Follicular lymphoma (FL) is a monoclonal B cell malignancy with each patient's tumor expressing a unique cell surface immunoglobulin (Ig), or B cell receptor (BCR), that can potentially recognize antigens and/or transduce signals into the tumor cell. Here, we evaluated the reactivity of tumor derived Igs for human tissue antigens. Self-reactivity was observed in 26% of tumor Igs (25/98). For one FL patient, the recognized self-antigen was identified as myoferlin. This patient's tumor cells bound recombinant myoferlin in proportion to their level of BCR expression and the binding to myoferlin was preserved despite ongoing somatic hypermutation of Ig variable regions. Furthermore, BCR-mediated signaling... More
Follicular lymphoma (FL) is a monoclonal B cell malignancy with each patient's tumor expressing a unique cell surface immunoglobulin (Ig), or B cell receptor (BCR), that can potentially recognize antigens and/or transduce signals into the tumor cell. Here, we evaluated the reactivity of tumor derived Igs for human tissue antigens. Self-reactivity was observed in 26% of tumor Igs (25/98). For one FL patient, the recognized self-antigen was identified as myoferlin. This patient's tumor cells bound recombinant myoferlin in proportion to their level of BCR expression and the binding to myoferlin was preserved despite ongoing somatic hypermutation of Ig variable regions. Furthermore, BCR-mediated signaling was induced following culture of tumor cells with myoferlin. These results suggest antigen stimulation may provide survival signals to tumor cells and that there is a selective pressure to preserve antigen recognition as the tumor evolves.
