Abstract 152: Stat4 Deficiency limits the Development and Progression of Atherosclerosis

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Paresa Taghavie-Moghadam ◽  
Matthew Butcher ◽  
Mark Kaplan ◽  
Jerry Nadler ◽  
Elena Galkina
Keyword(s):  
T Cells ◽  
B Cell ◽  
Plaque Burden ◽  
Chow Diet ◽  
Th1 Cells ◽  
Peripheral Tissues ◽  
The Impact ◽  
Deficient Mice

T helper 1 (Th1) cells constitute the majority of plaque infiltrating IFNγ+ T cells and play a pro-atherogenic role. Th1 cells are induced via IFNγ-dependent activation of T-box expressed in T cells (Tbet) and/or IL-12-dependent activation of signal transducer and activator of transcription 4 (Stat4). While the role of Tbet in atherosclerosis is established, the impact of the IL-12/Stat4-dependent pathway is not well defined. To address the role of Stat4 in atherosclerosis, we bred Stat4-deficient mice with Apolipoprotein E-deficient mice to generate Stat4-/-Apoe-/- mice. Deficiency of Stat4 resulted in approximately a 70% reduction in the plaque burden for 34 week old Stat4-/-Apoe-/- mice fed a chow diet and in 12 week old Stat4-/-Apoe-/- mice fed a western diet there was approximately a 40% reduction in plaque burden, both compared with diet matched Apoe-/- controls females (p<0.001). To assess the effect of Stat4 on Th1 and Treg cell differentiation, we performed an in vitro polarization assay. Deficiency of Stat4 reduced differentiation of IFNγ+ Th1 cells in Th1 conditions, but supported the induction of Tregs in Treg polarizing conditions, confirming the importance of Stat4 in regulating the Th1/Treg balance. In contrast to the in vitro results, we found no difference in the expression of both IFNγ and Foxp3 amongst Stat4-/-Apoe-/- and Apoe-/- lymph nodes and splenic CD4+ T cells; suggesting that additional cytokines in vivo may induce IFNγ+Th1 and inhibit Treg differentiation. Stat4 deficiency also resulted in increased splenic B cell numbers and a slight increase in B1a dependent T15/E06 mRNA expression. Stat4 is a powerful regulator of chemokine expression within peripheral tissues. Adoptively transferred Apoe-/- B cells and CD11b+ cells migrated more efficiently into Stat4-/-Apoe-/- aortas compared to Apoe-/- recipients. However, percentages of macrophages, as determined by CD11b+CD68+ were reduced within the spleens and aortas of Stat4-/-Apoe-/- mice as compared to Apoe-/- controls at steady state conditions. In conclusion, Stat4 deficiency results in reduced atherosclerosis via the modulation of B cell function and aortic leukocyte content.

P53 Prevents TCR-Dependent Peripheral T-Cell Lymphomagenesis From Chronically Stimulated T Cells.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2401-2401
Author(s):  
Emmanuel Bachy ◽  
Alexandra Traverse-Glehen ◽  
Sophie Gazzo ◽  
Baseggio Lucile ◽  
Martine Ffrench ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cell Lymphoma ◽  
Transformation Process ◽  
T Cell Lymphoma ◽  
T Cell Lymphomas ◽  
Deficient Mice

