TLR2 Agonist Decreases SARS-CoV-2 in Upper Respiratory Tract

Intranasal prophylactic administration of a TLR2/6 agonist INNA-051 exhibited a viral reduction in ferrets. This could offer a promising approach that is particularly useful for individuals at elevated risk of community transmission. TLR2 is a toll-like receptor protein and plays a role in the immune system. It recognizes foreign substances and the appropriate signals to the immune system. It is crucial to develop drugs that rapidly boost innate immunity at the primary site of respiratory infection. TLR2 receptors dimerize with TLR1 and TLR6 to recognize a range of commensal and pathogenic microbial structures.

Unlike other TLR molecules, TLR2/6 agonists of the INNA series do not directly activate type-1 interferons. The researchers used prophylactic intra-nasal administration of the novel compound INNA-051, in a SARS-CoV-2 challenge ferret model. The administration of INNA-051 did not induce any observable inflammation. Nasal and throat swabs were collected for viral RNA tests. The viral RNA reduced significantly: 10-fold reduction. For the nasal wash 15 reduction and throat swab, a 24-fold reduction in the viral RNA was observed in the treated animals when compared to the untreated ones. This implies enhanced antiviral host defense and airway immunity.

Ref link: https://www.biorxiv.org/content/10.1101/2020.09.25.309914v1.full