Integrin αvβ3 Upregulation in Response to Nutrient Stress Promotes Lung Cancer Cell Metabolic Plasticity
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Tumor-initiating cells can survive in harsh environments via stress tolerance and metabolic flexibility; studies on this topic can yield new targets for cancer therapy. Using cultured cells and live human surgical biopsies of non-small cell lung cancer, researchers demonstrated that nutrient stress drives a metabolic reprogramming cascade that allows tumor cells to thrive despite a nutrient-limiting environment. This cascade results from upregulation of integrin αvβ3, a cancer stem cell marker.
Potent HPIV3-Neutralizing IGHV5-51 Antibodies Identified from Multiple Individuals Show L Chain and CDRH3 Promiscuity
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Human parainfluenza virus 3 fusion glycoprotein (HPIV3 F), responsible for facilitating viral entry into host cells, is a major target of neutralizing antibodies that inhibit infection. More work is needed to understand these dynamics. Researchers characterized the genetic signatures, epitope specificity, neutralization potential, and publicness of HPIV3-specific antibodies identified across multiple individuals. From this work, they identified 12 potently neutralizing antibodies targeting three nonoverlapping epitopes on HPIV3 F.
Deep Analysis of CD4 T Cells in the Rhesus CNS During SIV Infection
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Systemic HIV infection results in chronic inflammation that causes lasting damage to the central nervous system (CNS), despite long-term antiretroviral therapy (ART). Researchers studied neurocognitive outcomes in male and female rhesus macaques infected with simian immunodeficiency virus (SIV) using an ART regimen simulating suboptimal adherence; one group received no ART, and the other received ART with periodic interruptions. Using single-cell transcriptomic profiling, the researchers also identified molecular programs induced in the brain upon infection.
Antiretroviral Therapy Timing Impacts Latent Tuberculosis Infection Reactivation in a Tuberculosis/Simian Immunodeficiency Virus Coinfection Model
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In the rhesus macaque model for Mycobacterium tuberculosis plus simian immunodeficiency virus (SIV) co-infection, chronic immune activation rather than depletion of CD4+ T cells correlates with reactivation of latent tuberculosis infection (LTBI). Researchers administered combined antiretroviral therapy (cART) at 2 weeks post-SIV co-infection to study whether restoration of CD4+ T cell immunity occurred more broadly, and whether this prevented LTBI compared to cART initiated at 4 weeks post-SIV.
Circulating Integrin α4β7+ CD4 T Cells Are Enriched for Proliferative Transcriptional Programs in HIV Infection
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HIV preferentially infects α4β7+ CD4 T cells, forming latent reservoirs that contribute to HIV persistence, yet the properties of α4β7+ CD4 T cells are poorly understood. Investigating HIV-infected humans and SHIV-infected rhesus macaques, investigators demonstrated that α4β7+ CD4 T cells in blood are enriched for genes regulating cell cycle progression and cellular metabolism. In contrast, rectal α4β7+ CD4 T cells exhibited a core tissue-residency gene expression program.
Antibody-Based CCR5 Blockade Protects Macaques From Mucosal SHIV Transmission
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The efficacy of antiretroviral therapy (ART) as pre-exposure prophylaxis against HIV is hindered by incomplete patient adherence and ART-resistant variants. Researchers found that competitive inhibition of HIV Env-CCR5 binding via the CCR5-specific antibody Leronlimab protects rhesus macaques against infection following repeated intrarectal challenges with a CCR5-tropic simian-human immunodeficiency virus (SHIVSF162P3). Biweekly injection of Leronlimab at 50 mg/kg provided complete protection from SHIV infection.
Psychosocial Stress Alters the Immune Response and Results in Higher Viral Load During Acute SIV Infection in a Pigtailed Macaque Model of HIV
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Social distancing is an important countermeasure for a pandemic, but social isolation may also have adverse health outcomes in the context of infectious diseases, such as HIV. Researchers compared commonly measured parameters of HIV progression between singly and socially housed simian immunodeficiency virus (SIV)-infected pigtailed macaques.
Effect of Single Housing on Innate Immune Activation in Immunodeficiency Virus–Infected Pigtail Macaques (Macaca nemestrina) as a Model of Psychosocial Stress in Acute HIV Infection
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Psychosocial stress is associated with immune system dysregulation and worsened clinical outcomes in people with HIV. Investigators performed a retrospective analysis of acute simian immunodeficiency virus (SIV) infection of male pigtail macaques to compare the innate immune responses of social and single housing. The singly housed macaques showed reduced expansion of classical and intermediate monocytes, prolonged thrombocytopenia, and suppression of platelet activation during the first 2 weeks after inoculation.
Orthotopic Transplantation of the Full-Length Porcine Intestine After Normothermic Machine Perfusion
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Successful intestinal transplantation currently is hindered by graft injury that occurs during procurement and storage, which contributes to postoperative sepsis and allograft rejection. Improved graft preservation could expand transplantable graft numbers and enhance post-transplant outcomes. Superior transplant outcomes recently have been demonstrated in clinical trials using machine perfusion to preserve the liver.
Neuroinflammatory Transcriptional Programs Induced in Rhesus Pre‑Frontal Cortex White Matter During Acute SHIV Infection
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Neuroinflammation has evolved as a protective immune response within the central nervous system (CNS), but chronic neuroinflammation leads to oxidative stress, cellular damage, and neurodegeneration. People living with HIV are at increased risk for age-related neurodegenerative diseases. Using rhesus macaques of both sexes, the researchers characterized the molecular underpinnings of acute neuroinflammation following simian–human immunodeficiency virus (SHIV) infection.