Abstract Abstract 2401 Background. Compelling evidence suggests that chronic infections by various pathogens are linked to lymphoma development. The transformation process is supposed to be either direct (eg for EBV) or indirect. The association between Helicobacter pylori chronic infection and gastric marginal zone lymphoma (MZL) is the best characterized example for an indirect transformation. Several other pathogens such as hepatitis C virus, Campylobacter jejuni or Streptococcus Pneumoniae (Spn) are also suspected to promote B-cell lymphoma development through repeated stimulations of the BCR and/or inflammation. However, except for gastric MZL, animal models are lacking to study potential correlations between chronic infections and lymphoma development. Methods. To amplify and precipitate lymphomagenesis by precluding repair of DNA lesions potentially generated during chronic immune response, p53-deficient mice were used as a permissive model. Given the suspected role of carbohydrates from encapsulated bacteria such as Spn in promoting chronic lymphocytic leukemia, p53−/− (n=15) and p53+/− (n=53) mice were chronically injected with heat-killed Spn until disease development. P53-deficient mice chronically injected with PBS were used as control. Results. Unexpectedly, chronic injections of Spn promoted T-cell rather than B-cell lymphomagenesis in both p53−/− and p53+/− mice and shortened survival in p53+/− mice (P=.004). Whereas mostly thymic CD4+CD8+ double positive T-cell lymphomas have been described in p53-deficient mice, a vast majority of lymphomas observed following chronic Spn injections were of peripheral origin (TdT−) and exhibited an effector memory phenotype (CD44hiCD62LloCCR7−CD25−). Clonality and transferability of those peripheral T-cell lymphomas (PTCL) were established. Furthermore, lymphoma cells showed features of chronically stimulated T cells such as TCR, CD3 or CD4/CD8 co-receptor down-regulations along with PD-1 up-regulation. Several lines of evidence suggested a contribution of the TCR to the development of these PTCL: 1/all PTCL following Spn injections exhibited a Vß repertoire usage bias (Vß8 in 100%) consistent with a transformation process originating from a chronically-stimulated T cell by a pathogen-specific immunodominant peptide; 2/cyclosporin A, a strong TCR signaling inhibitor, decreased cell survival in vitro, and prolonged mice survival following transfer of lymphoma cells into recipient mice; 3/engraftment of CD8+ PTCL in MHC class I KO mice was significantly reduced compared to wild type mice (P<.0001). Finally in vitro survival of PTCL was strongly dependent on the addition of γc cytokines (IL-7 and IL-15) in agreement with the expression of CD122 and CD127 and their potential memory origin. The absence of B-cell lymphoma development in p53−/− mice and its very late onset in p53+/− mice (ie >450 days) compared to T-cell lymphoma prompted us to dissect the potential role of p53 in mature T-cell response in a context of chronic stimulation. WT and p53−/− negatively selected CD4+ and CD8+ T cells were repeatedly (ie every 7–10 days) stimulated in vitro using anti-CD3/anti-CD28-coated beads. In agreement with previous reports, no significant difference of cell viability was observed after the first or the second stimulation confirming the minor role of p53 in initial activation and proliferation as well as in activation-induced cell death. Nonetheless, a dramatic increase in cell viability was observed 48h after the third stimulation of p53−/− T cells, indicating a crucial function of p53 in deletion of chronically activated T cells. Conclusion. Chronic stimulations with heat-killed Spn unexpectedly increased peripheral T-cell lymphoma development in p53-deficient mice. Phenotypic characterization was consistent with a transformation process occurring in a pathogen-specific chronically-stimulated T cell. The incidence of p53 mutations is higher in T-cell than in B-cell mature malignancies in humans and the p53 pathway is functionally impaired in virtually all enteropathy-associated T-cell lymphomas, which are supposed to be a key model for an antigen-driven process. Therefore, aside from its known role in immature T-cell lymphoma development and in progression of B-cell malignancies, our work sheds light on a previously unsuspected physiopathological role of the p53 pathway in peripheral T-cell lymphomagenesis. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Resistance to Experimental Visceral Leishmaniasis in Mice Infected With Leishmania infantum Requires Batf3

2020 ◽  
Vol 11 ◽  
Author(s):  
Manuel Soto ◽  
Laura Ramírez ◽  
José Carlos Solana ◽  
Emma C. L. Cook ◽  
Elena Hernández-García ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Infantum ◽  
Rational Design ◽  
Leucine Zipper ◽  
Basic Leucine Zipper ◽  
Vector Borne ◽  
The Impact ◽  
Deficient Mice

Unveiling the protective immune response to visceral leishmaniasis is critical for a rational design of vaccines aimed at reducing the impact caused by this fatal, if left untreated, vector-borne disease. In this study we sought to determine the role of the basic leucine zipper transcription factor ATF-like 3 (Batf3) in the evolution of infection with Leishmania infantum, the causative agent of human visceral leishmaniasis in the Mediterranean Basin and Latin America. For that, Batf3-deficient mice in C57BL/6 background were infected with an L. infantum strain expressing the luciferase gene. Bioluminescent imaging, as well as in vitro parasite titration, demonstrated that Batf3-deficient mice were unable to control hepatic parasitosis as opposed to wild-type C57BL/6 mice. The impaired microbicide capacities of L. infantum-infected macrophages from Batf3-deficient mice mainly correlated with a reduction of parasite-specific IFN-γ production. Our results reinforce the implication of Batf3 in the generation of type 1 immunity against infectious diseases.

scholarly journals L-selectin deficiency decreases aortic B1a and Breg subsets and promotes atherosclerosis

