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ABSTRACT: Macrophages and natural killer (NK) cells are important antitumor effectors by virtue of their ability to produce cytokines, chemokines and interferons (IFNs) and to mediate tumor cytotoxicity. Little is known about the impact of Toll-like receptor (TLR) and nucleotide binding and oligomerization domain (NOD)-like receptor (NLR) pathways on NK cell functions, and the role of TLRs and NLRs in macrophage activation is incompletely understood. In this study, we examined the capacities of expressed TLRs and NLRs to elicit cytokine production in human NK cells and THP1 macrophages, and to activate NK cytotoxicity against the squamous cell carcinoma of head and neck cell line Tu167 and erythroleukemia K562 cells. We found that NK cells express high levels of NOD2, NLRP3, TLR3, TLR7, and TLR9, while NOD1 was expressed at low levels. All tested NLR and TLR agonists potentiated NK cytotoxicity against Tu167 cells, whereas only poly (I:C) increased NK cytotoxicity against K562 cells. Poly (I:C) and Escherichia coli RNA markedly up-regulated TNF-α and IFN-γ expression in the NK92 cell line and human CD56(+)CD3(-) primary NK cells. High levels of NOD2, TLR7 and TLR9 proteins were observed in human THP1 cells, followed by TLR3, NOD1, and NLRP3. Stimulation of NLRP3 with E. coli RNA led to the highest induction of TNF-α, IL-6, IL-12p40, RANTES and IFN-β, whereas TLR7, TLR3, TLR9, NOD1 and NOD2 agonists had lower effects. Our data reveal involvement of TLRs and NLRs in potentiation of antitumor cytotoxicity and cytokine-producing activities of human NK cells and macrophages.
Innate Immunity 08/2011; 17(4):375-87. · 4.00 Impact Factor
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ABSTRACT: We have previously reported that many types of tumors can induce changes in human T cells that lead to the acquisition of suppressive function and phenotypic alterations resembling those found in senescent T cells. In the present study, we find a role for interleukin 7 (IL-7) in protecting T cells from these changes and further define involved signaling pathways.
We evaluated the ability of IL-7 treatment to prevent the gain of suppressive function and phenotypic alterations in human T cells after a short coculture with tumor cells in vitro. We then used inhibitors of components of the phosphoinositide 3-kinase (PI3K)/AKT pathway and short interfering RNA knockdown of Mcl-1 and Bim to evaluate the role of these signaling pathways in IL-7 protection.
We found that IL-7 inhibits CD27/CD28 loss and maintains proliferative capacity, IL-2 production, and reduced suppressive function. The protective ability of IL-7 depended on activation of the PI3K/AKT pathway, which inhibited activation of glycogen synthase kinase 3β, which, in turn, prevented the phosphorylation and loss of Mcl-1. We further showed a key role for Mcl-1 in that its knockdown or inhibition abrogated the effects of IL-7. In addition, knockdown of the Mcl-1 binding partner and proapoptotic protein Bim protected T cells from these dysfunctional alterations.
These observations confirm the role for Bcl-2 family members in cytokine signaling and suggest that IL-7 treatment in combination with other immunotherapies could lead to new clinical strategies to maintain normal T-cell function and reduce tumor-induced generation of dysfunctional and suppressor T cells.
Clinical Cancer Research 06/2011; 17(15):4975-86. · 7.74 Impact Factor
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ABSTRACT: Natural killer (NK) cells are innate effector lymphocytes that control the growth of major histocompatibility complex class I negative tumors. We show here that γδ T lymphocytes, expanded in vitro in the presence isopentenylpyrophosphate (IPP), induce NK cell-mediated killing of tumors that are usually resistant to NK cytolysis. The induction of cytotoxicity toward these resistant tumors requires priming of NK cells by immobilized human immunoglobulin G1 and costimulation through CD137L expressed on activated γδ T lymphocytes. This costimulation increases NKG2D expression on the NK-cell surface, which is directly responsible for tumor cell lysis. Moreover, culturing peripheral blood mononuclear cells with zoledronic acid, a γδ T lymphocyte activating agent, enhances NK-cell direct cytotoxicity and antibody-dependent cellular cytotoxicity against hematopoietic and nonhematopoietic tumors. Our data reveal a novel function of human γδ T lymphocytes in the regulation of NK cell-mediated cytotoxicity and provide rationale for the use of strategies to manipulate the CD137 pathway to augment innate antitumor immunity.
