An international team studied a molecule called TIM-3, which could play a key role in regulating immune responses. The study was conducted by scientists at McGill University Health Center (RI-MUHC), Montreal Children's Hospital and McGill University. In collaboration with colleagues from the Université Paris-Descartes and the Image Institute, they isolated this protein. Thanks to further studies, it could become a new target for treatments against cancers and other diseases.
When the TIM-3 protein is suppressed or inactive, the T lymphocytes become uncontrollable. This results in a rare form of lymphoma called a panniculite-like subcutaneous T-cell lymphoma. The team identified the two mutations that act on the TIM-3 protein, preventing it from attacking cancer cells.
The study is based on a previous work, in which scientists had detected the same form of lymphoma in two siblings. After sequencing the genomes, they found that both patients were carriers of the same mutation. The variant involved the HAVCR2 gene, which encodes the TIM-3 protein and is transmissible from the parents. It was thought that it was common especially in Asia, but further studies have denied it.
The study also found that this form of lymphoma is far more common than previously believed. Both responsible mutations are found in Asian, Australian and Polynesian individuals, as well as Europeans. Scientists have found similar cases in patients with Tyr82Cys and Ile97Met mutations, both on the same gene and in both European and Polynesian patients.