2014 ◽  
Vol 112 (10) ◽  
pp. 803-811 ◽  
Author(s):  
Breanne Gjurich ◽  
Parésa Taghavie-Moghadam ◽  
Klaus Ley ◽  
Elena Galkina
Keyword(s):  
B Cells ◽  
Neutrophil Migration ◽  
Fold Increase ◽  
Interleukin 10 ◽  
Plaque Burden ◽  
Chow Diet ◽  
Blood Neutrophil ◽  
Peripheral Tissues ◽  
Cell Counts

SummaryThere is a significant recruitment of leucocytes into aortas during atherogenesis. L-selectin regulates leucocyte migration into secondary lymphoid and peripheral tissues and was proposed to play a role in leucocyte homing into aortas. Here, we determine the role of L-selectin in atherosclerosis. L-selectin-deficient Apoe -/- (Sell -/- Apoe -/-) mice had a 74% increase in plaque burden compared to Apoe -/- mice fed a chow diet for 50 weeks. Elevated atherosclerosis was accompanied by increased aortic leucocyte content, but a 50% reduction in aortic B cells despite elevated B cell counts in the blood. Follicular B cells represented 65%, whereas B1a and regulatory B cells (Breg) comprised 5% of aortic B cells. B1a and Breg cell subsets were reduced in Sell -/- Apoe -/- aortas with accompanied two-fold decrease in aortic T15 antibody and 1.2-fold decrease of interleukin-10 (IL-10) levels. L-selectin was required for B1 cell homing to the atherosclerotic aorta, as demonstrated by a 1.5-fold decrease in the migration of Sell -/- Apoe -/- vs Apoe -/- cells. Notably, we found a 1.6-fold increase in CD68hi macrophages in Sell -/- Apoe -/- compared to Apoe -/- aortas, despite comparable blood monocyte numbers and L-selectin-dependent aortic homing. L-selectin had no effect on neutrophil migration into aorta, but led to elevated blood neutrophil numbers, suggesting a potential involvement of neutrophils in atherogenesis of Sell -/- Apoe -/- mice. Thus, L-selectin deficiency increases peripheral blood neutrophil and lymphocyte numbers, decreases aortic B1a and Breg populations, T15 antibody and IL-10 levels, and increases aortic macrophage content of Sell -/- Apoe -/- mice. Altogether, these data provide evidence for an overall atheroprotective role of L-selectin.

scholarly journals Fas/FasL Pathway Participates in Regulation of Antiviral and Inflammatory Response during Mousepox Infection of Lungs

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Karolina Bień ◽  
Justyna Sokołowska ◽  
Piotr Bąska ◽  
Zuzanna Nowak ◽  
Wanda Stankiewicz ◽  
...  
Keyword(s):  
T Cells ◽  
Inflammatory Response ◽  
Fas Ligand ◽  
Antiviral Response ◽  
Target Cells ◽  
Local Inflammatory Response ◽  
Induced Apoptosis ◽  
Deficient Mice

Fas receptor-Fas ligand (FasL) signalling is involved in apoptosis of immune cells as well as of the virus infected target cells but increasing evidence accumulates on Fas as a mediator of apoptosis-independent processes such as induction of activating and proinflammatory signals. In this study, we examined the role of Fas/FasL pathway in inflammatory and antiviral response in lungs using a mousepox model applied to C57BL6/J, B6. MRL-Faslpr/J, and B6Smn.C3-Faslgld/J mice. Ectromelia virus (ECTV) infection of Fas- and FasL-deficient mice led to increased virus titers in lungs and decreased migration of IFN-γexpressing NK cells, CD4+ T cells, CD8+ T cells, and decreased IL-15 expression. The lungs of ECTV-infected Fas- and FasL-deficient mice showed significant inflammation during later phases of infection accompanied by decreased expression of anti-inflammatory IL-10 and TGF-β1 cytokines and disturbances in CXCL1 and CXCL9 expression. Experiments in vitro demonstrated that ECTV-infected cultures of epithelial cells, but not macrophages, upregulate Fas and FasL and are susceptible to Fas-induced apoptosis. Our study demonstrates that Fas/FasL pathway during ECTV infection of the lungs plays an important role in controlling local inflammatory response and mounting of antiviral response.

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.

Elevated Serum IL-12 Levels Attenuate Tumor Immunity Via the TIM-3/Gal-9 Axis and Worsen Patient Prognosis in Follicular B-Cell Non-Hodgkin Lymphoma (NHL).

