Question

immunology question: can someone Analyze the following mild-to-moderate case of COVID-19

1. A 42-year-old man from Wuhan, China, presented to an emergency department in Paris, France. His symptoms started 4 days earlier with lethargy, sore throat, dry cough, chest pain, mild labored breathing and fever. He traveled from Wuhan to France 10 days before going to the ER. He had no contact with the Huanan seafood market or with known COVID-19 cases. He was otherwise healthy and was a non-smoker taking no medications. At presentation on day 4, SARS-CoV-2 was detected in a nasopharyngeal swab specimen by real-time reverse-transcriptase PCR.

At this point in this clinical case, explain:

1. How the virus entered the host, and which receptors are used for entry into which cells.

2. What innate immune responses are triggered when cells become infected:
   1. How is the virus recognized by the host? Explain and name the cells/receptors involved

2. What signaling pathways are triggered? Name and explain the major pathways needed to mount an antiviral response.

3. What is the result of these signaling events? Name the main effectors produced as the result of the signaling events, describe the effector functions.

4. Other coronaviruses such as SARS-CoV and MERS-CoV are known suppressors of Type I IFNs. Presumably, SARS-CoV-2 employs similar strategies. Explain how SARS-CoV and MERS-CoV may interfere with Type I IFN production and signaling through their receptors.

5. In immunological terms, how do you explain the clinical symptoms of chest pain and mild labored breathing, suggestive of pneumonia?

Answer 1

Ans 1- Virus might got entered by touching contaminated surface during travelling form wuhan to france.

and the recptor involved is ACE2 (angiotensin-converting enzyme 2) present on lung cells.

Ans2-What innate immune responses are triggered when cells become infected:early control of viral replication by type I interferons (IFN), complement proteins, and other innate immune mediators limit viral spread within the host during the early phases of the disease.

ans 3- How is the virus recognized by the host? Explain and name the cells/receptors involved- Coronaviruses utilize their S protein to enter host cells.this entry occurs via the host cell surface enzyme angiotensin-converting enzyme 2 (ACE2) receptor.

Ans 4- What signaling pathways are triggered? Name and explain the major pathways needed to mount an antiviral response. It triggers IFN sensing and signaling pathway. RNA viruses are internalized through several mechanisms, either fusion with the plasma membrane or binding to a surface receptor (ACE2 for SARS-CoV, carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) for MHV). That internalization exposes the genomic RNA to the dsRNA sensing machinery in the cell; TLR3, RIGI and MDA5. These proteins signal the IRF-3 cascade leading to induction of IFNb and production of secreted IFNβ protein. That IFNβ protein can then bind IFNα/β receptors (INFAR1) on the surface of the same cell or surrounding cells. This activates the Stat1 signaling pathway to activate the many anti-viral genes found with ISRE promoter elements.

Ans 5-What is the result of these signaling events? Name the main effectors produced as the result of the signaling events, describe the effector functions. this signaling results in the production of  IFNβ protein.  IFNs have various other functions: they activate immune cells, such as natural killer cells and macrophages; they increase host defenses by up-regulating antigen presentation by virtue of increasing the expression of major histocompatibility complex (MHC) antigens.

ANS- In immunological terms, how do you explain the clinical symptoms of chest pain and mild labored breathing, suggestive of pneumonia?- Pneumonia is a lung infection that causes inflammation in the tiny air sacs inside your lungs. They may fill up with so much fluid and pus that it’s hard to breathe. that may cause severe shortness of breath, a cough, a fever, chest pain, chills, or fatigue.

one can get pneumonia via virus such is the case in covid 19.