TY - JOUR
T1 - Heat shock fusion protein gp96-Ig mediates strong CD8 CTL expansion in vivo
AU - Štrbo, Nataša
AU - Yamazaki, Koichi
AU - Lee, Kelvin
AU - Rukavina, Daniel
AU - Podack, Eckhard R.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002/10
Y1 - 2002/10
N2 - Problem: As shown previously, gp96-Ig peptide complexes secreted by an ovalbumin transfected tumor (EG7) mediate strong, specific tumor immunity through a CD4 T cell independent CD8+ CTL response. In this study, we set out to develop a system to quantitatively determine the CD8 CTL response to gp96-Ig and to evaluate the influence of an established wild type tumor. Methods: Secreted heat shock protein gp96-Ig was constructed by replacement of the endoplasmic reticulum retention signal with the Fc portion of IgG1, transfected into EG7 (EG7-gp96-Ig) and used to induce CD8+ CTL expansion in vivo. Adoptively transferred, ovalbumin specific T-cell receptor (TCR) transgenic CD8+ cells (OT-1) responded with clonal expansion to the immunization with EG7-gp96-Ig. OT-1 expansion was quantitated with Kb-peptide-tetramers by flow cytometry. Results: In response to primary immunization with EG7-gp96-Ig, OT-1 expand from an initial frequency of 0.5 to 25% of all CD8 cells, and to 50% of all CD8 cells after a booster immunization. Endogenous ovalbumin specific CD8 cells also expand strongly. Antigen specific effector function was measured by enzyme-linked immunosorbent spot-forming cell assay (ELISPOT) for interferon-γ (IFN-γ). While effector function was strongly induced by secreted gp96-Ig, not all expanded OT-1 produce IFN-γ. EG7 does not cause OT-1 expansion, but rather induces anergy. If OT-1 are transferred into wild type EG7 tumor bearing mice to induce anergy of OT-1, immunization with EG7-gp96-Ig can partly overcome unresponsiveness. Conclusions: We conclude that secreted gp96-Ig is a powerful mediator of specific CD8+ CTL responses in vivo. Secretory gp96 mimics release of gp96 by damaged or necrotic cells that is able to activate dendritic cells without CD4 help. Gp96-Ig associated peptides have not been selected by binding to major histocompatibility complex (MHC). Specific immunization by secreted gp96-Ig therefore is expected to occur also in allogeneic settings.
AB - Problem: As shown previously, gp96-Ig peptide complexes secreted by an ovalbumin transfected tumor (EG7) mediate strong, specific tumor immunity through a CD4 T cell independent CD8+ CTL response. In this study, we set out to develop a system to quantitatively determine the CD8 CTL response to gp96-Ig and to evaluate the influence of an established wild type tumor. Methods: Secreted heat shock protein gp96-Ig was constructed by replacement of the endoplasmic reticulum retention signal with the Fc portion of IgG1, transfected into EG7 (EG7-gp96-Ig) and used to induce CD8+ CTL expansion in vivo. Adoptively transferred, ovalbumin specific T-cell receptor (TCR) transgenic CD8+ cells (OT-1) responded with clonal expansion to the immunization with EG7-gp96-Ig. OT-1 expansion was quantitated with Kb-peptide-tetramers by flow cytometry. Results: In response to primary immunization with EG7-gp96-Ig, OT-1 expand from an initial frequency of 0.5 to 25% of all CD8 cells, and to 50% of all CD8 cells after a booster immunization. Endogenous ovalbumin specific CD8 cells also expand strongly. Antigen specific effector function was measured by enzyme-linked immunosorbent spot-forming cell assay (ELISPOT) for interferon-γ (IFN-γ). While effector function was strongly induced by secreted gp96-Ig, not all expanded OT-1 produce IFN-γ. EG7 does not cause OT-1 expansion, but rather induces anergy. If OT-1 are transferred into wild type EG7 tumor bearing mice to induce anergy of OT-1, immunization with EG7-gp96-Ig can partly overcome unresponsiveness. Conclusions: We conclude that secreted gp96-Ig is a powerful mediator of specific CD8+ CTL responses in vivo. Secretory gp96 mimics release of gp96 by damaged or necrotic cells that is able to activate dendritic cells without CD4 help. Gp96-Ig associated peptides have not been selected by binding to major histocompatibility complex (MHC). Specific immunization by secreted gp96-Ig therefore is expected to occur also in allogeneic settings.
KW - Cytotoxicity
KW - Dendritic cells
KW - MHC tetramer
KW - Vaccine
UR - http://www.scopus.com/inward/record.url?scp=0036785091&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036785091&partnerID=8YFLogxK
U2 - 10.1034/j.1600-0897.2002.01118.x
DO - 10.1034/j.1600-0897.2002.01118.x
M3 - Article
C2 - 12516632
AN - SCOPUS:0036785091
VL - 48
SP - 220
EP - 225
JO - American Journal of Reproductive Immunology
JF - American Journal of Reproductive Immunology
SN - 1046-7408
IS - 4
ER -