scholarly journals Thymic selection of H-2-incompatible bone marrow cells in SCID mice. Differences in T help for induction of B cell IgG responses versus cytotoxic T cells.

1988 ◽  
Vol 168 (3) ◽  
pp. 1187-1192 ◽  
Author(s):  
R M Zinkernagel ◽  
E Rüedi ◽  
A Althage ◽  
H Hengartner ◽  
G Reimann
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Immune Responses ◽  
Vaccinia Virus ◽  
Cytotoxic T Cells ◽  
Scid Mice ◽  
Thymic Selection ◽  
Selection Of

Mice with congenital severe combined immunodeficiency disease (SCID) failed to mount either a T cell-independent IgM or T cell-dependent IgG anti-vesicular stomatitis virus (VSV) Indiana (IND) response. They did not generate cytotoxic T cells against lymphocytic choriomeningitis virus (LCMV) or vaccinia virus, but exhibited NK cell-like activities. When SCID mice were given bone marrow from syngeneic BALB/c (H-2d) nu/nu mice, all immune responses were expressed at control levels. If SCID mice were reconstituted with allogeneic H-2b C57BL/6 nu/nu bone marrow, the following primary anti-viral immune responses were measured. T-independent IgM anti-VSV-IND were normal, but T-dependent IgG anti-VSV-IND responses were absent. Cytotoxic T cell responses to LCMV and vaccinia virus were within normal ranges, were donor cell mediated, and were specific exclusively for the recipient SCID H-2d type. Since antigen presentation by spleen cells was functional in these chimaeras, the presented results indicate that (a) thymic selection of T cell restriction is strict; and (b) the type of T help necessary for B cells depends upon H-2-restricted contact between T and B cells, whereas, such contact-dependent help is not mandatory for the induction of virus-specific cytotoxic T cells.

Resistance of Quiescent Cells to T Cell Attack Determines Both the Efficacy and Specificity of Adoptive T Cell Therapy.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3161-3161
Author(s):  
I. Jedema ◽  
C.A.M. van Bergen ◽  
M.G.D. Kester ◽  
R. Willemze ◽  
J.H. Frederik Falkenburg
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Immune Responses ◽  
Target Cell ◽  
Cytotoxic T Cells ◽  
Precursor Cells ◽  
Adoptive T Cell Therapy ◽  
Target Cells ◽  
T Cell Therapy

Abstract Although profound anti-leukemic immune responses can be induced with donor lymphocyte infusions in patients with relapsed or persistent leukemia after allogeneic stem cell transplantation, (late) relapses of the same disease develop regularly even in patients initially entering a complete remission. This suggests that a subpopulation of leukemic (precursor) cells with ultimate self-renewal capacity is capable of resisting T cell attack. We hypothesized that quiescent leukemic precursor cells can evade anti-leukemic therapy by their capacity to survive and persist in the presence of competent cytotoxic T cells. In addition, selectivity of cytotoxic T cells (CTLs) for target cells in active cell cycle in general may also explain why powerful immune responses directed against antigens that are broadly expressed on all tissues of the recipient, like the male-specific HY-antigens, do not necessarily result in severe damage to all tissues of the recipient. Therefore, we determined the efficacy of high affinity CTL clones directed against allo-HLA or minor histocompatibility antigens to kill normal and leukemic hematopoietic cells in dormancy and in active cell cycle, comprising normal and leukemic CD34+ precursor cells, normal B cells, T cells and monocytes, and activated B cells (EBV-LCL) and activated T cells (PHA blasts). Using a CFSE-based cytotoxicity assay allowing the analysis of susceptibility to lysis of specific cell types within a heterogeneous target cell population, we found that all activated target cells were very efficiently lysed, resulting in 60–90% lysis already after 4 hours of exposure to the CTL clones (E/T ratios 1/1–5/1). In contrast, target cells in relative dormancy including the non-proliferating CD34+ CML stem cell fraction, unmanipulated CD34 progenitor cells, and resting T and B cells were protected from CTL-induced cell death (0–20% lysis). Since normal expression of adhesion and HLA class I molecules was shown on these dormant cells, we investigated whether decreased avidity of the T cell/target cell interaction was underlying the poor susceptibility. Therefore, we artificially enhanced the avidity by exogenous loading of the target cells with saturating concentrations of the relevant peptide. This was sufficient to restore the sensitivity to levels comparable to activated target cells, suggesting that decreased avidity of the interaction between high affinity CTL and resting target cells plays a role in the resistance phenomenon. However, even after restoration of the high avidity interaction, a small population of (leukemic) target cells (0,1–10% of the total cell population) was capable of residing, suggesting that additional factors like resistance of quiescent target cells to one or more of the T cell effector mechanisms are involved. To analyze the influence of the sensitivity to T cell lysis of specific target cell types on the specificity of adoptive T cell therapy, we used non-hematopoietic target cells like mesenchymal stem cells and biliary epithelium cells as target cells. Alloreactive T cells showed also diminished capacity to lyse these target cells (10–20% lysis). The addition of inflammatory cytokines like TNF and interferons slightly increased the recognition. In conclusion, under steady state conditions potent allo immune responses may have limited activity against quiescent target cells. Therefore in order to cure the disease, specific activation strategies and/or prolonged persistence of specific T cells will be needed to achieve a potent anti-leukemic effect with controlled GVHD.

scholarly journals Human fetal liver MSCs are more effective than adult bone marrow MSCs for their immunosuppressive, immunomodulatory, and Foxp3+ T reg induction capacity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi Yu ◽  
Alejandra Vargas Valderrama ◽  
Zhongchao Han ◽  
Georges Uzan ◽  
Sina Naserian ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Immune Responses ◽  
Molecular Mechanisms ◽  
Fetal Liver ◽  
Cytotoxic T Cells ◽  
Cell Contact ◽  
Adult Bone Marrow ◽  
Adult Bone

Abstract Background Mesenchymal stem cells (MSCs) exhibit active abilities to suppress or modulate deleterious immune responses by various molecular mechanisms. These cells are the subject of major translational efforts as cellular therapies for immune-related diseases and transplantations. Plenty of preclinical studies and clinical trials employing MSCs have shown promising safety and efficacy outcomes and also shed light on the modifications in the frequency and function of regulatory T cells (T regs). Nevertheless, the mechanisms underlying these observations are not well known. Direct cell contact, soluble factor production, and turning antigen-presenting cells into tolerogenic phenotypes, have been proposed to be among possible mechanisms by which MSCs produce an immunomodulatory environment for T reg expansion and activity. We and others demonstrated that adult bone marrow (BM)-MSCs suppress adaptive immune responses directly by inhibiting the proliferation of CD4+ helper and CD8+ cytotoxic T cells but also indirectly through the induction of T regs. In parallel, we demonstrated that fetal liver (FL)-MSCs demonstrates much longer-lasting immunomodulatory properties compared to BM-MSCs, by inhibiting directly the proliferation and activation of CD4+ and CD8+ T cells. Therefore, we investigated if FL-MSCs exert their strong immunosuppressive effect also indirectly through induction of T regs. Methods MSCs were obtained from FL and adult BM and characterized according to their surface antigen expression, their multilineage differentiation, and their proliferation potential. Using different in vitro combinations, we performed co-cultures of FL- or BM-MSCs and murine CD3+CD25−T cells to investigate immunosuppressive effects of MSCs on T cells and to quantify their capacity to induce functional T regs. Results We demonstrated that although both types of MSC display similar cell surface phenotypic profile and differentiation capacity, FL-MSCs have significantly higher proliferative capacity and ability to suppress both CD4+ and CD8+ murine T cell proliferation and to modulate them towards less active phenotypes than adult BM-MSCs. Moreover, their substantial suppressive effect was associated with an outstanding increase of functional CD4+CD25+Foxp3+ T regs compared to BM-MSCs. Conclusions These results highlight the immunosuppressive activity of FL-MSCs on T cells and show for the first time that one of the main immunoregulatory mechanisms of FL-MSCs passes through active and functional T reg induction.

scholarly journals T cell-independent antibody-mediated clearance of polyoma virus in T cell-deficient mice.

1996 ◽  
Vol 183 (2) ◽  
pp. 403-411 ◽  
Author(s):  
E Szomolanyi-Tsuda ◽  
R M Welsh
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Nude Mice ◽  
Knockout Mice ◽  
Cell Receptor ◽  
Genetically Engineered ◽  
Scid Mice ◽  
Myeloproliferative Disease ◽  
Alpha Beta

Polyomavirus (PyV) infection of SCID mice, which lack functional T and B cells, leads to a lethal acute myeloproliferative disease (AMD) and to high levels of virus replication in several organs by two wk after infection. This is in contrast to infection of T cell-deficient athymic nude mice, which are resistant to acute PyV-induced disease and poorly replicate the virus in their organs. This major difference in the virus load and in the outcome of PyV infection between SCID and nude mice suggested that an efficient, T cell-independent antiviral mechanism operates in T cell-deficient, PyV infected mice. To investigate this possibility, mice with different genetically engineered T and/or B cell deficiencies and SCID mice adoptively reconstituted with B and/or T cells were infected with PyV. The results indicated that the presence of B cells in the absence of T cells protected mice from the AMD, and this was accompanied by a major reduction of PyV in all organs tested. Sera from PyV-infected T cell receptor (TCR) alpha beta knockout or TCR alpha beta gamma delta knockout mice contained IgG2a antibodies to PyV. Sera or purified immunoglobulin fractions from PyV-infected TCR alpha beta knockout mice protected SCID mice from the PyV-induced AMD. To our knowledge, this is the first report of an effective T cell-independent antibody response clearing a virus and changing the outcome of infection from 100% mortality to 100% survival.

scholarly journals Selective Upregulation of Transcripts for Six Molecules Related to T Cell Costimulation and Phagocyte Recruitment and Activation among 734 Immunity-Related Genes in the Brain during Perforin-Dependent, CD8+ T Cell-Mediated Elimination of Toxoplasma gondii Cysts

mSystems ◽  
2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Jenny Lutshumba ◽  
Eri Ochiai ◽  
Qila Sa ◽  
Namrata Anand ◽  
Yasuhiro Suzuki
Keyword(s):  
T Cells ◽  
T Cell ◽  
Toxoplasma Gondii ◽  
Molecular Mechanisms ◽  
Cytotoxic T Cells ◽  
Scid Mice ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Content Type ◽  
Immune Related Genes

ABSTRACT We recently found that an invasion of CD8+ cytotoxic T cells into tissue cysts of Toxoplasma gondii initiates an elimination of the cysts in association with an accumulation of microglia and macrophages. In the present study, we compared mRNA levels for 734 immune-related genes in the brains of infected SCID mice that received perforin-sufficient or -deficient CD8+ immune T cells at 3 weeks after infection. At 7 days after the T cell transfer, mRNA levels for only six genes were identified to be greater in the recipients of the perforin-sufficient T cells than in the recipients of the perforin-deficient T cells. These six molecules included two T cell costimulatory molecules, inducible T cell costimulator receptor (ICOS) and its ligand (ICOSL); two chemokine receptors, C-X-C motif chemokine receptor 3 (CXCR3) and CXCR6; and two molecules related to an activation of microglia and macrophages, interleukin 18 receptor 1 (IL-18R1) and chitinase-like 3 (Chil3). Consistently, a marked reduction of cyst numbers and upregulation of ICOS, CXCR3, CXCR6, IL-18R1, and Chil3 mRNA levels were also detected when the perforin-sufficient CD8+ immune T cells were transferred to infected SCID mice at 6 weeks after infection, indicating that the CD8+ T cell-mediated protective immunity is capable of eliminating mature T. gondii cysts. These results together suggest that ICOS-ICOSL interactions are crucial for activating CD8+ cytotoxic immune T cells to initiate the destruction of T. gondii cysts and that CXCR3, CXCR6, and IL-18R are involved in recruitment and activation of microglia and macrophages to the T cell-attacked cysts for their elimination. IMPORTANCE T. gondii establishes a chronic infection by forming tissue cysts, which can grow into sizes greater than 50 μm in diameter as a consequence of containing hundreds to thousands of organisms surrounded by the cyst wall within infected cells. Our recent studies using murine models uncovered that CD8+ cytotoxic T cells penetrate into the cysts in a perforin-dependent manner and induce their elimination, which is accompanied with an accumulation of phagocytic cells to the T cell-attacked target. This is the first evidence of the ability of the T cells to invade into a large target for its elimination. However, the mechanisms involved in anticyst immunity remain unclear. Immune profiling analyses of 734 immune-related genes in the present study provided a valuable foundation to initiate elucidating detailed molecular mechanisms of the novel effector function of the immune system operated by perforin-mediated invasion of CD8+ T cells into large targets for their elimination.

scholarly journals Neonates Mount Robust and Protective Adult-Like CD8+-T-Cell Responses to DNA Vaccines

2002 ◽  
Vol 76 (23) ◽  
pp. 11911-11919 ◽  
Author(s):  
Jie Zhang ◽  
Nicole Silvestri ◽  
J. Lindsay Whitton ◽  
Daniel E. Hassett
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Viral Infections ◽  
Dna Vaccines ◽  
Neonatal Period ◽  
Cytotoxic T Cells ◽  
Lymphocytic Choriomeningitis ◽  
Cell Responses ◽  
Rapid Induction

ABSTRACT Neonates are thought to mount less vigorous adaptive immune responses than adults to antigens and infectious agents. This concept has led to a delay in the administration of many currently available vaccines until late infancy or early childhood. It has recently been shown that vaccines composed of plasmid DNA can induce both humoral and cell-mediated antimicrobial immunity when administered within hours of birth. In most of these studies, immune responses were measured weeks or months after the initial vaccination, and it is therefore questionable whether the observed responses were actually the result of priming of splenocytes within the neonatal period. Here we show that DNA vaccination at birth results in the rapid induction of antigen-specific CD8+ T cells within neonatal life. Analyses of T-cell effector functions critical for the resolution of many viral infections revealed that neonatal and adult CD8+ T cells produce similar arrays of cytokines. Furthermore, the avidities of neonatal and adult CD8+ T cells for peptide and the rapidity with which they upregulate cytokine production after recall encounters with antigen are similar. Protective immunity against the arenavirus lymphocytic choriomeningitis virus, which is mediated by CD8+ cytotoxic T cells, is also rapidly acquired within the neonatal period. Collectively these data imply that, at least in the case of CD8+ T cells, neonates are not as immunodeficient as previously supposed and that DNA vaccines may be an effective and safe means of providing critical cell-mediated antiviral immunity extremely early in life.

Disruption of Gamma Interferon Signaling through the STAT1 Pathway Enhances Alloreactivity While Abrogating GvHD

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3512-3512
Author(s):  
Christian M. Capitini ◽  
Shannon M. Larabee ◽  
Crystal L. Mackall ◽  
Terry J. Fry
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Tumor Vaccine ◽  
Gamma Interferon ◽  
Allogeneic Bone ◽  
Cell Recovery ◽  
Tumor Challenge ◽  
Tumor Protection

Abstract BACKGROUND: Strategies that allow for sufficient alloreactivity to mediate graft-versus-tumor (GVT) effects after allogeneic bone marrow transplant (BMT) while minimizing graft-versus-host-disease (GVHD) remain elusive. Historically, gamma interferon (IFNγ) has been implicated as a critical mediator of both GVT and GVHD pathophysiology, and high levels of IFNγ have been implicated in immunosuppression. Given that immunosuppression is also a hallmark of GVHD, we hypothesized that modulation of IFNγ signaling could have important effects on both GVHD and GVT following BMT. We therefore compared immunocompetence to tumor challenge and tumor vaccination, in the presence or absence of IFNγ receptor (R1) and STAT1 signaling (a primary downstream mediator of IFNγ signaling) on donor bone marrow. METHODS: We utilized a clinically relevant, minor histocompatibility antigen-mismatched, T cell-depleted BMT model, with delayed donor lymphocyte infusions (DLIs) into thymectomized mice to ensure that T cell recovery occurred exclusively from the DLI, as occurs in most clinical settings during the first 6 months post-BMT. Lethally irradiated female C57BL/6 (B6) × C3H.SW recipients were engrafted with normal B6, B6 IFNγR1-deficient, normal B6129, or B6129 STAT1-deficient bone marrow on day 0 and reconstituted with donor T cells on days 14 and 28 at a dose that induced sublethal GVHD, evidenced by weight loss, histology, and abrogated quantitative immune responses to an HY-directed tumor vaccine. Recipients were then challenged on day 42 with an HY-expressing tumor and followed for survival. Immune reconstitution was assessed by flow cytometry both prior to and after DLI administration. RESULTS: Mild GVHD prevents vaccine-mediated immune responses and HY-expressing tumor protection in thymectomized recipients. Both IFNγR1 and STAT1-deficient marrow abrogate GVHD. STAT1-deficient marrow increased absolute numbers of splenic plasmacytoid dendritic cells (CD11cint/Class II+/Gr-1+/B220+) prior to DLI administration. In addition, an increase in the percentage and absolute number of splenic regulatory T cells was observed at the time of tumor challenge. Surprisingly, despite the immunosuppressive milieu, recipients of IFNγR1-deficient marrow had enhanced vaccine-mediated tumor protection as measured by overall survival, similar to syngeneic BMT controls. CONCLUSION: IFNγ signaling is a critical mediator of GVHD pathophysiology, including the immunosuppression associated with this condition. Disrupting IFNγ signaling through the JAK1/STAT1 pathway is a novel strategy to selectively modulate alloreactivity, and results in enhanced anti-tumor immune responses following allogeneic BMT without exacerbating GVHD.

