Blocking the regulatory T cell molecule LAG-3 augments in vivo anti-tumor immunity in an autochthonous model of prostate cancer

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 2573-2573
Author(s):  
C. G. Drake ◽  
C. Kelleher ◽  
T. Bruno ◽  
T. Harris ◽  
D. Flies ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
T Cells ◽  
T Cell ◽  
Regulatory T Cell ◽  
Specific Antigen ◽  
Cell Activity ◽  
Cd8 T Cell ◽  
Regulatory Function

2573 Background: LAG-3 is a CD4 homolog expressed on activated T cells, NK cells, tumor infiltrating lymphocytes (TIL), and plasmacytoid dendritic cells. Recently, we showed that LAG-3 was relatively overexpressed in specific T cells rendered unresponsive in vivo by the presence of cognate self-antigen. These anergic T cells display regulatory function both in vitro and in vivo, and blockade of LAG-3 with a non-depleting monoclonal antibody significantly mitigates their regulatory T cell activity. Methods: Using a novel model of prostate cancer in which a tumor-specific antigen is expressed in autochthonous tumors, we tested whether treatment with a non-depleting anti-LAG-3 antibody affected trafficking and function of tumor-specific T cells. Results: LAG-3 blockade significantly augments specific CD8 T cell trafficking to antigen-expressing tumors, but not to normal tissue. Most significantly, LAG-3 blockade functionally reversed CD8 T cell tolerance as assayed by an in vivo cytotoxic T lymphocyte (CTL) assay. Combining LAG-3 blockade with specific anti-tumor vaccination results in a dramatic increase in activated CD8 T cells in the tumor parenchyma. Conclusions: Taken together, these data support the concept that treatment with a LAG-3 blocking antibody may significantly delay disease progression in patients with cancer. We have recently generated a panel of monoclonal antibodies directed against human LAG-3; several of these antibodies significantly augment human T cell responses in vitro. No significant financial relationships to disclose.

scholarly journals Cd40-Independent Pathways of T Cell Help for Priming of Cd8+ Cytotoxic T Lymphocytes

2000 ◽  
Vol 191 (3) ◽  
pp. 541-550 ◽  
Author(s):  
Zhengbin Lu ◽  
Lingxian Yuan ◽  
Xianzheng Zhou ◽  
Eduardo Sotomayor ◽  
Hyam I. Levitsky ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Cytotoxic T Lymphocyte ◽  
Cell Communication ◽  
Cd8 T Cell ◽  
Cd4 Help ◽  
T Cell Help

In many cases, induction of CD8+ CTL responses requires CD4+ T cell help. Recently, it has been shown that a dominant pathway of CD4+ help is via antigen-presenting cell (APC) activation through engagement of CD40 by CD40 ligand on CD4+ T cells. To further study this three cell interaction, we established an in vitro system using dendritic cells (DCs) as APCs and influenza hemagglutinin (HA) class I and II peptide–specific T cell antigen receptor transgenic T cells as cytotoxic T lymphocyte precursors and CD4+ T helper cells, respectively. We found that CD4+ T cells can provide potent help for DCs to activate CD8+ T cells when antigen is provided in the form of either cell lysate, recombinant protein, or synthetic peptides. Surprisingly, this help is completely independent of CD40. Moreover, CD40-independent CD4+ help can be documented in vivo. Finally, we show that CD40-independent T cell help is delivered through both sensitization of DCs and direct CD4+–CD8+ T cell communication via lymphokines. Therefore, we conclude that CD4+ help comprises at least three components: CD40-dependent DC sensitization, CD40-independent DC sensitization, and direct lymphokine-dependent CD4+–CD8+ T cell communication.

scholarly journals DNAM-1 promotes activation of cytotoxic lymphocytes by nonprofessional antigen-presenting cells and tumors

2008 ◽  
Vol 205 (13) ◽  
pp. 2965-2973 ◽  
Author(s):  
Susan Gilfillan ◽  
Christopher J. Chan ◽  
Marina Cella ◽  
Nicole M. Haynes ◽  
Aaron S. Rapaport ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Adhesion Molecules ◽  
Cd8 T Cells ◽  
Nk Cell ◽  
Cd8 T Cell ◽  
Antigen Presenting