Blood 09/2010; 116(10):1726-33. · 9.90 Impact Factor
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ABSTRACT: T cells develop into two major populations distinguished by their T cell receptor (TCR) chains. Cells with the αβ TCR generally express CD4 or CD8 lineage markers and mostly fall into helper or cytotoxic/effector subsets. Cells expressing the alternate γδ TCR in humans generally do not express lineage markers, do not require MHC for antigen presentation, and recognize nonpeptidic antigens. We are interested in the dominant Vγ2Vδ2+ T cell subset in human peripheral blood and the control of effector function in this population. We review the literature on γδ T cell generation and repertoire selection, along with recent work on CD56 expression and defining a cytotoxic/effector lineage within the phosphoantigen-reactive Vγ2Vδ2 cells. A unique mechanism for MHC-independent repertoire selection is linked to the control of effector function that is vital to the role for γδ T cells in tumor surveillance. Better understanding of these mechanisms will improve our ability to exploit this population for tumor immunotherapy.
Clinical and Developmental Immunology. 01/2010;
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ABSTRACT: T cells develop into two major populations distinguished by their T cell receptor (TCR) chains. Cells with the alphabeta TCR generally express CD4 or CD8 lineage markers and mostly fall into helper or cytotoxic/effector subsets. Cells expressing the alternate gammadelta TCR in humans generally do not express lineage markers, do not require MHC for antigen presentation, and recognize nonpeptidic antigens. We are interested in the dominant Vgamma2Vdelta2+ T cell subset in human peripheral blood and the control of effector function in this population. We review the literature on gammadelta T cell generation and repertoire selection, along with recent work on CD56 expression and defining a cytotoxic/effector lineage within the phosphoantigen-reactive Vgamma2Vdelta2 cells. A unique mechanism for MHC-independent repertoire selection is linked to the control of effector function that is vital to the role for gammadelta T cells in tumor surveillance. Better understanding of these mechanisms will improve our ability to exploit this population for tumor immunotherapy.
Clinical and Developmental Immunology 01/2010; 2010:732893. · 1.84 Impact Factor
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Xiaoyu Zhang,
Caroline J Voskens,
Michelle Sallin,
Amudhan Maniar,
Carolina L Montes,
Yue Zhang,
Wei Lin,
Guoyan Li,
Erin Burch,
Ming Tan,
Ronna Hertzano, Andrei I Chapoval,
Koji Tamada,
Brian R Gastman,
Dan H Schulze,
Scott E Strome
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ABSTRACT: CD137 (4-1BB)-mediated costimulation plays an important role in directing the fate of Ag-stimulated T cells and NK cells, yet the role of CD137 in mediating B cell function is unknown. We found that CD137 is expressed in vitro on anti-Ig-stimulated peripheral blood B cells and in vivo on tonsillar B cells with an activated phenotype. In vitro CD137 expression is enhanced by CD40 stimulation and IFN-gamma and is inhibited by IL-4, -10, and -21. The expression of CD137 on activated human B cells is functionally relevant because engagement with its ligand at the time of activation stimulates B cell proliferation, enhances B cell survival, and induces secretion of TNF-alpha and -beta. Our study suggests that CD137 costimulation may play a role in defining the fate of Ag-stimulated human B cells.
The Journal of Immunology 12/2009; 184(2):787-95. · 5.79 Impact Factor
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ABSTRACT: The expression of CD56, a natural killer cell-associated molecule, on alphabeta T lymphocytes correlates with their increased antitumor effector function. CD56 is also expressed on a subset of gammadelta T cells. However, antitumor effector functions of CD56(+) gammadelta T cells are poorly characterized.
To investigate the potential effector role of CD56(+) gammadelta T cells in tumor killing, we used isopentenyl pyrophosphate and interleukin-2-expanded gammadelta T cells from peripheral blood mononuclear cells of healthy donors.
Thirty to 70% of expanded gammadelta T cells express CD56 on their surface. Interestingly, although both CD56(+) and CD56(-) gammadelta T cells express comparable levels of receptors involved in the regulation of gammadelta T-cell cytotoxicity (e.g., NKG2D and CD94), only CD56(+) gammadelta T lymphocytes are capable of killing squamous cell carcinoma and other solid tumor cell lines. This effect is likely mediated by the enhanced release of cytolytic granules because CD56(+) gammadelta T lymphocytes expressed higher levels of CD107a compared with CD56(-) controls following exposure to tumor cell lines. Lysis of tumor cell lines is blocked by concanamycin A and a combination of anti-gammadelta T-cell receptor + anti-NKG2D monoclonal antibody, suggesting that the lytic activity of CD56(+) gammadelta T cells involves the perforin-granzyme pathway and is mainly gammadelta T-cell receptor/NKG2D dependent. Importantly, CD56-expressing gammadelta T lymphocytes are resistant to Fas ligand and chemically induced apoptosis.
