Immune System Finding Paves Way For Vaccine Use In Some Leukemia, Lymphoma Cancers
Fighting Lymphoma and Leukemia
Researchers at The University of Texas M. D. Anderson Cancer Center and the National Cancer Institute have found that an experimental vaccine can prime the immune system to help fight an aggressive form of lymphoma, even though prior therapy had eliminated virtually all of the B cells thought necessary to mount such a defense.
Their study, published in the September issue of Nature Medicine, has both important basic science and clinical implications, researchers say. It demonstrates that few, if any, B cells are needed to trigger an effective T-cell immune response a finding which overturns the commonly accepted notion that both are needed to prime the human immune system. The article will be available online on Aug. 21, 2005, at noon CDT.
Their research also tests the use of personalized vaccines to help lymphoma patients fend off a recurrence of their cancer after treatment. Several such cancer vaccines are in human testing. In this study, conducted at the Center for Cancer Research, National Cancer Institute, treatment with a B-cell depleting treatment regimen followed by an experimental vaccine resulted in an impressive 89% survival rate at 46 months for 26 patients with mantle cell lymphoma, which is difficult to control.
"This is the first human cancer vaccine study to see T-cell responses in the absence of B cells, and this paves the way to use vaccines in a number of hematological cancers that are treated by eliminating diseased B cells," says the study's first author, Sattva Neelapu, M.D., an assistant professor in the Department of Lymphoma at M. D. Anderson.
Those cancers include forms of lymphoma and leukemia in which the cancer evolves in B-cell lymphocytes, white blood cells whose job is to produce antibodies that activate a response by the immune system. New treatments, such as rituximab, are designed to completely wipe out diseased (as well as healthy) B cells and can prolong patient survival.