Publications by authors named "Justin Harper"

Article Synopsis
  • The study investigates the effects of blocking interleukin-10 (IL-10) and PD-1 on controlling HIV/SIV viral rebound after stopping antiretroviral therapy (ART).
  • In a trial with rhesus macaques, a combination treatment of anti-IL-10 and anti-PD-1 led to sustained control of viral levels in 9 out of 10 monkeys for over 24 weeks post-treatment interruption.
  • Outcomes indicated that specific immune responses, such as increased memory T cells and changes in cytokine levels, could predict successful viral control after ART cessation.
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Human immunodeficiency virus (HIV) cure efforts are increasingly focused on harnessing CD8 T cell functions, which requires a deeper understanding of CD8 T cells promoting HIV control. Here we identifiy an antigen-responsive TOXTCF1CD39CD8 T cell population with high expression of inhibitory receptors and low expression of canonical cytolytic molecules. Transcriptional analysis of simian immunodeficiency virus (SIV)-specific CD8 T cells and proteomic analysis of purified CD8 T cell subsets identified TOXTCF1CD39CD8 T cells as intermediate effectors that retained stem-like features with a lineage relationship with terminal effector T cells.

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Article Synopsis
  • HIV, once a death sentence, is now manageable with antiretroviral therapy (ART), which effectively halts AIDS progression and makes the virus untransmissible for many with undetectable viral loads.
  • Though ART significantly improves the life expectancy of people living with HIV (PLWH), it cannot eliminate the latent reservoir of the virus in infected cells.
  • Despite progress in reducing new infections and increased ART accessibility, researchers are still struggling to find a definitive cure for HIV, exploring various strategies to eradicate or control the virus long-term.
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Response to intervention (RTI) is a method for providing academic support to students and for identifying specific learning disabilities (SLDs). Using interrupted time series and hazard models, we examined if statewide RTI adoption in the U.S.

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One approach to 'functional cure' of HIV infection is to induce durable control of HIV replication after the interruption of antiretroviral therapy (ART). However, the major factors that determine the viral 'setpoint' level after treatment interruption are not well understood. Here we combine data on ART interruption following SIV infection for 124 total animals from 10 independent studies across 3 institutional cohorts to understand the dynamics and predictors of post-treatment viral control.

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Type I interferons (IFN-I) are critical mediators of innate control of viral infections but also drive the recruitment of inflammatory cells to sites of infection, a key feature of severe coronavirus disease 2019. Here, IFN-I signaling was modulated in rhesus macaques (RMs) before and during acute SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection using a mutated IFN-α2 (IFN-modulator; IFNmod), which has previously been shown to reduce the binding and signaling of endogenous IFN-I. IFNmod treatment in uninfected RMs was observed to induce a modest up-regulation of only antiviral IFN-stimulated genes (ISGs); however, in SARS-CoV-2-infected RMs, IFNmod reduced both antiviral and inflammatory ISGs.

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The human astrovirus (HAstV) is a non-enveloped, single-stranded RNA virus that is a common cause of gastroenteritis. Most non-enveloped viruses use membrane disruption to deliver the viral genome into a host cell after virus uptake. The virus-host factors that allow for HAstV cell entry are currently unknown but thought to be associated with the host-protease-mediated viral maturation.

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The immunopathological mechanisms driving the development of severe COVID-19 remain poorly defined. Here, we utilize a rhesus macaque model of acute SARS-CoV-2 infection to delineate perturbations in the innate immune system. SARS-CoV-2 initiates a rapid infiltration of plasmacytoid dendritic cells into the lower airway, commensurate with IFNA production, natural killer cell activation, and a significant increase of blood CD14CD16 monocytes.

