scholarly journals Small clonal B-cell population in the bone marrow as a possible tool in the diagnosis of occult primary parotid lymphoma

2016 ◽  
pp. 59-62 ◽  
Author(s):  
Martha Romero ◽  
Guido R. González-Fontal ◽  
Mónica Duarte ◽  
Carlos Saavedra ◽  
Andrés F. Henao-Martínez
Keyword(s):  
Bone Marrow ◽  
B Cell ◽  
Pulmonary Thromboembolism ◽  
Clinical Findings ◽  
Small Extent ◽  
Past Medical History ◽  
Warthin Tumor ◽  
Oncocytic Papilloma ◽  
New Onset

Case Description: An 82-years old Hispanic woman with a past medical history significant for pulmonary thromboembolism on oral anticoagulation, rheumatoid arthritis, and hypertension developed a new onset thrombocytopenia. Clinical Findings: Small clonal B-cells populations (SCBP) also known as monoclonal B-cell lymphocytosis was found as part of the workup for an idiopathic thrombocytopenia and lead ultimately to the diagnosis of parotid primary follicular lymphoma coexisting with Warthin tumor involving the bone marrow in a small extent and oncocytic papilloma located in the maxillary sinus. Treatment and Outcome: Patient was treated with Rituximab monotherapy with improvement on her platelet count. Clinical relevance: Although it is unclear the role of this clonal cells, they may work as a possible diagnostic tool for occult lymphomas. Further prospective studies are needed to confirm this possible association.

scholarly journals Lsh/HELLS is required for B lymphocyte development and immunoglobulin class switch recombination

2020 ◽  
Vol 117 (33) ◽  
pp. 20100-20108
Author(s):  
Yafeng He ◽  
Jianke Ren ◽  
Xiaoping Xu ◽  
Kai Ni ◽  
Andrew Schwader ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Bone Marrow Transplantation ◽  
B Cell ◽  
Marrow Transplantation ◽  
Class Switch Recombination ◽  
B Cell Development ◽  
Hematopoietic Cell ◽  
Cell Numbers ◽  
Class Switch

Mutation of HELLS (Helicase, Lymphoid-Specific)/Lsh in human DNA causes a severe immunodeficiency syndrome, but the nature of the defect remains unknown. We assessed here the role of Lsh in hematopoiesis using conditional Lsh knockout mice with expression of Mx1 or Vav Cre-recombinase. Bone marrow transplantation studies revealed that Lsh depletion in hematopoietic stem cells severely reduced B cell numbers and impaired B cell development in a hematopoietic cell-autonomous manner. Lsh-deficient mice without bone marrow transplantation exhibited lower Ig levels in vivo compared to controls despite normal peripheral B cell numbers. Purified B lymphocytes proliferated normally but produced less immunoglobulins in response to in vitro stimulation, indicating a reduced capacity to undergo class switch recombination (CSR). Analysis of germline transcripts, examination of double-stranded breaks using biotin-labeling DNA break assay, and End-seq analysis indicated that the initiation of the recombination process was unscathed. In contrast, digestion–circularization PCR analysis and high-throughput sequencing analyses of CSR junctions and a chromosomal break repair assay indicated an impaired ability of the canonical end-joining pathway in Lsh-deficient B cells. Our data suggest a hematopoietic cell-intrinsic role of Lsh in B cell development and in CSR providing a potential target for immunodeficiency therapy.

scholarly journals Mutations of the Igβ gene cause agammaglobulinemia in man

2007 ◽  
Vol 204 (9) ◽  
pp. 2047-2051 ◽  
Author(s):  
Simona Ferrari ◽  
Vassilios Lougaris ◽  
Stefano Caraffi ◽  
Roberta Zuntini ◽  
Jianying Yang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cell ◽  
Transmembrane Protein ◽  
Serum Levels ◽  
Cell Development ◽  
B Cell Development ◽  
Surrogate Light Chain ◽  
Human B Cell ◽  
Homozygous Nonsense Mutation

Agammaglobulinemia is a rare primary immunodeficiency characterized by an early block of B cell development in the bone marrow, resulting in the absence of peripheral B cells and low/absent immunoglobulin serum levels. So far, mutations in Btk, μ heavy chain, surrogate light chain, Igα, and B cell linker have been found in 85–90% of patients with agammaglobulinemia. We report on the first patient with agammaglobulinemia caused by a homozygous nonsense mutation in Igβ, which is a transmembrane protein that associates with Igα as part of the preBCR complex. Transfection experiments using Drosophila melanogaster S2 Schneider cells showed that the mutant Igβ is no longer able to associate with Igα, and that assembly of the BCR complex on the cell surface is abrogated. The essential role of Igβ for human B cell development was further demonstrated by immunofluorescence analysis of the patient's bone marrow, which showed a complete block of B cell development at the pro-B to preB transition. These results indicate that mutations in Igβ can cause agammaglobulinemia in man.

scholarly journals Analysis of the Role of IL-21 in Development of Murine B Cell Progenitors in the Bone Marrow

2011 ◽  
Vol 186 (9) ◽  
pp. 5244-5253 ◽  
Author(s):  
Nathalie Simard ◽  
Danijela Konforte ◽  
Anne H. Tran ◽  
Jessica Esufali ◽  
Warren J. Leonard ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cell

Multiplex Analysis of Serum Cytokine Levels in Waldenström Macroglobulinemia Patients.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2616-2616
Author(s):  
Sherine F. Elsawa ◽  
Anne J. Novak ◽  
Steven C. Ziesmer ◽  
Thomas E. Witzig ◽  
Vincent Rajkumar ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cell ◽  
Elevated Serum ◽  
Fold Increase ◽  
Serum Levels ◽  
Healthy Controls ◽  
Β2 Microglobulin ◽  
Healthy Donors ◽  
Cytokine Levels

Abstract Waldenström macroglobulinemia (WM) is a monoclonal B cell disorder characterized by a circulating monoclonal IgM protein that may lead to serum hyperviscosity in association with an infiltration of lymphoplasmacytic cells into the bone marrow. Although proinflammatory and chemotactic cytokines can profoundly affect tumor cells and the tumor microenvironment, and many cytokines have been shown to have potent therapeutic efficacy in preclinical cancer models, the role of cytokine networks in WM is not fully understood. In this study, we used a high-throughput xMAP multiplex immunobead assay technology (Luminex Corp., Austin, TX) to simultaneously test 30 cytokines, chemokines, angiogenic factors as well as growth factors and soluble receptors in the sera of WM patients and compared them with other B cell malignancies including IgM monoclonal gammopathy of undetermined significance (MGUS), follicular lymphoma, chronic lymphocytic leukemia (CLL) as well as healthy controls. Using a Mann-Whitney U test to analyze the differences between the groups, 15 of the 30 cytokines tested had significantly different levels in WM compared to healthy controls. Of those 15 cytokines, 11 were elevated in WM patients and 4 were decreased. Cytokines were grouped into 3 groups; those with < 2-fold difference, 2–8 fold difference and those having > 8-fold difference in their cytokine levels compared to healthy donors. There was a greater than 8-fold increase in the serum levels of Rantes, G-CSF and IL-2R (p<0.0001) in WM patients. Furthermore, 3 cytokines had between 2–8-fold increase in WM patients including IL-4 (p<0.0001), IL-6 (p<0.0019) and IP-10 (p<0.0006). Five cytokines had statistically elevated levels in WM patients compared to healthy controls, however the fold increase was < 2 including HGF (p<0.0185), IL-10 (p<0.0002), MIP-1α (P<0.0484), IL-2 (P<0.0130) and IL-12 (P<0.0155). Of the cytokines that had significantly lower levels in the sera of WM patients, IL-8 (p<0.0001) and EGF (p<0.0001) were > 8-fold decreased, MCP-1 (p<0.0001) was 2–8 fold lower and Eotaxin (p<0.0004) was < 2-fold lower in WM patients. All of the cytokines that had the greatest fold difference (> 8-fold) in WM patients compared to healthy donors also differed significantly from the MGUS patients. Rantes, G-CSF, IL-2R and EGF had significantly different levels compared to other B cell malignancies. We tested for a correlation between the cytokines that had > 2-fold difference between the WM group and control group with clinical features of the disease and found the cytokines IL-6 and IL-2R had a significant correlation with β2-microglobulin levels (p<0.01). We analyzed cytokine levels in the bone marrow plasma of the same patients and found that high levels of IL-2R in the bone marrow microenvironment significantly correlated with anemia and elevated serum β2-microglobulin (p<0.01). In conclusion, we have simultaneously analyzed sera from WM patients for 30 cytokines and found the most significantly elevated cytokines are Rantes, G-CSF and IL-2R and the most significantly downregulated cytokines are IL-8 and EGF. Furthermore, we found that elevated serum levels of IL-6 and IL-2R correlated with β2-microglobulin levels, a measure of disease activity. Further analysis of the biological role of these cytokines in WM may offer insight into disease pathogenesis and provide a basis for novel targeted therapies.

