AI and Immunology Considerations in Pandemics and SARS-CoV-2 COVID-19
Louis J. Catania in AI for Immunology, 2021
By definition, the traditional vaccine is a biological preparation that provides active, adaptive immunity to a particular infectious disease (e.g., SARS-CoV-2) by stimulating antibodies to the source of the infection. It typically contains an agent that resembles the disease-causing microorganism made from weakened or killed forms of the microbe (an attenuated virus), its toxins, or one of its surface proteins. The spike protein is the target for most of the COVID-19 vaccine human clinical trials and so research centers on how the immune system, particularly B- and T-cells, responds to the spike protein. B-cells are responsible for producing the antibodies that recognize SARS-CoV-2, while T-cells play an important role in supporting the development of the B-cell response (see Chapter 2).
Clinical Basis of COVID-19
Wenguang Xia, Xiaolin Huang in Rehabilitation from COVID-19, 2021
How does the 2019-nCoV work? The spike protein (S protein) on the surface of the virus enters the host cell by interacting with specific receptors on the cell surface. Then it enters the cell through membrane fusion and releases its genome into the cytoplasm. The virus mainly binds to angiotensin-converting enzyme 2 (ACE2) via the S protein on its surface. During fusion, the S protein undergoes structural rearrangement to fuse the viral membrane with the host cell membrane, thereby infecting human respiratory epithelial cells. It has a higher affinity than SARS-CoV and, therefore, is more infectious.
SARS-CoV Infections in Humans
Sunit K. Singh in Human Respiratory Viral Infections, 2014
The Spike protein is a type I membrane protein that inserts into the viral envelope, conferring the crown-like appearance of the virus in electron microscopy. This protein interacts with the cellular receptor, angiotensin-converting enzyme 2 (ACE2),48–50 mediating the entrance of the virus into the host cells. S protein induces membrane fusion between the viral envelope and the host plasma membrane. This protein is, thus, the major determining factor in the host range of SARS-CoV as well as tissue tropism of the virus.
Virus-associated ribozymes and nano carriers against COVID-19
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2021
Beyza Dönmüş, Sinan Ünal, Fatma Ceren Kirmizitaş, Nelisa Türkoğlu Laçin
SARS-CoV-2 has several proteins: structural spike (S) protein, membrane (M) protein, nucleocapsid (N) protein and envelope (E) protein. PP1a and PP1b, two viral replicase polyproteins, are produced that are processed into 16 mature non-structural proteins (NSPs). The Spike protein is a glycoprotein found on the outer surface of the virus and responsible for the recognition, attachment and entry to host cells [18]. Figure 1(A) shows the structure of the spike (S) protein. Overall, the perspective on anti-viral treatment strategies for COVID-19 infections is targeting spike (S) protein inhibition. Inhibitors are commonly used in anti-viral treatments. However, repeated virus mutations and viruses escaping immune system cells may be ineffective in binding viral inhibitors to their targets and cause toxicity and serious side effects due to non-specific binding [19–23]. At the same time, the interaction of inhibitors with other molecules can lead to low efficacy [24].
Immunotherapy for SARS-CoV-2: potential opportunities
Published in Expert Opinion on Biological Therapy, 2020
Mehrnoosh Pashaei, Nima Rezaei
Infections with SARS-CoV and SARS-CoV-2 are begun with the virus entry to the host cells through interaction of the receptor-binding domain (RBD) of the S1 subunit in viral spike (S) proteins on the surface of the virus with angiotensin-converting enzyme 2 (ACE2) on host cells [10]. Therefore, spike protein plays a key role in virus entry and the beginning of the viral lifecycle. Accordingly, interruption in the interaction of these proteins with specific neutralizing monoclonal antibodies can be a potential target for effective treatment against coronavirus infections. The neutralizing monoclonal antibodies either against ACE2 or receptor-binding domain (RBD) for SARS-CoV treatment can be helpful for SARS-CoV-2 [11]. With this in mind, Sui et al. in an in vitro study had reported 80 R scFv (single-chain variable fragment) is a human recombinant monoclonal antibody that binds to S1 domain of S protein of SARS-CoV and prevents the interaction of the virus with host cells that was tested by microneutralization assay and in another study by Sui et al. had shown intraperitoneal (IP) of 80 R IgG1 injected to BALB/c mice 1 day before SARS-CoV intranasal challenge, and 80 R IgG1 inhibited the replication of SARS-CoV in lung tissue of mice and its And its prophylactic role was highlighted [12,13].
An update on host immunity correlates and prospects of re-infection in COVID-19
Published in International Reviews of Immunology, 2022
Neema Negi, Shesh Prakash Maurya, Ravinder Singh, Bimal Kumar Das
Viruses are evolving since the dawn of life as the process follows the same Darwinian principles of evolution for life, involving natural selection, genetic variation and survival of the fittest [158]. SARS-CoV-2 is also following its natural trajectory just like any other virus and it does not have any special animosity toward human beings. The virus first crossed the species barrier possibly by jumping from bats to human [159] and it is now continuously evolving to adapt and have better transmissibility. SARS-CoV-2 is a 30 kb size single stranded positive sense RNA virus as shown in Figure 1 having 88% homology with bat-SL-CoVZC45 and bat-SL-CoVZXC21, 79.5% homology with SARS-CoV and around 50% with MERS-CoV [160–162]. SARS-CoV-2 genome encodes multiple genes including structural: S (spike), E (envelope), M (membrane), N (nucleocapsid); nonstructural: ORF1a, ORF1b; and accessory genes:ORF3a, ORF6, ORF7a, ORF7b, ORF8 and ORF10 [163] (Figure 1). World’s largest database of novel coronavirus genome sequences, The Global Initiative on Sharing All influenza Data (GISAID) has shown that the mutation rate of this novel virus is comparatively slower than other viruses such as HIV yet it has resulted in several major strains over time [164]. Some mutations in the receptor-binding domain of the virus’s spike protein have allowed better binding capacity to host cells [164, 165].
Related Knowledge Centers
- Coronavirus
- Protein
- Spike Protein
- Transmission Electron Microscopy
- Virus
- Glycoprotein
- Protein Trimer
- Negative Stain
- Viral Entry
- Host