Higher TIGIT+ γδ T _CM cells may predict poor prognosis in younger adult patients with non-acute promyelocytic AML

The first edition of the European LeukemiaNet (ELN) recommendations for diagnosis and management of acute myeloid leukemia (AML) in adults, published in 2010, has found broad acceptance by physicians and investigators caring for patients with AML. Recent advances, for example, in the discovery of the genomic landscape of the disease, in the development of assays for genetic testing and for detecting minimal residual disease (MRD), as well as in the development of novel antileukemic agents, prompted an international panel to provide updated evidence- and expert opinion-based recommendations. The recommendations include a revised version of the ELN genetic categories, a proposal for a response category based on MRD status, and criteria for progressive disease.

Naive T lymphocytes travel to T-cell areas of secondary lymphoid organs in search of antigen presented by dendritic cells. Once activated, they proliferate vigorously, generating effector cells that can migrate to B-cell areas or to inflamed tissues. A fraction of primed T lymphocytes persists as circulating memory cells that can confer protection and give, upon secondary challenge, a qualitatively different and quantitatively enhanced response. The nature of the cells that mediate the different facets of immunological memory remains unresolved. Here we show that expression of CCR7, a chemokine receptor that controls homing to secondary lymphoid organs, divides human memory T cells into two functionally distinct subsets. CCR7- memory cells express receptors for migration to inflamed tissues and display immediate effector function. In contrast, CCR7+ memory cells express lymph-node homing receptors and lack immediate effector function, but efficiently stimulate dendritic cells and differentiate into CCR7- effector cells upon secondary stimulation. The CCR7+ and CCR7- T cells, which we have named central memory (TCM) and effector memory (TEM), differentiate in a step-wise fashion from naive T cells, persist for years after immunization and allow a division of labour in the memory response.

Most treatments for patients with metastatic melanoma have a low rate of complete regression and thus overall survival in these patients is poor. We investigated the ability of adoptive cell transfer utilizing autologous tumor-infiltrating lymphocytes (TIL) to mediate durable complete regressions in heavily pretreated patients with metastatic melanoma. Ninety-three patients with measurable metastatic melanoma were treated with the adoptive transfer of autologous TILs administered in conjunction with interleukin-2 following a lymphodepleting preparative regimen on three sequential clinical trials. Ninety-five percent of these patients had progressive disease following a prior systemic treatment. Median potential follow-up was 62 months. Objective response rates by Response Evaluation Criteria in Solid Tumors (RECIST) in the 3 trials using lymphodepleting preparative regimens (chemotherapy alone or with 2 or 12 Gy irradiation) were 49%, 52%, and 72%, respectively. Twenty of the 93 patients (22%) achieved a complete tumor regression, and 19 have ongoing complete regressions beyond 3 years. The actuarial 3- and 5-year survival rates for the entire group were 36% and 29%, respectively, but for the 20 complete responders were 100% and 93%. The likelihood of achieving a complete response was similar regardless of prior therapy. Factors associated with objective response included longer telomeres of the infused cells, the number of CD8(+)CD27(+) cells infused, and the persistence of the infused cells in the circulation at 1 month (all P(2) < 0.001). Cell transfer therapy with autologous TILs can mediate durable complete responses in patients with metastatic melanoma and has similar efficacy irrespective of prior treatment. Clin Cancer Res; 17(13); 4550-7. ©2011 AACR.