Cd8+ T-Cells Specifically Cytotoxic to Renal Cell Carcinoma (RCC) Cells Can Be Isolated from Patients with Regressing Metastatic Kidney Cancer after Allogeneic Nonmyeloablative Hematopoietic Cell Transplantation (NMHCT).

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4984-4984
Author(s):  
Yoshiyuki Takahashi ◽  
Othon Mena ◽  
Ramaprasad Srinivasan ◽  
Takehito Igarashi ◽  
Andreas Lundqvist ◽  
...  

Abstract Graft-vs-tumor (GVT) effects following NMHCT induce disease regression in a subset of patients (pts) with advanced metastatic kidney cancer. At present, little is known about the antigens serving as tumor targets in responding pts. In an effort to characterize GVT effectors and their tumor antigens, we generated RCC cell lines to use as targets in cytotoxicity assays in three pts (one non-responder and two responders) undergoing a cyclophosphamide/fludarabine-based NMHCT from HLA matched siblings. Peripheral blood lymphocytes (PBL) were collected from pts at multiple time-points after transplantation and were expanded in-vitro with either irradiated patient (pre-transplant) PBL/EBV-LCL or autologous tumor cells. RCC pt #1 developed grade II skin GVHD on day 22 but did not have an objective tumor response and died from progressive tumor on day 203. In a Cr51 release assay, minor histocompatibility antigen specific (mHa) T-cell lines generated using pre-transplant pt PBL/EBV-LCL stimulators lysed 98% of pt CD40-ligand stimulated B cells (CD40L-B) but did not kill pt RCC cells. RCC pt #2 developed grade II skin GVHD on Day 51 and was noted to have regression of lung metastasis on day 183. Using PBL obtained during tumor regression, mHa- reactive T-cell lines were generated (pre-transplant pt PBL/EBV-LCL used as stimulators) that lysed 76% and 12% of pt EBV-LCL and autologous RCC tumor cells at a 20:1 E:T ratio. Following limiting dilution cloning, 6 CD8+ T cell clones were expanded that killed pt EBV-LCL (but not donor) including one MHC class-1 restricted T cell clone that lysed both pt EBV-LCL and pt tumor cells. RCC pt #3 developed grade III skin GVHD on day 120, had regression of lung metastasis on day 160, and survives more than 4 years after transplantation. PBL collected from this pt 40 months after transplant contained CD8+ T-cell populations that secreted IFN-g (0.9% by intracellular cytokine staining) when co-cultured with pt RCC cells but not after co-culture with pt CD40L-B cells. CD3+/CD8+ CTL were expanded from these PBL using pt RCC cells as stimulators; in vitro, these CTL killed the pt’s RCC cells but did not kill pt fibroblasts or pt EBV-LCL (Figure A). Following co-culture with tumor, intracellular IFN-g staining combined with TCR Vb antibodies revealed 3 tumor reactive CD8+ T-cell populations (TCR Vb7+, TCRVb5.1+, and TCRVb non-staining); 25.2% of these CTL were TCRVb7+. IFN-g secretion by TCR Vb7+ T cells was blocked when tumor cells were pre-incubated with mAbs to CD8, pan MHC class I and HLA-A11 (Figure B) consistent with recognition of an HLA-11 restricted tumor antigen. Following limiting dilution cloning, several CD8+ T-cell clones (both TCR Vb7+ and TCR Vb non-staining) with RCC-specific cytotoxicity were identified. We conclude that donor T-cells with both broad alloreactivity and tumor specificity play a role in mediating GVT effects in RCC pts having disease regression following NMHCT. Figure Figure

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 5118-5118
Author(s):  
Daniel Teschner ◽  
Eva Distler ◽  
Elke Schnuerer ◽  
Gregor Wenzel ◽  
Axl Neurauter ◽  
...  