Precursor B Cell Acute Lymphoblastic Leukemia Induces Pro-Leukemic Changes in the Bone Marrow Microenvironment That Contribute to Therapeutic Resistance

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1466-1466
Author(s):  
Christopher D Chien ◽  
Elizabeth D Hicks ◽  
Paul P Su ◽  
Haiying Qin ◽  
Terry J Fry
Keyword(s):  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
B Cells ◽  
B Cell ◽  
Lymphoblastic Leukemia ◽  
Cell Development ◽  
B Cell Development ◽  
Bone Marrow Microenvironment ◽  
Therapeutic Resistance

Abstract Abstract 1466 Pediatric acute lymphoblastic leukemia (ALL) is the most common childhood malignancy. Although cure rates for this disease are approximately 90%, ALL remains one of the leading causes cancer-related deaths in children. Thus, new treatments are needed for those patients that do not respond to or recur following standard chemotherapy. Understanding the mechanisms underlying resistance of pediatric ALL to therapy offers one approach to improving outcomes. Recent studies have demonstrated the importance of communication between cancer cells and their microenvironment and how this contributes to the progression and therapeutic resistance but this has not been well studied in the context of ALL. Since the bone marrow is presumed to be the site of initiation of B precursor ALL we set out in our study to determine how ALL cells utilize the bone marrow milieu in a syngeneic transplantable model of preB cell ALL in immunocompetent mice. In this model, intravenously injected preB ALL develops first in the bone marrow, followed by infiltration into the spleen, lymph node, and liver. Using flow cytometry to detect the CD45.2 isoform following injection into B6CD45.1+ congenic recipients, leukemic cells can be identified in the bone marrow as early as 5 days after IV injection with a sensitivity of 0.01%-0.1%. The pre-B ALL line is B220+/CD19+/CD43+/BP1+/IL-7Ralpha (CD127)+/CD25-/Surface IgM-/cytoplasmic IgM+ consistent with a pre-pro B cell phenotype. We find that increasing amounts of leukemic infiltration in the bone marrow leads to an accumulation of non-malignant developing B cells at stages immediately prior to the pre-pro B cell (CD43+BP1-CD25-) and a reduction in non-malignant developing pre B cells at the developmental stage just after to the pre-pro B cell stage (CD43+BP1+CD25+). These data potentially suggest occupancy of normal B cell developmental niches by leukemia resulting in block in normal B cell development. Further supporting this hypothesis, we find significant reduction in early progression of ALL in aged (10–12 month old) mice known to have a deficiency in B cell developmental niches. We next explored whether specific factors that support normal B cell development can contribute to progression of precursor B cell leukemia. The normal B cell niche has only recently been characterized and the specific contribution of this niche to early ALL progression has not been extensively studied. Using a candidate approach, we examined the role of specific cytokines such as Interleukin-7 (IL-7) and thymic stromal lymphopoietin (TSLP) in early ALL progression. Our preB ALL line expresses high levels of IL-7Ralpha and low but detectable levels of TLSPR. In the presence of IL-7 (0.1 ng/ml) and TSLP (50 ng/ml) phosphSTAT5 is detectable indicating that these receptors are functional but that supraphysiologic levels of TSLP are required. Consistent with the importance of IL-7 in leukemia progression, preliminary data demonstrates reduced lethality of pr-B cell ALL in IL-7 deficient mice. Overexpression of TSLP receptor (TSLPR) has been associated with high rates of relapse and poor overall survival in precursor B cell ALL. We are currently generating a TSLPR overepressing preBALL line to determine the effect on early ALL progression and are using GFP-expressing preB ALL cells to identify the initial location of preB ALL occupancy in the bone marrow. In conclusion, or model of early ALL progression provides insight into the role of the bone marrow microenvironment in early ALL progression and provides an opportunity to examine how these microenvironmental factors contribute to therapeutic resistance. Given recent advances in immunotherapy for hematologic malignancies, the ability to study this in an immunocompetent host will be critical. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Suppression of Anti-Tumor Immunity in Chronic Lymphocytic Leukemia Via Interleukin-10 Production