Natural killer (NK) cells and CD8 T cells require adhesion molecules for migration, activation, expansion, differentiation, and effector functions. DNAX accessory molecule 1 (DNAM-1), an adhesion molecule belonging to the immunoglobulin superfamily, promotes many of these functions in vitro. However, because NK cells and CD8 T cells express multiple adhesion molecules, it is unclear whether DNAM-1 has a unique function or is effectively redundant in vivo. To address this question, we generated mice lacking DNAM-1 and evaluated DNAM-1–deficient CD8 T cell and NK cell function in vitro and in vivo. Our results demonstrate that CD8 T cells require DNAM-1 for co-stimulation when recognizing antigen presented by nonprofessional antigen-presenting cells; in contrast, DNAM-1 is dispensable when dendritic cells present the antigen. Similarly, NK cells require DNAM-1 for the elimination of tumor cells that are comparatively resistant to NK cell–mediated cytotoxicity caused by the paucity of other NK cell–activating ligands. We conclude that DNAM-1 serves to extend the range of target cells that can activate CD8 T cell and NK cells and, hence, may be essential for immunosurveillance against tumors and/or viruses that evade recognition by other activating or accessory molecules.

scholarly journals Human memory CD8 T cell effector potential is epigenetically preserved during in vivo homeostasis

2017 ◽  
Vol 214 (6) ◽  
pp. 1593-1606 ◽  
Author(s):  
Hossam A. Abdelsamed ◽  
Ardiana Moustaki ◽  
Yiping Fan ◽  
Pranay Dogra ◽  
Hazem E. Ghoneim ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Human Memory ◽  
Memory Cd8 T Cells ◽  
Memory Cd8 T Cell ◽  
Cell Effector

Antigen-independent homeostasis of memory CD8 T cells is vital for sustaining long-lived T cell–mediated immunity. In this study, we report that maintenance of human memory CD8 T cell effector potential during in vitro and in vivo homeostatic proliferation is coupled to preservation of acquired DNA methylation programs. Whole-genome bisulfite sequencing of primary human naive, short-lived effector memory (TEM), and longer-lived central memory (TCM) and stem cell memory (TSCM) CD8 T cells identified effector molecules with demethylated promoters and poised for expression. Effector-loci demethylation was heritably preserved during IL-7– and IL-15–mediated in vitro cell proliferation. Conversely, cytokine-driven proliferation of TCM and TSCM memory cells resulted in phenotypic conversion into TEM cells and was coupled to increased methylation of the CCR7 and Tcf7 loci. Furthermore, haploidentical donor memory CD8 T cells undergoing in vivo proliferation in lymphodepleted recipients also maintained their effector-associated demethylated status but acquired TEM-associated programs. These data demonstrate that effector-associated epigenetic programs are preserved during cytokine-driven subset interconversion of human memory CD8 T cells.

scholarly journals Leptin: A Critical Regulator of CD4+ T-cell Polarization in Vitro and in Vivo

Endocrinology ◽  
2010 ◽  
Vol 151 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Arvind Batra ◽  
Besir Okur ◽  
Rainer Glauben ◽  
Ulrike Erben ◽  
Jakob Ihbe ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Polarization ◽  
Th2 Cells ◽  
Regulatory Function ◽  
Wild Type ◽  
T Helper ◽  
T Cell Polarization

Abstract Besides being mandatory in the metabolic system, adipokines like leptin directly affect immunity. Leptin was found to be necessary in T helper 1 (Th1)-dependent inflammatory processes, whereas effects on Th2 cells are rarely understood. Here, we focused on leptin in T-helper cell polarization and in Th2-mediated intestinal inflammation in vivo. The induction of cytokine-producing Th1 or Th2 cells from naive CD4+ T cells under polarizing conditions in vitro was generally decreased in cells from leptin-deficient ob/ob mice compared with wild-type mice. To explore the in vivo relevance of leptin in Th2-mediated inflammation, the model of oxazolone-induced colitis was employed in wild-type, ob/ob, and leptin-reconstituted ob/ob mice. Ob/ob mice were protected, whereas wild-type and leptin-reconstituted ob/ob mice developed colitis. The disease severity went in parallel with local production of the Th2 cytokine IL-13. A possible explanation for the protection of ob/ob mice in Th1- as well as in Th2-dependent inflammation is provided by a decreased expression of the key transcription factors for Th1 and Th2 polarization, T-bet and GATA-3, in naive ob/ob T cells. In conclusion, these results support the regulatory function of the adipokine leptin within T-cell polarization and thus in the acquired immune system and support the concept that there is a close interaction with the endocrine system.

scholarly journals Antigen-specific suppressor T-cell activity in genetically restricted immune spleen cells.

