Project description:Ocular immune privilege (IP) limits immune surveillance of intraocular tumors as certain immunogenic tumor cell lines (P815, E.G7-OVA) that are rejected when transplanted in the skin grow progressively when placed in the anterior chamber (a.c.) of the eye. As splenectomy (SPLNX) is known to terminate ocular IP, we characterized immune mechanisms responsible for spontaneous rejection of intraocular tumors in SPLNX mice as a first step toward identifying how to restore tumoricidal activity within the eye. Microarray data showed a 3-fold increase in interferon (IFN)-γ and a 2.7-fold increase in Fas ligand (FasL). There was a robust increase in transcripts (127 of 408 surveyed) from interferon (IFN)-stimulated genes and a marked decrease (in 40 of 192 surveyed) in the expression of cell-cycle-associated genes. Non-microarray data confirmed that IFNγ, FasL and CD8+ T cells but not perforin or TNFα were required for elimination of intraocular E.G7-OVA tumors that culminated in destruction of the eye (ocular phthsis). IFNγ and FasL did not target tumor cells directly as the majority of SPLNX IFNγR1-/- mice and Fas-defective lpr mice failed to eliminate ocular E.G7-OVA tumors that expressed Fas and IFNγR1. Bone marrow chimeras showed that immune cell expression of IFNγR1 and Fas was critical and that SPLNX increased the frequency of activated macrophages within ocular tumors in an IFNγ- and Fas/FasL-dependent manner. Rejection of intraocular tumors was associated with increased ocular mRNA expression of several inflammatory genes including FasL, NOS2, CXCL2 and T-bet. Our data support a model in which IFNγ- and Fas/FasL-dependent activation of intratumoral macrophage by CD8+ T cells promotes severe intraocular inflammation that indirectly eliminates intraocular tumors by inducing phthisis. The immunosuppressive mechanisms which maintain ocular IP likely interfere with the interaction between CD8+ T cells and macrophage to limit immunosurveillance of intraocular tumors. C57BL/6 mice that were splenectomized (Tumor_splnx) or were not surgically manipulated (Tumor_intact) were challenged with 10^4 luciferase-expressing E.G7-OVA cells injected into the anterior chamber of the eye. Fifteen days later, the animals were euthanized and tumor-bearing eyes were removed.

Project description:Ocular immune privilege (IP) limits immune surveillance of intraocular tumors as certain immunogenic tumor cell lines (P815, E.G7-OVA) that are rejected when transplanted in the skin grow progressively when placed in the anterior chamber (a.c.) of the eye. As splenectomy (SPLNX) is known to terminate ocular IP, we characterized immune mechanisms responsible for spontaneous rejection of intraocular tumors in SPLNX mice as a first step toward identifying how to restore tumoricidal activity within the eye. Microarray data showed a 3-fold increase in interferon (IFN)-γ and a 2.7-fold increase in Fas ligand (FasL). There was a robust increase in transcripts (127 of 408 surveyed) from interferon (IFN)-stimulated genes and a marked decrease (in 40 of 192 surveyed) in the expression of cell-cycle-associated genes. Non-microarray data confirmed that IFNγ, FasL and CD8+ T cells but not perforin or TNFα were required for elimination of intraocular E.G7-OVA tumors that culminated in destruction of the eye (ocular phthsis). IFNγ and FasL did not target tumor cells directly as the majority of SPLNX IFNγR1-/- mice and Fas-defective lpr mice failed to eliminate ocular E.G7-OVA tumors that expressed Fas and IFNγR1. Bone marrow chimeras showed that immune cell expression of IFNγR1 and Fas was critical and that SPLNX increased the frequency of activated macrophages within ocular tumors in an IFNγ- and Fas/FasL-dependent manner. Rejection of intraocular tumors was associated with increased ocular mRNA expression of several inflammatory genes including FasL, NOS2, CXCL2 and T-bet. Our data support a model in which IFNγ- and Fas/FasL-dependent activation of intratumoral macrophage by CD8+ T cells promotes severe intraocular inflammation that indirectly eliminates intraocular tumors by inducing phthisis. The immunosuppressive mechanisms which maintain ocular IP likely interfere with the interaction between CD8+ T cells and macrophage to limit immunosurveillance of intraocular tumors.

