Category: COVID-19 Immunology
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Rhesus Macaques Exhibit Robust Immune Response Upon Re-challenge with SARS-CoV-2; Alpha-1 Adrenergic Receptor Antagonists Alleviate Symptoms of Pneumonia and Acute Respiratory Distress Syndrome
In an effort to determine the SARS-CoV-2-specific antibody response longitudinally, a team of researchers infected rhesus macaques with the virus and measured the viral load and antibody titer over the course of several weeks. Initially, six macaques were administered intratracheal injections of SARS-CoV-2 viral particles. At 28 days post infection (dpi, equal to 0 days…
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CD147 Interacts with SARS-CoV-2 Spike Protein to Facilitate Infection; SARS-CoV-2-Reactive IgA is Found in Breastmilk
ACE2 is well established as the primary target for viral attachment and entry for both SARS-CoV-1 and SARS-CoV-2 (Li et al., 2005; Zhang et al., 2020). In addition, several other molecules have been discovered to play an accessory role in permitting viral entry into host cells. One of these accessory proteins is a molecule called…
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SARS-CoV-2 N Protein Enhances Lectin-Pathway Complement Activation; Type III Interferon is Implicated in the Host Immune Response to SARS-CoV-2; The Monoclonal Antibody 47D11 is a Potent Neutralizer of SARS-CoV-2
The complement system is an interdigitated array of three pathways that act as part of the innate immune response to protect against extracellular pathogens. Dysregulation or hyperactivation of the complement system is associated with various inflammatory and autoimmune conditions (Karpman et al., 2015; Ballanti et al., 2013; Jensen, 1967). The classical complement pathway consists of…
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SARS-CoV-2 Damages Secondary Lymphoid Organs; STAT-2 Signaling is Important for Establishing an Effective Immune Response to SARS-CoV-2
Increasingly, studies are being published that provide evidence for the tropism of SARS-CoV-2 to tissues outside the respiratory system – i.e., the affinity of SARS-CoV-2 to infect organs besides the lungs (Chu et al., 2020; Xiao, Tang et al., 2020). Of note, a postmortem study of six patients who died of COVID-19 revealed that the…
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Cytotoxic T Cells and Natural Killer Cells Express the Exhaustion Marker NKG2A; The SARS-CoV Antibody CR3022 Exhibits Cross-Reactivity to SARS-CoV-2 Spike Protein
I reported previously on observed functional exhaustion of T cells in patients with severe COVID-19 (see 4/13 updates). In that study, Diao et al. noted increased expression of the exhaustion markers PD-1 and Tim-3 on T cells that increased with the severity of the disease and recovered to normal levels in the convalescent period (Diao…
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Type-I Interferons Are Implicated in the Host Immune Response; Interleukin 6 is a Major Indicator of Disease Severity in COVID-19
Updates on the intricacies of the host immunological response to SARS-CoV-2 are published daily, giving us new insights into the clinical progression of COVID-19 and potential therapeutic routes to pursue. As we move through the worst of the pandemic, it will become increasingly important to turn our attention to untangling the interactions between the novel…
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Convalescent Plasma From Recovered Patients is a Viable Source of SARS-CoV-2 Antibody; The Exhaustion Markers PD-1 and Tim-3 Are Upregulated on T cells in COVID-19
Within the last week, more information concerning the immune mechanisms of SARS-CoV-2 has come to light. International studies characterizing the host response continue to provide updated information, and studies here in the US are beginning to gain momentum as the first wave of approval and funding reaches labs across the country. Much of what has…
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Lymphopenia and Cytokine Storm are Common in COVID-19 and Act as Markers of Disease Severity
Written by: Parker Davis Edited by: Jina Zhou and Esther Melamed 4/7/2020 The host immune response to SARS-CoV-2 infection has been documented and characterized to some extent over the course of the last few months. Still in the early stages of understanding, there is some contention about the exact mechanism of the coronavirus infection. The…