Letter from the Editor

This issue is the ninth of the Immunological Investigations’ thematic issues, and is entitled, “Regulatory Myeloid Cells in Neoplasia”. Dr. Scott Abrams is the guest editor of this issue and has provided a brief review article on this topic and invited an impressive selection of additional authors for this issue. The cover illustration entitled, Mechanisms of Tumor-Induced MDSC development depicts the communication that occurs between tumor cells and myeloid progenitor cells which results in the production of myeloid-derived suppressor cells (MDSCs) and immature dendritic cell (DCs) (not shown) which stimulate or facilitate tumor progression. This topic was chosen to highlight the importance of tumor cell-myeloid cell cross-talk and its impact on cancer immunosurveillance or immunotherapy.

In the 2 years prior to this thematic, articles which discuss efforts in developing immunotherapy “Immunomodulatory effects of radiofrequency ablation in a breast cancer model” (Todorova, 2010), “Number of treatment cycles influences development of cytotoxic T cells in metastatic breast cancer patients - a phase I/II study” (Wright, 2010) and articles which discuss efforts to understand the immune response to tumors entitled “Cyclophosphamide potentiates the antitumor effect of immunization with injection of immature dendritic cells into irradiated tumor.” (Park, 2011) and “Circulating regulatory T cells in endometrial cancer: a role for age and menopausal status” (Sawan 2011) were published and have whet our appetite for understanding the puzzle of the array of interactions of tumor cells with cells of both the innate and the acquired immune system.

The guest editor, Dr. Scott Abrams, Ph.D., Associate Member, Department of Immunology and Associate Professor of Oncology at Roswell Park Cancer, has had a long term interest in tumor immunotherapy. He received his Ph.D. in Microbiology & Immunology, from Indiana University School of Medicine, Indianapolis, Indiana, and did his Postdoctoral Fellowship at the Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, MO. Prior to joining Roswell Park Cancer Institute in 2008, he was a senior staff fellow and later an Investigator at the National Cancer Institute. Early studies by Dr. Abram’s focused on innate immunity and natural killer cell biology, followed by a body-of-work dedicated to adaptive immunity, tumor escape and cancer immunotherapy. He has a career total of research 65 publications, 13 invited reviews and 9 book chapters. He currently has DOD funding for “Granulopoietic Growth Factor Secretion in Ovarian Carcinoma as a Mechanism for the Emergence of Immune Suppressive Myeloid Subsets” and has NCI funding for “IRF-8 as a Negative Regulator of CD11b+Gr-1+ Myeloid Cell Production and Function”. He has received numerous awards and these award areas show his strength in combining academics and research. He was selected as the recipient of the Performance award of the Laboratory of Tumor Immunology and Biology at NCI 4 times, was nominated for the NCI outstanding mentor award and has been selected as co-chair both in 2011 and 2012 for the American Association of Immunology Tumor Immunology mini-symposium. He is also a frequent invited speaker. Through his speaking activities and his activities as co-chair at NIH, Dr. Abrams has developed an impressive cadre of colleagues that are experts in the field of tumor-associated regulatory myeloid cells, many of which graciously contributed to this issue. In addition he is a much appreciated new (2011) member of the editorial board of Immunological Investigations. For further information his website is: http://www.roswellpark.edu/scott-abrams. Dr. Paul Wallace of Roswell Park Cancer Institute kindly assisted Dr. Abrams in the review for this issue.

This talented guest editor has invited an outstanding group of scientists to showcase for Immunological Investigations the current state of the art in regulatory tumor associated myeloid cells. I am sure that you will enjoy the summary by Scott’s “Overview of Regulatory Myeloid Cells in Neoplasia”(Abrams 2012) and the following very exciting and thought-provoking articles giving overviews of MDSC-mediated mechanisms of tumor progression including possible therapeutic interventions and concluding with emerging concepts related to myeloid-derived stem cells and dendritic cells.

1.	Negative regulation of myeloid-derived suppressor cells in cancer, (Qu 2012)
2.	Immune Suppression: The Hallmark of Myeloid Derived Suppressor Cells (Haile 2012)
3.	Myeloid Suppressor Cells and anti-tumor T cells: a complex relationship, (Monu 2012)
4.	Metabolism of L-Arginine by Myeloid-Derived Suppressor Cells in Cancer: Mechanisms of T cell suppression and Therapeutic Perspectives (Raber 2012)
5.	PGE2-Driven Induction and Maintenance of Cancer-5. Associated Myeloid-Derived Suppressor Cells (Obermajer 2012)
6.	Myeloid-derived suppressor cells (MDSCs) in gliomas and glioma-development (Kohanbash,2012)
7.	Myeloid-derived suppressor cells adhere to physiologic STAT3- vs STAT5-dependent hematopoietic programming, establishing diverse tumor-mediated mechanisms of immunologic escape (Cohen 2012)
8.	Phenotypic plasticity of MDSC in cancers, (Manjili 2012)
9.	Highlights on molecular mechanisms of MDSC-mediated immune suppression: paving the way for new working hypotheses, (Solito 2012)
10.	Indoleamine 2,3-dioxygenase and Dendritic Cell Tolerogenicity, (Harden 2012)
11.	Host Indoleamine 2,3-Dioxygenase: Contribution to Systemic Acquired Tumor Tolerance (Johnson, 2012),

I hope that you enjoy this issue.

Kate Rittenhouse-Olson

Editor