Activated B-cells and Plasma cells are Resistant to Radiation Therapy.

Author(s):  
Ida Franiak-Pietryga ◽  
Sayuri Miyauchi ◽  
Sangwoo Shawn Kim ◽  
P. Dominick Sanders ◽  
Whitney Sumner ◽  
...  
2017 ◽  
Author(s):  
Joanne Dai ◽  
Micah A. Luftig

AbstractApoptosis is critical to B-cell maturation, but studies of apoptotic regulation in primary human B cells is lacking. Previously, we found that infecting human B cells with Epstein-Barr virus induces two different survival strategies (Priceet al., 2017). Here, we sought to better understand the mechanisms of apoptotic regulation in normal and activated B cells. Using intracellular BH3 profiling (iBH3), we defined the Bcl2-dependency of B-cell subsets from human peripheral blood and tonsillar lymphoid tissue as well as mitogen-activated B cells. We found that naïve and memory B cells were BCL-2 dependent, while germinal center B cells were MCL-1 dependent and plasma cells were BCL-XL dependent. Proliferating B cells activated by CpG or CD40L/IL-4 became more dependent upon MCL-1 and BCL-XL. As B-cell lymphomas often rely on survival mechanisms derived from normal and activated B cells, these findings offer new insight into potential therapeutic strategies for lymphomas.


Blood ◽  
2009 ◽  
Vol 114 (25) ◽  
pp. 5173-5181 ◽  
Author(s):  
Michel Jourdan ◽  
Anouk Caraux ◽  
John De Vos ◽  
Geneviève Fiol ◽  
Marion Larroque ◽  
...  

Abstract Human plasma cells (PCs) and their precursors play an essential role in humoral immune response but are rare and difficult to harvest. We report the generation of human syndecan-1+ and immunoglobulin secreting PCs starting from memory B cells in a 3-step and 10-day (D) culture, including a 6-fold cell amplification. We report the detailed phenotypic and Affymetrix gene expression profiles of these in vitro PCs as well as of intermediate cells (activated B cells and plasmablasts) compared with memory B cells and bone marrow PCs, which is accessible through an open web ATLAS (http://amazonia.transcriptome.eu/). We show this B cell–to-PC differentiation to involve IRF4 and AICDA expressions in D4 activated B cells, decrease of PAX5 and BCL6 expressions, and increase in PRDM1 and XBP1 expressions in D7 plasmablasts and D10 PCs. It involves down-regulation of genes controlled by Pax5 and induction of genes controlled by Blimp-1 and XBP1 (unfold protein response). The detailed phenotype of D10 PCs resembles that of peripheral blood PCs detected after immunization of healthy donors. This in vitro model will facilitate further studies in PC biology. It will likewise be helpful to study PC dyscrasias, including multiple myeloma.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yen-Ju Lin ◽  
Alexandra Goretzki ◽  
Stefan Schülke

Over the last decades, the frequency of allergic disorders has steadily increased. Immunologically, allergies are caused by abnormal immune responses directed against otherwise harmless antigens derived from our environment. Two of the main cell types driving allergic sensitization and inflammation are IgE-producing plasma cells and Th2 cells. The acute activation of T and B cells, their differentiation into effector cells, as well as the formation of immunological memory are paralleled by distinct changes in cellular metabolism. Understanding the functional consequences of these metabolic changes is the focus of a new research field termed “immune metabolism”. Currently, the contribution of metabolic changes in T and B cells to either the development or maintenance of allergies is not completely understood. Therefore, this mini review will introduce the fundamentals of energy metabolism, its connection to immune metabolism, and subsequently focus on the metabolic phenotypes of IL-4-activated B cells and Th2 cells.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1564-1564
Author(s):  
Selina Chen-Kiang ◽  
Scott Ely ◽  
Maurizio Di Liberto ◽  
Kaida Wu ◽  
John Shaughnessy ◽  
...  

