Comparative analysis of expression pattern of IL-10, IL-6, IL1β and TNF-α genes and genetic variation of ACE2 gene among COVID-19 patients cohort from Western India

Abstract

Background: Host factors ranging from cell surface receptor to immune and metabolic regulators, play an important role in deciding the fate of COVID-19 disease. Genetic variants tune our immune systems differently. Cellular factors (ACE2, TMPRSS2), detected in nasal and bronchial epithelia play a crucial role in cellular entry and HLA elicits specific antiviral immunity, thus contribute in immune system protection. There is a limited data on genetic differences, which contribute to individual variations in the susceptibility to SARS-CoV-2 infection and disease severity. Following exposure to SARS-CoV-2 leads Chronic inflammation in the lungs, persistent inflammation in the lungs is associated with increased level of inflammatory cytokines, IL-6, which impair the SARS-CoV-2 induced pathology. Immune associated genes play a role in innate and antiviral immune response. Cellular factors are involved in spread of virus and its pathogenesis. Clinical outcomes of SARS-CoV-2 infection are varied from individual to individual and population to population. This variation is linked with genetic background. Difference in responses of individuals to the infection and disease condition may influence by genetic variants of ACE 2, TMPRSS2, FUR and Immune and inflammation -related genes and different levels of expression and function of these proteins. Hence, we aimed to examine the genetic variation and expression of cellular factor and inflammation-related genes among COVID-19 patients. Objective: To examine the genetic variation of cellular factors (ACE2) and, expression of inflammation-related genes (IP-10, IL-6, IL1ȕ and TNF-Į) in COVID-19 patients and healthy individuals. Method: Examination of genetic variation of ACE2 gene was done in DNA samples of 201 COVID-19 patients and 200 healthy controls using PCR-RFLP method. Expression of inflammation -related genes (IP-10, IL-6, IL1ȕ and TNF-Į) was done in RNA samples of 14 COVID-19 patients and 14 healthy controls using RT-PCR. Results: ACE2 rs2106809 GA genotype and rs2106809A allele were associated with the reduced risk of SARS-CoV-2 infection (27.5% vs. 41.8%, P=0.001, OR=0.49, 95%CI: 0.31-0.77). ACE2 rs210680GG genotype and rs210680G allele were associated with impaired CRP level (11.5% vs. 2.2%; P=0.009, OR=6.67, 95%CI: 1.44-34.73; 27.0% vs. 15.1%, P=0.007, OR=2.08, 95% CI: 1.20-3.69). ACE2 rs210680AG and rs210680GG genotypes were associated with reduced risk of impaired ferritin level (10.5% vs. 40.4%, P=0.001, OR=0.16, 95%CI: 0.17-0.36; 2.3% vs. 7.0%, P=0.06, OR=0.20, 95%CI: 0.03-1.07). ACE2 -8970GA genotype was associated with higher risk of mild and moderate disease stage of COVID-19 patients (OR=3.09, P=0.05, OR =3.17, P =0.0003). ACE2 -8970A allele were associated with the risk of mild and moderate disease stage (P =0.007, OR =1.98, P =0.05, OR =1.80). We compared the expression level IL-1ȕ, IL-6, TNF-Į and IL-10 genes between COVID-19 patients and healthy controls. The expression of IL-1ȕ gene was significantly higher in COVID-19 patients than healthy controls (4.72 vs. 1.53, 3.08 fold). The expression of IL-6 gene was also higher in COVID-19 patients than healthy controls but could reach statistical significance (1.62 vs. 1.44, 1.12 fold). Similarly expression of TNF-Į gene was higher in COVID-19 patients than healthy controls (37.67 vs. 23.00, 1.64-fold). However, expression of IL-10 gene was decreased in COVID-19 patients than healthy controls (0.28 vs 3.38, 0.08-fold). Conclusions: ACE2 rs2106809 G/A may assist the increase the risk for SARS-CoV- 2 infection. ACE2 rs210680GG genotype may facilitate to increase CRP level and reduce the risk to increase ferritin level. ACE2 -8970GA genotype may contribute the mild and moderate disease stage. A higher expression of IL-1ȕ may facilitate the COVID-19 disease progression.