The role of B7 family molecules in hematologic malignancy

The B7 family consists of structurally related, cell-surface proteins that regulate immune responses by delivering costimulatory or coinhibitory signals through their ligands. Eight family members have been identified to date including CD80 (B7-1), CD86 (B7-2), CD274 (programmed cell death-1 ligand [PD-L1]), CD273 (programmed cell death-2 ligand [PD-L2]), CD275 (inducible costimulator ligand [ICOS-L]), CD276 (B7-H3), B7-H4, and B7-H6. B7 ligands are expressed on both lymphoid and nonlymphoid tissues. The importance of the B7 family in regulating immune responses is clear from their demonstrated role in the development of immunodeficiency and autoimmune diseases. Manipulation of the signals delivered by B7 ligands shows great potential in the treatment of cancers including leukemias and lymphomas and in regulating allogeneic T-cell responses after stem cell transplantation.

Ongoing development of monoclonal antibodies and antibody drug-conjugates in lymphoma

Rituximab, a monoclonal antibody (mAb) directed against CD20, has changed practices in the treatment of patients with B-cell lymphoma. The large success of rituximab has contributed to validate immunotherapy with monoclonal antibodies as a valuable strategy in lymphoma. Recently, better-engineered anti-CD20-mAbs have been designed to improve efficacy and safety. Also, new antibodies targeting other lymphoma subtypes including T-cell lymphoma and Hodgkin's disease have been developed. Ongoing pharmacology development is concentrating on immuno-drug-conjugates combining the toxicity of chemotherapy, isotopes, or toxins with the specificity of mAbs. This article offers an overview on the development of new antibodies and immuno conjugates in lymphoma.