The Hydropathy Index of the HCDR3 Region of the B-Cell Receptor Identifies Two Subgroups of IGHV-Mutated Chronic Lymphocytic Leukemia Patients With Distinct Outcome.

The HCDR3 sequences of the B-cell receptor (BCR) undergo constraints in length, amino acid use, and charge during maturation of B-cell precursors and after antigen encounter, leading to BCR and antibodies with high affinity to specific antigens. Chronic lymphocytic leukemia consists of an expansion of B-cells with a mixed immature and "antigen-experienced" phenotype, with either a mutated (M-CLL) or unmutated (U-CLL) tumor BCR, associated with distinct patient outcomes. Here, we investigated the hydropathy index of the BCR of 138 CLL patients and its association with the IGHV mutational status and patient outcome.

Low-count monoclonal B-cell lymphocytosis persists after seven years of follow up and is associated with a poorer outcome.

Low-count monoclonal B-cell lymphocytosis is defined by the presence of very low numbers of circulating clonal B cells, usually phenotypically similar to chronic lymphocytic leukemia cells, whose biological and clinical significance remains elusive. Herein, we re-evaluated 65/91 low-count monoclonal B-cell lymphocytosis cases (54 chronic lymphocytic leukemia-like and 11 non-chronic lymphocytic leukemia-like) followed-up for a median of seven years, using high-sensitivity flow cytometry and interphase fluorescence hybridization. Overall, the clone size significantly increased in 69% of low-count monoclonal B-cell lymphocytosis cases, but only one subject progressed to high-count monoclonal B-cell lymphocytosis.

A systematic approach for peptide characterization of B-cell receptor in chronic lymphocytic leukemia cells.

A wide variety of immunoglobulins (Ig) is produced by the immune system thanks to different mechanisms (V(D)J recombination, somatic hypermutation, and antigen selection). The profiling of Ig sequences (at both DNA and peptide levels) are of great relevance to developing targeted vaccines or treatments for specific diseases or infections. Thus, genomics and proteomics techniques (such as Next-Generation Sequencing (NGS) and mass spectrometry (MS)) have notably increased the knowledge in Ig sequencing and serum Ig peptide profiling in a high-throughput manner.

Host virus and pneumococcus-specific immune responses in high-count monoclonal B-cell lymphocytosis and chronic lymphocytic leukemia: implications for disease progression.

Patients diagnosed with chronic lymphocytic leukemia (CLL) display a high incidence of infections due to an associated immunodeficiency that includes hypogammaglobulinemia. A higher risk of infections has also been recently reported for high-count monoclonal B-cell lymphocytosis, while no information is available in low-count monoclonal B-cell lymphocytosis. Here, we evaluated the status of the humoral immune system in patients with chronic lymphocytic leukemia (n=58), as well as in low- (n=71) and high- (n=29) count monoclonal B-cell lymphocytosis healthy donors (n=91).

Subjects with chronic lymphocytic leukaemia-like B-cell clones with stereotyped B-cell receptors frequently show MDS-associated phenotypes on myeloid cells.

An increasing body of evidence suggests the potential occurrence of antigen encounter by the cell of origin in chronic lymphocytic leukaemia (CLL) and CLL-like monoclonal B-cell lymphocytosis (MBL). However, the scenario in which this event might occur remains unknown. In order to gain insight into this scenario we investigated the molecular, cytogenetic and haematological features of 223 CLL-like (n = 84) and CLL (n = 139) clones with stereotyped (n = 32) versus non-stereotyped (n = 191) immunoglobulin heavy chain variable region (IGHV) amino acid sequences.

Molecular and cytogenetic characterization of expanded B-cell clones from multiclonal versus monoclonal B-cell chronic lymphoproliferative disorders.

Chronic antigen-stimulation has been recurrently involved in the earlier stages of monoclonal B-cell lymphocytosis, chronic lymphocytic leukemia and other B-cell chronic lymphoproliferative disorders. The expansion of two or more B-cell clones has frequently been reported in individuals with these conditions; potentially, such coexisting clones have a greater probability of interaction with common immunological determinants. Here, we analyzed the B-cell receptor repertoire and molecular profile, as well as the phenotypic, cytogenetic and hematologic features, of 228 chronic lymphocytic leukemia-like and non-chronic lymphocytic leukemia-like clones comparing multiclonal (n=85 clones from 41 cases) versus monoclonal (n=143 clones) monoclonal B-cell lymphocytosis, chronic lymphocytic leukemia and other B-cell chronic lymphoproliferative disorders.

