Surfactant proteins A and D suppress alveolar macrophage phagocytosis via interaction with SIRP alpha.

ABSTRACT:

Rationale

Efficient removal of apoptotic cells is essential for the resolution of acute pulmonary inflammation. Alveolar macrophages ingest apoptotic cells less avidly than other professional phagocytes at rest but overcome this defect during acute inflammation. Surfactant protein (SP)-A and SP-D are potent modulators of macrophage function and may suppress clearance of apoptotic cells through activation of the transmembrane receptor signal inhibitory regulatory protein alpha (SIRP alpha).

Objectives

To investigate whether binding of SP-A and SP-D to SIRP alpha on alveolar macrophages suppresses apoptotic cell clearance.

Methods

Phagocytosis of apoptotic cells was assessed using macrophages pretreated with SP-A, SP-D, or the collectin-like molecule C1q. Binding of SP-

SUBMITTER: Janssen WJ 

PROVIDER: S-EPMC2453510 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature