Surfactant protein A stimulation of inflammatory cytokine and immunoglobulin production.
Pulmonary surfactant plays a variety of roles related to the regulation of immune function in the lung. Of particular interest in this regard is surfactant protein A (SP-A), a calcium-dependent lectin. We have reported previously that SP-A enhances concanavalin A-induced proliferation, and in this study we examined the secretion of tumor necrosis factor-alpha (TNF-alpha), interleukins 1 alpha, 1 beta, and 6, and interferon-gamma by human peripheral blood mononuclear cells. Levels of all of the cytokines except interferon-gamma were increased by SP-A. In rat peripheral blood cells, splenocytes, and alveolar macrophages we found a similar enhancement of TNF-alpha release by SP-A. In combinations of SP-A and surfactant lipids, the increased levels of TNF-alpha resulting from SP-A treatment decreased as the lipids increased. At higher relative concentrations of SP-A, the lipids had little or no effect. SP-A also enhanced the production of immunoglobulins A, G, and M by rat splenocytes. Levels of each isotype were increased severalfold over control levels. These data demonstrate that SP-A is capable of modulating immune cell function in the lung by regulating cytokine production and immunoglobulin secretion.
Kremlev
S G
SG
Department of Pediatrics, Pennsylvania State University College of Medicine, Hershey 17033.
Phelps
D S
DS
D000818:Animals; D016207:Cytokines / Q000096:biosynthesis*; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis*; D018836:Inflammation Mediators / Q000494:pharmacology*; D007375:Interleukin-1 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D011510:Proteolipids / Q000494:pharmacology*; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D016207:Cytokines; D007136:Immunoglobulins; D018836:Inflammation Mediators; D007375:Interleukin-1; D015850:Interleukin-6; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants; D014409:Tumor Necrosis Factor-alpha