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2668-2668
Author(s):  
Zhi-Zhang Yang ◽  
Steven C. Ziesmer ◽  
Anne J. Novak ◽  
Toshiro Niki ◽  
Mitsuomi Hirashima ◽  
...  
Keyword(s):  
T Cells ◽  
B Cell ◽  
Tumor Immunity ◽  
Cd8 T Cells ◽  
Cell Lymphoma ◽  
Elevated Serum ◽  
B Cell Lymphoma ◽  
Serum Levels

Abstract Abstract 2668 Poster Board II-644 Interleukin-12 (IL-12) has been demonstrated to induce IFN-g production by T and NK cells and thereby contribute to anti-tumor immunity. However, the administration of IL-12 to boost anti-tumor immunity in B-cell lymphoma has shown no clinical benefit. In fact, clinical trials of IL-12 in combination with rituximab in follicular B-cell lymphoma (FL) showed a lower response rate in patients treated with the combination than in patients treated with rituximab alone (Clin Cancer Res. 2006 15; 12:6056-63). The goal of this study was therefore to determine the role of IL-12 in the antitumor response in B-cell NHL. First, we measured serum levels of IL-12 in patients with untreated FL before treatment with rituximab and normal healthy controls. We found that serum IL-12 levels were elevated in FL patients compared to healthy individuals (median: 0.50 ng/ml, n=30 vs 0.32 ng/ml, n=22; p= 0.03) and that elevated serum IL-12 levels were associated with a poor outcome in these patients when treated with rituximab alone as initial therapy. Using 0.56 ng/ml as a cutoff, patients with serum IL-12 levels of greater than 0.56 ng/ml had a significantly shorter time to progression than patients with IL-12 levels less than 0.56 ng/ml (12 months versus 40 months; p=0.001). To determine the mechanism by which IL-12 may contribute to a poor prognosis, we investigated the role of IL-12 on induction of immune tolerance. First, we found that TIM-3, a member of the T cell immunoglobulin and mucin domain-containing protein (TIM) family that functions to terminate TH1-mediated immunity and promote tolerance, was constitutively expressed on a subset of intratumoral T cells accounting for approximately 15% and 25% of the intratumoral CD4+ and CD8+ T cells, respectively. In contrast, less than 2% of T cells from peripheral blood of normal individuals expressed TIM-3. TIM-3-expressing T cells were distinct from regulatory T cells since CD25+ and Foxp3+ T cells lacked TIM-3 expression. Secondly, we found that TIM-3-expressing CD4+ cells were unable to produce cytokines such as IL-2, IFN-g or IL-17 and that TIM-3-expressing CD8+ T cells failed to produce Granzyme B, IFN-g or IL-2. We also observed that TIM-3-expressing T cells lost the capacity to proliferate in response to TCR activation. These results suggest that TIM-3 expressing CD4+ and CD8+ T cells are functionally exhausted. Thirdly, we observed that TIM-3 expression on T cells could be induced by activation and that IL-12 was the strongest stimulus to induce TIM-3 expression on CD4+ and CD8+ T cells. Finally, we found by immunohistochemistry (IHC) that Galectin-9 (Gal-9), a ligand for TIM-3, was abundantly expressed on lymphoma B cells. In vitro incubation with a stable form of Gal-9 induced apoptosis of CD4+ and CD8+ T cells in a dose dependent fashion. Gal-9-mediated apoptosis of T cells was attenuated by a TIM-3 Fc protein and isolated TIM-3+ T cells exhibited a significantly higher apoptosis rate than TIM-3− T cells in response to Gal-9. These results indicate that, in contrast to the observations in vitro or in vivo in mice, IL-12 actually plays a detrimental role in lymphoma patients. Given the findings that IL-12 strongly induces TIM-3 expression on effector T cells and that the TIM-3/Gal-9 pathway impairs the immune response, we conclude that increased serum levels of IL-12 suppress anti-tumor immunity in follicular lymphoma patients and is associated with a poor prognosis. Disclosures: Witzig: Novartis: Research Funding.

scholarly journals P-Selectin Glycoprotein Ligand 1 (Psgl-1) Is a Physiological Ligand for E-Selectin in Mediating T Helper 1 Lymphocyte Migration