WT1-Specific Immune Responses in Patients with High-Risk Multiple Myeloma Undergoing Allogeneic T Cell-Depleted Hematopoietic Stem Cell Transplantation Followed by Donor Lymphocyte Infusions

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1993-1993 ◽  
Author(s):  
Eleanor Tyler ◽  
Achim A Jungbluth ◽  
Richard J. O'Reilly ◽  
Guenther Koehne
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Immune Responses ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Hematologic Malignancies ◽  
Hematopoietic Stem ◽  
Cell Responses

Abstract Abstract 1993 Wilm's tumor protein-1 (WT1) is over-expressed in a number of solid and hematologic malignancies including multiple myeloma (MM). The emergence of WT1-specific T cells has been shown to correlate with better relapse-free survival after allogeneic stem cell transplantation in patients (pts) with hematologic malignancies, such as leukemia. In MM, the expression of WT1 in the bone marrow has been shown to correlate with numerous negative prognostic factors, including disease stage and M protein ratio. Taken together, these findings suggest that immunotherapeutic augmentation of WT1-specific immune responses, such as adoptive transfer of WT1-specific T cells, may be capable of eradicating minimal residual disease and preventing relapse in MM. Thus, we examined the significance of WT1-specific cellular immune responses in pts with relapsed MM and high-risk cytogenetics who are undergoing allogeneic T cell-depleted hematopoietic stem cell transplantation (TCD HSCT). In this study, pts were eligible to receive low doses of donor lymphocyte infusions (DLI, 5×105-1×106 CD3+/kg) no earlier than 5 months post TCD HSCT. WT1-specific T-cell frequencies were measured in freshly isolated peripheral blood and bone marrow specimens. Frequencies were detected by staining for intracellular IFN-γ production in response to WT1 peptides, and/or by tetramer analysis, where available. Of 17 pts evaluated, all pts exhibited low frequencies of WT1-specific T-cell responses pre TCD HSCT. Ten of these pts received DLI post TCD HSCT. All 10 pts developed WT1-specific T cell responses post DLI. These increments in WT1-specific T-cell frequencies were associated with reduction in circulating myeloma proteins in all pts. Long-term evaluation demonstrated fluctuations in persisting WT1-specific T-cell frequencies following DLI. In one representative patient, a peak of 3.5% (72/ml) WT1-specific CD8+ T cells were detected in the peripheral blood by staining with the tetramer HLA-A*0201 RMF. This peak T-cell response occurred post TCD HSCT and DLI, and coincided with disease regression. This patient has remained in complete remission for more than 3 years post transplant, with fluctuating levels of WT1-specific CD8+ T cells ranging from 0.3–1.5% still persisting. Findings from concurrent molecular chimerism studies conducted on isolated T cells post TCD HSCT suggest that the WT1-specific T cells are of donor origin. Immunohistochemical analyses of WT1 and CD138 staining in MM bone marrow specimens demonstrated consistent co-expression within malignant plasma cells. WT1 expression in the bone marrow of all 6 pts tested correlated with the extent of malignant plasma cell infiltration. In contrast, no WT1 expression was observed when disease was low or absent. Taken together, our findings suggest a correlation between the emergence of WT1-specific T cells post DLI, and disease regression in pts being treated for relapsed MM. The present data support the development of adoptive immunotherapeutic approaches utilizing WT1-specific T cells for pts with MM. Disclosures: No relevant conflicts of interest to declare.

