Profiling viral receptors in nasal and amniotic samples at birth

ABSTRACT

Introduction/Aim: Children with wheeze and asthma present with airway epithelial vulnerabilities, such as impaired responses to viral infection. It is postulated that the in utero environment may contribute to the development of such airway epithelial vulnerabilities, that may predispose children to wheeze and asthma outcomes. To explore developmental mechanisms, further research is required using epithelial samples at birth. Our study asked whether amniotic epithelial samples from placentas show similar viral receptor expression to nasal epithelial cells at birth. We aimed to investigate expression of respiratory viral receptors for human rhinovirus (HRV), respiratory syncytial virus (RSV) and COVID-19-causing coronavirus (SARS-CoV-2) in nasal and amniotic epithelial samples. Methods: Unmatched nasal (n = 20 births) and amniotic (n = 33 newborns) epithelial samples were collected from ORIGINS cohort participants recruited into the AERIAL study. Using purified RNA, receptor expression for HRV (ICAM-1, LDLR, CDHR3), RSV (NCL, TLR4) and SARSCoV- 2 (ACE2, TMPRSS2) was assessed by qPCR. In addition, receptor protein expression was quantified through western blot and localized using immunohistochemistry in amniotic samples only. Results: Nasal epithelial and amniotic samples expressed various receptors for HRV, RSV and SARS-CoV-2 at the gene level in nasal (median(IQR) arbitrary units (AU);ICAM-1 11.44(63.18);LDLR 4.00(7.32);CDHR3 0.40 (1.14);NCL 2.32(2.18);CX3CR1 2.17(2.33);TLR4 2.20 (6.20);TMPRSS2 1.99(4.85);ACE2 0.36(0.52) AU) and amnion (ICAM-1 0.69(2.21);LDLR 0.39(1.38);CDHR3 1.0 x 10-4(3.0x10-4);NCL 1.03(0.55);CX3CR1 0.12(0.24);TLR4 0.10(0.13);TMPRSS2 3.0 x 10-4 (16.0x10-4);ACE2 0.01(0.02) AU). Amniotic samples also expressed these receptors at the protein level (ICAM-1 0.03(0.05);LDLR 0.06(0.03);CDHR3 0.28(0.15);NCL 0.96(1.19);CX3CR1 0.08(0.08);TMPRSS2 0.09(0.06);ACE2 0.34(0.92) AU) and expression within the amniotic epithelium was confirmed by immunohistochemistry. Conclusion: Newborn nasal and amniotic epithelial samples expressed receptors for respiratory viruses, HRV, RSV, SARS-CoV-2. These findings warrant further investigation of the clinical significance of receptor expression in relation to prenatal and postnatal exposures, as well as childhood asthma development.