Our data indicate that CD56(+) gammadelta T cells are potent antitumor effectors capable of killing squamous cell carcinoma and may play an important therapeutic role in patients with head and neck cancer and other malignancies.
Clinical Cancer Research 08/2008; 14(13):4232-40. · 7.74 Impact Factor
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ABSTRACT: Senescent and suppressor T cells are reported to be increased in select patients with cancer and are poor prognostic indicators. Based on the association of these T cells and poor outcomes, we hypothesized that tumors induce senescence in T cells, which negatively effects antitumor immunity. In this report, we show that human T cells from healthy donors incubated with tumor for only 6 h at a low tumor to T-cell ratio undergo a senescence-like phenotype, characterized by the loss of CD27 and CD28 expression and telomere shortening. Tumor-induced senescence of T cells is induced by soluble factors and triggers increases in expression of senescence-associated molecules such as p53, p21, and p16. Importantly, these T cells are not only phenotypically altered, but also functionally altered as they can suppress the proliferation of responder T cells. This suppression requires cell-to-cell contact and is mediated by senescent CD4(+) and CD8(+) subpopulations, which are distinct from classically described natural T regulatory cells. Our observations support the novel concept that tumor can induce senescent T cells with suppressor function and may effect both the diagnosis and treatment of cancer.
Cancer Research 03/2008; 68(3):870-9. · 7.86 Impact Factor
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Liqun Luo, Andrei I Chapoval,
Dallas B Flies,
Gefeng Zhu,
Fumiya Hirano,
Shengdian Wang,
Julie S Lau,
Haidong Dong,
Koji Tamada,
Andrew S Flies,
Yang Liu,
Lieping Chen
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ABSTRACT: B7-H3 is a B7 family molecule with T cell costimulatory function in vitro. The in vivo role of B7-H3 in the stimulation of tumor immunity is unclear. We report here that expression of B7-H3 by transfection of the mouse P815 tumor line enhances its immunogenicity, leading to the regression of tumors and amplification of a tumor-specific CD8+ CTL response in syngeneic mice. Tumor cells engineered to express B7-H3 elicit a rapid clonal expansion of P1A tumor Ag-specific CD8+ CTL in lymphoid organs in vivo and acquire the ability to directly stimulate T cell growth, division, and development of cytolytic activity in vitro. Our results thus establish a role for B7-H3 in the costimulation of T cell immune responses in vivo.
The Journal of Immunology 12/2004; 173(9):5445-50. · 5.79 Impact Factor
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ABSTRACT: T-cell anergy is a tolerance mechanism defined as a hyporesponsive status of antigen-specific T cells upon prior antigen encounter and is believed to play a critical role in the evasion of tumor immunity and the amelioration of allogeneic transplant rejection. Molecular mechanisms in controlling T-cell anergy are less known. We show here that administration of an agonistic monoclonal antibody (mAb) to CD137, a member of the tumor necrosis factor receptor superfamily, prevents the induction of CD8+ cytolytic T-lymphocyte (CTL) anergy by soluble antigens. More importantly, CD137 mAb restores the functions of established anergic CTLs upon reencountering their cognate antigen. As a result, infusion of CD137 mAb inhibits progressive tumor growth that is caused by soluble tumor antigen-induced tolerance in a P815R model. CD137 mAb also restores proliferation and effector functions of anergic alloreactive 2C T cells in a bone marrow transplantation model. Our results indicate that ligation of CD137 receptor delivers a regulatory signal for T-cell anergy and implicate manipulation of the CD137 pathway as a new approach to break T-cell tolerance.
Blood 02/2004; 103(1):177-84. · 9.90 Impact Factor
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ABSTRACT: We identify a B7 family molecule, B7-H4, by protein sequence analysis and comparative molecular modeling. While B7-H4 mRNA is widely distributed in mouse and human peripheral tissues, cell surface expression of B7-H4 protein is limited and shows an inducible pattern on hematopoietic cells. Putative receptor of B7-H4 can be upregulated on activated T cells. By arresting cell cycle, B7-H4 ligation of T cells has a profound inhibitory effect on the growth, cytokine secretion, and development of cytotoxicity. Administration of B7-H4Ig into mice impairs antigen-specific T cell responses whereas blockade of endogenous B7-H4 by specific monoclonal antibody promotes T cell responses. B7-H4 thus may participate in negative regulation of cell-mediated immunity in peripheral tissues.