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Elucidating the mechanisms underlying the persistence and location of the HIV reservoir is critical for developing cure interventions. While it has been shown that levels of T-cell activation and the size of the HIV reservoir are greater in rectal tissue and lymph nodes (LN) than in blood, the relative contributions of T-cell subsets to this anatomic difference are unknown. We measured and compared HIV-1 DNA content, expression of the T-cell activation markers CD38 and HLA-DR, and expression of the exhaustion markers programmed cell death protein 1 (PD-1) and T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) in naive, central memory (CM), transitional memory (TM), and effector memory (EM) CD4 and CD8 T-cells in paired blood and LN samples among 14 people with HIV who were receiving antiretroviral therapy.

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Persistence of the human immunodeficiency virus type-1 (HIV-1) latent reservoir in infected individuals remains a problem despite fully suppressive antiretroviral therapy (ART). While reservoir formation begins during acute infection, the mechanisms responsible for its establishment remain unclear. CD8 T cells are important during the initial control of viral replication.

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Type-I interferons (IFN-I) are critical mediators of innate control of viral infections, but also drive recruitment of inflammatory cells to sites of infection, a key feature of severe COVID-19. Here, and for the first time, IFN-I signaling was modulated in rhesus macaques (RMs) prior to and during acute SARS-CoV-2 infection using a mutated IFNα2 (IFN-modulator; IFNmod), which has previously been shown to reduce the binding and signaling of endogenous IFN-I. In SARS-CoV-2-infected RMs, IFNmod reduced both antiviral and inflammatory ISGs.

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Antiretroviral therapy (ART) is not curative due to the persistence of a reservoir of HIV-infected cells, particularly in tissues such as lymph nodes, with the potential to cause viral rebound after treatment cessation. In this study, fingolimod (FTY720), a lysophospholipid sphingosine-1-phosphate receptor modulator is administered to SIV-infected rhesus macaques at initiation of ART to block the egress from lymphoid tissues of natural killer and T-cells, thereby promoting proximity between cytolytic cells and infected CD4+ T-cells. When compared with the ART-only controls, FTY720 treatment during the initial weeks of ART induces a profound lymphopenia and increases frequencies of CD8+ T-cells expressing perforin in lymph nodes, but not their killing capacity; FTY720 also increases frequencies of cytolytic NK cells in lymph nodes.

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Despite the advent of effective antiretroviral therapy (ART), human immunodeficiency virus (HIV) continues to pose major challenges, with extensive pathogenesis during acute and chronic infection prior to ART initiation and continued persistence in a reservoir of infected CD4 T cells during long-term ART. CD101 has recently been characterized to play an important role in CD4 Treg potency. Using the simian immunodeficiency virus (SIV) model of HIV infection in rhesus macaques, we characterized the role and kinetics of CD101+ CD4 T cells in longitudinal SIV infection.

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Article Synopsis
  • Interleukin-10 (IL-10) is an immunosuppressive cytokine that aids in T follicular helper (Tfh) cell differentiation and germinal center formation, influencing SIV persistence in infected macaques.
  • Elevated IL-10 levels were found during SIV infection and remained high even after antiretroviral therapy (ART), correlating with SIV-DNA content in CD4+ memory cells, particularly Tfh cells.
  • Neutralizing IL-10 in ART-treated macaques disrupted the maintenance of B cell follicles and reduced memory CD4+ T cell populations, suggesting that targeting IL-10 could help improve immune response and reduce viral persistence in people living with HIV.
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Poly-L-lactic acid (PLLA) is an injectable biodegradable biostimulator that promotes collagen production and is approved for use in aesthetic facial augmentation. PLLA is well tolerated with minimal downtime and has demonstrated an excellent safety profile, as well as a longevity benefit of at least 2 years following injection. The robust safety and efficacy profile associated with PLLA for facial rejuvenation has resulted in a growing interest in the use of PLLA for other body areas such as the buttocks, which are an increasingly popular target of aesthetic enhancement.

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Unlabelled: The COVID-19 pandemic remains a global health crisis, yet, the immunopathological mechanisms driving the development of severe disease remain poorly defined. Here, we utilize a rhesus macaque (RM) model of SARS-CoV-2 infection to delineate perturbations in the innate immune system during acute infection using an integrated systems analysis. We found that SARS-CoV-2 initiated a rapid infiltration (two days post infection) of plasmacytoid dendritic cells into the lower airway, commensurate with IFNA production, natural killer cell activation, and induction of interferon-stimulated genes.

