Very Early Effects of Ibrutinib on Tumor and Immune Cells in Blood and Lymph Nodes in Relapsed or Refractory Chronic Lymphocytic Leukemia (CLL) Patients

Abstract In this study we analyzed the very early effects of the Bruton's tyrosine kinase (BTK) inhibitor ibrutinib on tumor and immune cells in 7 symptomatic, relapsed or refractory CLL patients during the first four weeks of treatment. Five of the patients had Rai stage IV at study entry and four patients had 17p deletion or TP53 mutation. Median number of previous treatment regimens was 2 (range 1-4). Peripheral blood (PB) samples were collected before (< 1 week) treatment start and at six different time points during the treatment (9 hours after treatment start on day 1; on day 2; day 4; day 8; day 15 and day 29). Fine needle aspiration of two pathological lymph nodes (LN) identified by ultrasound was performed before (< 1 week) treatment start and at day 2, day 8 and day 29. Flow-cytometry was performed to analyze the changes in the peripheral blood mononuclear cell populations in PB including CLL cells, Natural Killer (NK) cells, monocytes, dendritic cells (DC) and T cells memory subsets, helper subpopulations (Ths) and regulatory T cells (Tregs). Moreover, changes in expression of 18 B-cell activation and migration markers on CLL cells as well as T-cell activation and proliferation markers, were analyzed in paired LN and PB samples. Finally, plasma levels of 92 inflammation-related protein biomarkers were assessed by Multiplex Proximity Extension Assay (PEA). In six out of seven patients the size of the LN decreased gradually during the four weeks of observation, achieving complete clinical remission in three patients and partial remission in three other. In 5 evaluated patients, the CLL cell counts in PB increased already 9 hours after treatment start (fold increase 1.36-2.84). In all the patients, CLL cells were higher at day 2 and 8 compared to baseline (p=0.02), and decreased by day 29 to levels not significantly different from the baseline. Over the four weeks period CD4+ cells increased (p=0.03), while CD8+, NK, and NKT cells remained stable. The distribution of the CD4+ and CD8+ memory cell subsets remained unchanged. Th1 cells increased (p=0.01) while Th2, Th17 and Tregs were stable. Expression of Programmed cell death protein 1 (PD-1) and Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) in T cells was unaffected. No effect was seen on CLL apoptosis. Proliferating (Ki67+) CLL cells, which at baseline varied between 1.2-10.8%, were not detected in blood after 1 week of treatment (p=0.0006). Ki67+ T cells were also eliminated (p=0.0007), but with a delayed kinetics (4 weeks). Paired LN and PB samples were screened for changes in 18 surface markers relevant for B-cell activation and migration. With the exception of CD23, whose expression was lower in PB compared to LN (p=0.02), no difference was observed in the expression of the other analyzed surface markers on CLL cells from the two different tumor compartments at baseline. CD5 expression remained stable during treatment, albeit decreasing significantly by day 29 in PB (p=0.02). Expression of CD20 decreased in both compartments at day 8 (p=0.02) and CD40 decreased at day 8 only in PB (p=0.02). CD69 expression (MFI) decreased both in PB and LN by day 8 (p=0.02), while the percentage of positive cells significantly dropped already at day 2 in PB (p=0.02) and from day 8 in LN (p=0.03). CD23 MFI decreased in the LN compartment already at day 2 (p=0.02), but the percentage of positive cells was significantly lower only at day 8 (p=0.03). Compared to LN, CD23 expression was lower in PB before treatment and therefore the significant drop both in MFI and percentage of positive cells was seen only after 4 weeks (p=0.02). No change in the expression of CD49d was observed. In 5 evaluable patients, the plasmacytoid DCs, undetectable at baseline, increased during treatment (p=0.06), while CD16+SLAN+monocytes decreased (p=0.06). Finally, plasma levels of 50 molecules were significantly changed at ≥ 1 time point during treatment. With the exception of CST5 and IL-17C, which were increased, the residual 48 proteins were all down-regulated, some of them (e.g. CCL3 and CCL4) already by 9 hours. The majority of the cytokines with significantly reduced levels are pro-inflammatory molecules. In conclusion, these data indicate that ibrutinib causes major changes both in CLL and bystander cells as well as in the levels of several inflammation-related protein biomarkers already shortly after treatment initiation. Disclosures Lundin: Janssen: Research Funding. Kimby:Gilead: Honoraria, Other: honoraria for educational lecture in meeting sponsored by Gilead; Roche: Other: Honoraria for lecture in educational meetings; Pfizer: Other: Research grant; Celgene: Other: Honoraria for lecture. educational meeting; Jansen: Membership on an entity's Board of Directors or advisory committees, Other: Honoraria for lecture at educational session. Österborg:Janssen: Honoraria, Research Funding.