1978 ◽  
Vol 148 (5) ◽  
pp. 1271-1281 ◽  
Author(s):  
C W Pierce ◽  
J A Kapp
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Activity ◽  
Antibody Responses ◽  
Spleen Cells ◽  
Suppressor T Cells ◽  
Specific Suppressor T Cells ◽  
Immune Spleen Cells

Virgin spleen cells develop comparable primary antibody responses in vitro to syngeneic or allogeneic macrophages (Mphi) bearing the terpolymer L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT), whereas immune spleen cells primed with syngeneic or allogeneic GAT-Mphi develop secondary responses preferentially when stimulated with GAT-Mphi syngeneic to the GAT-Mphi used for priming in vivo. These restrictions are mediated by products of the I-A subregion of the H-2 complex and are operative at the level of the GAT-Mphi-immune helper T-cell interactions. To investigate why these immune spleen cells fail to develop a significant antibody response to GAT-Mphi other than those used for in vivo immunization and determine the mechanism by which the restriction is maintained, spleen cells from virgin and syngeneic or allogeneic GAT-Mphi-primed mice were co-cultured in the presence of GAT-Mphi of various haplotypes. Antibody responses to GAT developed only in the presence of GAT-Mphi syngeneic to the Mphi used for in vivo priming; responses in cultures with GAT-Mphi allogeneic to the priming Mphi, whether these Mphi were syngeneic or allogeneic with respect to the responding spleen cells, were suppressed. The suppression was mediated by GAT-specific radiosensitive T cells. Thus, development of GAT-specific suppressor T cells appears to be a natural consequence of the immune response to GAT in responder as well as nonresponder mice. The implications of stimulation of genetically restricted immune helper T cells, and antigen-specific, but unrestricted, suppressor T cells after immunization with GAT-Mphi in vivo are discussed in the context of regulatory mechanisms in antibody responses.

scholarly journals N-ras couples antigen receptor signaling to Eomesodermin and to functional CD8+ T cell memory but not to effector differentiation

2013 ◽  
Vol 210 (7) ◽  
pp. 1463-1479 ◽  
Author(s):  
Salvador Iborra ◽  
Manuel Ramos ◽  
David M. Arana ◽  
Silvia Lázaro ◽  
Francisco Aguilar ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Small Gtpase ◽  
T Cell Memory ◽  
Cell Memory ◽  
Cd8 T Cell Memory

Signals from the TCR that specifically contribute to effector versus memory CD8+ T cell differentiation are poorly understood. Using mice and adoptively transferred T lymphocytes lacking the small GTPase N-ras, we found that N-ras–deficient CD8+ T cells differentiate efficiently into antiviral primary effectors but have a severe defect in generating protective memory cells. This defect was rescued, although only partly, by rapamycin-mediated inhibition of mammalian target of rapamycin (mTOR) in vivo. The memory defect correlated with a marked impairment in vitro and in vivo of the antigen-mediated early induction of T-box transcription factor Eomesodermin (Eomes), whereas T-bet was unaffected. Besides N-ras, early Eomes induction in vitro required phosphoinositide 3-kinase (PI3K)–AKT but not extracellular signal-regulated kinase (ERK) activation, and it was largely insensitive to rapamycin. Consistent with N-ras coupling Eomes to T cell memory, retrovirally enforced expression of Eomes in N-ras–deficient CD8+ T cells effectively rescued their memory differentiation. Thus, our study identifies a critical role for N-ras as a TCR-proximal regulator of Eomes for early determination of the CD8+ T cell memory fate.

scholarly journals Increasing the potency of dendritic cell based vaccines for the treatment of cancer

2021 ◽  
Author(s):  
◽  
Dianne Sika-Paotonu
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cell Responses ◽  
Vaccination Strategies ◽  
Monophosphoryl Lipid A ◽  
Tlr Agonist

