Effects of surfactant protein A and surfactant lipids on lymphocyte proliferation in vitro.
We studied the effects of dipalmitoyl L-alpha-phosphatidylcholine (DPPC), Survanta, surfactant protein A (SP-A), and mixtures of these substances on mitogen-induced lymphocyte proliferation using concanavalin A as a mitogen. A concentration-dependent suppression of proliferation was observed with 50-250 micrograms/ml of DPPC or Survanta. However, when SP-A was added to cultures, proliferation was stimulated. The inhibitory effects of DPPC and Survanta were altered in mixtures that contained SP-A. When added to 50 micrograms/ml of Survanta, SP-A reversed the inhibitory influence of Survanta and caused increased proliferation. These findings suggest that surfactant phospholipids cause a suppression of mitogen-induced lymphocyte proliferation, which is reversed somewhat by addition of SP-A. We hypothesize that immune cell function in the lung varies with changes in the relative amounts of surfactant components. Changes in surfactant composition may occur during pulmonary inflammation or infection or with surfactant replacement therapy and may influence immune and inflammatory processes in the lung.
Kremlev
S G
SG
Department of Pediatrics, Pennsylvania State University, College of Medicine, Hershey 17033.
Umstead
T M
TM
Phelps
D S
DS
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000494:pharmacology; D000818:Animals; D001688:Biological Products; D002453:Cell Cycle; D002455:Cell Division / Q000187:drug effects; D004338:Drug Combinations; D008055:Lipids / Q000032:analysis / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D008297:Male; D011510:Proteolipids / Q000737:chemistry / Q000494:pharmacology*; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000737:chemistry* / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013154:Spleen / Q000166:cytology
D001688:Biological Products; D004338:Drug Combinations; D008055:Lipids; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants; D015060:1,2-Dipalmitoylphosphatidylcholine; C072197:beractant