Association between mutation of the NF2 gene and monosomy 22 in menopausal women with sporadic meningiomas.

Background: Meningioma was the first solid tumor shown to contain a recurrent genetic alteration e.g. monosomy 22/del(22q), NF2 being the most relevant gene involved.

Combined patterns of IGHV repertoire and cytogenetic/molecular alterations in monoclonal B lymphocytosis versus chronic lymphocytic leukemia.

Background: Chronic lymphocytic leukemia (CLL)-like monoclonal B lymphocytosis (MBL) with (MBL(hi)) or without (MBL(lo)) absolute B-lymphocytosis precedes most CLL cases,the specific determinants for malignant progression remaining unknown.

Methodology/principal Findings: For this purpose, simultaneous iFISH and molecular analysis of well-established cytogenetic alterations of chromosomes 11, 12, 13, 14 and 17 together with the pattern of rearrangement of the IGHV genes were performed in CLL-like cells from MBL and CLL cases. Our results based on 78 CLL-like MBL and 117 CLL clones from 166 subjects living in the same geographical area, show the existence of three major groups of clones with distinct but partially overlapping patterns of IGHV gene usage, IGHV mutational status and cytogenetic alterations.

Immunogenetics shows that not all MBL are equal: the larger the clone, the more similar to CLL.

Chronic lymphocytic leukemia (CLL) -like monoclonal B-cell lymphocytosis (MBL) shares common immunophenotype and cytogenetic abnormalities with CLL, from which it is discriminated by a cutoff value of 5 × 10(9)/L circulating clonal B cells. However, the clonal size in MBL is extremely variable and allows discrimination of two distinct entities (high-count [HC] and low-count [LC]-MBL) based on a cutoff value of 0.5 × 10(9)/L clonal B cells.

Common infectious agents and monoclonal B-cell lymphocytosis: a cross-sectional epidemiological study among healthy adults.

Background: Risk factors associated with monoclonal B-cell lymphocytosis (MBL), a potential precursor of chronic lymphocytic leukaemia (CLL), remain unknown.

Methods: Using a cross-sectional study design, we investigated demographic, medical and behavioural risk factors associated with MBL. "Low-count" MBL (cases) were defined as individuals with very low median absolute count of clonal B-cells, identified from screening of healthy individuals and the remainder classified as controls.

Non-CLL-like monoclonal B-cell lymphocytosis in the general population: prevalence and phenotypic/genetic characteristics.

Background: Monoclonal B-cell lymphocytosis (MBL) indicates <5 × 10(9) peripheral blood (PB) clonal B-cells/L in healthy individuals. In most cases, MBL cells show similar phenotypic/genetic features to chronic lymphocytic leukemia cells-CLL-like MBL-but little is known about non-CLL-like MBL.

Methods: PB samples from 639 healthy individuals (46% men/54% women) >40 years old (62 ± 13 years) with normal lymphocyte counts (2.

Prolonged idiotypic vaccination against follicular lymphoma.

During the last 2 decades, idiotypic vaccination has provided proof of principle of biological efficacy, clinical efficacy and clinical benefit in small follicular lymphoma trials. However, with the exception of anecdotal reports, most patients have received no more than 10 doses of their customised idiotype (Id) vaccine. Therefore, it is not known whether prolonged usage of idiotypic vaccination is safe.

Flow cytometric analysis of cytokine responses in stimulated whole blood: simultaneous quantitation of TNF-alpha-secreting cells and soluble cytokines.

This unit describes technical protocols aimed at the ex vivo or in vitro evaluation of the functional status of the immune system through the simultaneous identification and enumeration of cytokine-secreting cells and quantitation of the soluble cytokines produced by these cells.

Expanded cells in monoclonal TCR-alphabeta+/CD4+/NKa+/CD8-/+dim T-LGL lymphocytosis recognize hCMV antigens.

Recent studies suggest the potential involvement of common antigenic stimuli on the ontogeny of monoclonal T-cell receptor (TCR)-alphabeta(+)/CD4(+)/NKa(+)/CD8(-/+dim) T-large granular lymphocyte (LGL) lymphocytosis. Because healthy persons show (oligo)clonal expansions of human cytomegalovirus (hCMV)-specific TCRVbeta(+)/CD4(+)/cytotoxic/memory T cells, we investigate the potential involvement of hCMV in the origin and/or expansion of monoclonal CD4(+) T-LGL. Peripheral blood samples from patients with monoclonal TCR-alphabeta(+)/CD4(+) T-LGL lymphocytosis and other T-chronic lymphoproliferative disorders were evaluated for the specific functional response against hCMV and hEBV whole lysates as well as the "MQLIPDDYSNTHSTRYVTVK" hCMV peptide, which is specifically loaded in HLA-DRB1*0701 molecules.