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Hyaluronate-CD44 Interactions Can Induce Murine B-Cell Activation

Blood ◽

10.1182/blood.v89.8.2901 ◽

1997 ◽

Vol 89 (8) ◽

pp. 2901-2908 ◽

Cited By ~ 71

Author(s):

Asimah Rafi ◽

Mitzi Nagarkatti ◽

Prakash S. Nagarkatti

Keyword(s):

T Cells ◽

B Cells ◽

B Cell ◽

Cell Activation ◽

Critical Role ◽

Surface Glycoprotein ◽

B Cell Differentiation ◽

B Cell Activation ◽

Cell Surface Glycoprotein ◽

Immunodeficient Mice

Abstract CD44 is a widely distributed cell surface glycoprotein whose principal ligand has been identified as hyaluronic acid (HA), a major component of the extracellular matrix (ECM). Recent studies have demonstrated that activation through CD44 leads to induction of effector function in T cells and macrophages. In the current study, we investigated whether HA or monoclonal antibodies (MoAbs) against CD44 would induce a proliferative response in mouse lymphocytes. Spleen cells from normal and nude, but not severe combined immunodeficient mice, exhibited strong proliferative responsiveness to stimulation with soluble HA or anti-CD44 MoAbs. Furthermore, purified B cells, but not T cells, were found to respond to HA. HA was unable to stimulate T cells even in the presence of antigen presenting cells (APC) and was unable to act as a costimulus in the presence of mitogenic or submitogenic concentrations of anti-CD3 MoAbs. In contrast, stimulation of B cells with HA in vitro, led to B-cell differentiation as measured by production of IgM antibodies in addition to increased expression of CD44 and decreased levels of CD45R. The fact that the B cells were responding directly to HA through its binding to CD44 and not to any contaminants or endotoxins was demonstrated by the fact that F(ab)2 fragments of anti-CD44 MoAbs or soluble CD44 fusion proteins could significantly inhibit the HA-induced proliferation of B cells. Also, HA-induced proliferation of B cells was not affected by the addition of polymixin B, and B cells from lipopolysaccharide (LPS)-unresponsive C3H/HeJ strain responded strongly to stimulation with HA. Furthermore, HA, but not chondroitin-sulfate, another major component of the ECM, induced B-cell activation. It was also noted that injection of HA intraperitoneally, triggered splenic B cell proliferation in vivo. Together, the current study demonstrates that interaction between HA and CD44 can regulate murine B-cell effector functions and that such interactions may play a critical role during normal or autoimmune responsiveness of B cells.

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Distinct Gene Expression Signatures in Patients with Richter's Syndrome and Chronic Lymphocytic Leukemia with Prior Exposure to Ibrutinib

Blood ◽

10.1182/blood-2020-136172 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 30-31

Author(s):

Hanyin Wang ◽

Shulan Tian ◽

Qing Zhao ◽

Wendy Blumenschein ◽

Jennifer H. Yearley ◽

...

Keyword(s):

