Probes for INS

Infection by SARS-CoV-2 may be associated with testicular dysfunction that could affect male fertility.Testicles of fatal COVID-19 cases were investigated to detect virus in tissue and to evaluate histopathological and transcriptomic changes.Three groups were compared: a. uninfected controls (subjects dying of trauma or sudden cardiac death; n = 10); b. subjects dying of COVID-19 (virus-negative in testes; n = 15); c. subjects dying of COVID-19 (virus-positive in testes; n = 9). SARS-CoV-2 genome and nucleocapsid antigen were probed using RT-PCR, in situ hybridization, immunohistochemistry (IHC). Infiltrating leukocytes were typed by IHC. mRNA transcripts of immune-related and testis-specific genes were quantified using the nCounter method.SARS-CoV-2 was detected in testis tissue of 9/24 (37%) COVID-19 cases accompanied by scattered T-cell and macrophage infiltrates. Size of testicles and counts of spermatogenic cells were not significantly different among groups. Analysis of mRNA transcripts showed that in virus-positive testes immune processes were activated (interferon-alpha and -gamma pathways). By contrast, transcription of 12 testis-specific genes was downregulated, independently of virus positivity in tissue. By IHC, expression of the luteinizing hormone/choriogonadotropin receptor was enhanced in virus-positive compared to virus-negative testicles, while expression of receptors for androgens and the follicle-stimulating hormone were not significantly different among groups.In lethal COVID-19 cases, infection of testicular cells is not uncommon. Viral infection associates with activation of interferon pathways and downregulation of testis-specific genes involved in spermatogenesis. Due to the exceedingly high numbers of infected people in the pandemic, the impact of virus on fertility should be further investigated.

In the 2002 outbreak of severe acute respiratory syndrome (SARS) a number of patients presented abnormalities in the thyroid functioning, neuroendocrine and calcium homeostasis. It was detected in autopsies from SARS Coronavirus (SARS-CoV) patients that the thyroid gland was significantly affected by the disease, with extensive injury and death of follicular and parafollicular cells. In the present SARS-CoV-2 pandemic some studies start to report acute thyroiditis and alterations in the levels of thyroid hormones [(triiodothyronine (T3), thyroxine (T4), thyroid stimulating hormone (TSH)]. Thyroid cells present high levels of mRNA expression of angiotensin-converting enzyme 2 (ACE2), the host receptor for SARS-CoV-2. It remains poorly studied the thyroid expression of proteins that predispose to SARS-CoV-2 infection and if thyroid cells can be a direct or indirect target of SARS-CoV-2 infection.

The widespread coronavirus disease 2019 (COVID-19) is caused by infection with the novel coronavirus SARS-CoV-2. Currently, we have limited understanding of which cells become infected with SARS-CoV-2 in human tissues and where viral RNA localizes on the subcellular level. Here, we present a platform for preparing autopsy tissue for visualizing SARS-CoV-2 RNA using RNA fluorescence in situ hybridization (FISH) with amplification by hybridization chain reaction. We developed probe sets that target different regions of SARS-CoV-2 (including ORF1a and N), as well as probe sets that specifically target SARS-CoV-2 subgenomic mRNAs. We validated these probe sets in cell culture and tissues (lung, lymph node, and placenta) from infected patients. Using this technology, we observe distinct subcellular localization patterns of the ORF1a and N regions. In human lung tissue, we performed multiplexed RNA FISH HCR for SARS-CoV-2 and cell-type-specific marker genes. We found viral RNA in cells containing the alveolar type 2 (AT2) cell marker gene (SFTPC) and the alveolar macrophage marker gene (MARCO) but did not identify viral RNA in cells containing the alveolar type 1 (AT1) cell marker gene (AGER). Moreover, we observed distinct subcellular localization patterns of viral RNA in AT2 cells and alveolar macrophages. In sum, we demonstrate the use of RNA FISH HCR for visualizing different RNA species from SARS-CoV-2 in cell lines and FFPE (formalin fixation and paraffin embedding) autopsy specimens. We anticipate that this platform could be broadly useful for studying SARS-CoV-2 pathology in tissues, as well as extended for other applications, including investigating the viral life cycle, viral diagnostics, and drug screening. IMPORTANCE Here, we developed an in situ RNA detection assay for RNA generated by the SARS-CoV-2 virus. We found viral RNA in lung, lymph node, and placenta samples from pathology specimens from COVID patients. Using high-magnification microscopy, we can visualize the subcellular distribution of these RNA in single cells.

The SARS-CoV-2 pandemic has had a significant impact worldwide, particularly in middle- and low-income countries. While this impact has been well-recognized in certain age groups, the effects, both direct and indirect, on the neonatal population remain largely unknown. There are placental changes associated, though the contributions to maternal and fetal illness have not been fully determined. The rate of premature delivery has increased and SARS-CoV-2 infection is proportionately higher in premature neonates, which appears to be related to premature delivery for maternal reasons rather than an increase in spontaneous preterm labor. There is much room for expansion, including long-term data on outcomes for affected babies. Though uncommon, there has been evidence of adverse events in neonates, including Multisystem Inflammatory Syndrome in Children, associated with COVID-19 (MIS-C). There are recommendations for reduction of viral transmission to neonates, though more research is required to determine the role of passive immunization of the fetus via maternal vaccination. There is now considerable evidence suggesting that the severe visitation restrictions implemented early in the pandemic have negatively impacted the care of the neonate and the experiences of both parents and healthcare professionals alike. Ongoing collaboration is required to determine the full impact, and guidelines for future management. IMPACT: Comprehensive review of current available evidence related to impact of the COVID-19 pandemic on neonates, effects on their health, impact on their quality of care and indirect influences on their clinical course, including comparisons with other age groups. Reference to current evidence for maternal experience of infection and how it impacts the fetus and then neonate. Outline of the need for ongoing research, including specific areas in which there are significant gaps in knowledge.

