Peptide immunization excludes antigen-specific T cells from splenic lymphoid compartments

✍ Scribed by Lei Zhang; Elaine F. Lizzio; Trina Chen; Steven Kozlowski

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 622 KB
• Volume: 35
• Category: Article
• ISSN: 0014-2980
• DOI: 10.1002/eji.200425479

✦ Synopsis

Abstract

Using adoptive transfer of TCR‐transgenic T cells, we examined the homing of transgenic T cells to splenic compartments in situ. After systemic immunization with peptide or protein antigen, the location of clonotypic T cells, cytokine production, cell surface markers, and apoptosis were assessed. There were distinct differences in the splenic homing of CD4^+^ TCR‐transgenic T cells in mice immunized with peptide as compared to mice immunized with whole‐protein antigen. T cells in peptide‐immunized mice were found almost exclusively in the splenic red pulp, but not in the T and B cell zones (white pulp), while the majority of T cells immunized with whole protein were found in the white pulp. Many more Fas ligand‐expressing and apoptotic cells were present after peptide immunization than after whole‐protein immunization. Localization of IL‐4‐, IL‐2‐ and IFN‐γ‐producing cells to the lymphocyte‐containing splenic white pulp was only observed with whole‐protein immunization. The unique homing and increased apoptosis of immune cells post peptide immunization may help explain the ineffectiveness of many peptide vaccines. Linkage of the same peptide epitope to a carrier protein increased white pulp T cell localization and decreased apoptosis, suggesting a strategy to enhance peptide vaccine responses.