Publications by authors named "HICKMAN H"

Article Synopsis
  • - The oral mucosa has unique antiviral properties influenced by physical characteristics and immune cells, but much about its antiviral response is still not fully understood
  • - Several viruses, like herpesviruses and HPV, are known to infect the oral cavity, and recent outbreaks (e.g., SARS-CoV-2) have shown oral symptoms, indicating the oral cavity's role in viral transmission
  • - This Review explores antiviral responses in the oral cavity, discusses common viral infections affecting it, and examines current mouse models used for researching oral viral infections
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Flavivirus assembly at the endoplasmic reticulum is driven by the structural proteins envelope (E) and premembrane (prM). Here, contrary to the established paradigm for flavivirus assembly, we demonstrate that the biogenesis of flavivirus particles does not require an intact prM nor proteolytic activation. The expression of E preceded by a truncated version of prM (M-E) was sufficient for the formation of non-infectious Zika virus subviral particles and pseudo-infectious reporter virions.

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  • SARS-CoV-2 not only infects the respiratory system but also causes gastrointestinal (GI) symptoms, leading researchers to study its GI effects in both rhesus macaques and humans.
  • In macaques, infection resulted in viral RNA found in both the respiratory tract and stool, along with decreased levels of certain immune cells in the intestine, suggesting immune disturbance.
  • The study highlighted the translocation of bacteria across the gut barrier during infection and noted that humans recovering from COVID-19 showed decreases in inflammatory markers, indicating a resolution of inflammation linked to GI issues.
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  • The study investigates how inflammatory responses affect pulmonary disease during SARS-CoV-2 infection, specifically using the rhesus macaque model of mild COVID-19.
  • It highlights the contrasting roles of the cytokines IFNγ and IL-10, where IFNγ contributes to lung lesions but isn't necessary for viral replication suppression, while IL-10 reduces inflammation and aids in T cell memory without hindering viral clearance.
  • The research reveals that IL-10 plays a key role in fostering airway memory T cells, indicating its importance in the immune response during SARS-CoV-2 infection.
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The skin is a complex tissue that provides a strong physical barrier against invading pathogens. Despite this, many viruses can access the skin and successfully replicate in either the epidermal keratinocytes or dermal immune cells. In this review, we provide an overview of the antiviral T cell biology responding to cutaneous viral infections and how these responses differ depending on the cellular targets of infection.

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Specific learning disorder (SLD) is a neurodevelopmental disorder that affects 5-15% of school-aged children worldwide. Often, difficulties in reading (SLD-RD) and mathematics (SLD-MD) occur together. Deficits in phonological awareness (PA) have been identified as the common factor between the two difficulties.

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Rapid lymphocyte cell division places enormous demands on the protein synthesis machinery. Flow cytometric measurement of puromycylated ribosome-associated nascent chains after treating cells or mice with translation initiation inhibitors reveals that ribosomes in resting lymphocytes in vitro and in vivo elongate at typical rates for mammalian cells. Intriguingly, elongation rates can be increased up to 30% by activation in vivo or fever temperature in vitro.