Gene Expression ◽

B Cell ◽

Board Of Directors ◽

Research Funding ◽

Cell Activation ◽

Expression Profiles ◽

Lymphocytic Leukemia ◽

B Cell Activation ◽

Advisory Committees ◽

Upregulated Genes

Introduction: Richter's syndrome (RS) represents transformation of chronic lymphocytic leukemia (CLL) into a highly aggressive lymphoma with dismal prognosis. Transcriptomic alterations have been described in CLL but most studies focused on peripheral blood samples with minimal data on RS-involved tissue. Moreover, transcriptomic features of RS have not been well defined in the era of CLL novel therapies. In this study we investigated transcriptomic profiles of CLL/RS-involved nodal tissue using samples from a clinical trial cohort of refractory CLL and RS patients treated with Pembrolizumab (NCT02332980). Methods: Nodal samples from 9 RS and 4 CLL patients in MC1485 trial cohort were reviewed and classified as previously published (Ding et al, Blood 2017). All samples were collected prior to Pembrolizumab treatment. Targeted gene expression profiling of 789 immune-related genes were performed on FFPE nodal samples using Nanostring nCounter® Analysis System (NanoString Technologies, Seattle, WA). Differential expression analysis was performed using NanoStringDiff. Genes with 2 fold-change in expression with a false-discovery rate less than 5% were considered differentially expressed. Results: The details for the therapy history of this cohort were illustrated in Figure 1a. All patients exposed to prior ibrutinib before the tissue biopsy had developed clinical progression while receiving ibrutinib. Unsupervised hierarchical clustering using the 300 most variable genes in expression revealed two clusters: C1 and C2 (Figure 1b). C1 included 4 RS and 3 CLL treated with prior chemotherapy without prior ibrutinib, and 1 RS treated with prior ibrutinib. C2 included 1 CLL and 3 RS received prior ibrutinib, and 1 RS treated with chemotherapy. The segregation of gene expression profiles in samples was largely driven by recent exposure to ibrutinib. In C1 cluster (majority had no prior ibrutinb), RS and CLL samples were clearly separated into two subgroups (Figure 1b). In C2 cluster, CLL 8 treated with ibrutinib showed more similarity in gene expression to RS, than to other CLL samples treated with chemotherapy. In comparison of C2 to C1, we identified 71 differentially expressed genes, of which 34 genes were downregulated and 37 were upregulated in C2. Among the upregulated genes in C2 (majority had prior ibrutinib) are known immune modulating genes including LILRA6, FCGR3A, IL-10, CD163, CD14, IL-2RB (figure 1c). Downregulated genes in C2 are involved in B cell activation including CD40LG, CD22, CD79A, MS4A1 (CD20), and LTB, reflecting the expected biological effect of ibrutinib in reducing B cell activation. Among the 9 RS samples, we compared gene profiles between the two groups of RS with or without prior ibrutinib therapy. 38 downregulated genes and 10 upregulated genes were found in the 4 RS treated with ibrutinib in comparison with 5 RS treated with chemotherapy. The top upregulated genes in the ibrutinib-exposed group included PTHLH, S100A8, IGSF3, TERT, and PRKCB, while the downregulated genes in these samples included MS4A1, LTB and CD38 (figure 1d). In order to delineate the differences of RS vs CLL, we compared gene expression profiles between 5 RS samples and 3 CLL samples that were treated with only chemotherapy. RS samples showed significant upregulation of 129 genes and downregulation of 7 genes. Among the most significantly upregulated genes are multiple genes involved in monocyte and myeloid lineage regulation including TNFSF13, S100A9, FCN1, LGALS2, CD14, FCGR2A, SERPINA1, and LILRB3. Conclusion: Our study indicates that ibrutinib-resistant, RS-involved tissues are characterized by downregulation of genes in B cell activation, but with PRKCB and TERT upregulation. Furthermore, RS-involved nodal tissues display the increased expression of genes involved in myeloid/monocytic regulation in comparison with CLL-involved nodal tissues. These findings implicate that differential therapies for RS and CLL patients need to be adopted based on their prior therapy and gene expression signatures. Studies using large sample size will be needed to verify this hypothesis. Figure Disclosures Zhao: Merck: Current Employment. Blumenschein:Merck: Current Employment. Yearley:Merck: Current Employment. Wang:Novartis: Research Funding; Incyte: Research Funding; Innocare: Research Funding. Parikh:Verastem Oncology: Honoraria; GlaxoSmithKline: Honoraria; Pharmacyclics: Honoraria, Research Funding; MorphoSys: Research Funding; Ascentage Pharma: Research Funding; Genentech: Honoraria; AbbVie: Honoraria, Research Funding; Merck: Research Funding; TG Therapeutics: Research Funding; AstraZeneca: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Kenderian:Sunesis: Research Funding; MorphoSys: Research Funding; Humanigen: Consultancy, Patents & Royalties, Research Funding; Gilead: Research Funding; BMS: Research Funding; Tolero: Research Funding; Lentigen: Research Funding; Juno: Research Funding; Mettaforge: Patents & Royalties; Torque: Consultancy; Kite: Research Funding; Novartis: Patents & Royalties, Research Funding. Kay:Astra Zeneca: Membership on an entity's Board of Directors or advisory committees; Acerta Pharma: Research Funding; Juno Theraputics: Membership on an entity's Board of Directors or advisory committees; Dava Oncology: Membership on an entity's Board of Directors or advisory committees; Oncotracker: Membership on an entity's Board of Directors or advisory committees; Sunesis: Research Funding; MEI Pharma: Research Funding; Agios Pharma: Membership on an entity's Board of Directors or advisory committees; Bristol Meyer Squib: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Rigel: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Cytomx: Membership on an entity's Board of Directors or advisory committees. Braggio:DASA: Consultancy; Bayer: Other: Stock Owner; Acerta Pharma: Research Funding. Ding:DTRM: Research Funding; Astra Zeneca: Research Funding; Abbvie: Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Membership on an entity's Board of Directors or advisory committees; alexion: Membership on an entity's Board of Directors or advisory committees; Beigene: Membership on an entity's Board of Directors or advisory committees.

