Publications by authors named "Scott Sherrill-Mix"

Unlabelled: The SARS-CoV-2 pandemic was marked with emerging viral variants, some of which were designated as variants of concern (VOCs) due to selection and rapid circulation in the human population. Here, we elucidate functional features of each VOC linked to variations in replication rate. Patient-derived primary nasal cultures grown at air-liquid interface were used to model upper respiratory infection and compared to cell lines derived from human lung epithelia.

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Over the past few years, the human virome and its complex interactions with microbial communities and the immune system have gained recognition as a crucial factor in human health. Individuals with compromised immune function encounter distinctive challenges due to their heightened vulnerability to a diverse range of infectious diseases. This review aims to comprehensively explore and analyze the growing evidence regarding the role of the virome in immunocompromised disease status.

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Background: The gut microbiome is believed to contribute to bloodstream infection (BSI) via translocation of dominant gut bacteria in vulnerable patient populations. However, conclusively linking gut and blood organisms requires stringent approaches to establish strain-level identity.

Methods: We enrolled a convenience cohort of critically ill patients and investigated 86 bloodstream infection episodes that occurred in 57 patients.

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The SARS-CoV-2 pandemic was marked with emerging viral variants, some of which were designated as variants of concern (VOCs) due to selection and rapid circulation in the human population. Here we elucidate functional features of each VOC linked to variations in replication rate. Patient-derived primary nasal cultures grown at air-liquid-interface (ALI) were used to model upper-respiratory infection and human lung epithelial cell lines used to model lower-respiratory infection.

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Background: Patients with chronic lymphocytic leukemia (CLL) have reduced seroconversion rates and lower binding antibody (Ab) and neutralizing antibody (NAb) titers than healthy individuals following Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) mRNA vaccination. Here, we dissected vaccine-mediated humoral and cellular responses to understand the mechanisms underlying CLL-induced immune dysfunction.

Methods And Findings: We performed a prospective observational study in SARS-CoV-2 infection-naïve CLL patients (n = 95) and healthy controls (n = 30) who were vaccinated between December 2020 and June 2021.

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Decades of effort have yielded highly effective antiviral agents to treat HIV, but viral strains have evolved resistance to each inhibitor type, focusing attention on the importance of developing new inhibitor classes. A particularly promising new target is the HIV capsid, the function of which can be disrupted by highly potent inhibitors that persist long term in treated subjects. Studies with such inhibitors have contributed to an evolving picture of the role of capsid itself-the inhibitors, like certain capsid protein (CA) amino acid substitutions, can disrupt intracellular trafficking to alter the selection of target sites for HIV DNA integration in cellular chromosomes.

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HIV-1 and its SIV precursors share a broadly neutralizing antibody (bNAb) epitope in variable loop 2 (V2) at the envelope glycoprotein (Env) trimer apex. Here, we tested the immunogenicity of germ line-targeting versions of a chimpanzee SIV (SIVcpz) Env in human V2-apex bNAb heavy-chain precursor-expressing knock-in mice and as chimeric simian-chimpanzee immunodeficiency viruses (SCIVs) in rhesus macaques (RMs). Trimer immunization of knock-in mice induced V2-directed NAbs, indicating activation of V2-apex bNAb precursor-expressing mouse B cells.

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Chronic lymphocytic leukemia (CLL) patients have lower seroconversion rates and antibody titers following SARS-CoV-2 vaccination, but the reasons for this diminished response are poorly understood. Here, we studied humoral and cellular responses in 95 CLL patients and 30 healthy controls after two BNT162b2 or mRNA-2173 mRNA immunizations. We found that 42% of CLL vaccinees developed SARS-CoV-2-specific binding and neutralizing antibodies (NAbs), while 32% had no response.

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Article Synopsis
  • The SARS-CoV-2 pandemic originated from animal-to-human spillover, and white-tailed deer have been found to be significantly infected with the virus in North America.
  • In a study conducted in Pennsylvania, 16.3% of nasal swab samples from deer tested positive for SARS-CoV-2, revealing the presence of alpha and delta variants in this species.
  • The findings indicate that the virus may be circulating among deer populations, suggesting a potential new animal reservoir that could lead to future spillback infections in humans.
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As the second year of the COVID-19 pandemic begins, it remains clear that a massive increase in the ability to test for SARS-CoV-2 infections in a myriad of settings is critical to controlling the pandemic and to preparing for future outbreaks. The current gold standard for molecular diagnostics is the polymerase chain reaction (PCR), but the extraordinary and unmet demand for testing in a variety of environments means that both complementary and supplementary testing solutions are still needed. This review highlights the role that loop-mediated isothermal amplification (LAMP) has had in filling this global testing need, providing a faster and easier means of testing, and what it can do for future applications, pathogens, and the preparation for future outbreaks.

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The severe acute respiratory coronavirus-2 (SARS-CoV-2) is the cause of the global outbreak of COVID-19. Evidence suggests that the virus is evolving to allow efficient spread through the human population, including vaccinated individuals. Here, we report a study of viral variants from surveillance of the Delaware Valley, including the city of Philadelphia, and variants infecting vaccinated subjects.

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Over the course of the coronavirus disease 2019 (COVID-19) pandemic, several severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genetic variants of concern have appeared and spread throughout the world. Detection and identification of these variants are important to understanding and controlling their rapid spread. Current detection methods for a particularly concerning variant, B.

