Publications by authors named "Paul Lopez"

The induction of durable protective immune responses is the main goal of prophylactic vaccines, and adjuvants play a role as drivers of such responses. Despite advances in vaccine strategies, a safe and effective HIV vaccine remains a significant challenge. The use of an appropriate adjuvant is crucial to the success of HIV vaccines.

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T cells are involved in protective immunity against numerous viral infections. Data regarding functional roles of human T cells in SARS-CoV-2 (SARS2) viral clearance in primary COVID-19 are limited. To address this knowledge gap, we assessed samples for associations between SARS2 upper respiratory tract viral RNA levels and early virus-specific adaptive immune responses for 95 unvaccinated clinical trial participants with acute primary COVID-19 aged 18-86 years old, approximately half of whom were considered at high risk for progression to severe COVID-19.

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Rare B cells can have special pathogen-recognition features giving them the potential to make outsized contributions to protective immunity. However, rare naive B cells infrequently participate in immune responses. We investigated how germline-targeting vaccine antigen delivery and adjuvant selection affect priming of exceptionally rare BG18-like HIV broadly neutralizing antibody-precursor B cells (~1 in 50 million) in non-human primates.

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Clinical samples are routinely inactivated before molecular assays to prevent pathogen transmission. Antibody-based assays are sensitive to changes in analyte conformation, but the impact of inactivation on the analyte detectability has been overlooked. This study assessed the effects of commonly used inactivation-methods, Triton X-100 (0.

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The induction of durable protective immune responses is the main goal of prophylactic vaccines, and adjuvants play an important role as drivers of such responses. Despite advances in vaccine strategies, a safe and effective HIV vaccine remains a significant challenge. The use of an appropriate adjuvant is crucial to the success of HIV vaccines.

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The upper airway is an important site of infection, but immune memory in the human upper airway is poorly understood, with implications for COVID-19 and many other human diseases. Here we demonstrate that nasal and nasopharyngeal swabs can be used to obtain insights into these challenging problems, and define distinct immune cell populations, including antigen-specific memory B cells and T cells, in two adjacent anatomical sites in the upper airway. Upper airway immune cell populations seemed stable over time in healthy adults undergoing monthly swabs for more than 1 year, and prominent tissue resident memory T (T) cell and B (B) cell populations were defined.

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Unlabelled: A substantial percentage of the population remains at risk for cervical cancer due to pre-existing human papillomavirus (HPV) infections, despite prophylactic vaccines. Early diagnosis and treatment are crucial for better disease outcomes. The development of new treatments heavily relies on suitable preclinical model systems.

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Intravital microscopy has revolutionized live-cell imaging by allowing the study of spatial-temporal cell dynamics in living animals. However, the complexity of the data generated by this technology has limited the development of effective computational tools to identify and quantify cell processes. Amongst them, apoptosis is a crucial form of regulated cell death involved in tissue homeostasis and host defense.

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Cutaneous Leishmania major infection elicits a rapid T cell response that is insufficient to clear residually infected cells, possibly due to the accumulation of regulatory T cells in healed skin. Here, we used Leishmania-specific TCR transgenic mice as a sensitive tool to characterize parasite-specific effector and immunosuppressive responses in vivo using two-photon microscopy. We show that Leishmania-specific Tregs displayed higher suppressive activity compared to polyclonal Tregs, that was mediated through IL-10 and not through disrupting cell-cell contacts or antigen presentation.

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Article Synopsis
  • T cells play a crucial role in fighting off various viral infections, including SARS-CoV-2, which causes COVID-19.
  • A study involving 95 unvaccinated participants showed that most developed SARS2-specific T cell responses within 6 days of symptoms, indicating their importance in the immune response.
  • The research found that robust CD4 and CD8 T cell responses were linked to lower levels of the virus in the upper respiratory tract, highlighting their protective function even without considering antibody levels.
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Adjuvants and antigen delivery kinetics can profoundly influence B cell responses and should be critically considered in rational vaccine design, particularly for difficult neutralizing antibody targets such as human immunodeficiency virus (HIV). Antigen kinetics can change depending on the delivery method. To promote extended immunogen bioavailability and to present antigen in a multivalent form, native-HIV Env trimers are modified with short phosphoserine peptide linkers that promote tight binding to aluminum hydroxide (pSer:alum).

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Neutrophil recruitment and activation within the female genital tract are often associated with tissue inflammation, loss of vaginal epithelial barrier integrity, and increased risk for sexually transmitted infections, such as HIV-1. However, the direct role of neutrophils on vaginal epithelial barrier function during genital inflammation in vivo remains unclear. Using complementary proteome and immunological analyses, we show high neutrophil influx into the lower female genital tract in response to physiological surges in progesterone, stimulating distinct stromal, immunological, and metabolic signaling pathways.