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Single Cell Profiling Reveals Unique CXCL13 Positive T Cell Subsets in the Tumor Microenvironment of Lymphocyte Rich Classic Hodgkin Lymphoma

Blood ◽

10.1182/blood-2020-134929 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 32-33

Author(s):

Tomohiro Aoki ◽

Lauren C. Chong ◽

Katsuyoshi Takata ◽

Katy Milne ◽

Elizabeth Chavez ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cells ◽

Single Cell ◽

Immune Cells ◽

Research Funding ◽

Immune Cell ◽

Expression Patterns ◽

The Other ◽

Tfh Cells

Introduction: Classic Hodgkin lymphoma (CHL) features a unique crosstalk between malignant cells and different types of normal immune cells in the tumor-microenvironment (TME). On the basis of histomorphologic and immunophenotypic features of the malignant Hodgkin and Reed-Sternberg (HRS) cells and infiltrating immune cells, four histological subtypes of CHL are recognized: Nodular sclerosing (NS), Mixed cellularity, Lymphocyte-rich (LR) and Lymphocyte-depleted CHL. Recently, our group described the high abundance of various types of immunosuppressive CD4+ T cells including LAG3+ and/or CTLA4+ cells in the TME of CHL using single cell RNA sequencing (scRNAseq). However, the TME of LR-CHL has not been well characterized due to the rarity of the disease. In this study, we aimed at characterizing the immune cell profile of LR-CHL at single cell resolution. METHODS: We performed scRNAseq on cell suspensions collected from lymph nodes of 28 primary CHL patients, including 11 NS, 9 MC and 8 LR samples, with 5 reactive lymph nodes (RLN) serving as normal controls. We merged the expression data from all cells (CHL and RLN) and performed batch correction and normalization. We also performed single- and multi-color immunohistochemistry (IHC) on tissue microarray (TMA) slides from the same patients. In addition, an independent validation cohort of 31 pre-treatment LR-CHL samples assembled on a TMA, were also evaluated by IHC. Results: A total of 23 phenotypic cell clusters were identified using unsupervised clustering (PhenoGraph). We assigned each cluster to a cell type based on the expression of genes described in published transcriptome data of sorted immune cells and known canonical markers. While most immune cell phenotypes were present in all pathological subtypes, we observed a lower abundance of regulatory T cells (Tregs) in LR-CHL in comparison to the other CHL subtypes. Conversely, we found that B cells were enriched in LR-CHL when compared to the other subtypes and specifically, all four naïve B-cell clusters were quantitatively dominated by cells derived from the LR-CHL samples. T follicular helper (TFH) cells support antibody response and differentiation of B cells. Our data show the preferential enrichment of TFH in LR-CHL as compared to other CHL subtypes, but TFH cells were still less frequent compared to RLN. Of note, Chemokine C-X-C motif ligand 13 (CXCL13) was identified as the most up-regulated gene in LR compared to RLN. CXCL13, which is a ligand of C-X-C motif receptor 5 (CXCR5) is well known as a B-cell attractant via the CXCR5-CXCL13 axis. Analyzing co-expression patterns on the single cell level revealed that the majority of CXCL13+ T cells co-expressed PD-1 and ICOS, which is known as a universal