2000 ◽  
Vol 192 (11) ◽  
pp. 1669-1676 ◽  
Author(s):  
Takako Hirata ◽  
Glenn Merrill-Skoloff ◽  
Melissa Aab ◽  
Jing Yang ◽  
Barbara C. Furie ◽  
...  
Keyword(s):  
Contact Hypersensitivity ◽  
Th1 Cells ◽  
Wild Type ◽  
T Helper ◽  
Lymphocyte Migration ◽  
T Helper 1 ◽  
Deficient Mice

P-selectin glycoprotein ligand 1 (PSGL-1) is a sialomucin expressed on leukocytes that mediates neutrophil rolling on the vascular endothelium. Here, the role of PSGL-1 in mediating lymphocyte migration was studied using mice lacking PSGL-1. In a contact hypersensitivity model, the infiltration of CD4+ T lymphocytes into the inflamed skin was reduced in PSGL-1–deficient mice. In vitro–generated T helper (Th)1 cells from PSGL-1–deficient mice did not bind to P-selectin and migrated less efficiently into the inflamed skin than wild-type Th1 cells. To assess the role of PSGL-1 in P- or E-selectin–mediated migration of Th1 cells, the cells were injected into E- or P-selectin–deficient mice. PSGL-1–deficient Th1 cells did not migrate into the inflamed skin of E-selectin–deficient mice, indicating that PSGL-1 on Th1 cells is the sole ligand for P-selectin in vivo. In contrast, PSGL-1–deficient Th1 cells migrated into the inflamed skin of P-selectin–deficient mice, although less efficiently than wild-type Th1 cells. This E-selectin–mediated migration of PSGL-1–deficient or wild-type Th1 cells was not altered by injecting a blocking antibody to L-selectin. These data provide evidence that PSGL-1 on Th1 cells functions as one of the E-selectin ligands in vivo.

scholarly journals Epstein-Barr Virus Type 2 Latently Infects T Cells, Inducing an Atypical Activation Characterized by Expression of Lymphotactic Cytokines

2014 ◽  
Vol 89 (4) ◽  
pp. 2301-2312 ◽  
Author(s):  
Carrie B. Coleman ◽  
Eric M. Wohlford ◽  
Nicholas A. Smith ◽  
Christine A. King ◽  
Julie A. Ritchie ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Lymphoproliferative Diseases ◽  
Barr Virus ◽  
T Cell Lymphomas ◽  
Epstein Barr

ABSTRACTEpstein-Barr virus (EBV) is a well-established B-cell-tropic virus associated with various lymphoproliferative diseases of both B-cell and non-B-cell origin. EBV is associated with a number of T-cell lymphomas; however,in vitrostudies utilizing prototypical EBV type 1 (EBV-1) laboratory strains have generally failed to readily infect mature T cells in culture. The difficulties in performingin vitroT-cell experiments have left questions regarding the role of EBV in the pathogenesis of EBV-positive T-cell lymphoproliferative diseases largely unresolved. We report here that the EBV type 2 (EBV-2) strain displays a unique cell tropism for T cells. In remarkable contrast to EBV-1, EBV-2 readily infects primary T cellsin vitro, demonstrating a propensity for CD8+T cells. EBV-2 infection of purified T cells results in expression of latency genes and ultimately leads to T-cell activation, substantial proliferation, and profound alteration of cytokine expression. The pattern of cytokine production is strikingly skewed toward chemokines with roles in lymphocyte migration, demonstrating that EBV-2 has the ability to modulate normal T-cell processes. Collectively, these novel findings identify a previously unknown cell population potentially utilized by EBV-2 to establish latency and lay the foundation for further studies to elucidate the role of EBV in the pathogenesis of T-cell lymphoproliferative diseases.IMPORTANCEThe ability of EBV to infect T cells is made apparent by its association with a variety of T-cell lymphoproliferative disorders. However, studies to elucidate the pathogenic role of EBV in these diseases have been limited by the inability to conductin vitroT-cell infection experiments. Here, we report that EBV-2 isolates, compromised in the capacity to immortalize B cells, infect CD3+T cellsex vivoand propose a working model of EBV-2 persistence where alteration of T-cell functions resulting from EBV-2 infection enhances the establishment of latency in B cells. If indeed EBV-2 utilizes T cells to establish a persistent infection, this could provide one mechanism for the association of EBV with T-cell lymphomas. The novel finding that EBV-2 infects T cells in culture will provide a model to understand the role EBV plays in the development of T-cell lymphomas.

