ALBERT

Beschreibung: Background: The tumour microenvironment plays an important role in the biology of FL. Different cell populations have been explored, including T-regulatory lymphocytes, macrophages, and T-cell subpopulation. The involvement of γδT in lymph nodes from FL patients or from inflammatory diseases has been rarely documented. So far, their histological pattern and prognosis significance are unknown and must be defined in order to develop new therapeutic programs including in vivo or ex vivo expansion of γδT, as developed particularly in B-cell malignancies by us and different groups. In this study, we analyzed from FL patients 1/the number of circulating γδT and their ex vivo expansion, 2/ the presence and distribution of γδT in tumour lymph nodes, and different chemokines, in comparison to inflammatory lymph nodes (ILN), by immunochemistry. Patients and Methods: Circulating γδT cells were counted in peripheral blood from patients having FL by FACS analysis. Blood samples from 34 patients were collected and expanded in vitro by using γδT ligands, referred to as “phosphoantigens”, including IPH1101 (used in clinical trials) and interleukin 2. Tumour samples from 51 patients (35 at diagnosis and 16 at relapse) having FL were collected from a single institution. Immunochemistry was used to study numbers and distribution of CD8, γδT cells, and the expression of CCL19, 21 and SDF1 chemokines. CCR7/γδT cells were analyzed by double immunofluorescence. Results were compared to 28 samples from patients having ILN. Results: The mean of circulating γδT was 0.36% (0.03–2.5) representing a mean of 2.2% of the CD3 cells. The mean percentage of γδT cells obtained after in vitro culture was 85% (2.1–95) with a mean 220-fold expansion (2-1050). The median number of γδT cells (cells/mm2) in FL lymph node was 18 versus 47.5 in the ILN (mean: 30 versus 82,5), P

Beschreibung: Background: By using gene expression profiling, a major role for T-lymphocytes and macrophages (M) have been observed, defining 2 prognostic subgroups. Then, conflicting results were published with both positive and negative impacts of different T-cells subpopulations, particularly for T-regulatory (Tregs) cells. In addition, CD8 and CD4 T-cells were mentioned as key cells in progression and/or transformation process and CD68+ M associated with a poor outcome. Functional studies have suggested that follicular dendritic cells have to be considered as important cells in comprehensive biology of FL, and that the function is probably associated with the proximity of tumour cells, different in intra-or inter-follicular location. We investigate the role CD8+ T cells, FOXP3+ Tregs and M, and calculate in large fields the different numbers of these cells, particularly focusing on their intra-versus inter-follicular localisation. To approach a more dynamical view of the immune response we correlate the ratio CD8+/Treg in these 2 compartments and correlated results with clinical parameters and outcome. Patients and Methods: Immunochemistry was used to study numbers and distribution of CD8, CD68, and Tregs cells in 89 patients with FL (65 at diagnosis and 24 at relapse). Since it can be expected that overall effect of Tregs depends on their number in relation to CD8+ effectors T cells, we determined the corresponding ratio for each patient and correlated the results with clinical parameters. Results: The median age of the patients was 58 years (range 23–91 years), and the male/ female ratio was 1.2. There were 67 % of the patients with grade1, 17 % grade 2 and 16 % grade 3a. Advanced stage (Ann Arbor IV) was observed in 24 %. The distribution of the population according to the FLIPI was the following: low risk 36 %, intermediate risk 45 % and high risk, 19 %. The interfollicular CD8/FOXP3+ cell ratio was significantly higher in patients with grade 3 tumours (2.04 versus 1.63) and with a high risk FLIPI index (2.99 versus 1.53) compared with those with grade 1–2 tumours or a low–intermediate FLIPI index. The same results were obtained with the intra-follicular CD8+/FOXP3 + cell ratio. The inter-follicular CD8/FOXP3 ratio was found to have prognostic value for overall survival with a 5-years OS of 82% versus 59% for a ratio of less or more than 1.68. Moreover, an inter-follicular FOXP3+ cell number of more than 86 cells/mm2 was correlated with a more favourable outcome (p = 0.03). When comparing the 2 groups at diagnosis and relapse, we observed a significant difference between the number of CD68 cells both in intra-follicular locations (39.23 at diagnosis versus 32 at relapse, p= 0.07) and inter-follicular locations (96 at diagnosis versus 62 at relapse, p=0.05). The CD8/FOXP3 ratio in inter-follicular locations was significantly different (1 .66 at diagnosis versus 2.2 at relapse, p=0.05). Conclusion: The presence of abundant FOXP3+ cells with a low CD8/FOXP3 ratio is probably the mark of an active immune response during tumour development, with lymphoma cells acting as targets or bystanders.