Surfactant Protein A Enhances the Degradation of LPS-Induced TLR4 in Primary Alveolar Macrophages Involving Rab7, β-arrestin2, and mTORC1
Katja Freundt, Christian Herzmann, Dominika Biedziak, Claudia Scheffzük, Karoline I. Gaede, Cordula Stamme
Abstract
mice, TLR4 levels are increased after pulmonary LPS challenge. SP-A-induced activation of mechanistic target of rapamycin complex 1 (mTORC1) kinase requires β-arrestin2 and is critically involved in degradation of LPS-induced TLR4. The data suggest that SP-A post-translationally limits LPS-induced TLR4 expression in primary AMs by lysosomal degradation comprising Rab7, β-arrestin2, and mTORC1. This study may indicate a potential role of SP-A-based therapeutic interventions in unrestricted TLR4-driven immune responses to lower respiratory tract infections caused by Gram-negative bacteria.
Topics & Concepts
TLR4BiologyLipopolysaccharideImmune systemCell biologyInnate immune systemReceptormTORC1Surfactant protein AProtein degradationMicrobiologyLungToll-like receptorImmunologySignal transductionPattern recognition receptorRespiratory systemRespiratory tractPulmonary surfactantKinaseProtein kinase AHomeostasisAutophagyPhosphorylationHMGB1Surfactant protein DPhagocytosisImmunityAlveolar macrophageNeonatal Respiratory Health ResearchImmune Response and InflammationImmune cells in cancer