Anti-LAP antibody helps kill cancer cells
Scientists studying multiple sclerosis have stumbled upon a finding that a specific antibody enhances antitumor immune responses in several types of cancer. The study, led by Howard Weiner at Harvard Medical School and published in the journal Science Immunology, provides a potential strategy for cancer immunotherapy.
Regulatory T cells, or Tregs, are a subpopulation of T cells that function in modulating the immune system, maintaining tolerance to self-antigens, and abrogating autoimmune disease. Due to their important functions, Tregs are vital for the body's health. However, these cells can also promote cancer by suppressing antitumor immune responses. Therefore, targeting Tregs represents a promising way for developing tumor immunotherapy.
Weiner's team have been studying Tregs for a long time, and when they investigated the mechanism of multiple sclerosis, they surprisingly found that anti-LAP antibody, which targets the LAP/TGF-β complex on Tregs and other cells, is able to unleash the immune system to fight cancer cells. The anti-LAP antibody was tested in models of melanoma, colorectal carcinoma, and glioblastoma. Results showed that the antibody boosted antitumor immune responses and therefore reduced tumor growth.
There is evidence that LAP positive cells are upregulated in human cancer and correlate with poor patient outcome. This study showed that antibodies to LAP reduced the levels of LAP positive Tregs and tolerogenic dendritic cells. These cells appeared to promote tumor growth.
Together, the data indicate that targeting LAP with antibodies could be a strategy to develop cancer immunotherapy.