TFH marker, but co-expression of CXCR5, another common TFH marker, was variable. Notably, classical TFH cells co-expressing CXCR5 and PD-1 were significantly enriched in RLN, whereas PD-1+ CXCL13+ CXCR5- CD4+ T cells were significantly enriched in LR-CHL. These co-expression patterns were validated using flow cytometry. Moreover, the expression of CXCR5 on naïve B cells in the TME was increased in LR-CHL compared to the other CHL subtypes We next sought to understand the spatial relationship between CXCL13+ T cells and malignant HRS cells. IHC of all cases revealed that CXCL13+ T cells were significantly enriched in the LR-CHL TME compared to other subtypes of CHL, and 46% of the LR-CHL cases showed CXCL13+ T cell rosettes closely surrounding HRS cells. Since PD-1+ T cell rosettes are known as a specific feature of LR-CHL, we confirmed co-expression of PD-1 in the rosetting cells by IHC in these cases. Conclusions: Our results reveal a unique TME composition in LR-CHL. LR-CHL seems to be distinctly characterized among the CHL subtypes by enrichment of CXCR5+ naïve B cells and CD4+ CXCL13+ PD-1+ T cells, indicating the importance of the CXCR5-CXCL13 axis in the pathogenesis of LR-CHL. Figure Disclosures Savage: BeiGene: Other: Steering Committee; Merck, BMS, Seattle Genetics, Gilead, AstraZeneca, AbbVie: Honoraria; Roche (institutional): Research Funding; Merck, BMS, Seattle Genetics, Gilead, AstraZeneca, AbbVie, Servier: Consultancy. Scott:Janssen: Consultancy, Research Funding; Celgene: Consultancy; NanoString: Patents & Royalties: Named inventor on a patent licensed to NanoString, Research Funding; NIH: Consultancy, Other: Co-inventor on a patent related to the MCL35 assay filed at the National Institutes of Health, United States of America.; Roche/Genentech: Research Funding; Abbvie: Consultancy; AstraZeneca: Consultancy. Steidl:AbbVie: Consultancy; Roche: Consultancy; Curis Inc: Consultancy; Juno Therapeutics: Consultancy; Bayer: Consultancy; Seattle Genetics: Consultancy; Bristol-Myers Squibb: Research Funding.

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Distinct microbial and immune niches of the human colon

10.1101/2019.12.12.871657 ◽

2019 ◽

Cited By ~ 2

Author(s):

KR James ◽

T Gomes ◽

R Elmentaite ◽

N Kumar ◽

EL Gulliver ◽

...

Keyword(s):

Immune Cells ◽

Cell Activation ◽

T Regulatory Cells ◽

Bacterial Species ◽

Human Colon ◽

Mesenteric Lymph Nodes ◽

Gastrointestinal Microbiota ◽

Regional Specificity ◽

Transcriptional Adaptation ◽

And Migration

AbstractGastrointestinal microbiota and immune cells interact closely and display regional specificity, but little is known about how these communities differ with location. Here, we simultaneously assess microbiota and single immune cells across the healthy, adult human colon, with paired characterisation of immune cells in the mesenteric lymph nodes, to delineate colonic immune niches at steady-state. We describe distinct T helper cell activation and migration profiles along the colon and characterise the transcriptional adaptation trajectory of T regulatory cells between lymphoid tissue and colon. Finally, we show increasing B cell accumulation, clonal expansion and mutational frequency from caecum to sigmoid colon, and link this to the increasing number of reactive bacterial species.

