159 Adoptively transferred CD8+ T cells that target neoantigen persist and regress melanomas to a greater extent than those that target self/tumor-antigen

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A173-A173
Author(s):  
Amalia Rivera Reyes ◽  
Megan Wyatt ◽  
Connor Dwyer ◽  
Hannah Knochelmann ◽  
Aubrey Smith ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Fate ◽  
Cd8 T Cells ◽  
Tumor Antigen ◽  
Cytotoxic T Cells ◽  
List Type ◽  
Secondary Tumor ◽  
Affinity Peptide ◽  
Self Antigen

BackgroundIn patients treated with immunotherapy, mechanisms underlying why some respond to or fail treatment are not fully understood. Higher tumor mutational burden is often correlated with better responses, because the immune system reacts more strongly against mutated antigens (versus self antigens) due to a higher affinity interaction with the T cell receptor. In adoptive T cell transfer therapy (ACT), engraftment and persistence of the T cells are critical to prolonged antitumor responses. It remains unclear whether the affinity of the interaction between tumor antigen and TCR alone impacts the engraftment and persistence of tumor-specific T cells post ACT.MethodsTo simulate this clinical scenario in mice, we used two different melanoma models: 1) B16F10 expressing a low affinity peptide (mgp100 = i.e. tumor/self-antigen), or 2) B16F10 expressing a higher affinity peptide (hgp100), which represents a neoantigen-expressing tumor.1 Pmel-1 CD8+ T cells expressing a TCR that recognizes gp100 were adoptively transferred into mice bearing B16F10 melanoma.ResultsWe posited that the function and persistence of adoptively transferred pmel-1 T cells would be increased in mice with neoantigen- compared to self- antigen expressing tumors. Indeed, we found that pmel-1 were less exhausted as well as engrafted and persisted far better in mice bearing tumors expressing neoantigens. Moreover, these large subcutaneous hot tumors shrank post ACT treatment and the animals survived long-term. Beneficial outcome was correlated with the appearance of vitiligo. Importantly, these cured mice were protected when rechallenged with a secondary tumor even after an intravenous rechallenge, implicating this ACT treatment mediates durable memory responses.ConclusionsHerein, we underscore how tumor antigen affinity can drastically change T cell fate. Future work will concentrate in exploring in depth the correlation of less differentiated cytotoxic T cells treating neo/self-antigen expressing melanomas mimicking a clinical setting.ReferenceHanada K, Yu Z, Chappell GR, Park AS, Restifo NP. An effective mouse model for adoptive cancer immunotherapy targeting neoantigens. JCI Insight 2019;4(10).

scholarly journals Role of PD-1 and its ligand, B7-H1, in early fate decisions of CD8 T cells

Blood ◽  
2007 ◽  
Vol 110 (1) ◽  
pp. 186-192 ◽  
Author(s):  
Monica V. Goldberg ◽  
Charles H. Maris ◽  
Edward L. Hipkiss ◽  
Andrew S. Flies ◽  
Lijie Zhen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Fate ◽  
Cd8 T Cells ◽  
T Cell Response ◽  
Activated T Cells ◽  
Cell Fate Decisions ◽  
Self Antigen

Expression of the PD-1 receptor on T cells has been shown to provide an important inhibitory signal that down-modulates peripheral effector responses in normal tissues and tumors. Furthermore, PD-1 up-regulation on chronically activated T cells can maintain them in a partially reversible inactive state. The function of PD-1 in the very early stages of T-cell response to antigen in vivo has not been fully explored. In this study, we evaluate the role of PD-1 and its 2 B7 family ligands, B7-H1 (PD-L1) and B7-DC (PD-L2), in early fate decisions of CD8 T cells. We show that CD8 T cells specific for influenza hemagglutinin (HA) expressed as a self-antigen become functionally tolerized and express high levels of surface PD-1 by the time of their first cell division. Blockade of PD-1 or B7-H1, but not B7-DC, at the time of self-antigen encounter mitigates tolerance induction and results in CD8 T-cell differentiation into functional cytolytic T lymphocytes (CTLs). These findings demonstrate that, in addition to modulating effector functions in the periphery, B7-H1:PD-1 interactions regulate early T-cell–fate decisions.

Regulation of Tim-3 function by binding to phosphatidylserine

2021 ◽  
Vol 478 (22) ◽  
pp. 3999-4004
Author(s):  
Lawrence P. Kane
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Transmembrane Protein ◽  
Cytotoxic T Cells ◽  
Cross Presentation ◽  
First Time

Tim-3 is a transmembrane protein that is highly expressed on subsets of chronically stimulated CD4+ helper and CD8+ cytotoxic T cells, with more transient expression during acute activation and infection. Tim-3 is also constitutively expressed by multiple types of myeloid cells. Like other TIM family members, Tim-3 can bind to phosphatidylserine displayed by apoptotic cells, and this interaction has been shown to mediate uptake of such cells by dendritic cells and cross-presentation of antigens to CD8+ T cells. In contrast, how the recognition of PS by Tim-3 might regulate the function of Tim-3+ T cells is not known. In their recent paper, Lemmon and colleagues demonstrate for the first time that recognition of PS by Tim-3 leads to enhanced T cell activation.

scholarly journals TCF-1 limits the formation of Tc17 cells via repression of the MAF–RORγt axis

2019 ◽  
Vol 216 (7) ◽  
pp. 1682-1699 ◽  
Author(s):  
Lisa A. Mielke ◽  
Yang Liao ◽  
Ella Bridie Clemens ◽  
Matthew A. Firth ◽  
Brigette Duckworth ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Fate ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
T Cell Subsets ◽  
Double Positive ◽  
Cell Fate Decisions ◽  
Healthy Humans ◽  
Tc17 Cells

Interleukin (IL)-17–producing CD8+ T (Tc17) cells have emerged as key players in host-microbiota interactions, infection, and cancer. The factors that drive their development, in contrast to interferon (IFN)-γ–producing effector CD8+ T cells, are not clear. Here we demonstrate that the transcription factor TCF-1 (Tcf7) regulates CD8+ T cell fate decisions in double-positive (DP) thymocytes through the sequential suppression of MAF and RORγt, in parallel with TCF-1–driven modulation of chromatin state. Ablation of TCF-1 resulted in enhanced Tc17 cell development and exposed a gene set signature to drive tissue repair and lipid metabolism, which was distinct from other CD8+ T cell subsets. IL-17–producing CD8+ T cells isolated from healthy humans were also distinct from CD8+IL-17− T cells and enriched in pathways driven by MAF and RORγt. Overall, our study reveals how TCF-1 exerts central control of T cell differentiation in the thymus by normally repressing Tc17 differentiation and promoting an effector fate outcome.

Stromal Cells Protect B-CLL Cells from Killing by Antigen-Specific Cytotoxic T Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2814-2814
Author(s):  
Katja Zirlik ◽  
Meike Burger ◽  
Philipp Brantner ◽  
Gabriele Prinz ◽  
Maike Buchner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Line ◽  
Cd8 T Cells ◽  
Stromal Cells ◽  
Stromal Cell ◽  
Cytotoxic T Cells ◽  
Protective Effects ◽  
Stromal Cell Line