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3215-3215
Author(s):  
Sara S Alhakeem ◽  
Mary K McKenna ◽  
Sunil K Nooti ◽  
Karine Z Oben ◽  
Vivek M Rangnekar ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Tumor Immunity ◽  
Lymphocytic Leukemia ◽  
Clonal Variation ◽  
Bcr Signaling

Abstract The most common human leukemia is B-cell chronic lymphocytic leukemia (B-CLL), which is characterized by a progressive accumulation of abnormal B-lymphocytes in blood, bone marrow and secondary lymphoid organs. Typically disease progression is slow, but as the number of leukemic cells increases, they interfere with the production of other important blood cells, causing the patients to be in an immunosuppressive state. To study the basis of this immunoregulation, we used cells from the transgenic Eμ-Tcl1 mouse, which spontaneously develop B-CLL due to a B-cell specific expression of the oncogene, Tcl1. Previously we showed that Eμ-Tcl1 CLL cells constitutively produce an anti-inflammatory cytokine, IL-10. Here we studied the role of IL-10 in CLL cell survival in vitro and the development of CLL in vivo. We found that neutralization of IL-I0 using anti-IL-10 antibodies or blocking the IL-10 receptor (IL-10R) using anti-IL-10R antibodies did not affect the survival of CLL cells in vitro. On the other hand, adoptively transferred Eμ-Tcl1 cells grew at a slower rate in IL-10R KO mice vs. wild type (WT) mice. There was a significant reduction in CLL cell engraftment in the spleen, bone marrow, peritoneal cavity and liver of the IL-10R KO compared to WT mice. Further studies revealed that IL-10 could be playing a role in the tumor microenvironment possibly by affecting anti-tumor immunity. This was seen by a reduction in the activation of CD8+ T cells as well as a significantly lower production of IFN-γ by CD4+ T cells purified from CLL-injected WT mice compared to those purified from CLL-injected IL-10R KO mice. These studies demonstrate that CLL cells suppress host anti-tumor immunity via IL-10 production. This led us to investigate possible mechanisms by which IL-10 is produced. We found a novel role of B-cell receptor (BCR) signaling pathway in constitutive IL-10 secretion. Inhibition of Src or Syk family kinases reduces the constitutive IL-10 production by Eμ-Tcl1 cells in a dose dependent manner. In addition, we found that Eμ-Tcl1 CLL cells exhibit clonal variation in their IL-10 production in response to BCR cross-linking. Further studies are being performed to understand the mechanisms by which BCR signaling affects IL-10 production. Disclosures No relevant conflicts of interest to declare.