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Dissecting the Immune Cell Progeny of CAR-Expressing Hematopoietic Stem Cells in a Humanized Mouse Model

Blood ◽

10.1182/blood-2019-129746 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 4640-4640

Author(s):

Heng-Yi Liu ◽

Nezia Rahman ◽

Tzu-Ting Chiou ◽

Satiro N. De Oliveira

Keyword(s):

Stem Cells ◽

T Cells ◽

T Cell ◽

Hematopoietic Stem Cells ◽

Cell Lines ◽

Immune Cells ◽

Research Funding ◽

Humanized Mice ◽

Tumor Challenge ◽

Hematopoietic Stem

Background: Chemotherapy-refractory or recurrent B-lineage leukemias and lymphomas yield less than 50% of chance of cure. Therapy with autologous T-cells expressing chimeric antigen receptors (CAR) have led to complete remissions, but the effector cells may not persist, limiting clinical efficacy. Our hypothesis is the modification of hematopoietic stem cells (HSC) with anti-CD19 CAR will lead to persistent generation of multilineage target-specific immune cells, enhancing graft-versus-cancer activity and leading to development of immunological memory. Design/Methods: We generated second-generation CD28- and 4-1BB-costimulated CD19-specific CAR constructs using third-generation lentiviral vectors for modification of human HSC for assessment in vivo in NSG mice engrafted neonatally with human CD34-positive cells. Cells were harvested from bone marrows, spleens, thymus and peripheral blood at different time points for evaluation by flow cytometry and ddPCR for vector copy numbers. Cohorts of mice received tumor challenge with subcutaneous injection of lymphoma cell lines. Results: Gene modification of HSC with CD19-specific CAR did not impair differentiation or proliferation in humanized mice, leading to CAR-expressing cell progeny in myeloid, NK and T-cells. Humanized NSG engrafted with CAR-modified HSC presented similar humanization rates to non-modified HSC, with multilineage CAR-expressing cells present in all tissues with stable levels up to 44 weeks post-transplant. No animals engrafted with CAR-modified HSC presented autoimmunity or inflammation. T-cell populations were identified at higher rates in humanized mice with CAR-modified HSC in comparison to mice engrafted with non-modified HSC. CAR-modified HSC led to development of T-cell effector memory and T-cell central memory phenotypes, confirming the development of long-lasting phenotypes due to directed antigen specificity. Mice engrafted with CAR-modified HSC successfully presented tumor growth inhibition and survival advantage at tumor challenge with lymphoma cell lines, with no difference between both constructs (62.5% survival for CD28-costimulated CAR and 66.6% for 41BB-costimulated CAR). In mice sacrificed due to tumor development, survival post-tumor injection was directly correlated with tumor infiltration by CAR T-cells. Conclusions: CAR modification of human HSC for cancer immunotherapy is feasible and continuously generates CAR-bearing cells in multiple lineages of immune cells. Targeting of different malignancies can be achieved by adjusting target specificity, and this approach can augment the anti-lymphoma activity in autologous HSC recipients. It bears decreased morbidity and mortality and offers alternative therapeutic approach for patients with no available sources for allogeneic transplantation, benefiting ethnic minorities. Disclosures De Oliveira: National Institute for Health Research Biomedical Research Centre at Great Ormond Street Hospital for Children NHS Foundation Trust and University College London: Research Funding; NIAID, NHI: Research Funding; Medical Research Council: Research Funding; CIRM: Research Funding; National Gene Vector Repository: Research Funding.

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Depletion of Collagen II-Reactive T Cells and Blocking of B Cell Activation Prevents Collagen II-Induced Arthritis in DBA/1j Mice

The Journal of Immunology ◽

10.4049/jimmunol.168.8.4164 ◽

2002 ◽

Vol 168 (8) ◽

pp. 4164-4172 ◽

Cited By ~ 30

Author(s):

Huang-Ge Zhang ◽

PingAr Yang ◽

Jinfu Xie ◽

Zhongyu Liu ◽

Di Liu ◽

...

Keyword(s):

T Cells ◽

B Cell ◽

Cell Activation ◽

B Cell Activation ◽

Collagen Ii

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Dominant Role of CD80–CD86 Over CD40 and ICOSL in the Massive Polyclonal B Cell Activation Mediated by LATY136F CD4+ T Cells

Frontiers in Immunology ◽

10.3389/fimmu.2012.00027 ◽

2012 ◽

Vol 3 ◽

Cited By ~ 7

Author(s):

Stéphane Chevrier ◽

Céline Genton ◽

Bernard Malissen ◽

Marie Malissen ◽

Hans Acha-Orbea

Keyword(s):

T Cells ◽

B Cell ◽

Cd4 T Cells ◽

Cell Activation ◽

Dominant Role ◽

B Cell Activation

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T cell regulation of B cell activation. Lyt-1+,2-T cells modify the MHC-restricted function of heterogeneous and cloned T suppressor cells.

