Surfactant proteins A (SP-A) and D (SP-D) are soluble innate immune molecules which maintain lung homeostasis through their dual roles as anti-infectious and immunomodulatory agents. SP-A and SP-D bind numerous viruses including influenza A virus, respiratory syncytial virus (RSV) and human immunodeficiency virus (HIV), enhancing their clearance from mucosal points of entry and modulating the inflammatory response. They also have diverse roles in mediating innate and adaptive cell functions and in clearing apoptotic cells, allergens and other noxious particles. Here, we review how the properties of these first line defense molecules modulate inflammatory responses, as well as host-mediated immunopathology in response to viral infections. Since SP-A and SP-D are known to offer protection from viral and other infections, if their levels are decreased in some disease states as they are in severe asthma and chronic obstructive pulmonary disease (COPD), this may confer an increased risk of viral infection and exacerbations of disease. Recombinant molecules of SP-A and SP-D could be useful in both blocking respiratory viral infection while also modulating the immune system to prevent excessive inflammatory responses seen in, for example, RSV or coronavirus disease 2019 (COVID-19). Recombinant SP-A and SP-D could have therapeutic potential in neutralizing both current and future strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus as well as modulating the inflammation-mediated pathology associated with COVID-19. A recombinant fragment of human (rfh)SP-D has recently been shown to neutralize SARS-CoV-2. Further work investigating the potential therapeutic role of SP-A and SP-D in COVID-19 and other infectious and inflammatory diseases is indicated.
【저자키워드】 Inflammation, Coronavirus disease 2019, therapeutic, immunoregulation, severe acute respiratory syndrome Coronavirus 2 (2019-nCoV), Surfactant protein D, surfactant protein A, recombinant fragment of human SP-D (rfhSP-D), 【초록키워드】 COVID-19, coronavirus disease, SARS-CoV-2, Asthma, pathology, HIV, viral infection, coronavirus, adaptive, Inflammatory responses, influenza A virus, lung, immunopathology, immune system, virus, viral infections, COPD, excessive inflammatory response, Protein, infections, respiratory syncytial virus, RSV, surfactant, Neutralizing, Human immunodeficiency virus, disease, homeostasis, respiratory viral infection, function, pulmonary disease, Immunomodulatory agents, innate immune, mucosal, Inflammatory response, recombinant, strain, allergen, acute respiratory syndrome, Particles, apoptotic cells, increased risk, therapeutic potential, Defense, inflammatory disease, clearance, offer, Prevent, Cell, neutralize, shown, virus, example, indicated, modulate, maintain, chronic obstructive, modulating, noxious, with COVID-19, 【제목키워드】 property, molecule,