These cross-reactive T cells were found to be subdominant during the primary response, and the sequence of infection influenced the

www.selleckchem.com/products/Gefitinib.html hierarchy of these subdominant cross-reactive T cells after secondary heterologous challenge 32, 33. In our model, the immunodominant CD8+ T-cell epitope was found to be cross-reactive, but to differing degrees, following either JEV or WNV infection. Our detailed characterization of these epitope-specific responses did not demonstrate an alteration in epitope hierarchy, but rather differences in cytokine profiles and T-cell phenotype. As previous studies have elucidated a role for subdominant cross-reactive CD4+ and CD8+ T cells in protection as well as immunopathology, future experiments will address Cytoskeletal Signaling inhibitor the role of the two cross-reactive CD4+ T-cell epitopes we identified and subdominant cross-reactive CD8+ T-cell epitopes along with the immunodominant cross-reactive CD8+ T-cell epitope in secondary heterologous JEV and WNV infections 10, 11. Here, we have shown that primary infections with JEV and WNV give rise to functionally and phenotypically distinct CD8+ T-cell responses. These

differences are due to the infecting virus (JEV versus WNV) rather than the stimulating variant (WNV S9 versus JEV S9) or viral pathogenicity. The JEV/WNV cross-reactive CD4+ and CD8+ T-cell epitopes we have identified will be useful tools to study the pathogenesis of sequential heterologous flavivirus infections. Flaviviruses continue to emerge into new geographic regions of the world, giving rise

to the possibility of new patterns of sequential infection with unknown outcomes (e.g. WNV into dengue- and yellow fever virus-endemic regions of South America). Altered CD8+ T-cell effector functions between flaviviruses may to lead to immunopathology or protection upon a secondary flavivirus infection. Additional experiments are needed to determine whether cross-reactivity aminophylline occurs between other members of the flavivirus family and its possible impact on disease outcome. JEV strain SA14-14-2 was provided by Dr. Thomas Monath (Acambis, Inc.). JEV strain Beijing was provided by Dr. Alan Barrett (University of Texas Medical Branch, Galveston, TX, USA). WNV strain 3356 was provided by Dr. Kristen Bernard (Wadsworth Center, Albany, NY, USA). Flaviviruses were propagated and titered in Vero cells (ATCC). The EL-4 T-cell lymphoma cell line (H-2b) served as target cells. Peptide (15–19mer) arrays corresponding to the entire proteome of WNV were obtained through the NIH Biodefense and Emerging Infections Research Resources Repository, NIAID, NIH (BEI Resources, Manassas, VA, USA). Peptide truncations (>70 or >90% purity) were obtained from AnaSpec (San Jose, CA, USA) and 21st Century Biochemicals (Marlborough, MA, USA).