Abstract B-cell malignancy-derived immunoglobulin (idiotype) and survivin, a member of the inhibitor of apoptosis gene family and a shared tumor-associated antigen, are expressed by B-CLL cells. Idiotype- and survivin-specific cytotoxic T cells (CTLs), capable of lysing primary autologous B-CLL cells, can be induced in patients with B-CLL. However, the leukemia cell microenvironment was shown to protect B-CLL cells from apoptosis. The protective effects of stromal cells can be reversed by CXCR4 antagonists in vitro and resensitize CLL cells to spontaneous and chemotherapy-induced apoptosis. The aim of the present study is to investigate whether stromal cell contact impairs CLL killing by CTLs raised against immunoglobulin- or survivin-derived peptides and whether the addition of CXCR4 inhibitors enhances T cell mediated cytotoxicity. To analyze the T cell response, we isolated CD8+ T cells and PBMCs from HLA-A2+ healthy donors. PBMCs were differentiated into dendritic cells (DCs) and CD40-activated B cells. CD8+ T cells were primarily stimulated with peptide-pulsed DCs and then restimulated weekly with peptide-pulsed CD40-activated B cells. Heteroclitic framework region (FR−), heteroclitic complementarity-determining region (CD−) derived peptides, and native and heteroclitic survivin-derived peptides were used for CTL induction. As expected, heteroclitic peptide modifications increased the binding affinity to HLA-A*0201 compared to the native peptide as predicted by the Parker Score (Median change of predicted half-time of dissociation to HLA class I molecules 1429 minutes) and measured by the T2 binding assay (Fluorescence Index (FI) native 0.2; FI heteroclitic 0.9). Cytotoxicity of T cells was assessed by chromium release assay and by flow cytometry against CFSE-labelled CLL cells alone and in co-culture with unlabelled stromal cells in the absence or presence of CXCR4 blocking agents. The induced CTLs efficiently lysed allogenic HLA-A2+ CLL cells (mean cytotoxicity at 30:1, 10:1, 3:1 effector-to-target (E:T) ratio: 15,5%+/−2,8; 7,5%+/−2,8; and 1,9%+/− 0,6), but not HLA-A2 negative CLL cells. Co-culture of CLL cells with the murine stromal cell line M2-10B4 resulted in protection of CLL cells from lysis by antigen-specific cytotoxic T cells in vitro, indeed suggesting a protective role of the microenvironment (mean cytotoxicity at 30:1, 10:1, 3:1 E:T ratio: 5,2%+/−4,1; 0,4%+/−1,6; 1,2%+/−2,0). In contrast to apoptosis induced by fludarabine, CXCR4 blocking agents did not reverse the protective effects of the stromal cell line on T cell mediated cytotoxicity (mean cytotoxicity 30:1, 10:1, 3:1 E:T ratio: 3,1%+/−2,4; 0,8%+/−2,5; 2,3%+/−1,6). These data indicate that the microenvironment may exert protective effects against immunotherapeutic strategies in CLL. However, the protective interaction is not entirely mediated by the CXCR4 - CXCL12 axis. Additional cell-cell interactions appear to play a role and need to be identified as therapeutic targets in order to effectively interrupt the protective effect of the microenvironment on T cell mediated cytotoxicity of B-CLL cells.

Donor Immunization with WT1 Peptide Augments Anti-Leukemic Activity After MHC-Matched Bone Marrow Transplantation

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1896-1896
Author(s):  
Holbrook E Kohrt ◽  
Antonia MS Mueller ◽  
Jeanette B Baker ◽  
Matthew J Goldstein ◽  
Evan Newell ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Tumor Antigen ◽  
Cd4 T Cell ◽  
Leukemia Cells ◽  
Peptide Vaccination ◽  
Tumor Bearing ◽  
Ifn Γ ◽  
Anti Tumor Activity