Immunity 07/2003; 18(6):849-61. · 21.64 Impact Factor
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ABSTRACT: Costimulatory signal(s) in addition to engagement of T cell receptor is important for optimal activation of T lymphocytes. During last decade several dozens of new costimulatory molecules, including 4-1BB, CD40, OX40, CD27, and ICOS, have been identified. It is likely that in Post-Genome Era more molecules with potential costimulatory properties will be brought to our attention. We describe here a simple and reliable strategy for evaluating the functional activities of potential costimulatory molecules using soluble fusion protein between extracellular portion of costimulatory ligand and Fc portion of mouse IgG2a.
Molecular Biotechnology 08/2002; 21(3):259-64. · 2.17 Impact Factor
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Ryan A Wilcox, Andrei I Chapoval,
Kevin S Gorski,
Mizuto Otsuji,
Tahiro Shin,
Dallas B Flies,
Koji Tamada,
Robert S Mittler,
Haruo Tsuchiya,
Drew M Pardoll,
Lieping Chen
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ABSTRACT: Interaction between dendritic cells (DCs) and T cells is a prerequisite for the initiation of a T cell response. The molecular nature of this interaction remains to be fully characterized. We report in this work that freshly isolated mouse splenic DCs and bone marrow-derived DCs express CD137 on the cell surface and in soluble form. Triggering CD137 increased the secretion of IL-6 and IL-12 from DCs. More importantly, infusion of an agonistic mAb to CD137 into naive mice enhanced the ability of DCs to stimulate T cell proliferation in response to both alloantigens and a nominal Ag in vitro. This enhancement of DC function is not mediated through activation of T cells, because the effect was also observed in RAG-1 knockout mice that lack T cells. Our findings implicate CD137 as an important receptor involved in the modulation of DC function.
The Journal of Immunology 06/2002; 168(9):4262-7. · 5.79 Impact Factor
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ABSTRACT: Treatment of advanced, poorly immunogenic tumors in animal models, considered the closest simulation available thus far for conditions observed in cancer patients, remains a major challenge for cancer immunotherapy. We reported previously that established tumors in mice receiving an agonistic mAb to the T cell costimulatory molecule 4-1BB (CD137) regress due to enhanced tumor antigen-specific cytotoxic T lymphocyte responses. In this study, we demonstrate that several poorly immunogenic tumors, including C3 tumor, TC-1 lung carcinoma, and B16-F10 melanoma, once established as solid tumors or metastases, are refractory to treatment by anti-4-1BB mAb. We provide evidence that immunological ignorance, rather than anergy or deletion, of tumor antigen--specific CTLs during the progressive growth of tumors prevents costimulation by anti-4-1BB mAb. Breaking CTL ignorance by immunization with a tumor antigen-derived peptide, although insufficient to stimulate a curative CTL response, is necessary for anti--4-1BB mAb to induce a CTL response leading to the regression of established tumors. Our results suggest a new approach for immunotherapy of human cancers.
Journal of Clinical Investigation 04/2002; 109(5):651-9. · 15.39 Impact Factor
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ABSTRACT: CD62L was evaluated as a determinant of human pre-effector T cells.
Phenotype and cytokine secretion profiles of CD62L cells were determined based on activation status.
CD62L(Low) T cells demonstrated significantly higher secretion of interleukin (IL)-10 and interferon (IFN)-gamma than did CD62L(High) T cells. After activation, the majority of cells expressed high levels of the CD62L surface marker. Postactivation levels of IL-10 production remained elevated or unchanged. In a murine B16 melanoma model, freshly isolated CD62L(Low) tumor draining lymph nodes (TDLN) T cells showed increased secretion of IL-2 and IL-4 but not of IL-10 or IFN-gamma. The surface expression of CD62L and cytokine secretion patterns were maintained after activation with concomitant increases in IL-10.
Our results provide evidence that CD62L(Low) T cells in TDLNs of progressively growing squamous cell carcinoma of the head and neck differ phenotypically and functionally from those of mouse origin.
Characterization of this human CD62L(Low) T cell population provides initial insight regarding novel surface markers in TDLN T cells that might correlate with antitumor reactivity.
