The outcome of cross-priming during virus infection is not directly linked to the ability of the antigen to be cross-presented.
The initiation of CD8(+) T cell (CTL) immune responses can occur via cross-priming. Recent data suggested a relationship between cross-presentation and immunodominance of epitope-specific T cells. To test this association, we evaluated the efficacy of cross-presentation for several virus epitopes in vitro and examined if this can be extrapolated in vivo. Employing lymphocytic choriomeningitis virus (LCMV), we demonstrate that the cross-presentation and cross-priming of LCMV antigens were dominated by NP396, but not NP205 when analyzing the LCMV-NP. Although with LCMV-GP, cross-presentation was dominated by GP276, and cross-priming was dominated by GP33. Importantly, although NP396 was significantly more efficient than GP33 in cross-presentation, cross-priming of their specific CTL was comparable. In a subsequent virus challenge after cross-priming, GP33-specific CTL dominated the response. Accordingly, based on our data, the ability of viral epitopes to be cross-presented in vitro does not entirely reflect what would occur in cross-priming. Thus, weak cross-presenting antigens may still cross-prime an efficient CTL response depending on other in vivo elements such as the naïve T-cell precursor frequencies.
Alatery
Attiya
A
Department of Microbiology and Immunology, Queen's University, Kingston, ON, Canada.
Tarrab
Esther
E
Lamarre
Alain
A
Basta
Sameh
S
D000818:Animals; D000956:Antigens, Viral / Q000276:immunology / Q000378:metabolism; D001117:Arenaviridae Infections / Q000276:immunology*; D002460:Cell Line; D049109:Cell Proliferation; D045142:Cross-Priming; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology* / Q000472:pathogenicity; D008264:Macrophages / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D051379:Mice; D008810:Mice, Inbred C57BL; D010446:Peptide Fragments / Q000276:immunology / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000378:metabolism* / Q000473:pathology
D000956:Antigens, Viral; D016056:Immunodominant Epitopes; D010446:Peptide Fragments