Monoclonal antibodies in the treatment of hematologic malignancy

The natural killer cell immunotherapy platform: an overview of the landscape of clinical trials in liquid and solid tumors

The translation of natural killer (NK) cells to the treatment of malignant disease has made significant progress in the last few decades. With a variety of available sources and improvements in both in vitro and in vivo NK cell expansion, the NK cell immunotherapy platform has come into its own. The enormous effort continues to further optimize this platform, including ways to enhance NK cell persistence, trafficking to the tumor microenvironment, and cytotoxicity. As this effort bears fruit, it is translated into a plethora of clinical trials in patients with advanced malignancies. The adoptive transfer of NK cells, either as a standalone therapy or in combination with other immunotherapies, has been applied for the treatment of both liquid and solid tumors, with numerous early-phase trials showing promising results. This review aims to summarize the key advantages of NK cell immunotherapy, highlight several of the current approaches being taken for its optimization, and give an overview of the landscape of clinical trials translating this platform into clinic.

A naturally processed HLA-DR-bound peptide from the IL-9 receptor alpha of HTLV-1-transformed T cells serves as a T helper epitope

Human T cell leukemia virus type 1 (HTLV-1) induced adult T cell leukemia/lymphoma (ATLL) is usually a fatal lymphoproliferative malignant disease. Thus, the enhancement of T cell immunity to ATLL through the development of therapeutic vaccines using characterized T cell peptide epitopes could be of value. We isolated and characterized HLA-DR-bound peptides from HTLV-1-transformed T cells by fractionating on reverse-phase high performance liquid chromatography and Edman NH(2)-terminal sequencing and were able to identify five independent peptide sequences. One of the identified peptide sequences corresponded to a fragment of the human interleukin-9 receptor alpha (IL-9Rα), which is commonly expressed by HTLV-1-infected T cell lymphoma cells. Using a synthetic peptide corresponding to the identified IL-9Rα sequence, we generated antigen-specific CD4 helper T lymphocytes in vitro, which were restricted by HLA-DR15 or HLA-DR53 molecules and could recognize and kill HTLV-1+, IL-9Rα+ T cell lymphoma cells. These results indicate that IL-9Rα functions as T cell leukemia/lymphoma-associated antigen for CD4 T cells and that synthetic peptides such as the one described here could be used for T cell-based immunotherapy against IL-9Rα positive ATLL.