Activation of cytotoxic T-cell receptor gd T lymphocytes in response to specific stimulation in myelodysplastic syndromes

Results Vγ9Vδ2 T cells, the major circulating γδ T-cell subset, were reduced in myelodysplastic syndromes, but mainly in myelodysplastic syndromes’ patients with associated autoimmune diseases, suggesting that this anomaly was largely due to the autoimmune component. On the other hand, bromohalohydrin pyrophosphate-induced expansion of the Vγ9Vδ2 T-cell population in all 15 control samples, but in only 26 of 43 (60%) myelodysplastic syndromes patients. The response to bromohalohydrin pyrophosphate was independent of World Health Organization subtype, cytogenetic findings and International Prognostic Scoring System score. In responding myelodysplastic syndromes patients, expanded Vγ9Vδ2 T cells exhibited normal cytolytic and secretory activity against leukemic and myelodysplastic syndromes cell lines; fluorescence in situ hybridization analysis indicated that these Vγ9Vδ2 T cells were not derived from the myelodysplastic syndromes clone. However, these Vγ9Vδ2 T cells from the MDS patients had limited proliferative capacity in response to interleukin-2 despite having normal expression of interleukin-2 receptor chains (αβγ).