Abstract In multiple myeloma (MM), impaired apoptosis is critical for clonal expansion of malignant MM cells in the bone marrow (BM), although the precise underlying mechanism has not been defined. During physiologic plasma cell differentiation, clonal expansion of antigen-activated B cells in the germinal center requires CD40 signalling, which mediates CD40L signals from activated T cells to promote B cell activation and survival. Terminal differentiation of plasma cells from activated B cells is then accompanied by a progressive reduction of CD40 expression, suggesting that the life span of normal plasma cells may be limited by the loss of CD40L signalling. Here we show that CD40L and CD40 are both aberrantly expressed in primary BM MM cells, but not in normal BM plasma cells, their likely normal counterparts. CD40L is also copiously expressed in multiple cell types in myeloma and normal bone marrows, indicating that autocrine and paracrine CD40L signalling may prolong the survival of MM cells in the bone marrow microenvironment. Supporting this hypothesis, disruption of CD40L signalling by an antagonizing CD40L antibody markedly accelerates apoptosis of BM MM cells ex vivo. In the majority of MM cases (N=50), CD40 is expressed at either greater than 90% of BM MM cells or lower than 30% of BM MM cells in vivo, but rarely in between. However, there is no apparent correlation between the frequency of CD40 expression in BM MM cells in vivo and immunoglobulin isotype or treatment history, including bortezomib therapy. Ex vivo, the level of CD40 expression in BM MM cells is enhanced in response to bortezomib, which rapidly activates CD40 transcription. Moreover, killing of primary BM MM cells by bortezomib ex vivo is attenuated by CD40L signalling, at least in part through sustaining NF-?B activation that is required for MM cell survival. Together, our findings suggest that autocrine and paracrine CD40L signalling is critical for the survival of MM cells in the bone marrow and may contribute to the development of drug resistance.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 743-743
Author(s):  
Tomasz Sewastianik ◽  
Jianjun Zhao ◽  
Meng Jiang ◽  
Jianli Wang ◽  
Vinodh Pillai ◽  
...  

Abstract MicroRNA (miR)-mediated gene regulation plays critical roles in B-cell development and dysregulated expression of miRs has been implicated in the pathogenesis of various types of B-cell malignancies. Somatic deletions of chromosome 13q14, harboring miR-15a/16-1, occurs frequently in B-cell lymphomas suggesting that members of this miR family are tumor suppressors. Consistently, mice with CD19-Cre-induced deletion of miR-15a/16-1 in early B-cells and follicular B-cells develop chronic lymphocytic leukemia (CLL). Since the 13q14 deletion is observed in a broader range of B-cell malignancies, we hypothesized that the type of B-cell malignancy resulting from miR-15a/16-1 down-regulation may depend on the stage of B-cell development at which this deletion occurs. Therefore, we generated a transgenic mouse model in which conditional deletion of miR-15a/16-1 takes place at later stages of B-cell development. To delete miR-15a/16-1 in activated B-cells, miR-15a/16-1fl/fl mice were mated with AID-Cre+/+ mice to obtain AID-Cre+/-; miR-15a/16-1fl/fl compound mice that expressed Cre recombinase from the Activation-induced Cytidine Deaminase (AID promoter) gene - a gene needed for generation of somatic hypermutations in the immunoglobulin (Ig) variable region (V) genes that is highly expressed in activated B-cells and is a well-known marker for germinal center (GC) B-cells. Expression levels of both miR-15a and miR-16-1, but not miR-15b were decreased in GC B-cells of AID-Cre+/-; miR-15a/16-1fl/fl mice as compared with control AID-Cre+/- mice when evaluated by In Situ Hybridization (ISH) analysis. Given that in humans miR-15a, b and 16 are also expressed in GC B-cells, these results demonstrate the validity of this mouse model in which the biological consequences of miR-15a/16-1 deletion can be studied. Next we assessed whether miR-15a/16-1 deletion could affect proliferation and/or survival of GC B-cells. GCs in the spleens of AID-Cre+/-; miR-15a/16-1fl/fl mice at 10 weeks of age were significantly increased in both number and size, and contained a larger number of Ki-67-positive B-cells as compared with spleens of AID-Cre+/- mice. No significant differences in the number of apoptotic cells, neither in the expression of the miR-15a/16-1 putative target BCL2 were detected, indicating that miR-15a/16-1 may play important roles in the proliferation, but not survival of GC B-cells. Apart from mild splenic enlargement and increased number and size of GCs, AID-Cre+/-, miR-15a/16-1fl/fl mice where indistinguishable from AID-Cre+/- mice between 8 and 40 weeks of age as assessed by weight and posture. However, after 48 weeks of age and at variable times thereafter, 80% (32/40) of AID-Cre+/-, miR-15a/16-1fl/fl mice but none from control cohorts (0/30) showed signs of disease. Gross pathologic examination of euthanized AID-Cre+/-; miR-15a/16-1fl/fl mice revealed enlargement of the spleen and lymph nodes. Detailed histological examination revealed in most instances an effacement of normal tissue architecture by a nodular or diffuse population of atypical lymphoid cells, or less commonly by sheets of plasma cells in interfollicular areas. Two distinct patterns of B220+BCL6+BCL2- B-cell lymphomas were identified after detailed analysis. The most common (47%) resembled human follicular lymphoma (FL) and the next in frequency (28%) resembled human diffuse large B-cell lymphoma (DLBCL). The other group of tumors (25%) resembled human plasmacytoma (PC). All three tumor subtypes were clonal, hypermutated and associated with different degrees of preservation of the dendritic meshwork in the lymph nodes. The comparison of lymphomas arising in AID-Cre+/-; miR-15a/16-1fl/fl mice and CD19-Cre+/-; miR-15a/16-1fl/fl mice corroborated that deletion of miR-15a/16-1 at different stages of B-cell development leads to distinct subtypes of B-cell malignancies. Finally, we investigated miR-15a/16-1 expression in human FL and PC and showed that miR-15a/16-1 abundance is significantly decreased in those malignancies when compared with nodal B-cells in reactive GCs and normal plasma cells in interfollicular areas respectively, suggesting that miR-15a/16-1 may play important roles in normal GC B-cell development as well as in the pathogenesis of FL and PC in humans. Disclosures Ghobrial: BMS: Honoraria, Research Funding; Novartis: Honoraria; Celgene: Honoraria, Research Funding; Takeda: Honoraria; Noxxon: Honoraria; Amgen: Honoraria. Anderson:Oncoprep: Equity Ownership; Acetylon: Equity Ownership; Oncoprep: Equity Ownership; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Acetylon: Equity Ownership; Millennuim: Membership on an entity's Board of Directors or advisory committees; Millennuim: Membership on an entity's Board of Directors or advisory committees; C4 Therapeutics: Equity Ownership; C4 Therapeutics: Equity Ownership; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
1999 ◽  
Vol 93 (5) ◽  
pp. 1684-1696 ◽  
Author(s):  
Mary Crainie ◽  
Andrew R. Belch ◽  
Michael J. Mant ◽  
Linda M. Pilarski

