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Programed Death-Ligand 1 (PD-L1, also known as B7-H1 or CD274) is a cell surface protein that binds to Programmed Cell Death Protein 1 (PD-1, also known as CD279). An imbalance in PD-1/PD-L1 activity contributes to cancer immune escape.  PD-1 is expressed on the surface of antigen-stimulated T cells. The interaction between PD-L1 and PD-1 negatively regulates T cell-mediated immune responses. It has been suggested that disrupting the PD-L1/PD-1 signaling pathway can be used to treat cancers. The aberrant expression of PD-L1 on multiple tumor types supports this suggestion.

CD22 is a common cell surface glycoprotein expressed in B-cells and present in B-cell lymphomas; e.g., hairy cell leukemia (HCL), non-Hodgkins lymphoma (NHL), chronic lymphoblastic leukemia (CLL), and other cancers. It is therefore a target for cancer immunotherapy. Conjugation of anti-CD22 monoclonal antibodies with toxins or drugs has shown promise in clinical trials. However, all monoclonal anti-CD22 antibodies used in clinical trials are of murine origin.

Cancer cells may acquire drug resistance after prolonged chemotherapy. In many cases, cancer cells develop resistance to several drugs with distinct structures and modes of action. This multi-drug resistance phenomenon increases the complexity of cancer treatment.

Chimeric antigen receptors (CARs) are hybrid proteins consisting of an antibody binding fragment fused to protein signaling domains that cause T-cells which express the CAR to become cytotoxic.  Once activated, these cytotoxic T-cells can selectively eliminate the cells which they recognize via the antibody binding fragment of the CAR.  Thus, by engineering a T-cell to express a CAR that is specific for a certain cell surface protein, it is possible to selectively target those cells for destruction.  This promising new therapeutic approach is known as adoptive cell therapy.

Adoptive T-cell therapy (ACT) utilizes tumor-reactive T cells to induce disease remission. While ACT has been used effectively to treat metastatic melanoma and certain epithelial cancers, most patients do not respond to treatment. Although the mechanisms underlying this variable response to therapy are not fully elucidated, the phenotype of the adoptively transferred cell is known to be a key determinant of treatment efficacy.

Synovial sarcoma is a cancer affecting mesenchymal cells in connective tissues. This rare cancer is typically linked to genetic abnormalities or exposure to radiation. Metastatic growth throughout the body can occur primarily through blood circulation. More than 90% of synovial sarcomas show a characteristic t(X;18)(p11;q11) translocation involving the SYT and SSX genes. The resulting SYT-SSX abnormal fusion protein causes misregulation of downstream gene expression, leading to tumor formation.

Polo-like kinase 1 (Plk1), a member of the Polo-like kinase family, plays a critical role in regulating mitosis and cell cycle progression. Aberrant expression of Plk1 has been observed in a variety of human cancers, and it is known to be associated with tumorigenesis as well as poor prognosis in cancer patients. Unlike normal cells, some cancer cells are dependent on augmented Plk1 levels to remain viable and are killed when Plk1 function is attenuated.

One form of adoptive T cell therapy (ACT) consists of harvesting tumor infiltrating lymphocytes (TIL), screening and isolating TIL which display tumor antigen-specific T-cell receptors (TCR), expanding the isolated T cells in vitro, and reinfusing them into the patient for treatment. While highly active in the treatment of certain cancers (e.g., melanoma), current methods used to produce cancer-reactive T cells require significant time and may not adequately identify the desired TCRs which bind cancer targets.

Diverse human cancers like colorectal, pancreatic, ovarian, melanoma, and pre-cancers express NADPH oxidases (NOX) at high levels. Reactive oxygen species (ROS) produced from metabolic reactions catalyzed by NOX in tumors are essential to the tumor’s growth. Though drugs that inhibit ROS production by NOX could be effective against a variety of human cancers, these types of drugs are not widely available.

The blood brain barrier (BBB) is a specialized endothelium that prevents the uptake of substances from the systemic circulation into the central nervous system. This barrier, while protecting the sensitive physiological environment of the brain, is also a major impediment in administering therapeutics that need to pass through the BBB. A drug delivery platform that could deliver therapeutic agents directly to the brain is needed, and could have wide ranging significance in a variety of psychiatric, oncology, infectious, and neurodegenerative diseases.