Developing T-cell therapies for cancer in an academic setting

Adoptive immunotherapy mediated by ex vivo expanded natural killer T cells against CD1d-expressing lymphoid neoplasms

BACKGROUND

CD1d is a monomorphic antigen presentation molecule expressed in several hematologic malignancies. Alpha-galactosylceramide (alpha-GalCer) is a glycolipid that can be presented to cytotoxic CD1d-restricted T cells. These reagents represent a potentially powerful tool for cell mediated immunotherapy.

DESIGN AND METHODS

We set up an experimental model to evaluate the use of adoptively transferred cytotoxic CD1d-restricted T cells and alpha-GalCer in the treatment of mice engrafted with CD1d(+) lymphoid neoplastic cells. To this end the C1R cell line was transfected with CD1c or CD1d molecules. In addition, upon retroviral infection firefly luciferase was expressed on C1R transfected cell lines allowing the evaluation of tumor growth in xenografted immunodeficient NOD/SCID mice.

RESULTS

The C1R-CD1d cell line was highly susceptible to specific CD1d-restricted T cell cytotoxicity in the presence alpha-GalCer in vitro. After adoptive transfer of CD1d-restricted T cells and alpha-GalCer to mice engrafted with both C1R-CD1c and C1R-CD1d, a reduction in tumor growth was observed only in CD1d(+) masses. In addition, CD1d-restricted T-cell treatment plus alpha-GalCer eradicated small C1R-CD1d(+) nodules. Immunohistochemical analysis revealed that infiltrating NKT cells were mainly observed in CD1d nodules.

CONCLUSIONS

Our results indicate that ex vivo expanded cytotoxic CD1d-restricted T cells and alpha-GalCer may represent a new immunotherapeutic tool for treatment of CD1d(+) hematologic malignancies.

Breast cancer biology: the multifaceted roles of mesenchymal stem cells

Recent upsurge in the interest of breast cancer metastasis is partly attributed to the discovery of novel, yet unclear, mechanisms of breast cancer interaction with sites of distant metastasis such as the bone marrow microenvironment. In this review, we discuss the significance of the interactions between breast cancer cells and cells of the bone marrow. This is a subject of intense research studies aim to provide new methods of treatments and perhaps the identification of new drug targets. This review also discusses the role of inflammation and the bimodal function of the transforming growth factor-β signaling pathway in the process of tumorigenesis. We bring attention to future prospects in breast cancer research, including the role of microRNAs in cancer quiescence in the bone marrow and the application of microRNAs to basic science discoveries in oncology. Finally, we discuss the cancer stem cell hypothesis, which is not a new idea, but has resurged with investigative questions.