Journal of Experimental Medicine ◽

10.1084/jem.162.2.413 ◽

1985 ◽

Vol 162 (2) ◽

pp. 413-426 ◽

Cited By ~ 4

Author(s):

Y Asano ◽

R J Hodes

Keyword(s):

T Cells ◽

B Cells ◽

Cell Activation ◽

Cell Function ◽

Suppressor Cells ◽

Effector Function ◽

B Cell Activation ◽

Experimental Conditions ◽

Th Cells ◽

Mhc Restriction

Previous studies have shown the existence of both heterogeneous Lyt-1-,2+ suppressor (Ts) cells and cloned Lyt-1+,2- Ts cells which, despite the difference in their Lyt phenotypes, functioned in a similar antigen-specific and major histocompatibility complex (MHC)-restricted fashion to suppress the antibody responses generated by cloned helper T (Th) cells and hapten-primed B cells. Our studies were carried out to assess in further detail the genetically restricted cell interactions that mediate this immune response suppression. We show that the activation of both heterogeneous and cloned Ts cells is antigen-specific and MHC-restricted under our experimental conditions. After appropriate activation, the effector function of both cloned Lyt-1+,2-Ts cells and heterogeneous Lyt-1-,2+ Ts cells was also antigen-specific. In contrast, once activated, Ts cells suppressed the responses generated by cloned Th cells and hapten-primed B cells in an MHC-unrestricted fashion. We also showed, however, that a population of unprimed Lyt-1+,2-T cells was able to significantly alter the genetic restriction requirements for Ts cell function. The activity of this population was itself MHC-restricted, and was observed only when the unprimed Lyt-1+,2-T cells shared the MHC restriction specificity of the cloned Th cells functioning in a given response. When these requirements were satisfied, Lyt-1+,2- T cells significantly modified the suppression mediated by both heterogeneous and cloned Ts cells, resulting in suppression that was then MHC restricted in its effector function as well as in its activation requirements. Thus, our findings suggest that the observed MHC restriction in Ts function is the result of a complex interaction involving Ts cells, Th cells, and an additional population of MHC-restricted Lyt-1+,2- T cells. This newly characterized activity of Lyt-1+,2- T cells functionally resembles that of an MHC-restricted contrasuppressor population that selectively blocks a pathway of MHC-unrestricted Ts activity, while leaving intact susceptibility to MHC-restricted Ts effects.

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T Cell Accumulation in B Cell Follicles Is Regulated by Dendritic Cells and Is Independent of B Cell Activation

Journal of Experimental Medicine ◽

10.1084/jem.20021750 ◽

2003 ◽

Vol 197 (2) ◽

pp. 195-206 ◽

Cited By ~ 70

Author(s):

Simon Fillatreau ◽

David Gray

Keyword(s):

T Cells ◽

Dendritic Cells ◽

T Cell ◽

B Cells ◽

B Cell ◽

Cell Activation ◽

B Cell Activation ◽

Cell Accumulation ◽

Antigen Presenting ◽

Deficient Mice

We investigated the mechanism of CD4 T cell accumulation in B cell follicles after immunization. Follicular T cell numbers were correlated with the number of B cells, indicating B cell control of the niche that T cells occupy. Despite this, we found no role for B cells in the follicular migration of T cells. Instead, T cells are induced to migrate into B cell follicles entirely as a result of interaction with dendritic cells (DCs). Migration relies on CD40-dependent maturation of DCs, as it did not occur in CD40-deficient mice but was reconstituted with CD40+ DCs. Restoration was not achieved by the activation of DCs with bacterial activators (e.g., lipopolysaccharide, CpG), but was by the injection of OX40L–huIgG1 fusion protein. Crucially, the up-regulation of OX40L (on antigen-presenting cells) and CXCR-5 (on T cells) are CD40-dependent events and we show that T cells do not migrate to follicles in immunized OX40-deficient mice.

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