Consistent B Cell Receptor Immunoglobulin Features Between Siblings in Familial Chronic Lymphocytic Leukemia

Key processes in the onset and evolution of chronic lymphocytic leukemia (CLL) are thought to include chronic (antigenic) activation of mature B cells through the B cell receptor (BcR), signals from the microenvironment, and acquisition of genetic alterations. Here we describe three families in which two or more siblings were affected by CLL. We investigated whether there are immunogenetic similarities in the leukemia-specific immunoglobulin heavy (IGH) and light (IGL/IGK) chain gene rearrangements of the siblings in each family. Furthermore, we performed array analysis to study if similarities in CLL-associated chromosomal aberrations are present within each family and screened for somatic mutations using paired tumor/normal whole-genome sequencing (WGS). In two families a consistent IGHV gene mutational status (one IGHV-unmutated, one IGHV-mutated) was observed. Intriguingly, the third family with four affected siblings was characterized by usage of the lambda IGLV3-21 gene, with the hallmark R110 mutation of the recently described clinically aggressive IGLV3-21R110 subset. In this family, the CLL-specific rearrangements in two siblings could be assigned to either stereotyped subset #2 or the immunogenetically related subset #169, both of which belong to the broader IGLV3-21R110 subgroup. Consistent patterns of cytogenetic aberrations were encountered in all three families. Furthermore, the CLL clones carried somatic mutations previously associated with IGHV mutational status, cytogenetic aberrations and stereotyped subsets, respectively. From these findings, we conclude that similarities in immunogenetic characteristics in familial CLL, in combination with genetic aberrations acquired, point towards shared underlying mechanisms behind CLL development within each family.

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IGLV3-21R110 identifies an aggressive biological subtype of chronic lymphocytic leukemia with intermediate epigenetics

Blood ◽

10.1182/blood.2020008311 ◽

2020 ◽

Author(s):

Ferran Nadeu ◽

Romina Royo ◽

Guillem Clot ◽

Martí Duran-Ferrer ◽

Alba Navarro ◽

...

Keyword(s):

B Cells ◽

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Cell Receptor ◽

B Cell Receptor ◽

Lymphocytic Leukemia ◽

Immunoglobulin Gene ◽

Biological Features ◽

Mutational Status ◽

Bcr Signaling

B-cell receptor (BCR) signaling is crucial for chronic lymphocytic leukemia (CLL) biology. IGLV3-21-expressing B-cells may acquire a single point mutation (R110) that triggers autonomous BCR signaling conferring aggressive behavior. Epigenetic studies have defined three CLL subtypes based on methylation signatures reminiscent of naïve-like (n-CLL), intermediate (i-CLL) and memory-like B-cells (m-CLL) with different biological features. i-CLL carry a borderline IGHV mutational load and a significant higher usage of IGHV3-21/IGLV3-21. To determine the clinical and biological features of IGLV3-21R110 CLL and its relationship to these epigenetic subtypes we have characterized the immunoglobulin gene of 584 CLL cases using whole-genome/exome and RNA sequencing. IGLV3-21R110 was detected in 6.5% of cases, being 30/79 (38%) i-CLL, 5/291 (1.7%) m-CLL and 1/189 (0.5%) n-CLL. All stereotype subset #2 cases carried IGLV3-21R110 while 62% of IGLV3-21R110 i-CLL had non-stereotyped B-cell receptor immunoglobulins. IGLV3-21R110 i-CLL had significantly higher number of SF3B1 and ATM mutations, and total number of driver alterations. Nonetheless, the R110 mutation was the sole alteration in one i-CLL and accompanied only by del(13q) in three. Although composite regarding IGHV mutational status, IGLV3-21R110 i-CLL transcriptomically resembled naïve-like/unmutated IGHV CLL with a specific signature including WNT5A/B overexpression. Contrarily, i-CLL lacking the IGLV3-21R110 mirrored memory-like/mutated IGHV cases. IGLV3-21R110 i-CLL had a short time to first treatment and overall survival similar to n-CLL/unmutated IGHV cases whereas non-IGLV3-21R110 i-CLL had a good prognosis similar to memory-like/mutated IGHV. Altogether, IGLV3-21R110 defines a CLL subgroup with specific biological features and an unfavorable prognosis independent of the IGHV mutational status and epigenetic subtypes.

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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

Frontiers in Oncology ◽

10.3389/fonc.2021.723722 ◽

2021 ◽

Vol 11 ◽

Author(s):

Arancha Rodríguez-Caballero ◽

Blanca Fuentes Herrero ◽

Guillermo Oliva Ariza ◽

Ignacio Criado ◽

Miguel Alcoceba ◽

...