<p>Tumours can be eradicated by T cells that recognise unique tumour-associated antigens. These T cells are initially stimulated by dendritic cells (DCs) that have acquired antigens from tumour tissue. Vaccination strategies that increase the frequencies of tumour-specific T cells by enhancing the activity of DCs are being evaluated in the clinic as novel cancer therapies. Our hypothesis is that existing DC-based vaccination strategies can be improved by stimulating toll-like receptor (TLR) signalling in the DCs, and also by encouraging interactions with iNKT cells, as these two activities are known to enhance DC function. It was also hypothesised that superior T cell responses could be induced by combining these two activities together. We used the TLR 4 agonist monophosphoryl lipid A (MPL) alone and in combination with other TLR agonists to achieve effective activation of bone marrow-derived DCs (BM-DCs) cultured in-vitro, which was characterised by upregulated expression of maturation markers on the cell surface, and enhanced release of pro-inflammatory cytokines. Some TLR agonist combinations provided significantly enhanced activities in this regard, notably the combination of MPL with either the TLR 2 agonist Pam3Cys, or the TLR 7/8 agonist Resiquimod. Although in-vitro activated BM-DCs were unable to induce stronger antigen-specific CD8+ T cell responses after intravenous injection when compared to BMDCs without TLR stimulation, enhanced CD8+ T cell responses were achieved in-vivo with the co-administration of TLR ligands, implying that TLR stimulation needed to act on cells of the host. Further studies identified the langerin-expressing CD8ɑ+ splenic DC subset in the spleen as recipients of antigen that was transferred from injected cells, and that these recipients were participants in the cross-presentation and T cell priming activities driving the CD8+ T cell response after vaccination. Antigen-loaded BM-DCs carrying the NKT cell ligand ɑ-galactosylceramide (ɑ-GalCer) were found to consistently increase antigen-specific CD8+ T cell responses in-vivo, and also cytotoxic responses as seen in cytotoxic killing assays. Again, langerin-expressing CD8ɑ+ splenic DCs were shown to be involved in this response by acquiring antigen and ɑ-GalCer from the injected vaccine BM-DCs. Finally, it was possible to achieve even greater CD8+ T cell responses in-vivo by injecting BM-DCs carrying antigen and ɑ-GalCer, together with timely co-administration of the TLR agonist. These results suggest a reassessment of the activities of DC-based vaccines to include the important role of “courier” to DCs already resident in the host that can be exploited to improve vaccination outcomes.</p>

scholarly journals Neoleukin-2 enhances anti-tumour immunity downstream of peptide vaccination targeted by an anti-MHC class II VHH

Open Biology ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 190235 ◽  
Author(s):  
Stephanie J. Crowley ◽  
Patrick T. Bruck ◽  
Md Aladdin Bhuiyan ◽  
Amelia Mitchell-Gears ◽  
Michael J. Walsh ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class Ii ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Class Ii ◽  
Tumour Immunity ◽  
Tumour Rejection

Cancer-specific mutations can lead to peptides of unique sequence presented on MHC class I to CD8 T cells. These neoantigens can be potent tumour-rejection antigens, appear to be the driving force behind responsiveness to anti-CTLA-4 and anti-PD1/L1-based therapies and have been used to develop personalized vaccines. The platform for delivering neoantigen-based vaccines has varied, and further optimization of both platform and adjuvant will be necessary to achieve scalable vaccine products that are therapeutically effective at a reasonable cost. Here, we developed a platform for testing potential CD8 T cell tumour vaccine candidates. We used a high-affinity alpaca-derived VHH against MHC class II to deliver peptides to professional antigen-presenting cells. We show in vitro and in vivo that peptides derived from the model antigen ovalbumin are better able to activate naive ovalbumin-specific CD8 T cells when conjugated to an MHC class II-specific VHH when compared with an irrelevant control VHH. We then used the VHH-peptide platform to evaluate a panel of candidate neoantigens in vivo in a mouse model of pancreatic cancer. None of the candidate neoantigens tested led to protection from tumour challenge; however, we were able to show vaccine-induced CD8 T cell responses to a melanoma self-antigen that was augmented by combination therapy with the synthetic cytokine mimetic Neo2/15.

Phase I trial of anti-PSMA designer T-cell autografting in prostate cancer

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e16132-e16132
Author(s):  
M. Abedi ◽  
Q. Ma ◽  
A. Bais ◽  
E. Gomes ◽  
E. Beaudoin ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Clinical Trial ◽  
T Cells ◽  
T Cell ◽  
Phase I ◽  
Ex Vivo ◽  
Immune Therapy ◽  
Us Army

e16132 Background: We created chimeric immunoglobulin-T cell receptors (IgTCR) specific for prostate specific membrane antigen (PSMA). When expressed in patient T cells, these “designer T cells” specifically kill prostate cancer cells in vitro and in vivo in animal models, with 5/9 (55%) of xenografted mice experiencing complete remissions (Ma et al. Prostate 2004:61:12–25). A Phase I clinical trial was approved by the FDA in metastatic prostate cancers. Methods: Patient T cells are retrovirally transduced and expanded ex vivo to span dose levels of 10^9 to 10^11 T cells. Adapting methods of Dudley, Rosenberg and colleagues, patients undergo prior non-myeloablative (NMA) conditioning to create a “hematologic space” into which the infused designer T cells will stably engraft for prolonged in vivo efficacy. Patients are co-administered continuous infusion IL2. Outcomes will include Phase Ia goals of safety and toxicity and Phase Ib goals of establishing an optimal biologic dose in terms of designer T cell engraftment and tumor response. Results: For the first two patients, excellent T cell modifications of 50–60% were obtained. After NMA conditioning, T cells were infused and stable engraftments of 1–5% were observed post recovery, even at this lowest 10^9 T cell dose level, thus affirming one of the study end-points. The patients had PSA reductions of 50 and 70% in the two months following treatment. Patients experienced neutropenia and lymphopenia after conditioning, but no designer T cell-related toxicities. Results with additional patients will be described in terms of safety, engraftment efficiency and tumor responses. Conclusions: A new approach to adoptive immune therapy in metastatic prostate cancer has been devised. This clinical trial is funded by the US Army/DOD. No significant financial relationships to disclose.

