The Role of Host Genetic Factors in Coronavirus Susceptibility: Review of Animal and Systematic Review of Human Literature

Interactoma de predisposición y resistencia a SARS-CoV-2. Proteínas, genes y funciones

Se ha informado que la infección por SARS-CoV-2 tiene al menos tres aspectos: la capacidad patogénica del virus, la susceptibilidad y la interacción virus-huésped en un ambiente. Para varios virus, está demostrado que tienen receptores celulares específicos de unión con las células y son determinantes en la entrada o no del virus a las células. Para el virus SARS-CoV-2, se conoce que el receptor ACE2 (Enzima Convertidora de Angiotensina 2), es clave para que el virus se adhiera a la membrana celular del epitelio pulmonar, al neumocito. El receptor ACE2 tiene su gen específico con el mismo nombre localizado en el cromosoma Xp22.2 y tiene a su vez interacciones con algunos genes. Nos propusimos encontrar interacciones de proteínas que tengan relación con la entrada, sintomatología y progreso de la COVID-19 y con otras proteínas similares o coadyuvantes. Estas interacciones son extremadamente importantes para entender la fisiopatología de la enfermedad y los diversos grados de afectación que se han observado asintomáticos, leves, moderados, graves y críticos, lo que se conoce como heterogeneidad clínica. La heterogeneidad en los síntomas es probable que refleje una heterogeneidad de interacciones de proteínas que se encuentran interrelacionadas con la infección por el virus COVID-19 y su correlación entre sí. La meta final es encontrar los genes que comandan estas interacciones proteicas y asociarlas con la variación clínica. Este es un estudio inicial de interactoma proteico para continuar con el análisis de proteínas específicas y sus variantes en la población ecuatoriana.

Antibody-Dependent Enhancement and the Critical Pattern of COVID-19: Possibilities and Considerations

Coronavirus disease 2019 (COVID-19), a pandemic infection with profound effects on human society, has challenged our ability to control viral infections. Although at the beginning of the COVID-19 outbreak, the epidemic seemed controllable in Southern Iran, the disease presented a critical pattern as of May 2020. After a few months of the emergence of COVID-19, its severity and mortality increased dramatically. It has been proposed that antibodies produced during previous exposure to local circulating human coronaviruses or possibly severe acute respiratory syndrome coronavirus 2 might contribute to the development of more severe and lethal presentations of COVID-19 possibly by triggering antibody-dependent enhancement. The binding of virions complexed with antibodies to Fcγ receptors on the target cells initiates receptor-mediated signaling events, leading to enhanced expression of inflammatory cytokines and suppression of intracellular antiviral responses at the transcriptome level, followed by endocytosis of the virus and subsequent activation of immune cells. The activated immune cells might accumulate in the lung and promote cytokine storm and lymphopenia. Furthermore, the formation of immune complexes can promote complement activation and subsequent tissue damage. Although there are currently no clinical data to support this hypothesis, a better understanding of these immunopathologic phenomena and their relation to the disease course and severity might give insights into the development of the most efficient prophylactic and therapeutic approaches. This review demonstrates the critical pattern of COVID-19 in Southern Iran and highlights the possible interplay of factors leading to this condition.

Understanding the complexities of SARS-CoV2 infection and its immunology: A road to immune-based therapeutics

Emerging infectious diseases always pose a threat to humans along with plant and animal life. SARS-CoV2 is the recently emerged viral infection that originated from Wuhan city of the Republic of China in December 2019. Now, it has become a pandemic. Currently, SARS-CoV2 has infected more than 27.74 million people worldwide, and taken 901,928 human lives. It was named first 'WH 1 Human CoV' and later changed to 2019 novel CoV (2019-nCoV). Scientists have established it as a zoonotic viral disease emerged from Chinese horseshoe bats, which do not develop a severe infection. For example, Rhinolophus Chinese horseshoe bats harboring severe acute respiratory syndrome-related coronavirus (SARSr-CoV) or SARSr-Rh-BatCoV appear healthy and clear the virus within 2-4 months period. The article introduces first the concept of EIDs and some past EIDs, which have affected human life. Next section discusses mysteries regarding SARS-CoV2 origin, its evolution, and human transfer. Third section describes COVID-19 clinical symptoms and factors affecting susceptibility or resistance. The fourth section introduces the SARS-CoV2 entry in the host cell, its replication, and the establishment of productive infection. Section five describes the host's immune response associated with asymptomatic, symptomatic, mild to moderate, and severe COVID-19. The subsequent seventh and eighth sections mention the immune status in COVID-19 convalescent patients and re-emergence of COVID-19 in them. Thereafter, the eighth section describes viral strategies to hijack the host antiviral immune response and generate the "cytokine storm". The ninth section describes about transgenic humane ACE2 (hACE2) receptor expressing mice to study immunity, drugs, and vaccines. The article ends with the development of different immunomodulatory and immunotherapeutics strategies, including vaccines waiting for their approval in humans as prophylaxis or treatment measures.