T and B Cell Receptor Immune Repertoire Analysis using Next-generation Sequencing.

Immunological memory, the hallmark of adaptive immunity, is orchestrated by T and B lymphocytes. In circulation and different organs, there are billions of unique T and B cell clones, and each one can bind a specific antigen, leading to proliferation, differentiation and/or cytokine secretion. The vast heterogeneity in T and B cells is generated by random recombination of different genetic segments.

A phase II study of bisantrene in patients with relapsed/refractory acute myeloid leukemia.

Objectives: To determine the current role of bisantrene, an anthracene with anthracycline-like activity which was shown in earlier studies to be effective therapy in relapsed/refractory acute myeloid leukemia with no discernible cardiotoxicity, in the treatment of patients with R/R AML.

Methods: This phase 2, single-center study (NCT03820908) enrolled adult R/R AML to receive bisantrene (250 mg/m daily for 7 days) which was administered via an intravenous infusion over 2 hours on days 1-7. Disease assessment included routine blood work and bone marrow studies.

Reassessing the role of high dose cytarabine and mitoxantrone in relapsed/refractory acute myeloid leukemia.

A substantial segment of patients with acute myeloid leukemia (AML) will relapse following an initial response to induction therapy or will prove to be primary refractory. High-dose cytarabine and mitoxantrone (HiDAC/MITO) is an established salvage therapy for these patients. We studied all adult patients with relapsed/refractory (R/R) AML who were treated with HiDAC/MITO in our center between the years 2008-2017.

Platelets from Calreticulin mutated essential thrombocythemia patients are less reactive than JAK2 V617F mutated platelets.

Both JAK2V617F and calreticulin (CALR) mutated essential thrombocythemia (ET) patients have different clinical characteristics, with lower thrombosis risk in patients with CALR mutations. To elucidate the mechanism for this lower risk we studied platelet function in ET patients with either JAK2V617F or a CALR mutation. Platelet activation state was similar in ET and healthy controls at baseline using P-selectin and PAC1 flow cytometry analysis.

Calreticulin mutation burden--is it a stable clone in patients with essential thrombocythemia and myelofibrosis?

Calreticulin mutation represents the second most frequent mutation after JAK2 V617F in myeloproliferative disorder and is considered to be a driving mutation. Herein the mutation burden was evaluated in patients with essential thrombocythemia or myelofibrosis and found to increase by 5.7% over time unrelated to the time elapsed from the initial to the final positive test.

Assessment of Liver and Spleen Stiffness in Patients With Myelofibrosis Using FibroScan and Shear Wave Elastography.

Liver stiffness and spleen stiffness in patients with myelofibrosis have traditionally been assessed through manual palpation and thus influenced by interobserver variability. In this article, for the first time, liver stiffness and spleen stiffness of patients with myelofibrosis were evaluated through FibroScan and shear wave elastography (SWE). Nine patients with myelofibrosis comprised the study group.

Acquired familial Mediterranean fever associated with a somatic MEFV mutation in a patient with JAK2 associated post-polycythemia myelofibrosis.

Background: A study was designed to identify the source of fever in a patient with post-polycythemia myelofibrosis, associated with clonal Janus Kinase 2 (JAK2) mutation involving duplication of exon 12. The patient presented with 1-2 day long self-limited periodic episodes of high fever that became more frequent as the hematologic disease progressed.

Methods: After ruling out other causes for recurrent fever, analysis of the pyrin encoding Mediterranean fever gene (MEFV) was carried out by Sanger sequencing in peripheral blood DNA samples obtained 4 years apart, in buccal cells, laser dissected kidney tubular cells, and FACS-sorted CD3-positive or depleted mononucleated blood cells.

Characterizing T cells in SCID patients presenting with reactive or residual T lymphocytes.

Introduction: Patients with severe combined immunodeficiency (SCID) may present with residual circulating T cells. While all cells are functionally deficient, resulting in high susceptibility to infections, only some of these cells are causing autoimmune symptoms.

Methods: Here we compared T-cell functions including the number of circulating CD3(+) T cells, in vitro responses to mitogens, T-cell receptor (TCR) repertoire, TCR excision circles (TREC) levels, and regulatory T cells (Tregs) enumeration in several immunodeficinecy subtypes, clinically presenting with nonreactive residual cells (MHC-II deficiency) or reactive cells.

Ras oncoproteins transfer from melanoma cells to T cells and modulate their effector functions.

Lymphocytes establish dynamic cell-cell interactions with the cells they scan. Previous studies show that upon cell contact, various membrane-associated proteins, such as Ras-family proteins, transfer from B to T and NK lymphocytes. Mutations in RAS genes that encode constitutively active, GTP-bound, oncoproteins are rather common in human cancers; for instance, melanoma.

Cellular interactions of synovial fluid γδ T cells in juvenile idiopathic arthritis.

The pathogenesis of juvenile idiopathic arthritis (JIA) is thought to involve multiple components of the cellular immune system, including subsets of γδ T cells. In this study, we conducted experiments to define the functional roles of one of the major synovial fluid (SF) T cell subsets, Vγ9(+)Vδ2(+) (Vγ9(+)) T cells, in JIA. We found that as opposed to CD4(+) T cells, equally high percentages (∼35%) of Vγ9(+) T cells in SF and peripheral blood (PB) produced TNF-α and IFN-γ.

TNF activates a NF-kappaB-regulated cellular program in human CD45RA- regulatory T cells that modulates their suppressive function.

Emerging data suggest that regulatory T cell (Treg) dysfunction and consequent breakdown of immunological self-tolerance in autoimmunity can be mediated by factors that are not Treg-intrinsic (e.g., cytokines).

Reduced central tolerance in Omenn syndrome leads to immature self-reactive oligoclonal T cells.

Background: Omenn syndrome (OS) is characterized by a peculiar severe T-cell immune deficiency associated with autoimmunelike manifestations. Dysregulations of the central and peripheral immune tolerance, mediated by the protein autoimmune regulator (AIRE) and regulatory T cells, respectively, were proposed as possible mechanisms of this aberrant inflammatory process.

Objective: We studied mechanisms of central and peripheral tolerance in patients with OS and also examined the gene expression profile associated with OS features.

Epigenetic inheritance of DNA methylation limits activation-induced expression of FOXP3 in conventional human CD25-CD4+ T cells.

The transcription factor forkhead box P3 (FOXP3 in humans; Foxp3 in mice) controls the development and function of regulatory T cells (Treg). In mice, CD4(+)CD25(-) T cells do not express Foxp3 following TCR activation. Whether FOXP3 is a common activation-induced molecule in human T cells--hence not Treg restricted--is currently a controversial issue.