scholarly journals Feline Immunodeficiency Virus (FIV)-Specific Cytotoxic T Lymphocytes from Chronically Infected Cats Are Induced in Vitro by Retroviral Vector-Transduced Feline T Cells Expressing the FIV Capsid Protein

Virology ◽  
1995 ◽  
Vol 209 (2) ◽  
pp. 390-399 ◽  
Author(s):  
Wenru Song ◽  
Ellen W. Collisson ◽  
Junzhou Li ◽  
Alice M. Wolf ◽  
John H. Elder ◽  
...  
Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3534-3534
Author(s):  
Juan F Vera ◽  
Valentina Hoyos ◽  
Barbara Savoldo ◽  
Concetta Quintarelli ◽  
Greta A Giordano ◽  
...  

Abstract Providing a proliferative and survival advantage to tumor-specific cytotoxic T lymphocytes (CTLs) remains a challenge in the adoptive therapy of cancer patients. It is now evident that the in vivo expansion of T cells after adoptive transfer is best accomplished in the lymphodepleted host due to the increased production of endogenous IL15 and IL7, which help restore lymphopoiesis. We have found that antigen activated cytotoxic T lymphocytes (CTLs) directed to tumor associated epitopes (for example derived from EBV, or from cancer testis antigens such as PRAME) down regulate a chain of IL7R, a common γ chain cytokine receptor, impairing their capacity to respond to IL7. We hypothesized that despite receptor downregulation, the signal transduction pathway for IL7R would remain intact in the CTLs so that forced expression of IL7Rα would restore IL7 responsiveness and improve in vivo expansion and survival of CTLs. We used EBV-specific CTLs as our model, and showed in vitro that a functional IL-7Ra molecule can be expressed in CTLs using retroviral gene transfer so that the percentage of receptor + cells increased from 2.4%±0.5% to 50%±20. This modification restored the in vitro proliferation of genetically modified CTLs in response to IL7 so that cell numbers increased from 1×106 cells to 0.1×109 (range, 0.6×108 to 0.3×109)] comparable with the effects of IL2 [from 1×106 cells to 0.7×109 (range, 0.7×107 to 1.6×109)] In contrast, control EBV-CTL with IL7 progressively declined in number (p<0.001) These effects were accomplished without alteration of antigen specificity or responsiveness to other common γ chain cytokines, and cell survival remained antigen dependent. In a xenogeneic mouse model, CTLs expressing IL7Ra significantly expanded in vivo in response to EBV-tumor antigen and the administration of IL7. By day 15, both control CTLs and IL7Ra+ CTLs had modestly proliferated in response to IL-2 (2.3 fold, range 1.1–5.1 for control CTLs, and 2.67 fold, range 0.6 to 8.15 for IL7Ra+ CTLs). In contrast, only IL7Ra+ CTLs significantly expanded in the presence of IL7, showing a 6.09 fold increase (range 0.7 to 25.2) compared to mice that received control CTLs and IL7 (0.9 fold, range 0.5–1.7) (p<0.0001). Modified CTLs also provided enhanced anti-tumor activity. SCID mice engrafted i.p with 3×106 tumor cells marked with Firefly luciferase, showed a rapid increase in signal in the absence of CTLs (Fold increase in luminance = 29.8 median, range 4.4 to 103) by day 14 after tumor engraftment. Similar tumor growth was observed in mice receiving IL7Ra+ CTLs without cytokines (luminance increase14.4 fold, range 1 to 90). In contrast, mice receiving IL7Ra+ CTLs and either IL2 or IL7, had a decline in tumor luminance (fold expansion 0.7, range 0.08 to 2.9, and 0.8, range 0.004 to 3.5, respectively p<0.0001). Although growth of the transgenic T cells remained antigen dependent, as a further safety measure, we incorporated an inducible suicide gene based on icaspase9 that can be activated by exposure to a small chemical inducer of dimerization (CID) (AP20187). Incorporation of this suicide gene did not affect the in vitro or in vivo anti-tumor activity of the CTL’s but allowed them to be rapidly eliminated. So that after a single dose of CID (50 nM) the transgenic population were decreased by >98.5% We conclude that forced expression of the IL-7Ra by CTLs can be used to recapitulate the response of these cells to this cytokine and thereby promote their in vivo anti-tumor activity after adoptive transfer either in a lymphodepleted host or after the administration of the recombinant protein.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4079-4079
Author(s):  
Lei Bao ◽  
Mindy M Stamer ◽  
Kimberly Dunham ◽  
Deepa Kolaseri Krishnadas ◽  
Kenneth G Lucas