Abstract Abstract 5118 Introduction Efficient methods for the reliable in vitro expansion of tumor-reactive T cells will surely broaden the applicability of adoptive T cell therapy in cancer. In this study we investigated the antigen-independent stimulation and expansion of human T cells in peripheral blood mononuclear cells (PBMC) and in long-term cultured tumor-reactive CD8+ T cell lines using superparamagnetic beads coated with antibodies to CD3 and the costimulatory molecules CD28 and CD137. Methods T cell numbers were measured in healthy donor PBMC after in vitro stimulation with Dynabeads® coated with CD3/CD28/CD137 versus Dynabeads® coated with CD3/CD28 (all beads +/- 100 U/mL IL-2) versus IL-2 alone at different bead/cell ratios (3:1, 1:1). Expansion was also analyzed in human renal cell carcinoma-reactive CD8+ T cell lines after restimulation with tumor cells (weekly), CD3/CD28 beads and CD3/CD28/CD137 beads, respectively (bead/cell ratio of 1:5, 100 U/mL IL-2 added). Expanded T cell lines were phenotyped for expression of activation, differentiation and homing molecules (i.e. CD27, CD28, CD45RA, CD45RO, CD57, CD62L, CD137, CCR7) and were also tested for function. Results T cells in PBMC showed an increased expansion rate of up to 17-fold during a 2-week culture period using beads with IL-2 added versus IL-2 alone (p<0.0001 for CD3/CD28/CD137; p<0.0001 for CD3/CD28). The difference between CD3/CD28/CD137 beads and CD3/CD28 beads was not significant (p=0.4). Bead/cell ratios of 1:1 and 3:1 expanded T cells in PBMC with similar efficiency. In addition, IL-2 was essential to obtain maximum T cell proliferation. Peripheral blood CD4+ and CD8+ T cells showed a strong increase of CD137 surface expression starting 12-24 hours upon stimulation, regardless which beads were used. In contrast to PBMC, tumor-reactive CD8+ T cell lines expanded more rapidly using CD3/CD28/CD137 beads versus CD3/CD28 beads (p=0.03). Stimulation with CD3/CD28/CD137 beads was comparably efficient versus the control arm using weekly addition of tumor cells and IL-2. Simultaneous addition of beads and tumor cells did not have a synergistic effect. CD8+ T cell lines analyzed 12 days after bead-induced in vitro expansion versus weekly tumor stimulation showed a comparable level of tumor reactivity in IFN-g ELISPOT assay. Phenotypically, expression of CD137 on CD8+ T cell lines showed maximum up-regulation 24 hours after beads stimulation and persisted for at least 72 hours. In contrast, cultures stimulated solely with tumor cells showed a much shorter and transient CD137 expression with an earlier peak level after 12 hours. Other phenotypic markers were similar on tumor-reactive T cell cultures, except for increased CD62L expression after bead-induced stimulation. Conclusion Antigen-independent in vitro expansion of T cells in PBMC was equally efficient using CD3/CD28 beads or CD3/CD28/CD137 beads, respectively. In contrast, we observed an increased growth rate for tumor-reactive CD8+ T cell lines when activated with CD3/CD28/CD137 beads compared to CD3/CD28 beads. Antitumor reactivity of T cell lines was maintained during the antigen-independent stimulation step. Bead activation was associated with increased expression of the lymph node homing receptor CD62L on antitumor CD8+ T cell lines, which indicates a central memory phenotype. Our data suggest that the conjugation of anti-CD137 antibodies to the traditionally used CD3/CD28 beads improves their expansion capacity for antitumor CD8+ T cell lines. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2018-2018
Author(s):  
Rui-kun Zhong ◽  
Thomas A. Lane ◽  
Edward D. Ball

