Date of Award


Degree Name

Master of Science


Biological Sciences


Robert A. Kirken


Members of the CD28 co-inhibitory receptor family, Cytotoxic T-lymphocyte- associated antigen 4 (CTLA-4), Program death-1 (PD-1) and B- and T-lymphocyte attenuator (BTLA) are type I transmembrane proteins expressed on a variety of immune cells. Co- inhibitory receptors deliver "off" signals that play an important role in down regulating immune cell activation. Manipulation of inhibitory signals have shown to be a powerful strategy in the treatment of autoimmune diseases, infectious diseases and various forms of cancer. In fact, the FDA (Food and Drug Administration) has approved the use of monoclonal antibodies against CTLA-4 (Ipilimumab) for the treatment of metastatic melanoma, against PD-1 (Nivolumab, Pembrolizumab and Durvalumab) for the treatment of melanoma, non-small cell lung cancer among other cancers. However, little is known about the therapeutic value of monoclonal antibodies against BTLA and consequently of a combination of these co- inhibitory receptor inhibitors sequentially. To explore the therapeutic potential of targeting these receptors for the treatment of cancer and to further elucidate the effects of BTLA blockade CTLA-4, PD-1 and BTLA novel monoclonal antibodies (mAbs) against unique sites within the extracellular domains (ECD) of human CTLA-4, PD-1 and BTLA were developed. To evaluate the specificity of these novel mAbs, dot blot, western blotting, FACS analysis and cell Immunohistochemistry (IHC) were employed to confirm the in vitro ability of these antibodies to recognize their target protein. To evaluate their effect on tumor inhibition in vivo, a Balb/c breast cancer model was tested to investigate the effects of new monotherapies and combinational-therapies. This work has identified novel mAbs against three checkpoint inhibitors and were able to inhibit tumor growth in a murine model of human breast cancer. This work suggests that administration of unique checkpoint inhibitors that deploy BTLA harbor therapeutic value.




Received from ProQuest

File Size

73 pages

File Format


Rights Holder

Rosabril Acuna