IL15, but Not IL2, Supports Long-Term Survival and Function of Human and Macaque Antigen-Specific CD8+ T Cell Clones.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3237-3237
Author(s):  
Carolina S. Berger ◽  
Michael Jensen ◽  
Stanley R. Riddell
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cell ◽  
Term Survival ◽  
Long Term Survival ◽  
Cd8 T Cell Memory ◽  
And Function

Abstract The adoptive transfer of antigen-specific CD8+ cytotoxic T lymphocyte (CTL) clones that have been isolated and expanded in vitro is a promising treatment modality for both human malignancies and infections. However, establishing immunity of sufficient magnitude and persistence for sustained efficacy is a limitation of this approach. Recent studies have identified a critical role for cytokine signaling including that mediated by IL15 in the establishment and maintenance of CD8+ T cell memory, suggesting that protocols for generating and transferring antigen-specific T cells might be improved. Interleukin-2 (IL2) is the T cell growth factor that has been widely used in vitro and in vivo for promoting T cell proliferation and persistence, but prolonged exposure of T cells to IL2 can enhance susceptibility to cell death and limit CD8+ memory T cell survival. IL15 is a novel cytokine that shares some activities with IL2 such as the induction of T cell proliferation, but exerts contrasting effects on the homeostasis of CD8+ T cell memory in experimental models. Here, we study the utility of IL15 to enhance the long-term survival and function of human and macaque antigen-specific CD8+ CTL clones in vitro. Human and macaque CD8+ CTL clones reactive against CMV were isolated by limiting dilution, expanded over 14 days in the presence of IL2 or IL15 (1–10 ng/ml), and then rested for &gt;4 weeks in media alone and with IL2 or IL15 at 0.01–10 ng/ml. Surviving T cells were enumerated at intervals, monitored for cell surface phenotype, and assayed for cytotoxicity by chromium release assay. CTL expanded in IL2 or IL15 proliferated equivalently over 14 days with a median of 1100 and 1400 fold increase in number, displayed surface markers consistent with an effector memory phenotype (CD45RA−CD62L−CCR7−CD28−), and showed comparable cytotoxicity (n=4). However, exposure after 14 days to IL15 at doses as little as 0.05-0.1 ng/ml greatly enhanced the survival of the CD8+ CTL as determined by Annexin V staining. By contrast, cells cultured without cytokines or with IL2 declined &gt;80% in number over 3 or 11 days, respectively. Of note, IL15 at higher doses (&gt;0.5 ng/ml), but not IL2, efficiently promoted sustained cell growth illustrated by labeling cells with CFSE. Cells cultured with IL15 displayed 1.5-fold increased expression of antiapoptotic molecules such as Bcl-xL and Bcl-2 over those plated in IL2 (n=4), indicating IL15 mediated its effects at least in part by preventing apoptosis. Of note, the cytotoxicity of CTL rested in IL2 was markedly reduced (&gt;60%, n=3), while the presence of IL15 permitted for sustained CTL function and expansion after restimulation. The responses of human and macaque CTL clones to IL15 were equivalent suggesting in vivo studies of T cell transfer in macaques may be predictive of results in humans. We have constructed retroviral vectors encoding intracytoplasmic truncated macaque CD34 or CD19 genes that could serve as nonimmunogenic selectable marker to track macaque T cells after transfer. Macaque T cells were efficiently transduced to express CD34t and CD19t (&gt;50%), and enriched to high purity by immunomagnetic selection. Studies to examine the safety and utility of IL15 on the survival of adoptively transferred CTL in macaques are in progress. Collectively, our data support that novel cytokines such as IL15 may prove useful to augment the long-term survival and effector function of ex vivo expanded antigen-specific CD8+ CTL clones after transfer.

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