Keyword(s):

Patient Outcome ◽

B Cells ◽

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Cell Receptor ◽

Genetic Alterations ◽

B Cell Receptor ◽

Lymphocytic Leukemia ◽

Hydropathy Index ◽

B Cell Precursors

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. Overall, two clearly distinct subgroups of M-CLL patients emerged, based on a neutral (mean hydropathy index of -0.1) vs. negatively charged BCR (mean hydropathy index of -1.1) with molecular features closer to those of B-cell precursors and peripheral/mature B-cells, respectively. Despite that M-CLL with neutral HCDR3 did not show traits associated with a mature B-cell repertoire, important differences in IGHV gene usage of tumor cells and patient outcome were observed in this subgroup of patients once compared to both U-CLL and M-CLL with negatively charged HCDR3 sequences. Compared to M-CLL with negatively charged HCDR3 sequences, M-CLL with neutral HCDR3 sequences showed predominance of men, more advanced stages of the disease, and a greater frequency of genetic alterations—e.g., del(17p)—together with a higher rate of disease progression and shorter time to therapy (TTT), independently of other prognostic factors. Our data suggest that the hydropathy index of the HCDR3 sequences of CLL cells allows the identification of a subgroup of M-CLL with intermediate prognostic features between U-CLL and the more favorable subgroup of M-CLL with a negatively charged BCR.

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A unique proteomic profile on surface IgM ligation in unmutated chronic lymphocytic leukemia

Blood ◽

10.1182/blood-2011-02-335125 ◽

2011 ◽

Vol 118 (4) ◽

pp. e1-e15 ◽

Cited By ~ 12

Author(s):

Aurore Perrot ◽

Cédric Pionneau ◽

Sophie Nadaud ◽

Frédéric Davi ◽

Véronique Leblond ◽

...

Keyword(s):

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Heavy Chain ◽

Immunoglobulin Heavy Chain ◽

Cell Receptor ◽

B Cell Receptor ◽

Lymphocytic Leukemia ◽

Chain Gene ◽

Intermediate Form ◽

Proteomic Approach

Abstract Chronic lymphocytic leukemia (CLL) is characterized by a highly variable clinical course with 2 extreme subsets: indolent, ZAP70− and mutated immunoglobulin heavy chain gene (M-CLL); and aggressive, ZAP70+ and unmutated immunoglobulin heavy chain (UM-CLL). Given the long-term suspicion of antigenic stimulation as a primum movens in the disease, the role of the B-cell receptor has been extensively studied in various experimental settings; albeit scarcely in a comparative dynamic proteomic approach. Here we use a quantitative 2-dimensional fluorescence difference gel electrophoresis technology to compare 48 proteomic profiles of the 2 CLL subsets before and after anti-IgM ligation. Differentially expressed proteins were subsequently identified by mass spectrometry. We show that unstimulated M- and UM-CLL cells display distinct proteomic profiles. Furthermore, anti-IgM stimulation induces a specific proteomic response, more pronounced in the more aggressive CLL. Statistical analyses demonstrate several significant protein variations according to stimulation conditions. Finally, we identify an intermediate form of M-CLL cells, with an indolent profile (ZAP70−) but sharing aggressive proteomic profiles alike UM-CLL cells. Collectively, this first quantitative and dynamic proteome analysis of CLL further dissects the complex molecular pathway after B-cell receptor stimulation and depicts distinct proteomic profiles, which could lead to novel molecular stratification of the disease.

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Targeted inhibition of eIF4A suppresses B-cell receptor-induced translation and expression of MYC and MCL1 in chronic lymphocytic leukemia cells

Cellular and Molecular Life Sciences ◽

10.1007/s00018-021-03910-x ◽

2021 ◽

Author(s):

Sarah Wilmore ◽

Karly-Rai Rogers-Broadway ◽

Joe Taylor ◽

Elizabeth Lemm ◽

Rachel Fell ◽

...

Keyword(s):

B Cells ◽

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Mrna Translation ◽

Cell Receptor ◽

Memory B Cells ◽

B Cell Receptor ◽

Lymphocytic Leukemia ◽

Mrna Levels ◽

Mrna Stabilization

AbstractSignaling via the B-cell receptor (BCR) is a key driver and therapeutic target in chronic lymphocytic leukemia (CLL). BCR stimulation of CLL cells induces expression of eIF4A, an initiation factor important for translation of multiple oncoproteins, and reduces expression of PDCD4, a natural inhibitor of eIF4A, suggesting that eIF4A may be a critical nexus controlling protein expression downstream of the BCR in these cells. We, therefore, investigated the effect of eIF4A inhibitors (eIF4Ai) on BCR-induced responses. We demonstrated that eIF4Ai (silvestrol and rocaglamide A) reduced anti-IgM-induced global mRNA translation in CLL cells and also inhibited accumulation of MYC and MCL1, key drivers of proliferation and survival, respectively, without effects on upstream signaling responses (ERK1/2 and AKT phosphorylation). Analysis of normal naïve and non-switched memory B cells, likely counterparts of the two main subsets of CLL, demonstrated that basal RNA translation was higher in memory B cells, but was similarly increased and susceptible to eIF4Ai-mediated inhibition in both. We probed the fate of MYC mRNA in eIF4Ai-treated CLL cells and found that eIF4Ai caused a profound accumulation of MYC mRNA in anti-IgM treated cells. This was mediated by MYC mRNA stabilization and was not observed for MCL1 mRNA. Following drug wash-out, MYC mRNA levels declined but without substantial MYC protein accumulation, indicating that stabilized MYC mRNA remained blocked from translation. In conclusion, BCR-induced regulation of eIF4A may be a critical signal-dependent nexus for therapeutic attack in CLL and other B-cell malignancies, especially those dependent on MYC and/or MCL1.

