ABSTRACT
Background: COVID-19 has been a devastating disease and a major public health concern mainly to susceptible populations. Methods: We accessed two groups of pregnant women at the time of delivery: SARS-CoV2 active infection and convalescents. To investigate the factors contributing to COVID19 severity we have assessed several immunological parameters including cytokines/chemokine levels in the maternal and cord blood plasma. We have evaluated 33 cytokines. Our findings were validated in vitro in HTBE (Human tracheobronchial epithelial) cells infected with live SARS-COV2 (wild type). Results: Our cohort was enriched in high-risk subjects, including African American and obese women. Only 6% had severe or critical disease, contrasting with the 20-25% reported in some pregnant cohorts. TGFb2 levels were significantly associated with asymptomatic/mild disease in both active and convalescent cohorts, and inversely correlated with IP10, IL6 and IL8, known to be part of the cytokine storm post-infection. Pre-treatment of HTBE with TGFb2 for 48 hours led to a significant decay in viral loads at 72h post-infection. This control was associated with significantly higher IL-6 (IFNb2) levels prior to infection, and significantly higher expression of anti-viral genes at 72h pi (MX1, IFNA1, IFNA2, IFNL1, STAT1). Additionally, TGFb2 pre-treatment suppressed the expression of the cytokines IP-10, IL1b and IL8. Conclusion: Altogether this data suggested that TGFB2 plays a protective role in SARS-COV2 infection in this high-risk population by improving epithelial cells intrinsic antiviral function and by modulating the expression of the cytokines associated to the heightened inflammation in severe cases.