The receptor for hyaluronan (HA)-mediated motility (RHAMM) controls motility by malignant cells in myeloma and is abnormally expressed on the surface of most malignant B and plasma cells in blood or bone marrow (BM) of patients with multiple myeloma (MM). RHAMM cDNA was cloned and sequenced from the malignant B and plasma cells comprising the myeloma B lineage hierarchy. Three distinct RHAMM gene products, RHAMMFL, RHAMM−48, and RHAMM−147, were cloned from MM B and plasma cells. RHAMMFL was 99% homologous to the published sequence of RHAMM. RHAMM−48 and RHAMM−147 variants align with RHAMMFL, but are characterized by sequence deletions of 48 bp (16 amino acids [aa]) and 147 bp (49 aa), respectively. The relative frequency of these RHAMM transcripts in MM plasma cells was determined by cloning of reverse-transcriptase polymerase chain reaction (RT-PCR) products amplified from MM plasma cells. Of 115 randomly picked clones, 49% were RHAMMFL, 47% were RHAMM−48, and 4% were RHAMM−147. All of the detected RHAMM variants contain exon 4, which is alternatively spliced in murine RHAMM, and had only a single copy of the exon 8 repeat sequence detected in murine RHAMM. RT-PCR analysis of sorted blood or BM cells from 22 MM patients showed that overexpression of RHAMM variants is characteristic of MM B cells and BM plasma cells in all patients tested. RHAMM also appeared to be overexpressed in B lymphoma and B-chronic lymphocytic leukemia (CLL) cells. In B cells from normal donors, RHAMMFL was only weakly detectable in resting B cells from five of eight normal donors or in chronically activated B cells from three patients with Crohn’s disease. RHAMM−48 was detectable in B cells from one of eight normal donors, but was undetectable in B cells of three donors with Crohn’s disease. RHAMM−147 was undetectable in normal and Crohn’s disease B cells. In situ RT-PCR was used to determine the number of individual cells with aggregate RHAMM transcripts. For six patients, 29% of BM plasma cells and 12% of MM B cells had detectable RHAMM transcripts, while for five normal donors, only 1.2% of B cells expressed RHAMM transcripts. This work suggests that RHAMMFL, RHAMM−48, and RHAMM−147 splice variants are overexpressed in MM and other B lymphocyte malignancies relative to resting or in vivo–activated B cells, raising the possibility that RHAMM and its variants may contribute to the malignant process in B-cell malignancies such as lymphoma, CLL, and MM.


2021 ◽  
Vol 218 (8) ◽  
Author(s):  
Charlotte Viant ◽  
Tobias Wirthmiller ◽  
Mohamed A. ElTanbouly ◽  
Spencer T. Chen ◽  
Melissa Cipolla ◽  
...  

Memory B cells comprise a heterogenous group of cells that differ in origin and phenotype. During the early phases of the immune response, activated B cells can differentiate into IgM-expressing memory cells, short-lived plasma cells, or seed germinal centers (GCs). The memory compartment is subsequently enriched by B cells that have been through several rounds of division and selection in the GC. Here, we report on the use of an unbiased lineage-tracking approach to explore the origins and properties of memory B cell subsets in mice with an intact immune system. We find that activated B cells continue to differentiate into memory B cells throughout the immune response. When defined on the basis of their origins, the memory B cells originating from activated B cells or GCs differ in isotype and overall gene expression, somatic hypermutation, and their affinity for antigen.


