A case of myelodysplastic syndrome associated with CD14(+)CD56(+) monocytosis, expansion of NK lymphocytes and defect of HLA-E expression

Regulatory TR3-56 Cells in the Complex Panorama of Immune Activation and Regulation

The interplay between immune activation and immune regulation is a fundamental aspect of the functional harmony of the immune system. This delicate balance is essential to triggering correct and effective immune responses against pathogens while preventing excessive inflammation and the immunopathogenic mechanisms of autoimmunity. The knowledge of all the mechanisms involved in immune regulation is not yet definitive, and, probably, the overall picture is much broader than what has been described in the scientific literature so far. Given the plasticity of the immune system and the diversity of organisms, it is highly probable that numerous other cells and molecules are still to be ascribed to the immune regulation process. Here, we report a general overview of how immune activation and regulation interact, based on the involvement of molecules and cells specifically dedicated to these processes. In addition, we discuss the role of TR3-56 lymphocytes as a new cellular candidate in the immune regulation landscape.

Mechanical phenotyping of K562 cells by the Micropipette Aspiration Technique allows identifying mechanical changes induced by drugs

Mechanical properties of living cells can be used as reliable markers of their state, such as the presence of a pathological state or their differentiation phase. The mechanical behavior of cells depends on the organization of their cytoskeletal network and the main contribution typically comes from the actomyosin contractile system, in both suspended and adherent cells. In the present study, we investigated the effect of a pharmaceutical formulation (OTC – Ossitetraciclina liquida 20%) used as antibiotic, on the mechanical properties of K562 cells by using the Micropipette Aspiration Technique (MAT). This formulation has been shown to increase in a time dependent way the inflammation and toxicity in terms of apoptosis in in vitro experiments on K562 and other types of cells. Here we show that by measuring the mechanical properties of cells exposed to OTC for different incubation times, it is possible to infer modifications induced by the formulation to the actomyosin contractile system. We emphasize that this system is involved in the first stages of the apoptotic process where an increase of the cortical tension leads to the formation of blebs. We discuss the possible relation between the observed mechanical behavior of cells aspirated inside a micropipette and apoptosis.

Toxicological Implications and Inflammatory Response in Human Lymphocytes Challenged with Oxytetracycline

Antibiotics are widely used in zoo technical and veterinary practices as feed supplementation to ensure wellness of farmed animals and livestock. Several evidences have been suggesting both the toxic role for tetracyclines, particularly for oxytetracycline (OTC). This potential toxicity appears of great relevance for human nutrition and for domestic animals. This study aimed to extend the evaluation of such toxicity. The biologic impact of the drug was assessed by evaluating the proinflammatory effect of OTC and their bone residues on cytokine secretion by in vitro human peripheral blood lymphocytes. Our results showed that both OTC and OTC‐bone residues significantly induced the T lymphocyte and non‐T cell secretion of interferon (IFN)‐γ, as cytokine involved in inflammatory responses in humans as well as in animals. These results may suggest a possible implication for new potential human and animal health risks depending on the entry of tetracyclines in the food‐processing chain.

Natural killer expansion, human leukocyte antigens-E expression and CD14(+) CD56(+) monocytes in a myelodysplastic syndrome patient

Myelodysplastic syndromes (MDS) are clonal disorders characterized by ineffective hematopoiesis and possible evolution to acute leukemia. Occurrence of stem cell defects and of immune-mediated mechanisms was evidenced as relevant for pathophysiology of MDS. Here, we described one case of MDS patient carrying CD14(+) CD56(+) monocytes in bone marrow (BM), in the presence of a defective human leukocyte antigen (HLA)-E expression on peripheral blood (PB) cells and of natural killer (NK) cell expansion in PB and BM. The defective HLA-E expression and the NK expansion are proposed to be relevant for the pathogenesis of myelodysplasia in those patients showing CD14(+) CD56(+) monocytes in BM.

HLA-E and HLA class I molecules on bone marrow and peripheral blood polymorphonuclear cells of myelodysplatic patients

Relevance of immune-dysregulation for emergence, dominance and progression of dysplastic clones in myelodysplastic syndromes (MDS) was suggested, but valuable or predictive criteria on this involvement are lacking. We previously reported that reduced T-regulatory cells (Treg) and high CD54 expression on T cell identify a sub-group of patients in whom an immune-pathogenesis might be inferred. Here, we suggest the occurrence of immune-selection of dysplastic clones in a subgroup of MDS patients, with reduced HLA-I and HLA-E on PMN, and propose that an altered immune profile might represent a valuable criterion to classify Low/Int-1 patients on the basis of immune-pathogenesis of MDS.