Current approaches used in treating COVID-19 from a molecular mechanisms and immune response perspective

Abstract

Coronavirus disease 2019 (COVID-19), which is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared by the World Health Organization (WHO) as a global pandemic on March 11, 2020. SARS-CoV-2 targets the respiratory system, resulting in symptoms such as fever, headache, dry cough, dyspnea, and dizziness. These symptoms vary from person to person, ranging from mild to hypoxia with acute respiratory distress syndrome (ARDS) and sometimes death. Although not confirmed, phylogenetic analysis suggests that SARS-CoV-2 may have originated from bats; the intermediary facilitating its transfer from bats to humans is unknown. Owing to the rapid spread of infection and high number of deaths caused by SARS-CoV-2, most countries have enacted strict curfews and the practice of social distancing while awaiting the availability of effective U.S. Food and Drug Administration (FDA)-approved medications and/or vaccines. This review offers an overview of the various types of coronaviruses (CoVs), their targeted hosts and cellular receptors, a timeline of their emergence, and the roles of key elements of the immune system in fighting pathogen attacks, while focusing on SARS-CoV-2 and its genomic structure and pathogenesis. Furthermore, we review drugs targeting COVID-19 that are under investigation and in clinical trials, in addition to progress using mesenchymal stem cells to treat COVID-19. We conclude by reviewing the latest updates on COVID-19 vaccine development. Understanding the molecular mechanisms of how SARS-CoV-2 interacts with host cells and stimulates the immune response is extremely important, especially as scientists look for new strategies to guide their development of specific COVID-19 therapies and vaccines.

Non-linear link between temperature difference and COVID-19: Excluding the effect of population density

“…But if the TD is lower than 11.5°C, it presents a reverse linear relationship that the greater the temperature difference, the fewer updates of COVID-19. External temperature changes that affect the transmission mechanism of COVID-19 mainly reflect in two aspects: one is the impact of temperature on the survival of COVID-19 virus [25][26][27], which has been confirmed in early studies on SARS virus [28][29][30][31]; second, external temperature changes cause the migration and mobility of population [32][33][34]. Our study sheds some light on the non-linear relationship between ambient temperature and new confirmed cases of COVID-19, which verifies that the number of new confirmed cases of COVID-19 may increase daily without any public health interventions if the weather changes dramatically.…”

Role of Toll‐like receptors in the pathogenesis of COVID‐19

“…In addition, activation of Janus kinase transducers (JAK/STAT), which is induced by TLRs, could lead to macrophage activation syndrome. Therefore, TLRs have a dual role in viral infections 8,11‐15 . Besides this, TLRs also contribute to the activation of the adaptive immune system via the upregulation of major histocompatibility complex on dendritic cells 16 …”

Modulation of ACE-2 mRNA by inflammatory cytokines in human thyroid cells: a pilot study

“…The expression of this receptor recently raised great interest in view of the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Indeed, early steps of SARS-CoV-2 infection require the attachment of the virus through its S-glycoprotein to the ACE-2 receptor expressed on the host epithelial cells [ 10 ].…”