title: In vivo splenic CD11c cells downregulate CD4 T-cell response thereby decreasing systemic immunity to gene-modified tumour cell vaccine.
abstract: One of the factors influencing the efficacy of tumour cell vaccines is the site of immunization. We have shown previously that gene-modified vaccines delivered directly inside the spleen induced antigen cross-presentation by splenic antigen-presenting cells (not B cells). Here, we examined the interaction between splenic CD11c(+) cells and antigen-specific CD4(+) T cells. We used tumour cells expressing ovalbumin (OVA), a situation where CD4(+) T-cell help is required for the generation of a cytotoxic T lymphocyte response. Using in vivo bioluminescence imaging of luciferase-expressing EL4-OVA cells, we could demonstrate that tumour cells were located exclusively inside the spleen following intrasplenic injection. We showed that after intrasplenic immunization with T/SA-OVA cells, splenic class I(+) class II(+) CD11c(+) cells engulfed and presented in vivo the OVA class I-restricted peptide SIINFEKL. However, in vivo previously adoptively transferred 5,6-carboxy-succinimidyl-fluorescein-ester-labelled transgenic CD4(+)KJI-26(+) cells specific for the class II OVA(323-339) peptide underwent abortive proliferation in the spleen. These CD4(+)KJI-26(+) cells were only transiently activated and produced IL-10 and IL-4 and not IFN-gamma. It appears that splenic CD11c(+) cells can downregulate splenic specific CD4(+) T-cell response thereby leading to a decrease in antitumour systemic immunity.
authors: Charité-am-MDC, Campus Buch, Berlin, Germany. sophie.cayeux@mdc-berlin.de
authors: S
authors: S
authors: Cayeux
authors: B
authors: B
authors: Bukarica
authors: C
authors: C
authors: Buschow
authors: J
authors: J
authors: Charo
authors: M
authors: M
authors: Bunse
authors: B
authors: B
authors: Dörken
authors: T
authors: T
authors: Blankenstein
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D039521:CD11c Antigen; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D019496:Cancer Vaccines / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D045142:Cross-Priming; D003713:Dendritic Cells / Q000276:immunology*; D005434:Flow Cytometry; D015316:Genetic Therapy / Q000379:methods*; D007114:Immunization; D016753:Interleukin-10 / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D008163:Luminescent Measurements; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009369:Neoplasms / Q000276:immunology / Q000628:therapy; D010047:Ovalbumin / Q000235:genetics / Q000276:immunology; D013154:Spleen / Q000276:immunology* / Q000473:pathology
chemical_list: D039521:CD11c Antigen; D019496:Cancer Vaccines; D016753:Interleukin-10; D015847:Interleukin-4; D010047:Ovalbumin