title: Surfactant protein-A and toll-like receptor-4 modulate immune functions of preterm baboon lung dendritic cell precursor cells.
abstract: Lung infections are important risk factors for an increased morbidity and mortality in prematurely-delivered babies. Immaturity of the innate immune components makes them extremely susceptible to infection. Recently, we isolated lung dendritic cell (DC)-precursor cells from preterm fetal baboons. The isolated cells were found to be defective in phagocytosing Escherichia coli under basal conditions. In this study, we investigated the effects of exogenously-added purified native lung surfactant protein (SP)-A and recombinant toll-like receptor (TLR)-4-MD2 proteins on phagocytic uptake and cytokine secreting ability of fetal baboon lung DC-precursor cells. The cells were pulsed with SP-A and/or TLR4-MD2 proteins and the phagocytic function was investigated by incubating the cells with fluorescent-labeled E. coli bioparticles and analyzed by spectrofluorometry. The amounts of TNF-α secreted in cell-free supernatants were measured by ELISA. Our results demonstrate that SP-A and TLR4-MD2 proteins, whether added alone or together, induce phagocytosis of E. coli (p<0.05). The SP-A does not affect TNF-α secretion, while the TLR4-MD2 protein induces TNF-α. However, simultaneous addition of SP-A with TLR4-MD2 protein reduces the TLR4-MD2-protein induced TNF-α to basal level. In conclusion, our results indicate that an exogenous administration of SP-A can potentially induce phagocytic activity and anti-inflammatory effect in preterm babies, and help control infection and inflammation.
authors: Department of Pharmaceutical Sciences, University of Oklahoma Health Science Center, Oklahoma City, OK 73117, USA. Shanjana-Awasthi@ouhsc.edu
authors: Shanjana
authors: S
authors: Awasthi
authors: Rakhesh
authors: R
authors: Madhusoodhanan
authors: Roman
authors: R
authors: Wolf
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects / Q000276:immunology* / Q000382:microbiology; D004926:Escherichia coli / Q000276:immunology; D004927:Escherichia coli Infections / Q000276:immunology / Q000382:microbiology; D005434:Flow Cytometry; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008171:Lung Diseases / Q000276:immunology* / Q000382:microbiology; D018613:Microscopy, Confocal; D048530:Papio anubis; D010587:Phagocytosis / Q000276:immunology; D037662:Pulmonary Surfactant-Associated Protein A / Q000276:immunology* / Q000494:pharmacology; D051197:Toll-Like Receptor 4 / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D037662:Pulmonary Surfactant-Associated Protein A; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha