Interactions of recombinant human pulmonary surfactant protein d and sp-d multimers with influenza a. Hartshorn, Kevan, Donald Chang, Kevin Rust, Mitchell White, John Heuser, and Edmond Crouch. Departments of Medicine and Pathology, Boston University School of Medicine, and the Departments of Pathology and Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
APStracts 3:0101L, 1996.
To further study the structure and function of SP-D, recombinant human SP-D (RhSP-D) was isolated from the culture medium of CHO-K1 cells stably transfected with a full length hSP-D cDNA. Although a significant fraction of the secreted RhSP-D was recovered as dodecamers similar to recombinant rat SP-D (RrSP-D), a major fraction accumulated as multimers of dodecamers indistinguishable from human proteinosis SP-D. As previously shown for the rat protein, RhSP-D agglutinated specific strains of influenza A virus (IAV), inhibited viral hemagglutinin activity, and protected neutrophils (PMNs) from deactivation by IAV. However, the potency of RhSP-D multimers was several-fold greater than for purified dodecamers, comparable to natural, proteinosis hSP-D. Although RhSP-D multimers were also more potent than the serum collectins in mediating viral aggregation and protection of neutrophils, they were less potent than conglutinin in inhibiting infectivity in vitro. These studies establish that the propensity of hSP-D to form multimers of dodecamers is determined by its primary structure, and demonstrate CRD valency-dependent interactions of SP-D with IAV.

Received 30 January 1996; accepted in final form June 1996.
APS Manuscript Number L34-6.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 4 July 96