Association between the copper/selenium ratio and the immune response to SARS-CoV-2 infection.

Aim: To assess the association serum levels of selenium (Se) and copper (Cu) with symptoms and IgG immune response to SARS-CoV-2. Patients & methods/materials: Blood samples and nasopharyngeal swabs were obtained from 126 COVID-19 patients with mild and severe symptoms. The serum levels of Cu and Se were measured by atomic-absorption spectrophotometry. Results & conclusion: Mean Se was higher in patients with mild symptoms and IgG nonresponders, whereas mean Cu was higher in patients with severe symptoms and IgG responders. The Cu/Se ratio was lower in patients with no IgG responses to infection and mild symptoms versus IgG responders with severe symptoms. These results suggest the Cu/Se ratio as a nutritional biomarker of severity and IgG immune response in COVID-19 patients.

The association between the strong immune response to infections and trace elements such as copper (Cu) and selenium (Se) is well documented. Se and Cu are changed under infectious conditions. Since SARS-CoV-2 causes inflammation in the body, this study was conducted to evaluate the association between serum levels of Se and Cu changes with the symptoms and immune response to SARS-CoV-2, and then assess the Cu/Se ratio. Blood samples and nasopharyngeal swabs were obtained from 126 SARS-CoV-2 participants with mild and severe clinical symptoms. The SARS-CoV-2 infection and immune response to the virus were confirmed in the laboratory. Next, the Se and Cu serum levels were measured. Finally, we analyzed our findings. The median Se levels were higher in patients with mild symptoms (115 µg/l) in comparison with the severe symptoms group (99 µg/l), and the mean Se levels were higher in immune nonresponders (110.33 ± 3.38 µg/l) in comparison with the immune responders' group (102.42 ± 1.83 µg/l). However, the median Cu was higher in participants with severe symptoms (124 µg/dl) compared with the mild symptoms group (103 µg/dl), and the mean Cu levels were higher in immune responders (112 ± 9.98 µg/dl) in comparison with the immune nonresponders' group (105.1 ± 9.4 µg/dl). The Cu/Se ratio was lower (ratio <1) in participants with no responses to infection and mild symptoms versus responders with severe symptoms. Our results suggest that the Cu/Se ratio may act as a nutritional biomarker of severity and immune response in SARS-CoV-2-infected patients.

Curcumin: A Dietary Phytochemical for Targeting the Phenotype and Function of Dendritic Cells.

Dendritic cells (DCs) are the most powerful antigen-presenting cells which link the innate and adaptive immune responses. Depending on the context, DCs initiate the immune responses or contribute to immune tolerance. Any disturbance in their phenotypes and functions may initiate inflammatory or autoimmune diseases. Hence, dysregulated DCs are the most attractive pharmacological target for the development of new therapies aiming at reducing their immunogenicity and at enhancing their tolerogenicity. Curcumin is the polyphenolic phytochemical component of the spice turmeric with a wide range of pharmacological activities. It acts in several ways as a modulator of DCs and converts them into tolerogenic DCs. Tolerogenic DCs possess anti-inflammatory and immunomodulatory activities that regulate the immune responses in health and disease. Curcumin by blocking maturation markers, cytokines and chemokines expression, and disrupting the antigen-presenting machinery of DCs render them non- or hypo-responsive to immunostimulants. It also reduces the expression of co-stimulatory and adhesion molecules on DCs and prevents them from both migration and antigen presentation but enhances their endocytosis capacity. Hence, curcumin causes DCs-inducing regulatory T cells and dampens CD4+ T helper 1 (Th1), Th2, and Th17 polarization. Inhibition of transcription factors such as NF-κB, AP-1, MAPKs (p38, JNK, ERK) and other intracellular signaling molecules such as JAK/STAT/SOCS provide a plausible explanation for most of these observations. In this review, we summarize the potential effects of curcumin on the phenotypes and functions of DCs as the key players in orchestration, stimulation, and modulation of the immune responses.