Flow Cytometry Primary 10 Colours Panel for Chronic Lympho Proliferative Diseases Diagnosis

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 5190-5190
Author(s):  
Jonathan Brauner ◽  
Ingrid Beukinga ◽  
Zoulikha Amraoui ◽  
Zaina Kassengera ◽  
Michel Toungouz ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Lymphocytes ◽  
Plasma Cells ◽  
Cell Lymphoma ◽  
Cd10 Expression ◽  
Complete Characterisation

Abstract Abstract 5190 Objectives: Definition of the primary antibodies panel for 10 colours flow cytometry able to describe normal and clonal T, B lymphocytes and plamocytes in blood and bone marrow. Once clonalities are detected, the complete characterisation of Chronic Lymphoproliferative Diseases (CLPD) is supported by secondary panels chosen based on the results of CD5/CD10 expression for clonal B lymphocytes, CD27/CD38 for plasmatocytes and CD3/CD27 for clonal T cells. Materials and Methods: Blood and bone marrow of patients (N=50) with CLPD (mainly B-CLL). Samples are enumerated by haematology analyzer DxH 800 then 106 cells are washed three times, stained with the antibodies combination and red blood cells lysed with Versalyse (TM. Beckman Coulter). The samples were analysed on a 10 colours Navios flow cytometer (Beckman Coulter Fullerton, CA). The staining panel consists of 14 antibodies (CD45, CD8, CD4, CD5, CD3, CD19, CD38, λ, κ, CD23, CD5, CD10, CD14, CD27) conjugated with 10 different fluorochromes. The fixed gating strategy allows linking Navios analysis software to the middleware Remisol which drives the choice of the secondary panel. In some cases a third tube is performed for Ki67 or Zap-70 intra-cytoplasmic staining. Results: Monocytes are removed on the basis of their CD14/CD4 expression. B lymphocytes are CD19 positive. Normal naïve/memory B cells, hematogones and plasma cells are defined by their CD27, CD10 and CD38 expression. Eventual monoclonality is sought by analysis of the distribution of Kappa and Lambda light chains. A first classification of B cell lymphoma is achieved with the CD5 and CD10 expression of the clone (CD5+/CD10−: B-CLL MCL and few MZL, CD5−/CD10−: MZL and related, CD5−/CD10+ DLBCL and FL). Analysis of CD27, CD20 and CD23 expression allows discriminating between CD5+/CD10- lymphomas. All the 50 samples were correctly detected as CLPD and the automated Remisol choice of the second panel fit to the final diagnosis of all the cases of this small series. T lymphocytes are defined by their CD3 and CD5 expression. The analysis of CD4/CD8 balance and CD27/CD5 distribution are first line test when T cell clonality is suspected. There is a special gating to detect CD3-CD4+ T cell lymphoma and double negativity of CD4 and CD8 is a surrogate marker for gamma/delta T cells. NK cells are mentioned as not-T not-B lymphocytes, without specific staining. Conclusion/Discussion:This 10 colours 14 antibodies panel allows describing in one tube normal T and B cells, hematogones, memory and naives B cells plasma cells and detects T and B clonalities. This panel follows a similar logic than the Euroflow LST tube but with 10 colours and with Beckman Coulter's technology and antibodies. Moreover, this combination helps discriminating rapidly the CD5+/CD10- lymphomas while the complete characterisation of CD5 negative lymphomas only require less than 6 antibodies second tube. This is a paperless (all the process is driven and controlled by Remisol), fast and inexpensive diagnostic approach (always less than 20 antibodies required). Disclosures: Pradier: Beckman Coulter: Consultancy, Membership on an entity's Board of Directors or advisory committees.