Naturally occurring cytotoxic T cells directed against various leukemia associated antigens (LAA) expressed by acute myeloid leukemia (AML) cells have been described. However, these LAA-specific T cells are rare and obviously unable to initiate effective anti-leukemia responses. The challenge is how to investigate, select, activate and expand the rare LAA-specific T cells from the vast population of blood cells in patients with AML for immunotherapy. Based on our studies of inducing AML dendritic cell (AMLDC) differentiation and priming in situ AML-reactive T cells, we have developed a novel method of generating multiple autologous AML reactive T cell lines by limiting dilution AMLDC (LD-AMLDC) culture. The principle of LD-AMLDC is based on the assumption that autologous AML-reactive T cells or precursors are randomly distributed in the AML PBMC suspension, and that each one has an equal opportunity to respond to AML cells in the 96-well plates under optimized culture condition. By culturing AML PBMC (>90% blasts) in culture medium supplemented with GM-CSF/IL4/IL2/IL7/IL12 to induce AML DC differentiation and activate in situ autologous T cells, highly reactive anti-AML T cell lines (both CD4+ and CD8+ lines) were selected and expanded from LD-AMLDC culture using the appropriate numbers of AML PBMC in each culture well by the criterion of release of IFN-gamma in response to autologous AML blasts. By maximum likelihood solution, the estimated average frequency of AML reactive T cells or precursors is 6±3/1,000,000 AML PBMC (n=8). Strong intracellular IFN-gamma release of T cell lines obtained in LD-AMLDC was demonstrated by flow cytometry analysis after stimulation by autologous AML cells but not autologous B-lymphoblastoid cell line (LCL) (Figure). Effective specific lysis (up to 70% at E:T=20:1) of autologous AML cells but not autologous LCL or allogeneic AML cells by these T cell lines was observed. Two PR1 specific T cell lines were obtained by screening 39 AML reactive HLA-A2+ CD8+ T cell lines generated from 5 LD-AMLDC cultures, suggesting that other unidentified CD4 or CD8 lines with strong autologous AML responses may be reactive to known or unknown LAAs. These results encourage continued efforts to induce, activate and select T cells lines with high autologous AML reactivity using LD-AMLDC culture and to expand multi-LAA reactive T cell lines acquired from limiting dilution AML-DC culture for AML immunotherapy. Figure Figure


1996 ◽  
Vol 183 (1) ◽  
pp. 67-76 ◽  
Author(s):  
F S Wong ◽  
I Visintin ◽  
L Wen ◽  
R A Flavell ◽  
C A Janeway

T cells play an important role in the pathogenesis of diabetes in the nonobese diabetic (NOD) mouse. CD8 cytotoxic T cell lines and clones were generated from the lymphocytic infiltrate in the islets of Langerhans of young (7-wk-old). NOD mice by growing them on (NOD x B6-RIP-B7-1)F1 islets. These cells proliferate specifically to NOD islets and kill NOD islets in vitro. The cells are restricted by H-2Kd, and all bear T cell antigen receptor encoded by V beta 6. When these CD8 T cell lines and clones are adoptively transferred to irradiated female NOD, young NOD-SCID, and CB17-SCID mice, diabetes occurs very rapidly, within 10 d of transfer and without CD4 T cells.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3713-3713
Author(s):  
Seung-Tae Lee ◽  
Shujuan Liu ◽  
Pariya Sukhumalchandra ◽  
Jeffrey Molldrem ◽  
Patrick Hwu ◽  
...  

Abstract Adoptive T-cell therapy using donor lymphocyte infusions is a promising approach for treating hematological malignancies. But, efficacy is limited by the induction of graft-versus-host disease. Transfer of tumor-specific T-cell clones could enhance the graft-versus-tumor effect and eliminate graft-versus-host disease. However, isolating antigen-specific T-cell clones by the traditional limiting dilution approach is a time-consuming and laborious process. Here, we describe a novel strategy for rapidly cloning tumor-specific T cells. Lymphoma-specific T-cell lines were generated from two follicular lymphoma patients by repeated in vitro stimulation of lymphocytes isolated from tumor or blood with autologous soluble CD40 ligand-activated tumor cells. After four in vitro stimulations at 10-day intervals in the presence of IL-2 and IL-15, T-cell lines were found to be predominantly CD4+ T cells and produced significant amounts of TNF-a, GM-CSF, and IFN-γ in response to autologous tumor cells. The tumor reactivity was MHC class II restricted suggesting that it was mediated by CD4+ T cells. Staining with a TCR Vb antibody panel, a set of monoclonal antibodies against 24 human TCR Vb families, revealed that certain Vb families were overrepresented in each CD4+ T-cell line. In patient 1, 51% of CD4+ T cells were Vb1 positive, and in patient 2, 27% of CD4+ T cells were Vb8 positive. To clone lymphoma-specific T cells, CD4+ T-cell lines were labeled with CFSE and stimulated with autologous tumor cells. After 9 days of in vitro expansion in the presence of IL-2 and IL-15, CD4+ T-cell lines were stained with an anti-human CD4-APC monoclonal antibody and an anti-human TCR Vb-PE monoclonal antibody for each CD4+ T-cell line. Proliferating Vb1 cells from patient 1 and Vb8 cells from patient 2 were identified by their reduction in CFSE staining, and CD4+TCRV b +CFSEdim cells were sorted by flow cytometer. Monoclonality of the sorted cells was confirmed by PCR using a panel of optimized primers specific for 24 TCR Vb families, by TCR Vb spectratype analysis, and finally, by sequencing the TCR Vb gene used by each T-cell clone. Sorted tumor-specific T-cell clones could be expanded to large numbers using a 14-day rapid expansion protocol with allofeeder PBMCs, and confirmed to retain specificity against autologous tumor cells in a cytokine induction assay. This approach was also successfully used to isolate melanoma-specific CD8+ T-cell clones from two patients. We conclude that this approach is highly reproducible, rapid, and efficient for generating antigen-specific T-cell clones for adoptive T-cell therapy against human malignancies in the autologous or allogeneic setting.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1482-1482
Author(s):  
Seung-Tae Lee ◽  
Yun Fang Jiang ◽  
Soung-Chul Cha ◽  
Hong Qin ◽  
Larry W. Kwak ◽  
...  

