The quantitative analysis showed that the expression of SARS-CoV-2 entry factors on corneal and limbal cells is likely to be modulated in an age-dependent manner, in agreement with the increased susceptibility to COVID-19 in the elderly. Results: Immunofluorescence confirmed the localization of ACE2 and TMPRSS2 on the ocular surface and showed, for the first time, the localization of TMPRSS4 and DPP4 in limbal and corneal epithelial superficial cells.
The receptors' localization was investigated through immunofluorescence. Some of the main virus entry factors were analyzed and their expression was quantified and correlated with the age and sex of the donors through western blot.
Methods: Here, we performed a study over 10 adult corneal and limbal tissues from human donors, both male and female between 58 and 85 years of age. Moreover, the coexpression of angiotensin-converting enzyme 2 (ACE2) with other SARS-CoV-2 entry factors facilitates the virus infection. Purpose: Recent studies have shown the presence of SARS-CoV-2 entry factors on the ocular surface, identifying the eye as an additional entry route for the virus.
