Interaction of plasma fibronectin (pFN) with membranous constituents of peritoneal exudate cells and pulmonary macrophages

Journal Article · Thu Nov 01 00:00:00 EST 1984 · J. Leukocyte Biol.; (United States)

OSTI ID:5779448

Rovin, B; Molnar, J; Chevalier, D; Ng, P

The prominent role of plasma fibronectin (pFN) in the host defense system as an opsonin for gelatin (collagen)-coated colloids has been established. In the present study the authors investigated the interaction of pFN and membrane isolates from cells devoid of collagen, as well as several tissues. In a liver slice assay system it was shown that subcellular membrane fractions from lung macrophages, peritoneal exudate cells, spleen, testis, and liver were able to competitively inhibit the pFN-mediated uptake of /sup 125/I-gelatin coated latex beads (gLtx) at low concentrations. Endocytosis of /sup 125/I-labeled membrane isolates by macrophage monolayers was also promoted by addition of pFN. In an attempt to characterize the membrane component(s) interacting with pFN, it was found that mild extraction procedure with 1 M KBr could release a significant amount of this inhibitory activity. Further studies demonstrated that the agent(s) responsible for inhibition of gLtx uptake was heat sensitive, not altered by trypsin treatment, and did not contain actin, a protein known to interact with pFN. This work indicates that pFN interacts specifically with an as yet unknown membrane component(s) and that such interaction will promote clearance of cellular debris by macrophages. This suggests that pFN may be an important opsonin for the reticuloendothelial system in clearance of collagenous and noncollagenous cellular debris once they are exposed to interact with it.

• Research Organization: Univ. of Illinois, Chicago
• OSTI ID: 5779448
• Journal Information: J. Leukocyte Biol.; (United States), Vol. 36:5
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
IODINE 125
UPTAKE
RETICULOENDOTHELIAL SYSTEM
BIOCHEMISTRY
ANTIBODIES
CELL MEMBRANES
IMMUNITY
INHIBITION
LUNGS
MACROPHAGES
PERITONEUM
PHAGOCYTOSIS
PROTEINS
ANIMAL CELLS
ANIMAL TISSUES
BETA DECAY RADIOISOTOPES
BODY
CELL CONSTITUENTS
CHEMISTRY
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
MEMBRANES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PHAGOCYTES
RADIOISOTOPES
RESPIRATORY SYSTEM
SEROUS MEMBRANES
SOMATIC CELLS
TISSUES
550201* - Biochemistry- Tracer Techniques