Anaphylatoxin-like molecules generated during complement activation induce a dramatic enhancement of particle uptake in rainbow trout phagocytes.
Here we have identified a serum fraction containing approximately 8-kDa molecules with an unexpected capacity to greatly enhance particle uptake in trout head kidney leukocytes (HKLs). This approximately 8-kDa particle-uptake enhancing fraction (PUEF-8) was purified from complement-activated serum by gel filtration chromatography. Mass spectrometric analysis and reactivity of anti-trout C3-1 and C4 antibodies, indicated the presence of C3a, C4a and C5a molecules in PUEF-8. Using a newly developed flow cytometric assay that measures the capacity of cells to ingest fluorescent beads, we showed that PUEF-8 induced a striking enhancement (344+/-50% higher than the PBS control value) in the number of HKLs ingesting three or more beads. In contrast, the effect of PUEF-8 on peripheral blood leukocytes (PBLs) was almost negligible. Interestingly, PUEF-8 acted as a strong chemoattractant for both HKLs and PBLs. These findings suggest a novel role for the anaphylatoxins generated during complement activation in teleost fish.
Li
J
J
Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 413 Rosenthal, 3800 Spruce St., Philadelphia, PA 19104, USA.
Peters
R
R
Lapatra
S
S
Vazzana
M
M
Sunyer
J O
JO
D000706:Anaphylatoxins / Q000502:physiology*; D000818:Animals; D002465:Cell Movement / Q000276:immunology / Q000502:physiology; D003165:Complement System Proteins / Q000502:physiology*; D005434:Flow Cytometry; D007962:Leukocytes / Q000276:immunology / Q000502:physiology; D017686:Oncorhynchus mykiss / Q000276:immunology / Q000502:physiology*; D010586:Phagocytes / Q000276:immunology / Q000502:physiology*; D010587:Phagocytosis / Q000276:immunology / Q000502:physiology*; D013997:Time Factors
D000706:Anaphylatoxins; D003165:Complement System Proteins