Abstract Advanced stage follicular lymphoma remains an incurable disease with a median survival of 8 to 10 years that has not significantly changed over the last four decades. Therefore, novel treatment options are necessary to improve the clinical outcome in these patients. The observation of spontaneous regressions in a small percentage of patients suggested that augmenting the host immune response could potentially control this malignancy. Strategies using active specific immunotherapy with idiotype vaccines led to induction of clinical and molecular responses in a few patients but have met with only limited success possibly due to the low frequency of antigen-specific T cells induced in the patients. In contrast to active immunization, T cells of a given specificity and function may be selected and expanded in vitro to the desired number for adoptive cell transfer. Towards this goal, we stimulated tumor infiltrating lymphocytes (TILs) or peripheral blood mononuclear cells (PBMCs) from five follicular lymphoma patients with CD40 ligand-activated autologous tumor cells at approximately ten-day intervals in the presence of IL-2 and IL-15. After four rounds of stimulations, T cell lines generated from 3/5 patients recognized autologous unmodified tumor cells by producing significant amounts of TNF-α, GM-CSF and/or IFN-γ. By phenotypic analysis, the T cell lines were predominantly CD4+ T cells (&gt; 70%), and intracellular cytokine assay showed that up to 40% of the CD4+ T cells were tumor-reactive. The inhibition of cytokine production by anti-HLA class II but not class I blocking antibodies confirmed that the CD4+ T cells were tumor-reactive. Further characterization revealed that the T cells from one patient recognized autologous tumor but not autologous normal B cells suggesting that they were tumor-specific. While in a second patient CD4+ T cell clones generated from the T cell line by limiting dilution recognized autologous tumor and autologous normal B cells but not autologous monocytes suggesting that they were B cell lineage-specific. We conclude that follicular lymphoma-specific T cells exist and can be efficiently expanded in vitro from both TILs and PBMCs using CD40 ligand-activated autologous tumor cells for adoptive T cell therapy. Additionally, identification of antigens recognized by these T cells could lead to development of novel immunotherapeutic strategies for lymphomas.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 477-477
Author(s):  
Erica Dander ◽  
Giuseppina Li Pira ◽  
Ettore Biagi ◽  
Fabrizio Manca ◽  
Andrea Biondi ◽  
...  