scholarly journals Critical Role of T Cells in PF4/Heparin Antibody Production

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1554-1554
Author(s):  
Yongwei Zheng ◽  
Mei Yu ◽  
Anand Padmanabhan ◽  
Richard H. Aster ◽  
Renren Wen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Antibody Production ◽  
Cd4 T Cells ◽  
Wild Type ◽  
Specific Antibodies ◽  
Deficient Mice

Abstract Heparin-induced thrombocytopenia (HIT) is an antibody-mediated disorder that can cause arterial or venous thrombosis/thromboembolism, and platelet factor 4 (PF4)/ heparin-reactive antibodies are essential to the pathogenesis of HIT. Our recent studies have demonstrated that marginal zone (MZ) B cells play a major role in production of PF4/heparin-specific antibodies. However, the role of T cells in production of these pathogenic antibodies is not clear. Here we showed that PF4/heparin complex-induced production of PF4/heparin-specific antibodies was markedly impaired in mice, in which CD4 T cells were depleted by administration of GK1.5 anti-CD4 monoclonal antibody. As expected, the CD4 T cell-depleted mice responded normally to T cell-independent antigen TNP-Ficoll but not T cell-dependent antigen NP-CGG, in agreement with the lack of CD4 T cells in these GK1.5-treated mice. Further, following adoptive transfer of a mixture of wild-type splenic B cells and splenocytes from B cell-deficient μMT mice, T and B cell-deficient Rag1 knockout mice responded to PF4/heparin complex challenge to produce PF4/heparin-specific antibodies. In contrast, Rag1-deficient mice that received a mixture of wild-type splenic B cells and splenocytes from Rag1-deficient mice barely produced PF4/heparin-specific antibodies upon PF4/heparin complex challenge. These data suggest that T cells are required for production of PF4/heparin-specific antibodies. Consistent with this concept, mice with B cells lacking CD40 molecule, a B cell costimulatory molecule that helps T cell-dependent B cell responses, displayed a marked reduction of PF4/heparin-specific antibody production following PF4/heparin complex challenge. Also as expected, mice with CD40-deficient B cells were able to respond to T cell-independent antigen TNP-Ficoll but not T cell-dependent antigen NP-CGG, consistent with the lack of T-cell help in these mice. Taken together, these findings demonstrate that T cells play an essential role in production of PF4/heparin-specific antibodies by MZ B cells. Disclosures No relevant conflicts of interest to declare.

scholarly journals Intratumoral T cells have a differential impact on FDG-PET parameters in follicular lymphoma

2021 ◽  
Vol 5 (12) ◽  
pp. 2644-2649
Author(s):  
Karthik Nath ◽  
Soi-Cheng Law ◽  
Muhammed B. Sabdia ◽  
Jay Gunawardana ◽  
Lilia M. de Long ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Follicular Lymphoma ◽  
B Cell ◽  
Glucose Uptake ◽  
Fdg Pet ◽  
Prognostic Impact ◽  
The Impact

Data on the prognostic impact of pretherapy 18F-fluorodeoxyglucose–positron emission tomography (FDG-PET) in follicular lymphoma (FL) is conflicting. The predictive utility of pretherapy total metabolic tumor volume (TMTV) and maximum standardized uptake value (SUVmax) on outcome appears to vary between regimens. Chemoimmunotherapies vary in the extent of T-cell depletion they induce. The role of intratumoral T cells on pretherapy FDG-PET parameters is undefined. We assessed pretherapy FDG-PET parameters and quantified intratumoral T cells by multiple methodologies. Low intratumoral T cells associated with approximately sixfold higher TMTV, and FL nodes from patients with high TMTV showed increased malignant B-cell infiltration and fewer clonally expanded intratumoral CD8+ and CD4+ T-follicular helper cells than those with low TMTV. However, fluorescently labeled glucose uptake was higher in CD4+ and CD8+ T cells than intratumoral B cells. In patients with FDG-PET performed prior to excisional biopsy, SUVmax within the subsequently excised node associated with T cells but not B cells. In summary, TMTV best reflects the malignant B-cell burden in FL, whereas intratumoral T cells influence SUVmax. This may contribute to the contradictory results between the prognostic role of different FDG-PET parameters, particularly between short- and long-term T-cell–depleting chemoimmunotherapeutic regimens. The impact of glucose uptake in intratumoral T cells should be considered when interpreting pretherapy FDG-PET in FL.

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