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Clinical outcomes are inferior for individuals with HIV having suboptimal CD4 T-cell recovery during antiretroviral therapy (ART). We investigated if the levels of infection and the response to homeostatic cytokines of CD4 T-cell subsets contributed to divergent CD4 T-cell recovery and HIV reservoir during ART by studying virologically-suppressed immunologic responders (IR, achieving a CD4 cell count >500 cells/μL on or before two years after ART initiation), and virologically-suppressed suboptimal responders (ISR, did not achieve a CD4 cell count >500 cells/μL in the first two years after ART initiation). Compared to IR, ISR demonstrated higher levels of HIV-DNA in naïve, central (CM), transitional (TM), and effector (EM) memory CD4 T-cells in blood, both pre- and on-ART, and specifically in CM CD4 T-cells in LN on-ART.

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HIV associated immune activation (IA) is associated with increased morbidity in people living with HIV (PLWH) on antiretroviral therapy, and remains a barrier for strategies aimed at reducing the HIV reservoir. The underlying mechanisms of IA have not been definitively elucidated, however, persistent production of Type I IFNs and expression of ISGs is considered to be one of the primary factors. Plasmacytoid DCs (pDCs) are a major producer of Type I IFN during viral infections, and are highly immunomodulatory in acute HIV and SIV infection, however their role in chronic HIV/SIV infection has not been firmly established.

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Unlike HIV infection, which progresses to AIDS absent suppressive anti-retroviral therapy, nonpathogenic infections in natural hosts, such African green monkeys, are characterized by a lack of gut microbial translocation and robust secondary lymphoid natural killer cell responses resulting in an absence of chronic inflammation and limited SIV dissemination in lymph node B-cell follicles. Here we report, using the pathogenic model of antiretroviral therapy-treated, SIV-infected rhesus macaques that sequential interleukin-21 and interferon alpha therapy generate terminally differentiated blood natural killer cells (NKG2a/cCD16) with potent human leukocyte antigen-E-restricted activity in response to SIV envelope peptides. This is in contrast to control macaques, where less differentiated, interferon gamma-producing natural killer cells predominate.

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Natural killer (NK) cells play a critical understudied role during HIV infection in tissues. In a natural host of SIV, the African green monkey (AGM), NK cells mediate a strong control of SIVagm infection in secondary lymphoid tissues. We demonstrate that SIVagm infection induces the expansion of terminally differentiated NKG2a NK cells in secondary lymphoid organs displaying an adaptive transcriptional profile and increased MHC-E-restricted cytotoxicity in response to SIV Env peptides while expressing little IFN-γ.

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Background: Since the approval of Sculptra Aesthetic, the amount of sterile water used to reconstitute the product has gradually increased in clinical practice. A retrospective chart review was conducted to evaluate patient safety associated with a larger reconstitution volume, and to investigate specific parameters for how Sculptra Aesthetic is used in a real-world clinical setting.

Objective: The primary objective of the study was to evaluate the safety of Sculptra Aesthetic when using a reconstitution volume of 7 to 10 mL, via collection of adverse events related to the product or injection procedure reported in medical records.

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SARS-CoV-2-induced hypercytokinemia and inflammation are critically associated with COVID-19 severity. Baricitinib, a clinically approved JAK1/JAK2 inhibitor, is currently being investigated in COVID-19 clinical trials. Here, we investigated the immunologic and virologic efficacy of baricitinib in a rhesus macaque model of SARS-CoV-2 infection.

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Article Synopsis
  • * In a study using rhesus macaques infected with SARS-CoV-2, baricitinib did not decrease viral shedding or specific immune responses but significantly reduced overall immune activation and lung inflammation.
  • * The findings suggest that baricitinib could be beneficial as a treatment for severe COVID-19 by suppressing harmful immune responses while not affecting the virus directly.
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