Abstract BACKGROUND: Reactivation of latent CMV in immunocompromised recipients of allogeneic stem cell transplantation remains a major cause of morbidity and mortality. Reconstitution of immunity by CMV specific immunotherapy is an attractive alternative to drugs currently used, which show high toxicity and are sometimes ineffective. It has been demonstrated that CD4 helper T-cell function is crucial for the persistence of in vivo transferred CD8 CMV-specific CTL. Based on this finding, we have explored the feasibility of generating both anti-CMV CD4 and anti-CMV CD8 T-cell lines. METHODS: Dendritic Cells (DC) were generated from donor peripheral blood (PB) monocytes after a 7-day culture in the presence of GM-CSF plus IL-4 and matured with TNF-α, IFN-α, IFN-γ, IL1-β, POLI I:C. Matured-DC were then pulsed with a pool of 50 peptides spanning pp65 and IE1 proteins which are recognised by both CD4 and CD8 T lymphocytes. Donor T cells were stimulated three times at a T cell/DC ratio of 1:6 on day 0, +7 and +14 with mature peptide pulsed-DC. At the end of the culture the specificity of generated T cells was determined as percentage of pentamer-positive cells and intracellular IFN-γ production after incubation with peptide pulsed-DC. Cultured T cells were also analysed for their ability to proliferate in response to peptide pulsed-target cells, to kill them in a standard citotoxicity assay and to migrate in response to inflammatory (CXCL9, CCL3 and CCL5) and constitutive (CXCL12) chemokines. RESULTS: CMV-specific T cell lines were generated from five CMV seropositive donors. In four cases CD4 and CD8 CMV-specific T cell lines were expanded successfully. Cultured T cells expressed CD8 (mean= 70%, range 60–81%) and CD4 (mean= 20%, range 15–28%) and showed a CD45RA- CCR7- Effector Memory phenothype (mean=26%, range 19–30%) or a CD45RA+ CCR7- T Effector Memory RA-Positive phenothype (mean=67%, range 59–77%). An enriched CMV-specific T cell population was observed after staining with pentamers (7–45% pentamer-positive T cells). Furthermore, 90% of CD8+ and 40% of CD4+ T cells expressed high levels of intracytoplasmatic perforin and granzyme. In 4/5 cases tested, cutured T cells showed a cytolitic activity against CD8-peptide pulsed target cells (average lysis=50%, range 40–55%) and to a lesser extent against CD4-peptide pulsed target cells (average lysis=35%, range 30–40%). In addition, cultured T lymphocytes were able to proliferate and to produce intracytoplasmic IFN-γ (average production=50%, range 35–60%) after exposure to peptide-pulsed DC. Finally, Cultured T cells strongly migrated in response to chemokines (CXCL9, CCL3 and CCL5) involved in the recruitment of effector cells during viral infection. DISCUSSION: In conclusion, a great advantage of this method is represented by the possibility to generate anti-CMV CD4+ T cells, which could support in vivo the persistence of re-infused CMV-specific CTL. Moreover, the possibility of generating peptides under GMP conditions would facilitate the translation of this approach into clinical intervention.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3249-3249
Author(s):  
Avital L. Amir ◽  
Lloyd J.A. D’Orsogna ◽  
Marleen M. van Loenen ◽  
Dave L. Roelen ◽  
Ilias I.N. Doxiadis ◽  
...  

