Submitted to: International Symposium on Avian Influenza
Publication Type: Abstract Only
Publication Acceptance Date: January 28, 2009
Publication Date: April 5, 2009
Citation: Kapczynski, D.R., Liljebjelke, K.A., Kulkarni, G., Hunt, H.D., Petkov, D. 2009. Cross reactive antibody and cytotoxic T lymphocytes from avian influenza H9N2 infected chickens against homologous and heterologous avian influenza isolates [abstract]. 7th International Avian Influenza Symposium, April 5-8, 2009, Athens, Georgia. p. 87. Technical Abstract: Immunity against avian influenza (AI) is largely based on the induction of neutralizing antibodies produced against the hemagglutinin, although cytotoxic T lymphocytes (CTL’s) have been reported as critical for clearance of virus from infected cells. Antibody production against a particular virus typically will only protect against homologous or antigenically matched isolates. In contrast, CTL’s responses in mice and humans for influenza A viruses have been shown to be broad and multispecific. With regards to chickens, very little is known about cross reactive CTL’s against AI. In these studies, major histocompatibility complex (MHC)-defined (B2/B2) chickens were infected with a recent H9N2 AI isolate, and antibody and CTL cross reactivity against homologous (H9N2) and heterosubtypic (H6N2 and H5N9) AI viruses were determined ex vivo. Results indicate antibodies produced against H9N2 AI displayed better cross reactivity to the H6N2 isolate than the H5N9 isolate. Additionally, splenic lymphocytes from H9N2-infected chickens displayed cross reactive lysis of B2/B2 lung target cells infected with any of the isolates tested here. Removal of the CD8+ population, but not CD4+ T cells, abrogated specific lysis of target cells. Taken together, these studies provide insight into the cross reactive nature of avian CTL’s against homologous and heterosubtypic AI viruses.