DUAL ROLES OF CANCER CELL-EXPRESSED IMMUNOGLOBULINS IN CANCER IMMUNOLOGY

Abstract

While the expression of immunoglobulins and T cell receptors on cancer cells has been well-established for decades, the potential roles and mechanisms of action of these cancerous antigen receptors have not been fully elucidated. A monoclonal antibody designated as RP215, which reacts specifically with the carbohydrate-associated epitope located on the heavy chain region of cancerous immunoglobulins and T cell receptors, was used as a unique probe to study the roles of antigen receptors in the immunology of cancer cells. Through extensive cell-based biological and immunological studies, it was found that both anti-antigen receptors and RP215 demonstrated similar actions on the gene regulations involved in the growth/proliferation of cancer cells, as well as on toll-like receptors involved in innate immunity. In addition, RP215-specific cancerous immunoglobulins are believed to capture or neutralize circulating antigen/antibodies which may be harmful to cancer cells within the human body. In contrast to normal B and T cells and their respective receptors in the conventional immune system, cancer cells co-express both immunoglobulins and T cell receptors and immune protection is exercised by unique mechanisms. For example, these cancer cell-expressed antigen receptors display a lack of class switching, limited hyper-mutation, aberrant glycosylations and a strong influence on the toll-like receptors of cancer cells. Therefore, it is hypothesized that both normal and cancerous immune systems may co-exist and operate simultaneously within the human body. The balance of these two immune factors for respective surveillance and protection may be relevant to the outcome of cancer immunotherapy in humans. A potential therapeutic strategy is being developed by using RP215 as a drug candidate to target cancer cells based on these observations.