Abstract Abstract 4079 Poster Board III-1014 MAGE A1 and MAGE A3 are cancer testis antigens that are expressed on a number of malignant tumor cells, but not by normal cells, except for male germ cells which lack HLA expression. Therefore, MAGE cytotoxic T lymphocytes are strictly tumor-specific. Adoptive transfer of antigen specific cytotoxic T lymphocytes (CTL) provides immediate graft-versus tumor effects while minimizing risk for graft-versus-host disease. The aim of the current study was to find ideal conditions for expansion of CTL targeting tumor-associated antigens from peripheral blood mononuclear cells (PBMCs) of healthy donors to be used in allogenic cell therapy. In this study we investigated the ability to generate MAGE A1 and MAGE A3 specific cytotoxic T cells using autologous dendritic cells (DC) loaded with MAGE A1 and MAGE A3 overlapping peptides. CTL lines specific for MAGE A1 and MAGE A3 were established by stimulating CD8 T cells from healthy donors with autologous dendritic cells loaded with MAGE A1 or MAGE A3 overlapping pooled peptides in round-bottomed, 96-well plates. CD8+ T cells were restimulated with the same ratio of peptide pulsed DC on days 7 and 14 in the presence of IL-2 (50 U/ml), IL-7 and IL-15 (5 ng/ml). These microcultures were screened 10 days after the third stimulation for their capacity to produce interferon-gamma (IFN-gamma) when stimulated with autologous EBV-transformed B lymphocytes (BLCL) transduced with lentivirus(LV) encoding MAGE A1 or MAGE A3 and autologous BLCL transduced with LV encoding GFP. MAGE A1 and MAGE-A3 specific IFN-gamma producing cells were rapidly expanded in OKT3 and IL2. The specificity of the rapidly expanded MAGE A1 and MAGE A3 specific T cells was confirmed by IFN-gamma production as measured by intracellular cytokine staining and ELISA as well as antigen specific cytotoxicity by a standard 51chromium (51Cr) release assay. We successfully generated MAGE A1 and MAGE A3 specific CTL lines from healthy donors using this method. Specific CTL lines showed cytotoxicity in vitro not only to target cells pulsed with MAGE A1 or MAGE A3 peptides but also to target cells transduced with LV-MAGE A1 or LV-MAGE A3. Specific cytolytic activity was accompanied by IFN-gamma secretion. These data indicate that tumor antigen specific CTL can be expanded using overlapping peptides regardless of an individual's HLA specificity. The ability to generate tumor specific CTL from donors of various HLA backgrounds provide a rationale for utilizing MAGE A1 and MAGE A3 overlapping peptides for expansion of antigen specific T cells for adoptive T-cell therapy against MAGE A1 or MAGE A3 expressing tumors. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
1999 ◽  
Vol 94 (9) ◽  
pp. 3084-3093 ◽  
Author(s):  
Premlata Shankar ◽  
Zhan Xu ◽  
Judy Lieberman