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In October of 2020, researchers from around the world met online for the sixth annual International Workshop on Microbiome in HIV Pathogenesis, Prevention, and Treatment. New research was presented on the roles of the microbiome on immune response and HIV transmission and pathogenesis and the potential for alterations in the microbiome to decrease transmission and affect comorbidities. This article presents a summary of the findings reported.

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Article Synopsis
  • The study investigates the evolution of SARS-CoV-2 variants in the Delaware Valley and examines how these variants infect vaccinated individuals between March 2020 and September 2021.
  • Researchers analyzed viral genomes from 2,621 samples and 159 breakthrough infections, noting an initial prevalence of B.1 lineages, then a dominance of B.1.617.2 (delta) by the end of the sampling period.
  • The study revealed that delta variant infections were three times more likely in vaccinated individuals, alongside specific viral substitutions like N501Y, emphasizing the changing dynamics of the virus and its impact on vaccine effectiveness.
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Red blood cells (RBCs) are essential for aerobic respiration through delivery of oxygen to distant tissues. However, RBCs are currently considered immunologically inert, and few, if any, secondary functions of RBCs have been identified. Here, we showed that RBCs serve as critical immune sensors through surface expression of the nucleic acid–sensing Toll-like receptor 9 (TLR9).

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Not all persons recovering from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection develop SARS-CoV-2-specific antibodies. We show that nonseroconversion is associated with younger age and higher reverse transcription PCR cycle threshold values and identify SARS-CoV-2 viral loads in the nasopharynx as a major correlate of the systemic antibody response.

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  • The rapid spread of SARS-CoV-2 during the pandemic created a demand for quick and cost-effective diagnostic methods beyond the expensive RT-PCR tests, leading to interest in RT-LAMP as an alternative.
  • This study presents the development of molecular beacons for RT-LAMP, enhancing the detection of SARS-CoV-2 RNA with improved specificity and the ability to multiplex different targets in a single reaction.
  • The LAMP-BEAC assay showed strong agreement with traditional RT-qPCR results, making it a practical and affordable option for large-scale population screening, especially for saliva samples.
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Infection with human and simian immunodeficiency viruses (HIV/SIV) requires binding of the viral envelope glycoprotein (Env) to the host protein CD4 on the surface of immune cells. Although invariant in humans, the Env binding domain of the chimpanzee CD4 is highly polymorphic, with nine coding variants circulating in wild populations. Here, we show that within-species CD4 diversity is not unique to chimpanzees but found in many African primate species.

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Article Synopsis
  • The study investigates the spread of COVID-19 in Philadelphia during its first wave, using full-genome sequencing of SARS-CoV-2 samples from hospitalized patients between March and July 2020.
  • Findings show that most viral sequences were closely related to those circulating earlier in New York, indicating primary transmission from that location, but also revealed some local transmission and other potential sources.
  • The presence of specific genetic markers (like the D614G substitution) in the viral spike suggests ongoing mutations, but no clear link between genetic variations and disease outcomes was found.
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Type 1 interferons (IFN-I) are potent innate antiviral effectors that constrain HIV-1 transmission. However, harnessing these cytokines for HIV-1 cure strategies has been hampered by an incomplete understanding of their antiviral activities at later stages of infection. Here, we characterized the IFN-I sensitivity of 500 clonally derived HIV-1 isolates from the plasma and CD4 T cells of 26 individuals sampled longitudinally after transmission or after antiretroviral therapy (ART) and analytical treatment interruption.

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Objectives: To evaluate the presence of dehiscences and changes in alveolar bone height and width in the area of the mandibular central incisors pre- and post-orthodontic treatment.

Materials And Methods: In 60 skeletal Class II patients, cone-beam computed tomographic (CBCT) images were obtained and the patients were divided into four groups based on the presence of dehiscences at pre- and post-orthodontic treatment. The alveolar bone height and width were measured on CBCT in cross section along the long axis of the teeth.

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In October of 2019, researchers and community members from around the world met at the NIH for the fifth annual International Workshop on Microbiome in HIV. New research was presented on the role of the microbiome on chronic inflammation and vaccine design, interactions of genetics, environment, sexual practice and HIV infection with the microbiome and the development and clinical trials of microbiome-based therapeutic approaches intended to decrease the probability of HIV acquisition/transmission or ameliorate sequelae of HIV. The keynote address by Dr.

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The gut of healthy human neonates is usually devoid of viruses at birth, but quickly becomes colonized, which-in some cases-leads to gastrointestinal disorders. Here we show that the assembly of the viral community in neonates takes place in distinct steps. Fluorescent staining of virus-like particles purified from infant meconium or early stool samples shows few or no particles, but by one month of life particle numbers increase to 10 per gram, and these numbers seem to persist throughout life.

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Article Synopsis
  • * The researchers created a method called HIV-1 SortSeq to isolate rare HIV-1-infected cells from individuals where the virus is usually suppressed, analyzing these cells reveals pathways related to RNA decay and viral activity.
  • * They discovered that HIV-1 causes unusual transcription in host genes by integrating its RNA and promoting its own activity, which means these processes could be targeted for new treatments to help manage or eliminate HIV-1 persistence.
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