scholarly journals CYT-0853, a Novel RAD51 Inhibitor, Modulates Immunoregulatory B-Lymphocytes

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2330-2330
Author(s):  
Tamar Aprahamian ◽  
ED Keniston ◽  
Jane Branca ◽  
Muneer G Hasham ◽  
Melinda Day ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Antibody Production ◽  
Cytidine Deaminase ◽  
Autoreactive B Cells ◽  
Freund’S Adjuvant ◽  
Freund's Adjuvant

Activation Induced Cytidine Deaminase (AICDA/AID) is a DNA-directed cytidine deaminase that is normally only expressed in activated B-cells to promote somatic hypermutations and immunoglobulin class switching. In cancer cells, AID causes significant genotoxic stress through DNA replication fork damage, creating a dependency upon the homologous recombination repair factor, RAD51, for survival. We have demonstrated anti-cancer activity through disruption of this axis in multiple preclinical lymphoid cancer models. Autoreactive B cells depend on RAD51 for survival and are chronically auto-stimulated and therefore continually re-express AID. It has been shown that ectopic expression of AID in autoreactive B-cells causes genome-wide DNA damage (similar to cancers). Given the role of autoreactive B cells and autoantibodies in autoimmune disorders, we hypothesize that immunomodulation of B cells via the RAD51/AID axis will remediate inflammatory disease processes. Our previous data suggests that RAD51 modulation enhances the CD73+ B cell population and reduces antibody diversity in T1D mice, indicating precise effects on AID-mediated antibody diversification. CYT-0853 is a novel RAD51 inhibitor that sensitizes cells to AID activity. Here, we assessed the in vivo effect of CYT-0853 on primary B cells and antibody production. Wild-type C57BL/6 mice were treated with 40mg/kg CYT-0853 or vehicle for five weeks. One-week post-treatment start, mice were immunized with DNP-KLH antigen mixed with Complete Freund's Adjuvant. A second booster with DNP-KLH antigen mixed with Incomplete Freund's Adjuvant was administered two weeks later. At termination, blood, spleen, and bone marrow was collected for analysis by flow cytometry. Surface expression of CD45, CD19, IgM, and IgG1 was assessed to determine white blood cell count, B cells, and pre- and post-class switch recombination (CSR), respectively. While no significant changes to B cell populations were observed in bone marrow or spleen, we demonstrate that CYT-0853 significantly decreases the median number of circulating CD45+ and IgG1 (post-CSR) B cells (61.8% vs. 31.6% and 8.7% vs. 4.4%, respectively). In addition, we observed a modest, significant increase in the amount of IgM+ (pre-CSR) B cells. These results were complemented by an associated overall significant decrease in circulating IgM levels. Of note, no adverse effects were observed in these mice over this treatment period. Based on these data and the role of B cells not only in antibody production, but also as antigen-presenting cells in multiple sclerosis, we tested our molecule in the myelin oligodendrocyte glycoprotein35-55-experimental autoimmune encephalomyelitis model of multiple sclerosis. Prophylactic treatment using 40mg/kg CYT-0853 did not affect disease activity or circulating cytokine production, however we observed a significant decrease in the spleen. Based on these results, further exploration is warranted to harness the power of CYT-0853 on the AID/RAD51 axis. This specific targeting may elicit beneficial therapeutic changes to B-lymphocyte populations and provide a novel immunomodulatory target to treat immunity and inflammation. Taken together, these data provide a foundation for continued preclinical development of CYT-0853 with applicability towards autoimmune diseases. Disclosures Aprahamian: Cyteir Therapeutics: Consultancy. Day:Cyteir Therapeutics: Employment. Mills:Cyteir Therapeutics: Employment, Equity Ownership.

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