TY - JOUR
T1 - The role of regulatory b cell-like malignant cells and Treg Cells in the mouse model of BCL1 tumor dormancy
AU - BitMansour, Andrew
AU - Pop, Laurentiu M.
AU - Vitetta, Ellen S.
N1 - Publisher Copyright:
© 2016 BitMansour et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2016/12
Y1 - 2016/12
N2 - Cancer dormancy is a clinical state in which residual tumor cells persist for long periods of time but do not cause detectable disease. In the mouse B cell lymphoma model (BCL1), dormancy can be induced and maintained by immunizing mice with a soluble form of the IgM expressed on the surface of the tumor cells. Immunization induces an anti-idiotype antibody response that maintains dormancy. Mice with dormant tumor have low numbers of BCL1 cells in their spleens that divide and are killed at the same rate. When the anti-Id antibodies wane, the tumor cells grow rapidly and kill the host. Spleens from tumor-bearing mice contain both effector (CD4+ and CD8+) and regulatory T cells (Tregs). In other tumor models, it has been reported that Tregs promote tumor progression by preventing effector cells from killing the tumor. In this report, we demonstrate that the tumor site with rapidly dividing BCL1 cells has fewer Tregs than the tumor site harboring dormant BCL1 cells. In both cases, the Tregs were equally suppressive in vitro. In spleens from mice with actively growing tumor, CD8+ but not CD4+ T cells were virtually absent. In vitro analysis demonstrated a tumor-mediated elimination of CD8+ T cells that was contact dependent and involved the caspase-3 pathway. Most importantly, we found that the BCL1 cells expressed characteristics of B10 regulatory B cells, i.e., they were CD1dhiCD5+ and secreted high levels of IL-10. These BCL1 tumor cells can inhibit anti-tumor immune responses by depleting CD8+ effector T cells.
AB - Cancer dormancy is a clinical state in which residual tumor cells persist for long periods of time but do not cause detectable disease. In the mouse B cell lymphoma model (BCL1), dormancy can be induced and maintained by immunizing mice with a soluble form of the IgM expressed on the surface of the tumor cells. Immunization induces an anti-idiotype antibody response that maintains dormancy. Mice with dormant tumor have low numbers of BCL1 cells in their spleens that divide and are killed at the same rate. When the anti-Id antibodies wane, the tumor cells grow rapidly and kill the host. Spleens from tumor-bearing mice contain both effector (CD4+ and CD8+) and regulatory T cells (Tregs). In other tumor models, it has been reported that Tregs promote tumor progression by preventing effector cells from killing the tumor. In this report, we demonstrate that the tumor site with rapidly dividing BCL1 cells has fewer Tregs than the tumor site harboring dormant BCL1 cells. In both cases, the Tregs were equally suppressive in vitro. In spleens from mice with actively growing tumor, CD8+ but not CD4+ T cells were virtually absent. In vitro analysis demonstrated a tumor-mediated elimination of CD8+ T cells that was contact dependent and involved the caspase-3 pathway. Most importantly, we found that the BCL1 cells expressed characteristics of B10 regulatory B cells, i.e., they were CD1dhiCD5+ and secreted high levels of IL-10. These BCL1 tumor cells can inhibit anti-tumor immune responses by depleting CD8+ effector T cells.
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U2 - 10.1371/journal.pone.0167618
DO - 10.1371/journal.pone.0167618
M3 - Article
C2 - 27959896
AN - SCOPUS:85006018318
SN - 1932-6203
VL - 11
JO - PloS one
JF - PloS one
IS - 12
M1 - e0167618
ER -