Blood ◽  
1999 ◽  
Vol 93 (5) ◽  
pp. 1684-1696 ◽  
Author(s):  
Mary Crainie ◽  
Andrew R. Belch ◽  
Michael J. Mant ◽  
Linda M. Pilarski

Abstract The receptor for hyaluronan (HA)-mediated motility (RHAMM) controls motility by malignant cells in myeloma and is abnormally expressed on the surface of most malignant B and plasma cells in blood or bone marrow (BM) of patients with multiple myeloma (MM). RHAMM cDNA was cloned and sequenced from the malignant B and plasma cells comprising the myeloma B lineage hierarchy. Three distinct RHAMM gene products, RHAMMFL, RHAMM−48, and RHAMM−147, were cloned from MM B and plasma cells. RHAMMFL was 99% homologous to the published sequence of RHAMM. RHAMM−48 and RHAMM−147 variants align with RHAMMFL, but are characterized by sequence deletions of 48 bp (16 amino acids [aa]) and 147 bp (49 aa), respectively. The relative frequency of these RHAMM transcripts in MM plasma cells was determined by cloning of reverse-transcriptase polymerase chain reaction (RT-PCR) products amplified from MM plasma cells. Of 115 randomly picked clones, 49% were RHAMMFL, 47% were RHAMM−48, and 4% were RHAMM−147. All of the detected RHAMM variants contain exon 4, which is alternatively spliced in murine RHAMM, and had only a single copy of the exon 8 repeat sequence detected in murine RHAMM. RT-PCR analysis of sorted blood or BM cells from 22 MM patients showed that overexpression of RHAMM variants is characteristic of MM B cells and BM plasma cells in all patients tested. RHAMM also appeared to be overexpressed in B lymphoma and B-chronic lymphocytic leukemia (CLL) cells. In B cells from normal donors, RHAMMFL was only weakly detectable in resting B cells from five of eight normal donors or in chronically activated B cells from three patients with Crohn’s disease. RHAMM−48 was detectable in B cells from one of eight normal donors, but was undetectable in B cells of three donors with Crohn’s disease. RHAMM−147 was undetectable in normal and Crohn’s disease B cells. In situ RT-PCR was used to determine the number of individual cells with aggregate RHAMM transcripts. For six patients, 29% of BM plasma cells and 12% of MM B cells had detectable RHAMM transcripts, while for five normal donors, only 1.2% of B cells expressed RHAMM transcripts. This work suggests that RHAMMFL, RHAMM−48, and RHAMM−147 splice variants are overexpressed in MM and other B lymphocyte malignancies relative to resting or in vivo–activated B cells, raising the possibility that RHAMM and its variants may contribute to the malignant process in B-cell malignancies such as lymphoma, CLL, and MM.


Blood ◽  
2001 ◽  
Vol 97 (6) ◽  
pp. 1817-1822 ◽  
Author(s):  
Gaëtan Jego ◽  
Régis Bataille ◽  
Catherine Pellat-Deceunynck

Interleukin-6 (IL-6), although often regarded as a B-cell differentiation factor, was recently described as the essential survival factor for human plasmablasts in vivo in reactive plasmacytosis. The present study reinvestigated the roles of IL-6 and IL-2 in the generation of plasma cells from human memory B cells in vitro. The cells involved in this differentiation process were identified as preplasmablasts (CD20±CD38±CD138−), plasmablasts (CD20−CD38++CD138−), and early plasma cells (CD20−CD38+++CD138+++). IL-2 or IL-10 induced a strong generation of plasmablasts and early plasma cells (PCs). Compared to IL-2 or IL-10, IL-6 alone was inefficient at PC generation. However, when combined with IL-2 or IL-10, IL-6 enhanced generation of early PCs. Moreover, anti–IL-6 monoclonal antibody markedly reduced IL-2–induced generation of early plasma cells, but not of plasmablasts. These roles of IL-2 and IL-6 were consistent with the difference in the expression of their respective receptors (R). CD25 (IL-2Rα) was increased 72 ± 10-fold on activated B cells, but decreased and then disappeared on plasmablasts. Conversely, CD126 (IL-6Rα) was barely expressed on activated B cells, but increased 18 ± 2-fold on preplasmablasts. Finally, IL-6 enhanced the proliferation (2-fold increase) of IL-2–generated plasmablasts. In conclusion, the data indicate that IL-6 is a growth factor for nonmalignant human plasmablasts.


2020 ◽  
Author(s):  
Dillon G. Patterson ◽  
Christopher D. Scharer ◽  
Tian Mi ◽  
Madeline J. Price ◽  
Sakeenah L. Hicks ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document