Submitted to: Developmental and Comparative Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 4, 2005
Publication Date: August 1, 2005
Citation: Min, W., Lillehoj, H.S. 2005. Sequence and functional properties of chicken interleukin-16. Developmental and Comparative Immunology 28:153-162.
Interpretive Summary: Limited informatin concerning chicken immunity and immune system hinders rapid progress in the development novel control strategy against many poultry diseases. In this paper, ARS scientists describe the molecular cloning and functional analysis of an important chicken cytokine which is secreted by activated chicken T-lymphocytes. This cytokine is homologous to mammalian Interleukin-16 (IL-16) and is a chemoattractant factor. IL-16 mediates important function during host immune response to pathogens and IL-16 expression has been implicated in the inflammatory responses in many human disease conditions. ARS scientists describe its importance in avian coccidioiss for the first time and ability to develop recombinant chicken IL-16 will facilitate the development of novel control methods for many poultry pathogens.
Interleukin-16 is a proinflammatory cytokine synthesized as a precursor protein (pro-IL-16). By nucleoride sequence homology, we identified a cDNA from an ESTcDNA library prepared from intestinal intraepithelial lymphocytes of Eimeria-infected chickens that contained a full-length open reading frame of pro-IL-16. The encoded protein, preducted to consist of 607 amino acids, showed 86% sequence homology to duck pro-IL-16 and 49-52% homology to various mammalian homologues. By Northern blot analysis, IL-16 transcripts were identified in chicken lymphoid tissues but none of the non-lymphoid tissues examined. A recombinant protein containing the COOH-terminal 149 amino acids of pro-IL-16 when expressed in COS-7 cells showed chemoattractant activity for splenic lymphocytes.