Otolaryngology Head and Neck Surgery 03/2002; 126(2):180-7. · 1.72 Impact Factor
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ABSTRACT: To investigate the role of HLA-DQ molecules and/or CD4(+) T cells in the pathogenesis of allergic asthma, we generated HLA-DQ6 and HLA-DQ8 transgenic mice lacking endogenous class II (Abeta(null)) and CD4 genes and challenged them intranasally with short ragweed allergenic extract (SRW). We found that DQ6/CD4(null) mice developed a strong eosinophilic infiltration into the bronchoalveolar lavage and lung tissue, while DQ8/CD4(null) mice were normal. However, neither cytokines nor eosinophil peroxidase in the bronchoalveolar lavage of DQ6/CD4(null) mice was found. In addition, the airway reactivity to methacholine was elevated moderately in DQ6/CD4(null) mice compared with the high response in DQ/CD4(+) counterparts and was only partially augmented by CD4(+) T cell transfer. The DQ6/CD4(null) mice showed Th1/Th2-type cytokines and SRW-specific Abs in the immune sera in contrast to a direct Th2 response observed in DQ6/CD4(+) mice. The proliferative response of spleen mononuclear cells and peribronchial lymph node cells demonstrated that the response to SRW in DQ6/CD4(null) mice was mediated by HLA-DQ-restricted CD4(-)CD8(-)NK1.1(-) T cells. FACS analysis of PBMC and spleen mononuclear cells demonstrated an expansion of double-negative (DN) CD4(-)CD8(-)TCRalphabeta(+) T cells in SRW-treated DQ6/CD4(null) mice. These cells produced IL-4, IL-5, IL-13, and IFN-gamma when stimulated with immobilized anti-CD3. IL-5 ELISPOT assay revealed that DN T cells were the cellular origin of IL-5 in allergen-challenged DQ6/CD4(null) mice. Our study shows a role for HLA-DQ-restricted CD4(+) and DN T cells in the allergic response.
The Journal of Immunology 02/2002; 168(2):890-9. · 5.79 Impact Factor
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Andrei I. Chapoval,
Jian Ni,
Julie S. Lau,
Ryan A. Wilcox,
Dallas B. Flies,
Ding Liu,
Haidong Dong,
Gabriel L. Sica,
Gefeng Zhu,
Koji Tamada,
Lieping Chen
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ABSTRACT: We describe here a newly identified member of the human B7 family, designated B7 homolog 3 (B7-H3), that shares 20−27% amino acid identity with other B7 family members. B7-H3 mRNA is not detectable in peripheral blood mononuclear cells, although it is found in various normal tissues and in several tumor cell lines. Expression of B7-H3 protein, however, can be induced on dendritic cells (DCs) and monocytes by inflammatory cytokines and a combination of phorbol myristate acetate (PMA) + ionomycin. Soluble B7-H3 protein binds a putative counter-receptor on activated T cells that is distinct from CD28, cytotoxic T lymphocyte antigen 4 (CTLA-4), inducible costimulator (ICOS) and PD-1. B7-H3 costimulates proliferation of both CD4+ and CD8+ T cells, enhances the induction of cytotoxic T cells and selectively stimulates interferon (IFN-) production in the presence of T cell receptor signaling. In contrast, inclusion of antisense B7-H3 oligonucleotides decreases the expression of B7-H3 on DCs and inhibits IFN- production by DC-stimulated allogeneic T cells. Thus, we describe a newly identified costimulatory pathway that may participate in the regulation of cell-mediated immune responses.
Nature Immunology. 02/2001; 2(3):269-274.
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Koji Tamada,
Koji Shimozaki, Andrei I. Chapoval,
Gefeng Zhu,
Gabriel Sica,
Dallas Flies,
Tom Boone,
Hailing Hsu,
Yang-Xin Fu,
Shigekazu Nagata,
Jian Ni,
Lieping Chen
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ABSTRACT: LIGHT was recently described as a member of the tumor necrosis factor (TNF)
'superfamily'. We have isolated a mouse homolog of human LIGHT
and investigated its immunoregulatory functions in vitro and in
vivo. LIGHT has potent, CD28-independent co-stimulatory activity leading
to T-cell growth and secretion of gamma interferon and granulocyte−macrophage
colony-stimulating factor. Gene transfer of LIGHT induced an antigen-specific
cytolytic T-cell response and therapeutic immunity against established mouse
P815 tumor. In contrast, blockade of LIGHT by administration of soluble receptor
or antibody led to decreased cell-mediated immunity and ameliorated graft-versus-host
disease. Our studies identify a previously unknown T-cell co-stimulatory pathway
as a potential therapeutic target.
Nature Medicine. 02/2000; 6(3):283-289.
