Conclusion
The chimeric HLA-A2:β2M:Ig fusion protein-based assays provided a sensitive tool that may be paramount to measure virus-specific CD8+ T-cell response in a range of viral infections of clinical relevance.
Methods
In the present study a chimeric HLA-A2:β2M:Ig fusion protein was produced, purified, and evaluated in functional CD8+ T-cell response studies using samples from Influenza A patients and humanized mice upon adenoviral vaccination.
Objective
Search for the ideal assays to assess the function of antigen-specific CD8+ T-cells.
Results
The HLA-A2:β2M:Ig molecule, bound to immunodominant viral peptides by passive transfer, was able to induce robust antiviral CD8+ T-cell responses mediated by IFN-γ. The in vitro IFN-γ release assay using the chimeric HLA-A2:β2M:Ig fusion protein detected bona fide human CD8+ T-cells, demonstrating superior production of IFN-γ by human CD8+ T-cells induced by Influenza A immunodominant GILGFVFTL peptide. Removal of antigen-presenting cells and CD8+ T-cell enrichment improved significantly the IFN-γ production. The chimeric HLA-A2:β2M:Ig fusion protein also triggered HLA-A2-restricted CD8+ T-cell response in a humanized mouse model upon vaccination with adenovirus encoding HLA-A2-restricted HIV p24 antigen. The results strongly suggest the use of tailor-made assays for detecting HLA-A2-restricted CD8+ T-cell Responses in the Humanized Mouse Model.