Association between the HLA haplotype and the TCR-Vbeta repertoire of anti-hCMV specific memory T-cells in immunocompetent healthy adults.

Background: Despite the key role of memory T-cells specific for human cytomegalovirus (hCMV) in protecting against hCMV-reinfection early after immunodeficiency episodes, the precise characterization and definition of the essential components of a protective CD4 T-cell response still remain to be established.

Methods: We analyzed by flow cytometry hCMV-specific immune responses driven by peripheral blood antigen-presenting cells (APC) and CD4 memory T-cells at both the cellular and soluble levels, and their cooperation in priming and sustaining the effector function of specific CD8 T cells in adult healthy individuals using a hCMV whole viral lysate stimulatory model.

Results: Overall, activated T-cells showed a heterogeneous phenotype, with a marked predominance of CD45RA(-)/CCR7(+/-) memory CD4(+) T-cells.

Clinical benefit associated with idiotypic vaccination in patients with follicular lymphoma.

Background: Follicular lymphoma is considered incurable, although cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy can induce sequential remissions. A patient's second complete response is typically shorter than that patient's first complete response. Idiotype vaccines can elicit specific immune responses and molecular remissions in patients with follicular lymphoma.

Combined vaccination with idiotype-pulsed allogeneic dendritic cells and soluble protein idiotype for multiple myeloma patients relapsing after reduced-intensity conditioning allogeneic stem cell transplantation.

Background And Objective: To combine the use of idiotype-pulsed allogeneic dendritic cells (alloDC) and soluble protein Id conjugated with KLH (Id-KLH) in a vaccine strategy for multiple myeloma (MM).

Design And Methods: Four MM patients received the combined vaccine after having experienced disease relapse/progression following reduced intensity conditioning (RIC) allogeneic stem cell transplantation (alloSCT) and failure to rescue therapy with donor lymphocyte infusion or chemotherapy (CHT).

Results: Vaccination was well tolerated and induced an anti-KLH antibody response in all 4 patients as well as substantial cell proliferation.

Affinity binding of cells to cryogel adsorbents with immobilized specific ligands: effect of ligand coupling and matrix architecture.

The capture of human acute myeloid leukemia KG-1 cells expressing the CD34 surface antigen and the fractionation of human blood lymphocytes were evaluated on polyvinyl alcohol (PVA)-cryogel beads and dimethyl acrylamide (DMAAm) monolithic cryogel with immobilized protein A. The affinity ligand (protein A) was chemically coupled to the reactive PVA-cryogel beads and epoxy-derivatized monolithic cryogels through different immobilization techniques and the binding efficiency of the cell surface receptors specific antibody-labeled cells to the gels/beads was determined. The binding of cells to monolithic cryogel was higher (90-95%) compared with cryogel beads (76%).

A new simple whole blood flow cytometry-based method for simultaneous identification of activated cells and quantitative evaluation of cytokines released during activation.

The multiple cellular and soluble elements of the immune system respond in a coordinated way, orchestrated by cytokines, to preserve the integrity of the organism. In this study, we describe a new and unique whole blood method that, with minimal sample manipulation, allows an overall evaluation of immune responses by simultaneously measuring cell activation and cytokine secretion. The identification of cells actively secreting cytokines is based on the stabilization of tumor necrosis factor alpha (TNFalpha) at the cell surface through the use of a specific inhibitor of the TNFalpha-converting enzyme.

A new method for detecting TNF-alpha-secreting cells using direct-immunofluorescence surface membrane stainings.

In the present study, a new flow cytometric method for the identification of TNF-alpha-secreting cells based on the use of a TNF-alpha converting enzyme (TACE) inhibitor compound (BB3103) is described. TNF-alpha secreting cells were measured in parallel in stimulated peripheral blood samples (n=4), using the BB3103 TACE inhibitor or brefeldin A as secretion blocking agents. To induce TNF-alpha production by PB T-cells and monocytes, whole blood samples were stimulated either for 4 h with PMA plus ionomycin or for 6 h with LPS plus IFNgamma, respectively.