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Chronic lymphocytic leukemia: revelations from the B-cell receptor

Blood ◽

10.1182/blood-2003-12-4312 ◽

2004 ◽

Vol 103 (12) ◽

pp. 4389-4395 ◽

Cited By ~ 286

Author(s):

Freda K. Stevenson ◽

Federico Caligaris-Cappio

Keyword(s):

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Cell Receptor ◽

B Cell Receptor ◽

Lymphocytic Leukemia ◽

Cell Of Origin ◽

Regulatory B Cell ◽

V Genes

Abstract The finding that chronic lymphocytic leukemia (CLL) consists of 2 clinical subsets, distinguished by the incidence of somatic mutations in the immunoglobulin (Ig) variable region (V) genes, has clearly linked prognosis to biology. Antigen encounter by the cell of origin is indicated in both subsets by selective but distinct expression of V genes, with evidence for continuing stimulation after transformation. The key to distinctive tumor behavior likely relates to the differential ability of the B-cell receptor (BCR) to respond. Both subsets may be undergoing low-level signaling in vivo, although analysis of blood cells limits knowledge of critical events in the tissue microenvironment. Analysis of signal competence in vitro reveals that unmutated CLL generally continues to respond, whereas mutated CLL is anergized. Differential responsiveness may reflect the increased ability of post-germinal center B cells to be triggered by antigen, leading to long-term anergy. This could minimize cell division in mutated CLL and account for prognostic differences. Unifying features of CLL include low responsiveness, expression of CD25, and production of immunosuppressive cytokines. These properties are reminiscent of regulatory T cells and suggest that the cell of origin of CLL might be a regulatory B cell. Continuing regulatory activity, mediated via autoantigen, could suppress Ig production and lead to disease-associated hypogammaglobulinemia. (Blood. 2004;103:4389-4395)

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B-cell receptor signaling in chronic lymphocytic leukemia leans on Lyn

Leukemia & Lymphoma ◽

10.3109/10428194.2012.754097 ◽

2013 ◽

Vol 54 (6) ◽

pp. 1125-1126 ◽

Cited By ~ 2

Author(s):

Yair Herishanu ◽

Aaron Polliack

Keyword(s):

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Cell Receptor ◽

B Cell Receptor ◽

Lymphocytic Leukemia ◽

Receptor Signaling ◽

B Cell Receptor Signaling ◽

Cell Receptor Signaling

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Silenced B-cell receptor response to autoantigen in a poor-prognostic subset of chronic lymphocytic leukemia

Haematologica ◽

10.3324/haematol.2014.106054 ◽

2014 ◽

Vol 99 (11) ◽

pp. 1722-1730 ◽

Cited By ~ 7

Author(s):

A.-C. Bergh ◽

C. Evaldsson ◽

L. B. Pedersen ◽

C. Geisler ◽

K. Stamatopoulos ◽

...

Keyword(s):

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Cell Receptor ◽

B Cell Receptor ◽

Lymphocytic Leukemia ◽

Receptor Response

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Role of NFAT in Chronic Lymphocytic Leukemia and Other B-Cell Malignancies

Frontiers in Oncology ◽

10.3389/fonc.2021.651057 ◽

2021 ◽

Vol 11 ◽

Author(s):

Ilenia Sana ◽

Maria Elena Mantione ◽

Piera Angelillo ◽

Marta Muzio

Keyword(s):

Chronic Lymphocytic Leukemia ◽

B Cell ◽

Therapeutic Potential ◽

Cell Receptor ◽

Distinct Pattern ◽

B Cell Receptor ◽

Lymphocytic Leukemia ◽

B Cell Malignancies ◽

Activated T Cells ◽

Inflammatory Microenvironment

In recent years significant progress has been made in the clinical management of chronic lymphocytic leukemia (CLL) as well as other B-cell malignancies; targeting proximal B-cell receptor signaling molecules such as Bruton Tyrosine Kinase (BTK) and Phosphoinositide 3-kinase (PI3Kδ) has emerged as a successful treatment strategy. Unfortunately, a proportion of patients are still not cured with available therapeutic options, thus efforts devoted to studying and identifying new potential druggable targets are warranted. B-cell receptor stimulation triggers a complex cascade of signaling events that eventually drives the activation of downstream transcription factors including Nuclear Factor of Activated T cells (NFAT). In this review, we summarize the literature on the expression and function of NFAT family members in CLL where NFAT is not only overexpressed but also constitutively activated; NFAT controls B-cell anergy and targeting this molecule using specific inhibitors impacts on CLL cell viability. Next, we extend our analysis on other mature B-cell lymphomas where a distinct pattern of expression and activation of NFAT is reported. We discuss the therapeutic potential of strategies aimed at targeting NFAT in B-cell malignancies not overlooking the fact that NFAT may play additional roles regulating the inflammatory microenvironment.

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