Phagocytic dendritic cells from myelomas activate tumor-specific T cells at a single cell level.
Antigen-presenting cells (APCs) from subcutaneous mouse MOPC315 plasmacytoma phagocytosed immunoglobulin G-coated magnetic beads, enabling efficient isolation within 2 hours by magnetic separation (APC-MB). Cell morphology was heterogeneous, with some of the cells having dendrites. The surface phenotype of purified tumor APCs-MB was CD11b(+), CD11c(+), CD40(+), CD80(+), CD86(+), and MHC class II(+). Tumor APCs-MB expressed messenger RNA for fractalkine and ABCD-1 chemokines, and for CC-type chemokine receptors CCR5 and CCR7, indicating the presence of mature dendritic cells (DCs). Visualized at a single cell level within 4 hours after disruption of the tumor, APCs-MB induced rapid Ca(++) mobilization in MHC class II-restricted tumor idiotype (Id)-specific cloned CD4(+) T cells. In long-term assays, tumor APCs-MB induced proliferation of naive T cells from Id-specific T-cell receptor transgenic mice. The results suggest that tumor APCs-MB represent a heterogeneous cell population that includes myeloid-derived DCs of various stages of maturation. A considerable fraction (> or = 15%) of DCs is spontaneously primed with tumor-specific antigen.
Dembic
Z
Z
Institute of Immunology, Department of Physiology, and Department of Oral Biology, University of Oslo, Norway. zlatko.dembric@labmed.uio.no
Røttingen
J A
JA
Dellacasagrande
J
J
Schenck
K
K
Bogen
B
B
D000818:Animals; D017951:Antigen Presentation; D015703:Antigens, CD / Q000276:immunology; D002450:Cell Communication / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology* / Q000473:pathology; D051379:Mice; D010587:Phagocytosis / Q000276:immunology; D010954:Plasmacytoma / Q000276:immunology* / Q000473:pathology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000473:pathology
D015703:Antigens, CD