Abstract Graft versus host disease (GVHD) in allogeneic stem cell transplantation (SCT) and graft rejection is caused by alloreactive T-cells. Alloreactivity can be exerted by naïve as well as by memory T-cells. Persistent latent viral infections, like those with herpes viruses, have a profound impact on the repertoire of memory T-cells. This implies that virus specific memory T-cells are also potentially alloreactive. Previously it has been shown that virus specific T-cell clones can cross react against allo-HLA. We investigated the frequency of alloreactivity mediated by virus specific T-cells. Mixed lymphocyte reactions, previously used to determine precursor frequencies of alloreactive T-cells, give an underestimation of the total frequency of alloreactive T-cells, due to limited number of allo-HLA alleles tested in this system. Therefore, in this study multiple CD8+ virus specific T-cells lines and clones were tested for alloreactivity against almost all frequent HLA class I and II alleles. From different healthy individuals we derived CD8+ virus specific T-cell lines, specific for Epstein Barr virus (EBV), Cytomegalovirus (CMV), Varicella Zoster virus (VZV) and Influenza virus (Flu) which were restricted to different HLA molecules. The generation of the T-cell lines and clones was performed by bulk sorting and single cell sorting, based on staining with viral peptide/MHC complex specific tetramers. The viral specificity of the expanded lines and clones was confirmed by tetramer staining and cytotoxicity and cytokine production assays. Polyclonality of the T-cell lines and monoclonality of the T-cell clones was confirmed by TCR Vβ analysis. Next, the T-cell lines and clones were screened for alloreactivity by testing against a panel of 29 different EBV transformed LCLs, together covering almost all frequent HLA class I and II molecules. 90% of tested virus specific T-cell lines and 40% of virus specific T-cell clones were found to be alloreactive, recognizing at least one of the allo-HLA alleles. For several lines and clones the specific recognized allo-HLA molecule was further identified using a panel of HLA typed target cells in combination with HLA specific blocking antibodies. Additionally, single HLA antigen expressing cell lines were used as target cells. Thus far we found EBV EBNA3A specific, HLA-A3 restricted T-cell clones to recognize HLA-A31. A CMV pp50 specific, HLA-A1 restricted T-cell line recognized HLA-A68. One VZV IE62 specific, HLA-A2 restricted clone showed recognition of HLA-B57, while another clone with the same specificity but with a different TCR Vβ recognized HLA-B55. An EBV BMLF specific, HLA-A2 restricted T-cell line showed recognition of HLA-A11. Finally an EBV BRLF specific, HLA-A3 restricted clone recognized HLA-A2. Our results show that a high percentage of virus specific T-cells can exert alloreactivity against allo- HLA molecules. Previously it was assumed that virus specific T-cells are not alloreactive against foreign HLA, allowing safe application of virus specific T-cell lines derived from HLA disparate donors in patients without the risk of inducing GVHD. Our data indicate that applying virus specific T-cell lines over HLA barriers does give a significant risk of GVHD and suggest that lines should be tested for alloreactivity against patient specific HLA alleles prior to application. A substantial part of the memory T-cell pool consists of virus specific T-cells, which are dominated by a limited repertoire of virus specific T-cell clones, present in high frequencies. Thus, virus specific T-cells recognizing allo-HLA alleles may also play an essential role in graft rejection.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2222-2222
Author(s):  
Maarten L. Zandvliet ◽  
J.H. Frederik Falkenburg ◽  
Inge Jedema ◽  
Roelof Willemze ◽  
Henk-Jan Guchelaar ◽  
...  