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  • Lymph node germinal centers (GCs) are vital for B cell activation, developing after specialized macrophages filter antigens from the lymph.
  • The study tracked Zika virus (ZIKV) in mice to understand how lymph nodes capture viral antigens from the blood, noting that GC formation occurred even in non-draining lymph nodes despite initial delays in infection.
  • Findings suggest that CD169 macrophages in lymph nodes can still activate antiviral B cells from blood-borne viruses, highlighting a pathway for immune response even when the lymph nodes are not directly draining infected tissue.
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  • - Alphaviruses, transmitted by mosquitoes, cause high levels of the virus in the bloodstream that help in spreading the infection to new hosts through a two-phase transport mechanism to the draining lymph node (DLN).
  • - The first phase of transport occurs shortly after infection before the virus replicates, while the second phase requires the virus to replicate in the skin, enabling it to enter the bloodstream.
  • - Depleting a specific type of immune cell called Ly6C monocytes reduces infection rates in the skin, slows down the transport of the virus to the DLN, and delays its spread to other body parts, indicating that these monocytes play a crucial role in enhancing alphavirus infection and spread.
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Infection with chikungunya virus (CHIKV) causes disruption of draining lymph node (dLN) organization, including paracortical relocalization of B cells, loss of the B cell-T cell border, and lymphocyte depletion that is associated with infiltration of the LN with inflammatory myeloid cells. Here, we found that, during the first 24 hours of infection, CHIKV RNA accumulated in MARCO-expressing lymphatic endothelial cells (LECs) in both the floor and medullary LN sinuses. The accumulation of viral RNA in the LN was associated with a switch to an antiviral and inflammatory gene expression program across LN stromal cells, and this inflammatory response - including recruitment of myeloid cells to the LN - was accelerated by CHIKV-MARCO interactions.

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Cancers associated with the oncogenic gammaherpesviruses, Epstein-Barr virus and Kaposi sarcoma herpesvirus, are notable for their constitutive activation of the transcription factor signal transducer and activator of transcription 3 (STAT3). To better understand the role of STAT3 during gammaherpesvirus latency and the B cell response to infection, we used the model pathogen murine gammaherpesvirus 68 (MHV68). Genetic deletion of STAT3 in B cells of mice reduced peak MHV68 latency approximately sevenfold.

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Macrophages orchestrate tissue immunity from the initiation and resolution of antimicrobial immune responses to the repair of damaged tissue. Murine studies demonstrate that tissue-resident macrophages are a heterogenous mixture of yolk sac-derived cells that populate the tissue before birth, and bone marrow-derived replacements recruited in adult tissues at steady-state and in increased numbers in response to tissue damage or infection. How this translates to species that are constantly under immunologic challenge, such as humans, is unknown.

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Human poxvirus infections have caused significant public health burdens both historically and recently during the unprecedented global Mpox virus outbreak. Although vaccinia virus (VACV) infection of mice is a commonly used model to explore the anti-poxvirus immune response, little is known about the metabolic changes that occur during infection. We hypothesized that the metabolome of VACV-infected skin would reflect the increased energetic requirements of both virus-infected cells and immune cells recruited to sites of infection.

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Infection with chikungunya virus (CHIKV) causes disruption of draining lymph node (dLN) organization, including paracortical relocalization of B cells, loss of the B cell-T cell border, and lymphocyte depletion that is associated with infiltration of the LN with inflammatory myeloid cells. Here, we find that during the first 24 h of infection, CHIKV RNA accumulates in MARCO-expressing lymphatic endothelial cells (LECs) in both the floor and medullary LN sinuses. The accumulation of viral RNA in the LN was associated with a switch to an antiviral and inflammatory gene expression program across LN stromal cells, and this inflammatory response, including recruitment of myeloid cells to the LN, was accelerated by CHIKV-MARCO interactions.

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Article Synopsis
  • After recognizing an antigen, CD8 T cells release granzymes, which, alongside perforin, help kill target cells; however, the specific roles of some granzymes, like granzyme C, remain unclear.
  • Research shows that granzyme C is consistently found in certain skin-resident antiviral lymphocytes, like dendritic epidermal T cells (DETCs) and virus-specific CD8 memory T cells.
  • Granzyme C expression can increase in response to local viral infections and environmental factors, suggesting its involvement in functions beyond direct cell killing in tissue-resident immune cells.
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Mucosal delivery of IL-27 has been shown to have a therapeutic benefit in murine models of inflammatory bowel disease (IBD). The IL-27 effect was associated with phosphorylated STAT1 (pSTAT1), a product of IL27 receptor signaling, in bowel tissue. To determine whether IL-27 acted directly on colonic epithelium, murine colonoids and primary intact colonic crypts were shown to be unresponsive to IL-27 and to lack detectable IL-27 receptors.

