A comprehensive review about immune responses and exhaustion during coronavirus disease (COVID-19).

Coronavirus disease (COVID-19) is a viral infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. The infection was reported in Wuhan, China, in late December 2019 and has become a major global concern due to severe respiratory infections and high transmission rates. Evidence suggests that the strong interaction between SARS-CoV-2 and patients' immune systems leads to various clinical symptoms of COVID-19. Although the adaptive immune responses are essential for eliminating SARS-CoV-2, the innate immune system may, in some cases, cause the infection to progress. The cytotoxic CD8+ T cells in adaptive immune responses demonstrated functional exhaustion through upregulation of exhaustion markers. In this regard, humoral immune responses play an essential role in combat SARS-CoV-2 because SARS-CoV-2 restricts antigen presentation through downregulation of MHC class I and II molecules that lead to the inhibition of T cell-mediated immune response responses. This review summarizes the exact pathogenesis of SARS-CoV-2 and the alteration of the immune response during SARS-CoV-2 infection. In addition, we've explained the exhaustion of the immune system during SARS-CoV-2 and the potential immunomodulation approach to overcome this phenomenon. Video Abstract.

Sustainable Closed-Loop Mask Supply Chain Network Design Using Mathematical Modeling and a Fuzzy Multi-Objective Approach

The outbreak of the deadly coronavirus, which is increasing the number of victims every day, has created many changes in today’s world. The use of various masks is the most important social tool against this virus. Given the importance of rapid and quality supply of masks in the current situation, it is necessary to study supply chain in particular. In this research, the design of a closed chain supply chain network for different types of masks is assessed. The studied supply chain includes suppliers, manufacturers, distributors, and retailers in the forward flow and collection centers, separate centers, recycling centers, and disposal centers in the backward flow. In this regard, a multi-objective mathematical model with the objectives of increasing the total profit and reducing the total environmental impact, and maximizing social responsibility is presented. The optimization of this mathematical model has been done using a fuzzy optimization approach in GAMS software. The results of this study show that maximizing the total profit and minimizing the environmental effects and maximizing social responsibility are in contrast to each other. In addition, the sensitivity analysis indicated that the customers’ demand can affect all aspects of the sustainable supply chain simultaneously.

Nano-curcumin therapy, a promising method in modulating inflammatory cytokines in COVID-19 patients.

BACKGROUND: As an ongoing worldwide health issue, Coronavirus disease 2019 (COVID-19) has been causing serious complications, including pneumonia, acute respiratory distress syndrome (ARDS), and multi-organ failure. However, there is no decisive treatment approach available for this disorder, which is primarily attributed to the large amount of inflammatory cytokine production. We aimed to identify the effects of Nano-curcumin on the modulation of inflammatory cytokines in COVID-19 patients. METHOD: Forty COVID-19 patients and 40 healthy controls were recruited and evaluated for inflammatory cytokine expression and secretion. Subsequently, COVID-19 patients were divided into two groups: 20 patients receiving Nano-curcumin and 20 patients as the placebo group. The mRNA expression and cytokine secretion levels of IL-1ß, IL-6, TNF-α and IL-18 were assessed by Real-time PCR and ELISA, respectively. RESULT: Our primary results indicated that the mRNA expression and cytokine secretion of IL-1ß, IL-6, TNF-α, and IL-18 were increased significantly in COVID-19 patients compared with healthy control group. After treatment with Nano-curcumin, a significant decrease in IL-6 expression and secretion in serum and in supernatant (P = 0.0003, 0.0038, and 0.0001, respectively) and IL-1ß gene expression and secretion level in serum and supernatant (P = 0.0017, 0.0082, and 0.0041, respectively) was observed. However, IL-18 mRNA expression and TNF-α concentration were not influenced by Nano-curcumin. CONCLUSION: Nano-curcumin, as an anti-inflammatory herbal based agent, may be able to modulate the increased rate of inflammatory cytokines especially IL-1ß and IL-6 mRNA expression and cytokine secretion in COVID-19 patients, which may cause an improvement in clinical manifestation and overall recovery.