Abstract Abstract 1896 The curative potential of MHC-matched allogeneic bone marrow transplantation (BMT) is in part due to immunologic graft-versus-tumor (GvT) reactions mediated by donor T cells that recognize host minor histocompatibility antigens. Immunization with leukemia-associated antigens, such as Wilm's Tumor 1 (WT1) peptides, induces a T cell population that is tumor antigen specific. We determined whether BMT combined with immunotherapy using WT1 peptide vaccination of donors induced more potent anti-tumor activity when combined with allotransplantation. WT1 peptide vaccinations of healthy syngeneic or allogeneic donor mice with a 9-mer WT1 peptide (amino acids 126–134, the WT1 9-mer which has the highest binding affinity for H-2Db) and Incomplete Freund's Adjuvant induced CD8+ T cells that were specifically reactive to WT1-expressing FBL3 leukemia cells. We found that compared to vaccination with IFA alone, four weekly WT1 vaccinations induced an increased percentage of WT1-tetramer+CD8 T-cells (0.15% vs. 1%) in the peripheral blood 28 days following the first vaccination (Figure A *p<.001). CD8 T-cells producing IFN-γ+ after co-culture with tumor cells were similarly increased (0.11% vs. 13.6%) at this timepoint (Figure B *p<.001). They were CD44hi suggesting a memory phenotype, specifically reactive to WT1-expressing tumor (FBL3 and not H11), and increased in a vaccination dose-dependent fashion (Figure A and B). Four weekly WT1 vaccinations prevented tumor growth in donors following intravenous leukemia challenge. In contrast, in tumor-bearing mice, WT1 vaccinations failed to induce WT1-tetramer+ or IFN-γ+ CD8 T-cells and were ineffective as a therapeutic vaccine based on intensity of bioluminescence from luciferase-labeled FBL3 leukemia and mortality. BMT from WT1 vaccinated MHC-matched donors including LP/J and C3H.SW, but not C57BL/6 syngeneic donors, into C57BL/6 recipient tumor-bearing mice was effective as a therapeutic maneuver and resulted in eradication of luciferase-labeled FBL3 leukemia and survival of 70–90% of mice. Interestingly, the transfer of total CD8+ T cells from immunized donors was more effective than the transfer of WT1-tetramer+CD8+ T cells, likely as a result of alloreactive and tumor-antigen reactive T cells contained with the donor total CD8+ T cells. Total and tetramer+CD8+ T cells required CD4+ T cell help for maximal anti-tumor activity, which was equivalent in efficacy from immunized or unimmunized CD4+ T cell donors. Total CD4+ T cells, alone, from immunized donors provided no anti-tumor activity. The infused donor LP/J or C3H.SW CD8+ T cells collected from cured C57BL/6 recipients, were highly reactive against WT1-expressing FBL3 leukemia cells (14% IFN-γ+) compared to non-WT1-expressing H11 leukemia cells (5% IFN-γ+). The circulating, WT1-tetramer+CD8+ T cell population expanded in cured recipients, peaking at 3.5% on day 50 and contracting through day 100 post-BMT to 0.56%. These findings show that peptide vaccination of donor mice with a tumor antigen dramatically enhances GvT activity and is synergistic with allogeneic BMT. This novel and broadly applicable approach, using leukemia-associated antigen immunization to enhance GvT by creating an “educated” donor T cell graft for allogeneic transplantation of patients with acute myeloid leukemia and myelodysplastic syndrome, is currently being translated to a Phase 1 clinical trial at our institution. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Expansion of HIV-specific CD4+ and CD8+ T cells by dendritic cells transfected with mRNA encoding cytoplasm- or lysosome-targeted Nef

Blood ◽  
2006 ◽  
Vol 107 (5) ◽  
pp. 1963-1969 ◽  
Author(s):  
Daniel G. Kavanagh ◽  
Daniel E. Kaufmann ◽  
Sherzana Sunderji ◽  
Nicole Frahm ◽  
Sylvie Le Gall ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Cytotoxic T Cells ◽  
T Cell Response ◽  
Peripheral Blood Mononuclear ◽  
T Cell Lines

Transfection with synthetic mRNA is a safe and efficient method of delivering antigens to dendritic cells for immunotherapy. Targeting antigens to the lysosome can sometimes enhance the CD4+ T-cell response. We transfected antigen-presenting cells (APCs) with mRNA encoding Gag-p24 and cytoplasmic, lysosomal, and secreted forms of Nef. Antigen-specific cytotoxic T cells were able to lyse the majority of transfected targets, indicating that transfection was efficient. Transfection of APCs with a Nef construct bearing lysosomal targeting signals produced rapid and prolonged antigen presentation to CD4+ and CD8+ T cells. Polyclonal CD4+ and CD8+ T-cell lines recognizing multiple distinct epitopes were expanded by coculture of transfected dendritic cells with peripheral blood mononuclear cells from viremic and aviremic HIV-infected subjects. Importantly, lysosome-targeted antigen drove a significantly greater expansion of Nef-specific CD4+ T cells than cytoplasmic antigen. The frequency of recognition of CD8 but not CD4 epitopes by mRNA-expanded T cells was inversely proportional to sequence entropy and was similar to ex vivo responses from a large chronic cohort. Thus human dendritic cells transfected with mRNA encoding lysosome-targeted HIV antigen can expand a broad, polyclonal repertoire of antiviral T cells, offering a promising approach to HIV immunotherapy.

scholarly journals Tumor antigen–specific CD8 T cells infiltrating the tumor express high levels of PD-1 and are functionally impaired

Blood ◽  
2009 ◽  
Vol 114 (8) ◽  
pp. 1537-1544 ◽  
Author(s):  
Mojgan Ahmadzadeh ◽  
Laura A. Johnson ◽  
Bianca Heemskerk ◽  
John R. Wunderlich ◽  
Mark E. Dudley ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
T Lymphocytes ◽  
Cd8 T Cells ◽  
Tumor Antigen ◽  
Ki 67 ◽  
Normal Tissues ◽  
Functionally Impaired ◽  
Underlying Mechanisms