Cytotoxic T lymphocytes (CTL) lyse antigen-bearing target cells by two distinct pathways. Whereas granule exocytosis targets any antigen-bearing cell, fas-mediated cytotoxicity kills only fas-expressing cells and does not require antigen expression. Fas pathway activation can potentially lead to lysis of uninfected bystander cells. We examined the relative usage of the two pathways by CTL clones and cell lines directed against four different human immunodeficiency virus (HIV) proteins in lysing primary HIV-infected targets. Although fas was expressed on HIV-infected primary CD4+ T cells, their lysis by antigen-specific CD8+ CTL was only by the granule pathway. Fas ligand (fasL) was not detectable on antigen-specific CD8 clones, T-cell lines, or circulating HIV-specific CD8 T cells from HIV-infected donors, stained with a tetrameric HLA-A2-HIV-peptide complex. FasL expression by HIV-specific CTL clones was not activated by exposure to HIV-presenting cells, but was after unphysiological stimulation with phorbol myristate acetate (PMA). CTL clones did not lyse bystander Jurkat cells, but HIV-infected primary CD4+ T cells lysed uninfected bystander cells by the fas-mediated pathway. These results suggest that HIV-specific CD8+ CTL do not cause HIV immunopathology by lysing bystander cells. On the contrary, fas-mediated lysis of uninfected cells by HIV-infected cells may contribute to CD4 decline.


1987 ◽  
Vol 165 (6) ◽  
pp. 1508-1523 ◽  
Author(s):  
J Bastin ◽  
J Rothbard ◽  
J Davey ◽  
I Jones ◽  
A Townsend

The conserved epitopes of influenza nucleoprotein (NP) recognized by class I MHC-restricted CTL from CBA (H-2k) and C57BL/10 (H-2b) mice have been defined in vitro with synthetic peptides 50-63 and 365-379, respectively. Two Db-restricted clones were described that recognize different epitopes on peptide 365-379. Finally, the recognition of complete NP was shown to be approximately 200-fold less efficient than peptide in the cytotoxicity assay. These phenomena are closely related to results with class II-restricted T cells and they strengthen the hypothesis that influenza proteins are degraded in the infected cell before recognition by class I-restricted CTL.


Blood ◽  
2000 ◽  
Vol 96 (4) ◽  
pp. 1474-1479 ◽  
Author(s):  
Marcelo J. Kuroda ◽  
Jörn E. Schmitz ◽  
Aruna Seth ◽  
Ronald S. Veazey ◽  
Christine E. Nickerson ◽  
...  

Major histocompatibility class I–peptide tetramer technology and simian immunodeficiency virus of macaques (SIVmac)-infected rhesus monkeys were used to clarify the distribution of acquired immunodeficiency syndrome virus-specific cytotoxic T lymphocytes (CTL) in secondary lymphoid organs and to assess the relationship between these CTL and the extent of viral replication in the various anatomic compartments. SIVmac Gag epitope-specific CD8+ T cells were evaluated in the spleen, bone marrow, tonsils, thymus, and 5 different lymph node compartments of 4 SIVmac-infected rhesus monkeys. The average percentage of CD8+ T lymphocytes that bound this tetramer in all the different lymph node compartments was similar to that in peripheral blood lymphocytes in individual monkeys. The percentage of CD8+ T cells that bound the tetramer in the thymus was uniformly low in the monkeys. However, the percentage of CD8+ T cells that bound the tetramer in bone marrow and spleen was consistently higher than that seen in lymph nodes and peripheral blood. The phenotypic profile of the tetramer-binding CD8+ T lymphocytes in the different lymphoid compartments was similar, showing a high expression of activation-associated adhesion molecules and a low level expression of naive T-cell–associated molecules. Surprisingly, no correlation was evident between the percentage of tetramer-binding CD8+ T lymphocytes and the magnitude of the cell-associated SIV RNA level in each lymphoid compartment of individual monkeys. These studies suggest that a dynamic process of trafficking may obscure the tendency of CTL to localize in particular regional lymph nodes or that some lymphoid organs may provide milieus that are particularly conducive to CTL expansion.


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