IL-21 and IL-6 Mediate Interactions Between T Cells and Malignant B Cells in the Bone Marrow Microenvironment in Waldenstrom's Macroglobulinemia

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1554-1554
Author(s):  
Lucy S. Hodge ◽  
Steve Ziesmer ◽  
Frank J Secreto ◽  
Zhi-Zhang Yang ◽  
Anne Novak ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Tumor Microenvironment ◽  
B Cell ◽  
Bone Marrow Microenvironment ◽  
Waldenström’S Macroglobulinemia ◽  
Waldenström's Macroglobulinemia

Abstract Abstract 1554 T cells in the tumor microenvironment influence the biology of malignant cells in many hematologic malignancies, often through cytokine-mediated interactions. Recent studies involving healthy B cells and CD4+T cells identified an interplay between IL-6 and IL-21, whereby IL-6 increased IL-21 production by T cells, driving the differentiation and IL-6 secretion of nearby B cells. In addition to their known effects on healthy B cell function, IL-6 and IL-21 have also been implicated in the pathology of various lymphomas. In Waldenstrom's macroglobulinemia (WM), IL-6 is elevated in the bone marrow and is associated with increased IgM production. However, the function of IL-21 in the WM tumor microenvironment and its relationship to IL-6 is poorly understood. Our objective in this study was to characterize IL-21 production and function in WM and to examine the role of IL-6 and IL-21 in regulating interactions between malignant B cells and T cells in the tumor microenvironment. Immunohistochemistry revealed significant IL-21 staining in bone marrows of patients with WM (n=5), but the areas of infiltration by WM in the bone marrow sections appeared negative for IL-21 staining. To better understand the origin of IL-21 in in the tumor microenvironment, IL-21 expression was assessed by PCR in the CD19−CD138− fraction of cells remaining in patient bone marrow aspirates after positive selection for malignant B cells (n=5). IL-21 transcript was detected in 4/5 samples. CD19−CD138− cells activated with anti-CD3 and anti-CD28 antibodies expressed higher levels of IL-21 transcript and secreted significantly higher levels of IL-21 protein compared to unstimulated cells, suggesting that IL-21 in the WM bone marrow is derived from activated T cells. Intracellular expression of IL-21 protein was confirmed in CD4+ and CD8+ cells within the CD19−CD138− population using flow cytometry. Furthermore, dual staining of WM bone marrow sections with antibodies against IL-21 and CD3 or CD20 revealed co-staining of IL-21 with CD3+ T cells but not with CD20+ B cells. The response of WM B cells to T-cell derived IL-21 was then assessed in positively selected CD19+CD138+ WM B cells (n=5) and in the MWCL-1 cell line. Using flow cytometry, both the IL-21 receptor and the required common gamma chain subunit were detected on all patient samples as well as on MWCL-1 cells. Treatment of MWCL-1 cells with IL-21 (100 ng/mL) for 72 h increased proliferation by 35% (p<0.05) and IgM secretion by 80% (p<0.005). Similarly, in primary CD19+CD138+ WM cells (n=5), proliferation increased on average by 38% and IgM secretion by 71%. No apoptotic effects were associated with IL-21 in WM. Characterization of STAT activation in response to IL-21 revealed significant phosphorylation of STAT3 in both CD19+CD138+ WM cells and MWCL-1 cells and was associated with increases in BLIMP-1 and XBP-1 protein and decreases in PAX5. As STAT3 activation is known to regulate IL-6, we assessed the effect of IL-21 on B cell-mediated IL-6 secretion using ELISA. IL-21 significantly increased IL-6 secretion by both primary CD19+CD138+ WM cells (n=4) and MWCL-1 cells (87.9 +/− 10.9 ng/mL vs. 297.8 +/− 129.2 ng/mL, p<0.05). Treatment with IL-6 and IL-21 together had no additional effect over IL-21 alone on proliferation or IgM secretion in MWCL-1 cells, but culturing anti-CD3/anti-CD28-activated CD19−CD138−cells from WM bone marrows with IL-6 significantly increased IL-21 secretion (n=3). Overall, these data indicate that T-cell derived IL-21 significantly promotes growth and immunoglobulin production by malignant WM B cells and that subsequent IL-6 secretion by malignant B cells may enhance the secretion of IL-21 by T cells within the bone marrow microenvironment. Disclosures: No relevant conflicts of interest to declare.

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