations that render infected cells insensitive to CTLs directed at common epitopes. To solve this problem, we identified CTLs that could recognize epitopes from latent HIV-1 that were unmutated in every chronically infected patient tested. Upon stimulation, these CTLs eliminated target cells infected with autologous virus derived from the latent reservoir, both in vitro and in patient-derived humanized mice. The predominance of CTL-resistant viruses in the latent reservoir poses a major challenge to viral eradication. Our results demonstrate that chronically infected patients retain a broad-spectrum viral-specific CTL response and that appropriate boosting of this response may be required for the elimination of the latent reservoir.
Serum cytokine profiling is a powerful tool to link host immune defense with disease pathogenesis. Although several multiplex assays are commercially available, none has been rigorously validated in ...the context of chronic infectious disease (such as HIV infection). Here we compared the measurement of proinflammatory cytokines by two multiplex platforms: the Meso Scale Discovery (MSD) electrochemiluminescence assay and the Becton Dickinson Cytometric Bead Array (CBA) flow cytometric assay, using serum samples from HIV-infected and -uninfected donors. We evaluated the ability of these assays to: a) quantify circulating levels of native cytokines (IL-6, IL-8, IL-10, TNF-α, IL-12p70, IL-1β), and b) accurately recover known amounts of recombinant cytokines added to serum samples. Based on the standard curves, the sensitivity of the MSD system was only slightly better than the CBA. However, in serum the MSD platform consistently quantified levels of endogenous IL-12p70, TNF-α, and IL-10 that were undetectable by the CBA assay. The MSD assay was also more accurate as determined by an enhanced capacity to recover known concentrations of recombinant cytokines added to serum. Both assays performed equally well in quantifying IL-6 and IL-8, while neither assay quantified IL-1β with accuracy and precision. Interestingly, HIV infection did not affect the performance of either assay. Overall, the MSD assay provided a more reliable assessment of the proinflammatory cytokines tested in the serum of healthy and HIV-infected individuals.
► In this study we compare the performance of two muliplex cytokine assays ► We examined the CBA and MSD platforms using serum from HIV
+ donors ► We find serum matrix effects influence assay performance independent of HIV status ► Overall, the MSD assay performed better detecting endogenous cytokines in serum
Claims of accelerated or premature aging are frequently made. However, the lack of standard criteria for measuring speed of aging makes such claims highly questionable. Because of fundamental gaps in ...our current understanding of the biological mechanisms of aging, the development of specific phenotypes that are due to aging is difficult and such phenotypes can only be derived by observational data. However, a clinical phenotype of aging exists that is experienced by all living individuals and is pervasive across multiple physiologic systems. Characterizing this phenotype can serve as a basis for measuring the speed of aging, and can facilitate a better understanding of the aging process and its interaction with chronic diseases.
•Aging research has been hampered by lack of an agreed-upon phenotype of aging.•Absent such a phenotype, claims of accelerated or slowed aging are dubious at best.•Aging changes body composition, energetic, homeostatic, and neural integrity.•These changes form an aging phenotype for all people and all physiologic systems.•Using this phenotype, studies of mechanisms and rate of aging would be more valid.
•Immunosenescence refers to immune system changes during aging.•Chronic low-grade inflammatory phenotype (CLIP) is a feature of immunosenescence (84).•Emerging data suggest sex as an important factor ...influencing immunosenescence.•Immunosenescence affects susceptibility to infection, chronic disease, and frailty (85).•Chronic CMV infection contributes to immunosenescence in aging and HIV infection (83).
Aging is characterized by significant immune remodeling at both cellular and molecular levels, also known as immunosenescence. Older adults often manifest a chronic low-grade inflammatory phenotype. These age-related immune system changes have increasingly been recognized not only to lead to immune functional decline and increased vulnerability to infections, but also to play an important role in many chronic conditions such as frailty in older adults. In addition to sex as an important biological factor, chronic viral infections including that by human immunodeficiency virus (HIV) and cytomegalovirus (CMV) are all known to have major impact on the aging immune system. This article provides an overview of our current understanding of aging immunity, sex, inflammation, frailty, and HIV and CMV infections.
Side-population (SP) cells within cancers and cell lines are rare cell populations known to enrich cancer stem-like cells. In this study, we characterized SP cells from the human breast cancer cell ...line MCF7 as a model for cancer stem-like cells. Compared with non-SP cells, MCF7 SP cells had higher colony-formation ability in vitro and greater tumorigenicity in vivo, suggesting that MCF7 SP cells enrich cancer stem-like cells. cDNA microarray analysis of the SP cells indicated higher expression of ATP-binding cassette transporters and genes involved in quiescence, which were confirmed by quantitative RT-PCR and flow cytometry cell cycle analysis. To identify signal pathways important for cancer stem-like cells, we analyzed cDNA microarray data and identified nine pathways that were altered in the SP cells. To analyze the protein signaling networks, we used reverse-phase signaling pathway protein microarray technology and identified three signaling proteins that are significantly different between MCF7 SP and non-SP cells. Notably, signaling of phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR), signal transduction and activator of transcription (STAT3), and phosphatase and tensin homolog (PTEN) was confirmed to be critical for MCF7 SP cell survival and proliferation by pathway specific inhibitors, selected gene knockdown, and in vivo tumorigenicity assay. The STAT3 pathway was found to be positively regulated by mTOR signaling, whereas PTEN served as a negative regulator of both STAT3 and mTOR signaling. This study suggests the existence of prosurvival signaling pathways critical for cancer stem-like cell maintenance, which could be selectively targeted for inhibiting cancer stem-like cells for improved treatment.
OBJECTIVE:To examine the incidence and risk factors for anal cancer in a multicenter cohort of human immunodeficiency virus (HIV) positive and HIV-negative men who have sex with men followed between ...1984 and 2006 (Multicenter AIDS Cohort Study).
METHODS:Prospective analysis using Poisson regression and Cox proportional hazard models and a nested case-control study using conditional logistic regression.
RESULTS:There were 28 cases of anal cancer among the 6972 men who were evaluated. The incidence rate was significantly higher in HIV-positive men than in HIV-negative men (incidence rate = 69 vs 14 per 100,000 person-years). Among HIV-positive men, anal cancer incidence was higher in the highly active antiretroviral therapy (HAART) era than the pre-HAART era (incidence rate = 137 vs 30 per 100,000 person-years). In multivariate analysis restricted to the HAART era, anal cancer risk increased significantly with HIV infection (relative hazard = 4.7, 95% confidence interval = 1.3 to 17) and increasing number of unprotected receptive anal sex partners at the first 3 study visits (P trend = 0.03). Among HIV-positive men, current HAART use did not decrease anal cancer risk.
CONCLUSIONS:HIV-positive men had increased risk of anal cancer. Improved survival of HIV-positive individuals after HAART initiation may allow for sufficient time for human papillomavirus-associated anal dysplasias to develop into malignancies, thus explaining the increased incidence of anal cancer in the HAART era.
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