Abstract Tumor antigen–specific T cells are found within melanomas, yet tumors continue to grow. Although the tumor microenvironment is thought to influence the suppression of tumor-reactive T cells, the underlying mechanisms for this T-cell dysfunction are not clear. Here, we report that the majority of tumor infiltrating T lymphocytes (TIL), including MART-1/Melan-A melanoma antigen–specific CD8 T cells, predominantly expressed PD-1, in contrast to T cells in normal tissues and peripheral blood T lymphocytes (PBL). PD-1+ TIL expressed CTLA-4 and Ki-67, markers that were not expressed by PD-1− TIL and T cells in the normal tissues and PBL. Moreover, PD-1+ TIL were primarily HLA-DR+ and CD127−, in contrast to PD-1− TIL. Effector cytokine production by PD-1+ TIL was impaired compared with PD-1− TIL and PBL. Collectively, the phenotypic and functional characterizations of TIL revealed a significantly higher frequency and level of PD-1 expression on TIL compared with normal tissue T-cell infiltrates and PBL, and PD-1 expression correlated with an exhausted phenotype and impaired effector function. These findings suggest that the tumor microenvironment can lead to up-regulation of PD-1 on tumor-reactive T cells and contribute to impaired antitumor immune responses.

Expansion of CMV-specific CD8+CD45RA+CD27- T cells in B-cell chronic lymphocytic leukemia

Blood ◽  
2003 ◽  
Vol 102 (3) ◽  
pp. 1057-1063 ◽  
Author(s):  
Wendelina J. M. Mackus ◽  
Florine N. J. Frakking ◽  
Annette Grummels ◽  
Laila E. Gamadia ◽  
Godelieve J. de Bree ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Immune Responses ◽  
B Cell ◽  
Cd8 T Cells ◽  
Cytotoxic T Cells ◽  
Lymphocytic Leukemia ◽  
The Absolute ◽  
Cell Chronic Lymphocytic Leukemia

Abstract In patients with B-cell chronic lymphocytic leukemia (B-CLL), the absolute number of T cells is increased. Although it has been suggested that these T cells might be tumor specific, concrete evidence for this hypothesis is lacking. We performed a detailed immunophenotypic analysis of the T-cell compartment in the peripheral blood of 28 patients with B-CLL (Rai 0, n = 12; Rai I-II, n = 10; Rai III-IV, n = 6) and 12 healthy age-matched controls and measured the ability of these patients to mount specific immune responses. In all Rai stages a significant increase in the absolute numbers of CD3+ cells was observed. Whereas the number of CD4+ cells was not different from controls, patients with B-CLL showed significantly increased relative and absolute numbers of CD8+ cells, which exhibited a CD45RA+CD27- cytotoxic phenotype. Analysis of specific immune responses with tetrameric cytomegalovirus (CMV)–peptide complexes showed that patients with B-CLL had significantly increased numbers of tetramer-binding CMV-specific CD8+ T cells. The rise in the total number of CD8+ cytotoxic T cells was evident only in CMV-seropositive B-CLL patients. Thus, our data suggest that in patients with B-CLL the composition of T cells is shifted toward a CD8+ cytotoxic cell type in an effort to control infections with persistent viruses such as CMV. Moreover, they offer an explanation for the high incidence of CMV reactivation in CLL patients treated with T cell–depleting agents, such as the monoclonal antibody (mAb) alemtuzumab (Campath; α-CD52 mAb). Furthermore, because in CMV-seronegative patients no increase in cytotoxic CD8+ T cells is found, our studies do not support the hypothesis that tumor-specific T cells account for T-cell expansion in B-CLL.

scholarly journals CD73 Ectonucleotidase Restrains CD8+ T Cell Metabolic Fitness and Anti-tumoral Activity

2021 ◽  
Vol 9 ◽  
Author(s):  
Pedro Briceño ◽  
Elizabeth Rivas-Yañez ◽  
Mariana V. Rosemblatt ◽  
Brian Parra-Tello ◽  
Paula Farías ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cytotoxic T Cells ◽  
Cd8 T Cell ◽  
Tumor Burden ◽  
Effector Cells ◽  
Cd73 Expression ◽  
Metabolic Fitness

