Establishment and characterization of αs1-casein–specific T-cell lines from patients allergic to cow’s milk: Unexpected higher frequency of CD8+ T-cell lines

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.

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Generation of Acute Myeloid Leukemia (AML)-Specific Autologous CD4 and CD8 T Cell Lines by Limiting Dilution AML Dendritic Cell Culture.

Blood ◽

10.1182/blood.v108.11.2018.2018 ◽

2006 ◽

Vol 108 (11) ◽

pp. 2018-2018

Author(s):

Rui-kun Zhong ◽

Thomas A. Lane ◽

Edward D. Ball

Keyword(s):

T Cells ◽

T Cell ◽

Cell Lines ◽

Myeloid Leukemia ◽

Cd8 T Cell ◽

Ifn Gamma ◽

T Cell Lines ◽

Limiting Dilution ◽

Acute Myeloid

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

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Isolation and Characterization of CD4+ T Cells Specific for the HPA 1a Epitope Associated with Neonatal Alloimmune Thrombocytopenia.

Blood ◽

10.1182/blood.v110.11.2091.2091 ◽

2007 ◽

Vol 110 (11) ◽

pp. 2091-2091

Author(s):

Maria T. Ahlen ◽

Mette K. Killie ◽

Bjorn Skogen ◽

Anne Husebekk ◽

Tor B. Stuge

Keyword(s):

Flow Cytometry ◽

T Cells ◽

T Cell ◽

Cell Lines ◽

Cell Detection ◽

Severe Thrombocytopenia ◽

Isolation And Characterization ◽

T Cell Lines ◽

Alloimmune Thrombocytopenia

Abstract Neonatal alloimmune thrombocytopenia (NAIT) can cause severe complications such as intrauterine death or intracranial hemorrhage (ICH) in the newborn, and is caused by the transfer of platelet-depleting antibodies from the mother to the fetus during pregnancy. These antibodies react with allogeneic epitopes, most commonly human platelet antigen (HPA) 1a, when present on fetal platelets. Although these responses are thought to be a result of a T cell-dependent immune response, HPA 1a specific T cells have not yet been isolated. To examine whether HPA 1a specific T cells could be detected and isolated, we collected PBMC post delivery from an HPA 1a negative mother who gave birth to an HPA 1a positive neonate suffering from severe thrombocytopenia (platelet count <50×109/L). The cells were stimulated with HPA 1a peptides (20aa) in long term cultures supplemented with IL-7 and IL-2, and subsequently, IL-15. After 4 weeks in culture these cells were labeled with CFSE dye and restimulated with HPA 1a or control peptides. After additional 2 weeks in culture supplemented with IL-2 and IL-15, specific proliferative responses were detectable by CFSE dye dilution by flow cytometry. The cells were cloned by fluorescent-activated cell sorting (FACS) and expanded in numbers with anti-CD3 stimulation in the presence of irradiated allogeneic PBMC and IL-2. The resulting clonal T cell lines were characterized in proliferation assays, ELISPOT assays and phenotyped by flow cytometry. All clones were CD3+, CD4+ and CD19−, and the majority of the clones proliferated and secreted cytokines in response to stimulation with HPA 1a peptides, but not control peptides. In ELISPOT assays, peptide-pulsed antigen-presenting cells were required for T cell detection. These clonal HPA 1a specific CD4+ T cell lines represent formal evidence of the existence of HPA 1a specific T cell responses related to NAIT and will serve as important tools for further characterization of maternal immune responses associated with NAIT.

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Universal CD137 Expression upon Activation Allows Efficient Isolation of a Broad Repertoire of Virus-Specific CD8+ and CD4+ T Cells for Adoptive Immunotherapy.

Blood ◽

10.1182/blood.v112.11.2222.2222 ◽

2008 ◽

Vol 112 (11) ◽

pp. 2222-2222

Author(s):

Maarten L. Zandvliet ◽

J.H. Frederik Falkenburg ◽

Inge Jedema ◽

Roelof Willemze ◽

Henk-Jan Guchelaar ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Lines ◽

Cd8 T Cells ◽

Cd4 T Cells ◽

Cd8 T Cell ◽

Cell Populations ◽

T Cell Lines ◽

Kinetics Of ◽

Ifng Production

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.

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