Persistent decreased bone marrow CD3⁺CD56⁺ T lymphocytes are inversely associated with mature granulocytes in myelodysplastic syndromes

Abstract

Leone et al. have recently documented a trend-increase of bone marrow (BM) CD3 + CD56 + T regulatory cells in myelodysplastic syndromes (MDS), with concomitant reduction of cytotoxic T cell activity favoring escape of leukemic blasts to immunological surveillance.

Adaptive and Innate Cytotoxic Effectors in Chronic Lymphocytic Leukaemia (CLL) Subjects with Stable Disease

“…Since lymphocytes are mainly composed of B cells in CLL patients, the small percentage of T cells within the lymphocyte compartment appears to exhibit a preferential expansion of Treg and T R3-56 regulatory cell subsets, as a possible immune escape mechanism. Our data confirm the Treg expansion in CLL [78][79][80] and highlight an expansion also of the recently characterised regulatory T R3-56 population [51,52,81,82].…”

“…The role of altered HLA-G [78,80,81] expression in CLL is still controversial and of unclear prognostic significance [81]. Here, we demonstrated a preferentially increased expression of HLA-G on B cells, but not on T cells, from CLL patients with stable disease.…”

“…These data suggest that a higher proportion of circulating CTL characterises the T-cell compartment in CLL subjects with stable disease. The functions of immune effectors have been described to depend on cell-mediated regulatory networks involving Treg [41][42][43][44][45] and T R3-56 -cell subset that we recently described to preferentially modulate CTL effectiveness in autoimmune [51] and in tumour disease [52,81,82].…”

The potential etiopathogenetic role and diagnostic utility of CD3+CD56+ regulatory T lymphocytes in Myelodysplastic Syndromes

“…Serio et al conclude that BM T R3-56 frequency could be a flow-cytometry marker for MDS diagnosis, since consistently increased in high-risk MDS and AML, highlighting the role for this cell subset in promoting expansion of the dysplastic precursor/s with consequent ineffective myelopoiesis. 1 Serio et al data support the etiopathogenetic role of T R3-56 in MDS and the possible use of this population as diagnostic/prognostic marker of the disease. We previously suggested that type 1 diabetes (T1D) progression is associated with the loss of T R3-56 -dependent control of CTL effector functions 3 and, as commented by Serio et al, we highlighted the trend-increase of BM T R3-56 cells, with concomitant reduction of cytotoxic T-cell activity in MDS.…”

“…To the Editor, Serio et al 1 show a significant reduction of CD3 + CD56 + regulatory T cells (T R3-56 ) in bone marrow (BM) of low-risk myelodysplastic subjects, as compared with the high-risk and the AML group; in addition, the BM frequency of mature granulocytes, a recognised marker of residual effective haematopoiesis, was observed to inversely correlate with T R3-56 in the MDS cohort. Such data are of great interest and confirm and extend, in an independent MDS cohort, the trend-increase of BM T R3-56 from very low/low risk to high/very high risk MDS and the inverse correlation with the cytotoxic T-cell (CTL) activity, likely fostering the escape of leukaemic blasts to immune-surveillance, by us recently described.…”