Project description:Webb2002 - Fas/FasL mediated tumor T-cell interaction This deterministic model of immunological surveillance involving tumour cell–T-lymphocyte interaction, cell surface expression of Fas/FasL, and their secreted soluble forms. This model is described in the article: Cells behaving badly: a theoretical model for the Fas/FasL system in tumour immunology. Webb SD, Sherratt JA, Fish RG. Math Biosci 2002 Sep-Oct; 179(2): 113-129 Abstract: One proposed mechanism of tumour escape from immune surveillance is tumour up-regulation of the cell surface ligand FasL, which can lead to apoptosis of Fas receptor (Fas) positive lymphocytes. Based upon this 'counterattack', we have developed a mathematical model involving tumour cell-lymphocyte interaction, cell surface expression of Fas/FasL, and their secreted soluble forms. The model predicts that (a) the production of soluble forms of Fas and FasL will lead to the down-regulation of the immune response; (b) matrix metalloproteinase (MMP) inactivation should lead to increased membrane FasL and result in a higher rate of Fas-mediated apoptosis for lymphocytes than for tumour cells. Recent studies on cancer patients lend support for these predictions. The clinical implications are two-fold. Firstly, the use of broad spectrum MMP inhibitors as anti-angiogenic agents may be compromised by their adverse effect on tumour FasL up-regulation. Also, Fas/FasL interactions may have an impact on the outcome of numerous ongoing immunotherapeutic trials since the final common pathway of all these approaches is the transduction of death signals within the tumour cell. This model is hosted on BioModels Database and identified by: BIOMD0000000661. To cite BioModels Database, please use: Chelliah V et al. BioModels: ten-year anniversary. Nucl. Acids Res. 2015, 43(Database issue):D542-8. To the extent possible under law, all copyright and related or neighbouring rights to this encoded model have been dedicated to the public domain worldwide. Please refer to CC0 Public Domain Dedication for more information.

Project description:Some unicellular organisms exhibit collective decision-making through intercellular communication once a quorum of members sense an environmental stress. Whether T cells at different states of differentiation may also synchronize their behavior on a population basis through direct interactions remains unclear. We report that memory CD8+ T cells (TMem) directly interact with naive T cells (TN) during priming, affecting the phenotypic, functional, transcriptional and metabolic differentiation of TN-derived progeny. This previously unrecognized, contact and concentration-dependent interaction between naive (TN) and memory CD8+ T cells (TMem) directly enhanced TN effector differentiation through non-apoptotic Fas signaling resulting in downstream Akt pathway activation. TN primed with TMem exhibited significantly impaired persistence and antitumor activity compared with TN primed alone. Disruption of FasL-Fas signaling in TN cells limited differentiation and enhanced anti-tumor immunity while provision of exogenous FasL in the absence of TMem impaired anti-tumor immunity by augmenting TN differentiation. These findings reveal that the full therapeutic potential of TN-derived cells for adoptive immunotherapy requires physical separation from TMem prior to priming or antagonism of Fas-signaling. FACS-sorted in vitro differentiated TMem samples were without stimulation (0 hours) (n=3), and FACS-sorted in vitro differentiated TMem samples were stimulated using CD3-specific and CD28-specific antibodies and IL-2 for 18 (n=3) and 96 (n=3) hours. FACS-sorted naive Pmel-1 CD8+ T cell samples were without stimulation (0 hours) (n=3), and FACS-sorted TN-derived Pmel-1 CD8+ T cell samples were stimulated using CD3-specific and CD28-specific antibodies and IL-2 for 18 (n=3) and 96 (n=3) hours. FACS-sorted TN-derived Pmel-1 CD8+ T cell samples were stimulated in the presence of TMem using CD3-specific and CD28-specific antibodies and IL-2 for 18 (n=3) and 96 (n=3) hours. FACS-sorted in vitro differentiated TMem samples were stimulated in the presence of TN using CD3-specific and CD28-specific antibodies and IL-2 for 18 (n=3) and 96 (n=3) hours. All samples were done in triplicate as biological repeats.

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Alternatively activated mononuclear phagocytes from the skin site of infection and the impact of IL-4Rα signaling on CD4+T cell survival in draining lymph nodes after repeated exposure to Schistosoma mansoni cercariae

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