Submitted to: Immunology Research Workshop
Publication Type: Abstract Only
Publication Acceptance Date: 11/1/2003
Publication Date: 12/1/2003
Citation: Rath, N.C. 2003. Acute phase proteins in relation to disease and immunity: An avian paradigm [abstract]. Immunology Research Workshop. p. 42-43. Interpretive Summary:
Technical Abstract: Acute phase proteins (APPs) are serum proteins elevated in response to a variety of physiological injuries including infection and inflammation. These are pathogen nonspecific proteins predominantly synthesized in the liver and other tissues such as endothelium, and modulate both innate and acquired immune responses. However, the physiological significance of different APPs is not well understood. In monitoring veterinary health the APPs are used as diagnostic and prognostic indicators. But their use to improve immunity has not been explored. The avian APP response and their significance are much less understood compared to mammals. The object of our study was to understand avian APP response and their possible significance. We induced experimental inflammation in young broiler chickens, by the use of intramuscular injection either of bacterial lipopolysacharides (LPS), gram positive bacterial cell walls, or croton oil, and compared the serum proteins profiles with sham injected control sera using polyacrylamide gel electrophoresis. Our results showed quantitative changes in several protein bands of which a band corresponding to MW of 65-66 kD was significantly elevated in response to inflammation (1-4). Further analyses using two-dimensional gel electrophoresis and electroblotting onto PVDF membrane, the spots equivalent to 65 kD MW was N-terminal sequenced to yield a molecular homology to ovotransferrin (OVT) (3,4). Using an anti-serum transferrin antibody and western blot, the results further proved that the serum protein was the same as the egg white transferrin. We developed an enzyme-immunoassay to measure OVT concentrations and showed that the serum transferrin levels are elevated in response to a variety of bacterial and viral infections (5). To understand the possible significance of elevated OVT in relation to immunity, we studied its in vitro effects on macrophages and heterophil functions under non-stimulated and endotoxin stimulated conditions. Our results show that OVT augmented the functional activity of both of these cell types as measured using nitric oxide, interleukin-6, matrix metalloproteinase, reactive oxygen production as indicators (6). Additionally, OVT also stimulated heterophil degranulation. These studies provide a paradigm of the possible usefulness of monitoring serum OVT to identify the presence of avian health problems and its function as an immunity modifying protein in poultry.