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Cancers associated with the oncogenic gammaherpesviruses, Epstein-Barr virus and Kaposi sarcoma herpesvirus, are notable for their constitutive activation of the transcription factor STAT3. To better understand the role of STAT3 during gammaherpesvirus latency and immune control, we utilized murine gammaherpesvirus 68 (MHV68) infection. Genetic deletion of STAT3 in B cells of mice reduced peak latency approximately 7-fold.

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Article Synopsis
  • The Zika virus is thought to spread through myeloid immune cells, but the exact timing and mechanisms of this process are still not fully understood.
  • Researchers found that ZIKV rapidly infects stationary CD169 macrophages in lymph nodes, rather than relying on migrating immune cells for transmission.
  • This infection of macrophages is enough to kickstart viremia, suggesting that targeting macrophages in lymph nodes could be a new strategy for antiviral treatment.
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B cell follicles in the lymph node protect vaccines to enhance immune responses.

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The success of poxviruses as pathogens depends on their antagonism of host responses by multiple immunomodulatory proteins. The largest of these expressed by ectromelia virus (the agent of mousepox) is C15, one member of a well-conserved poxviral family previously shown to inhibit T cell activation. Here, we demonstrate by quantitative immunofluorescence imaging that C15 also limits contact between natural killer (NK) cells and infected cells .

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  • The study investigates how two cytokines, IFNγ and IL-10, influence inflammation and immune responses during SARS-CoV-2 infection in rhesus macaques.
  • Blocking IFNγ reduced lung inflammation without significantly affecting immune cell types, whereas blocking IL-10 increased lung inflammation and the presence of virus-specific T cells but hampered their development into specialized cells.
  • Overall, neither cytokine blockade significantly altered the viral load, indicating that these inflammatory pathways play a minimal role in controlling SARS-CoV-2 replication, though IL-10 is important for regulating T cell responses in the lungs.
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  • Disseminated coccidioidomycosis (DCM) is a serious illness caused by Coccidioides fungi, primarily affecting individuals in the southwestern U.S. and Mexico, with only 30% of infected individuals showing symptoms and less than 1% developing DCM.
  • Through whole-exome sequencing of 67 DCM patients, researchers identified genetic mutations, including haploinsufficient STAT3 and defects in β-glucan sensing and response, in a significant number of cases, influencing disease dissemination.
  • A validation study with an additional 111 patients confirmed specific variants in genes like CLEC7A and PLCG2 that linked to weakened immune responses, indicating that impaired recognition of the fungi and lowered cytok
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Defective gastrointestinal barrier function and, in turn, microbial translocation have been identified as significant contributors to persistent inflammation in antiretroviral (ARV)-treated people living with HIV. Metabolic supplementation of short-chain fatty acids (SCFAs), generally produced by the commensal microbiome, may improve these outcomes. Butyrate is a SCFA that is essential for the development and maintenance of intestinal immunity and has a known role in supporting epithelial integrity.

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  • SARS-CoV-2 primarily replicates in mucosal sites, and this study used rhesus macaques to investigate the immune responses during mild COVID-19.
  • Viral RNA levels peaked shortly after infection and decreased rapidly, while lung abnormalities and immune cell activation were observed a few days later.
  • T cell responses (CD8 and CD4 T cells) appeared later, indicating that innate immunity may effectively limit the virus's replication before these specific immune cells respond.
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The induction of interferon (IFN)-stimulated genes by STATs is a critical host defense mechanism against virus infection. Here, we report that a highly expressed poxvirus protein, 018, inhibits IFN-induced signaling by binding to the SH2 domain of STAT1, thereby preventing the association of STAT1 with an activated IFN receptor. Despite encoding other inhibitors of IFN-induced signaling, a poxvirus mutant lacking 018 was attenuated in mice.

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