CD39 and CD73 are ectoenzymes that dephosphorylate ATP into its metabolites; ADP, AMP, and adenosine, and thus are considered instrumental in the development of immunosuppressive microenvironments. We have previously shown that within the CD8+ T cell population, naïve and memory cells express the CD73 ectonucleotidase, while terminally differentiated effector cells are devoid of this enzyme. This evidence suggests that adenosine might exert an autocrine effect on CD8+ T cells during T cell differentiation. To study the possible role of CD73 and adenosine during this process, we compared the expression of the adenosinergic signaling components, the phenotype, and the functional properties between CD73-deficient and WT CD8+ T cells. Upon activation, we observed an upregulation of CD73 expression in CD8+ T cells along with an upregulation of the adenosine A2A receptor. Interestingly, when we differentiated CD8+ T cells to Tc1 cells in vitro, we observed that these cells produce adenosine and that CD73-deficient cells present a higher cytotoxic potential evidenced by an increase in IFN-γ, TNF-α, and granzyme B production. Moreover, CD73-deficient cells presented a increased glucose uptake and higher mitochondrial respiration, indicating that this ectonucleotidase restrict the mitochondrial capacity in CD8+ T cells. In agreement, when adoptively transferred, antigen-specific CD73-deficient CD8+ T cells were more effective in reducing the tumor burden in B16.OVA melanoma-bearing mice and presented lower levels of exhaustion markers than wild type cells. All these data suggest an autocrine effect of CD73-mediated adenosine production, limiting differentiation and cytotoxic T cells’ metabolic fitness.

Restoration of tumor specific human leukocyte antigens class I-restricted cytotoxicity by dendritic cell stimulation of tumor infiltrating lymphocytes in patients with advanced ovarian cancer

2004 ◽  
Vol 14 (1) ◽  
pp. 64-75 ◽  
Author(s):  
A. D. Santin ◽  
S. Bellone ◽  
M. Palmieri ◽  
B. Bossini ◽  
S. Cane' ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Tumor Antigen ◽  
Advanced Ovarian Cancer ◽  
Human Leukocyte ◽  
Hla Class I ◽  
Class I ◽  
Autologous Tumor

Despite the large number of potentially cytotoxic tumor-infiltrating (TIL) and tumor-associated (TAL) lymphocytes accumulated in the peritoneal cavity ascitic fluid and tumor tissue, advanced ovarian cancer is a progressive disease, suggesting that TIL and TAL populations eventually become functionally suppressed in vivo. Dendritic cells (DC) are the most powerful professional antigen presenting cells known in humans and recently, ovarian tumor antigen pulsed DC have been shown to elicit tumor specific human leukocyte antigens (HLA)-class I-restricted cytotoxicity from the peripheral blood of advanced ovarian cancer patients. In this study, we have evaluated the potential of tumor antigen-pulsed fully mature DC stimulation in restoring tumor-specific cytotoxicity in anergic TIL populations from advanced ovarian cancer patients. In addition, we have compared tumor-specific T-cell responses induced by tumor antigen-loaded DC in TIL to those induced in TAL and peripheral blood lymphocytes (PBL). DC stimulation induced powerful cytotoxicity against autologous tumor target cells in TIL-derived CD8+ T-cells from all patients tested, while autologous Epstein–Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL) were not lysed. Killing of autologous tumor cells was higher by CD8+ T-cells from TIL compared to PBL and TAL (P < 0.01) and was more strongly inhibited by anti-HLA class I MAb (P < 0.05 compared to PBL and TAL). Phenotypically, all cytotoxic T lymphocyte (CTL) populations were CD3+/CD8+, with variable levels of CD56 expression. Finally, although a marked Type 1 cytokine bias [ie, interferon-gamma/interleukin-4 (IFN-γhigh/IL-4low)] was observable in all DC-stimulated CD8+ T-cell populations, TIL derived CD8+ T-cells showed a higher percentage of IFN-γ positive cells compared to TAL and PBL. Taken together, these data show that tumor lysate-pulsed DC can consistently restore strong CD8+ CTL responses from TIL against autologous ovarian cancer cells. DC-stimulated TIL may represent a superior source of tumor-specific CTL for adoptive T-cell immunotherapy for advanced ovarian cancer.

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