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in a global health emergency. In addition to common respiratory symptoms, some patients with COVID-19 infections may experience a range of extra-pulmonary manifestations, such as digestive system involvement. Patients with COVID-19 have been reported to suffer from acute mesenteric ischemia (AMI) that is associated with disease-related severity and mortality. However, in the context of COVID-19, the exact cause of AMI has yet to be clearly defined. This review provides a comprehensive overview of the available data and elucidates the possible underlying mechanisms linking COVID-19 to AMI, in addition to highlighting therapeutic approaches for clinicians. Finally, given the severe global impact of COVID-19, we emphasize the importance of coordinated vaccination programs.

SARS-CoV-2, the etiologic agent of COVID-19, uses ACE2 as a cell entry receptor. Soluble ACE2 has been shown to have neutralizing antiviral activity but has a short half-life and no active transport mechanism from the circulation into the alveolar spaces of the lung. To overcome this, we constructed an ACE2-human IgG1 fusion protein with mutations in the catalytic domain of ACE2. A mutation in the catalytic domain of ACE2, MDR504, significantly increased binding to SARS-CoV-2 spike protein, as well as to a spike variant, in vitro with more potent viral neutralization in plaque assays. Parental administration of the protein showed stable serum concentrations with excellent bioavailability in the epithelial lining fluid of the lung, and ameliorated lung SARS-CoV-2 infection in vivo. These data support that the MDR504 hACE2-Fc is an excellent candidate for treatment or prophylaxis of COVID-19 and potentially emerging variants.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) not only affects the respiratory tract but also causes neurological symptoms such as loss of smell and taste, headache, fatigue or severe cerebrovascular complications. Using transgenic mice expressing human angiotensin-converting enzyme 2 (hACE2), we investigated the spatiotemporal distribution and pathomorphological features in the CNS following intranasal infection with SARS-CoV-2 variants, as well as after prior influenza A virus infection. Apart from Omicron, we found all variants to frequently spread to and within the CNS. Infection was restricted to neurons and appeared to spread from the olfactory bulb mainly in basally oriented regions in the brain and into the spinal cord, independent of ACE2 expression and without evidence of neuronal cell death, axonal damage or demyelination. However, microglial activation, microgliosis and a mild macrophage and T cell dominated inflammatory response was consistently observed, accompanied by apoptotic death of endothelial, microglial and immune cells, without their apparent infection. Microgliosis and immune cell apoptosis indicate a potential role of microglia for pathogenesis and viral effect in COVID-19 and the possible impairment of neurological functions, especially in long COVID. These data may also be informative for the selection of therapeutic candidates and broadly support the investigation of agents with adequate penetration into relevant regions of the CNS.

Vaccination has been a game changer in our efforts to address the coronavirus disease 2019 (COVID-19) pandemic. However, the disease might still represent a clinical crisis for several more years, in part because of the inevitable emergence of variants capable of evading the pre-existing immunity. Drugs affecting viral spread will help curtail transmission, but therapeutics are needed to treat the more severe cases requiring hospitalization. A deep analysis of the evolving immune landscape of COVID-19 suggests that understanding the molecular bases of the distinct clinical stages is paramount if we are to limit the burden of inflammation, which can lead to death in frail individuals, according to age, sex and comorbidities. Different phases can be defined using immune biomarkers and need specific therapeutic approaches, tailored to the underlying immune contexture.

Chilblain-like lesions (CLL), known in the lay press as “COVID toes,” increased significantly during the COVID-19 pandemic. The phenotypic similarity of chilblains in the monogenic type 1 interferonopathies, coupled with the consistent clinical phenotype across multiple countries and temporospatial association with COVID-19 spread, suggest a SARS-CoV-2 triggered immune phenomenon. Yet direct evidence of this relationship has been limited due to low rates of SARS-CoV-2 positivity utilizing conventional testing. We prospectively enrolled a cohort of 79 patients with CLL across 4 waves of the SARS-CoV-2 pandemic in Wisconsin collecting serial blood samples and lesional skin biopsies. Immunophenotyping including the type 1 interferon (IFN-1) signature was investigated utilizing multiplex immunohistochemistry in affected tissue. Proteomics and RNA sequencing were performed on the peripheral blood at serial time points. RNAscope for S gene and depositional immunohistochemistry for evidence of SARS-CoV-2 were performed on tissue. Antibody responses and T-cell specific responses to SARS-CoV-2 were performed and an animal model (golden hamster) provided mechanistic evidence of dissemination of viral RNA to acral sites with local IFN-1 activation. Our results support an inducible local and peripheral IFN-1 signature, which abrogates within weeks, with evidence of viral SARS-CoV-2 RNA as the trigger.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel type b coronavirus responsible for the COVID-19 pandemic. With over 224 million confirmed infections with this virus and more than 4.6 million people dead because of it, it is critically important to define the immunological processes occurring in the human response to this virus and pathogenetic mechanisms of its deadly manifestation. This perspective focuses on the contribution of the recently discovered interaction of SARS-CoV-2 Spike protein with neuropilin 1 (NRP1) receptor, NRP1 as a virus entry receptor for SARS-CoV-2, its role in different physiologic and pathologic conditions, and the potential to target the Spike-NRP1 interaction to combat virus infectivity and severe disease manifestations.