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T cells actively migrate along reticular networks within lymphoid organs in search for cognate antigen, but how these behaviors impact HIV entry and infection is unclear. Here, we show that migratory T cells in 3D collagen matrix display significantly enhanced infection and integration by cell-free R5-tropic lab adapted and transmitted/founder molecular HIV clones in the absence of exogenous cytokines or cationic polymers. Using two different collagen matrices that either support or restrict T cell migration, we observe high levels of HIV fusion in migratory T cells, whereas non-motile T cells display low viral entry and integration.

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Papillomavirus L1 and L2, the major and minor capsid proteins, play significant roles in viral assembly, entry, and propagation. In the current study, we investigate the impact of L1 and L2 on viral life cycle and tumor growth with a newly established mouse papillomavirus (MmuPV1) infection model. MmuPV1 L1 knockout, L2 knockout, and L1 plus L2 knockout mutant genomes (designated as L1ATGko-4m, L2ATGko, and L1-L2ATGko respectively) were generated.

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Inflammatory fibroid polyps (IFPs) are rare mesenchymal neoplasms affecting the gastrointestinal tract which are considered benign and noninvasive. We present a case of an invasive IFP in a 46-year-old woman who presented with signs of intestinal obstruction due to ileal intussusception. A segment of the small intestine was resected and subsequently intestinal continuity was restored.

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Immune cells migrate and communicate through cell-to-cell interactions and cytokines to coordinate the specificity and timing of the immune response. While studying these events in cell culture are standard procedure, spatiotemporal dynamics of cell-to-cell interactions within three-dimensional (3D) environments are critical in generating appropriate effector functions. Here, we present a detailed protocol to study cells within an all-in-one 3D collagen matrix that is amenable to live-cell microscopy and immunohistochemistry.

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Trafficking of cell-associated HIV-1 from the genital mucosa to lymphoid organs represents a critical first step toward systemic infection. Mature DCs capture and transmit HIV-1 to T cells, but insights into DC-to-T cell viral spread dynamics within a 3-dimensional environment is lacking. Using live-cell imaging, we show that mature DCs rapidly compartmentalize HIV-1 within surface-accessible invaginations near the uropod.

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Hyperprogressive disease (HPD) is an adverse outcome of immunotherapy consisting of an acceleration of tumor growth associated with prompt clinical deterioration. The definitions based on radiological evaluation present important technical limitations. No biomarkers have been identified yet.

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Macrophages are susceptible to HIV infection and play an important role in viral dissemination through cell-cell contacts with T cells. However, our current understanding of macrophage-to-T cell HIV transmission is derived from studies that do not consider the robust migration and cell-cell interaction dynamics between these cells. Here, we performed live-cell imaging studies in 3-dimensional (3D) collagen that allowed CD4 T cells to migrate and to locate and engage HIV-infected macrophages, modeling the dynamic aspects of the environment in which these contacts frequently occur.

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HIV-1 primarily infects T lymphocytes and uses these motile cells as migratory vehicles for effective dissemination in the host. Paradoxically, the virus at the same time disrupts multiple cellular processes underlying lymphocyte motility, seemingly counterproductive to rapid systemic infection. Here we show by intravital microscopy in humanized mice that perturbation of the actin cytoskeleton via the lentiviral protein Nef, and not changes to chemokine receptor expression or function, is the dominant cause of dysregulated infected T cell motility in lymphoid tissue by preventing stable cellular polarization required for fast migration.

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Background: It is hypothesized that in individuals without clinical cardiovascular disease (CVD), but at increased CVD risk, a 50% to 60% reduction in CVD risk could be achieved using fixed dose combination (FDC) therapy (usually comprised of multiple blood-pressure agents and a statin [with or without aspirin]) in a single "polypill". However, the impact of a polypill in preventing clinical CV events has not been evaluated in a large randomized controlled trial.

Methods: TIPS-3 is a 2x2x2 factorial randomized controlled trial that will examine the effect of a FDC polypill on major CV outcomes in a primary prevention population.

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Rationale: A cleavable linker is designed and synthesized for the selective capture of azide-containing compounds. This article presents a proof of concept methodology involving the use of peptide-functionalized aminopropyl silica, on which the peptide is constructed by solid-phase peptide synthesis.

Methods: The peptide linker has L-propargylglycine (Pra) at one terminal end to allow the conjugation of azide-containing molecules by copper assisted azide alkyne cycloaddition, also known as click reaction.

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The primary goal of this study was to develop a method to study the N-glycosylation of IgG from swine in order to detect epitopes containing N-glycolylneuraminic acid (Neu5Gc) and/or terminal galactose residues linked in α1-3 susceptible to cause xenograft-related problems. Samples of immunoglobulin were isolated from porcine serum using protein-A affinity chromatography. The eluate was then separated on electrophoretic gel, and bands corresponding to the N-glycosylated heavy chains were cut off the gel and subjected to tryptic digestion.

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