Publication Date



Open access

Degree Name

Master of Science (MS)


Cancer Biology (Medicine)

Date of Defense


First Committee Member

Joseph Rosenblatt

Second Committee Member

Eli Gilboa

Third Committee Member

Robert Levy

Fourth Committee Member

Izidore Lossos

Fifth Committee Member

Stefan Gluck


CD20 is a 35kDa surface antigen expressed on B cells from the early pre-B stage through the mature B stage. Moreover, the CD20 antigen is found on a majority of B cell malignancies. Rituximab is a chimeric anti-CD20 monoclonal antibody which has been extensively used alone or in combination in the treatment of CD20+ B cell malignancies including acute lymphoblastic leukemia (ALL), non-Hodgkin’s lymphomas (NHL) and chronic lymphocytic leukemia (CLL), as well as in the treatment of numerous autoimmune disorders. Despite its emerging use in the clinic, 30% to 50% of patients with low-grade NHL exhibit no clinical response to Rituximab. Previous work to elucidate the mechanisms of Rituximab resistance has established that antibody dependent cellular cytotoxicity (ADCC) is important as a predominant mechanism of lymphoma cell clearance and that Fcγ receptors (FcγRs) are critical for the in vivo actions of Rituximab in NHL. Natural killer group 2D, NKG2D is a major activating receptor on T lymphocytes and natural killer cells. The NKG2D–ligand (NKG2D-L) interaction triggers an activating signal which results in cytotoxic lysis of the cell expressing the ligand. One potential ligand for murine NKG2D is the retinoic acid early 1β (Rae-1β) protein which is expressed during cellular stress and has a high affinity for the NKG2D receptor in mice. We have recently shown that an anti-HER2-IgG3 fused to murine NKG2D Ligand, Rae1β inhibited HER2+ tumor growth significantly more than Herceptin alone. Similarly, our objective is to enhance the performance of anti-CD20 directed therapy through activation of NK cells by an anti-CD20 antibody encoding the same NK activation ligand. Previous results with anti-HER2-IgG3-Raelβ led us to hypothesize that a CD20 specific fusion protein will bind to CD20 expressing tumor cells and deliver an activation signal to local NKG2D receptors on effector cells triggering a non-FcγR dependent anti-tumor response. Here we show that anti-CD20-NKG2D-L can be synthesized and tested for its ability to bind human CD20 and activate NK cells through the NKG2D receptor in vitro.


NKG2D; NK cells; CD20; Antibody; Rituximab; ADCC