Abstract Reactivation of adenovirus (ADV), cytomegalovirus (CMV) and Epstein-Barr virus (EBV) can cause serious morbidity and mortality during the prolonged period of immune deficiency following allogeneic stem cell transplantation. It has been shown that adoptive transfer of donor-derived virus-specific T cells can be a successful strategy to control viral reactivation. To provide safe and effective anti-viral immunotherapy, we aimed to generate combined CD8+ and CD4+ T cell lines with high specificity for a broad range of viral epitopes. Isolation by the IFNg capture assay of virus-specific T cells that produce IFNg upon activation allows the generation of highly specific T cell lines without the need for extensive culture. However, it has been recently shown that specific upregulation of the co-stimulatory molecule CD137 upon antigen-specific activation of CD8+ and CD4+ T cells can also be used for isolation. We therefore analyzed IFNg production and CD137 expression by CD8+ and CD4+ T cells upon incubation of peripheral blood mononuclear cells (PBMC) from seropositive donors with peptides corresponding to 17 defined MHC class I restricted minimal epitopes from 10 different ADV, CMV, EBV and influenza (FLU) proteins, and 15-mer or 30-mer peptides containing MHC class II restricted epitopes from CMV pp65 or ADV hexon. Using tetramer and intracellular IFNg staining we first determined the fraction of CD8+ T cells that produced IFNg upon activation with the minimal epitopes. Specific IFNg production was observed for 58–100% of tetramer+ CD8+ T cells specific for CMV pp65 (n=6), and 83% for FLU (n=1), but only 18–58% for CMV pp50 (n=3) or IE-1 (n=3), 4–91% for EBV latent (n=3) and lytic (n=3) epitopes, and 41–63% for ADV hexon (n=2). In contrast to the variation in the fraction of IFNg-producing cells, we observed homogeneous upregulation of CD137 by the virus-specific tetramer+ T cell populations upon activation. In 2 cases where no CD137 expression by tetramer+ T cells could be detected, no IFNg production was observed either. These data suggest that the majority of CD8+ T cells specific for CMV pp65 or FLU can be isolated on basis of IFNg production, but only part of CD8+ T cell populations specific for other viral proteins, while complete virus-specific CD8+ T cell populations may be isolated on basis of CD137 expression. Activation of CD4+ T cells specific for CMV pp65 or ADV hexon with 15-mer or 30-mer peptides induced both specific IFNg production and CD137 expression. To investigate whether multiple virus-specific T cell populations could be isolated simultaneously, we next determined the kinetics of IFNg production after activation with defined MHC class I epitopes or peptides containing MHC class II epitopes. CMV- and EBV-specific CD8+ T cells and CMV-specific CD4+ T cells showed a rapid induction of IFNg production, which peaked after 4 hours and decreased thereafter. In contrast, ADV- and FLU-specific CD8+ T cells and ADV-specific CD4+ T cells, predominantly having a more early differentiation phenotype (CD27+CD28+) compared to CMV- and EBV-specific T cells, showed peak IFNg production after 8 hours that continued for more than 48 hours. This difference in phenotype and IFNg kinetics may suggest that the persistent and frequent presentation of CMV and EBV epitopes in vivo, in contrast to an intermittent exposure to ADV and FLU epitopes, drives differentiation and shapes the kinetics of the IFNg response of specific T cells. Kinetic analysis of CD137 expression showed uniform upregulation by virus-specific CD8+ T cell populations from day 1 to day 4 after activation, which peaked at day 2, suggesting that this may be the optimal time point for CD137-based isolation. In a limited number of experiments, virus-specific CD8+ and CD4+ T cells could be isolated based on CD137 expression within the same timeframe. These data indicate that virus-specific T cell populations can be more efficiently isolated at one time point on basis of CD137 expression than on basis of IFNg production, due to differences in IFNg kinetics. In conclusion, this study shows that T cell lines generated by CD137 isolation may comprise a significant number of virus-specific T cells which do not produce IFNg, but may have other effector functions. Furthermore, CD137-based enrichment may be more robust and allows the efficient simultaneous isolation of multiple virus-specific T cell populations due to uniform kinetics of CD137 expression.


Open Biology ◽  
2016 ◽  
Vol 6 (11) ◽  
pp. 160293 ◽  
Author(s):  
Lee Kim Swee ◽  
Zhen Wei Tan ◽  
Anna Sanecka ◽  
Nagisa Yoshida ◽  
Harshil Patel ◽  
...  

T-cell identity is established by the expression of a clonotypic T-cell receptor (TCR), generated by somatic rearrangement of TCRα and β genes. The properties of the TCR determine both the degree of self-reactivity and the repertoire of antigens that can be recognized. For CD8 T cells, the relationship between TCR identity—hence reactivity to self—and effector function(s) remains to be fully understood and has rarely been explored outside of the H-2 b haplotype. We measured the affinity of three structurally distinct CD8 T-cell-derived TCRs that recognize the identical H-2 L d -restricted epitope, derived from the Rop7 protein of Toxoplasma gondii . We used CD8 T cells obtained from mice generated by somatic cell nuclear transfer as the closest approximation of primary T cells with physiological TCR rearrangements and TCR expression levels. First, we demonstrate the common occurrence of secondary rearrangements in endogenously rearranged loci. Furthermore, we characterized and compared the response of Rop7-specific CD8 T-cell clones upon Toxoplasma gondii infection as well as effector function and TCR signalling upon antigenic stimulation in vitro . Antigen-independent TCR cross-linking in vitro uncovered profound intrinsic differences in the effector functions between T-cell clones. Finally, by assessing the degree of self-reactivity and comparing the transcriptomes of naive Rop7 CD8 T cells, we show that lower self-reactivity correlates with lower effector capacity, whereas higher self-reactivity is associated with enhanced effector function as well as cell cycle entry under physiological conditions. Altogether, our data show that potential effector functions and basal proliferation of CD8 T cells are set by self-reactivity thresholds.


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