What is the fine-grained topic of the following text: The findings, which so far have been demonstrated in a mouse model, show how DNA mutations of antibody genes in germinal centres – where B cells activate during immune response – reprogram these self-reactive antibodies, making them stop binding to mouse tissue, and increasing their binding capacity to foreign invaders by up to 5,000 times. Only return the topic.
DNA mutations reprogramming self-reactive antibodies in germinal centres