Expansion of CD8+ Cytotoxic T Cells in vitro and in vivo Using MHC Class I Tetramers

Tumor Biology ◽  
2007 ◽  
Vol 28 (2) ◽  
pp. 70-76 ◽  
Author(s):  
Philip Savage ◽  
Maggie Millrain ◽  
Sofia Dimakou ◽  
Justin Stebbing ◽  
Julian Dyson
2000 ◽  
Vol 192 (12) ◽  
pp. 1685-1696 ◽  
Author(s):  
Joke M.M. den Haan ◽  
Sophie M. Lehar ◽  
Michael J. Bevan

Bone marrow–derived antigen-presenting cells (APCs) take up cell-associated antigens and present them in the context of major histocompatibility complex (MHC) class I molecules to CD8+ T cells in a process referred to as cross-priming. Cross-priming is essential for the induction of CD8+ T cell responses directed towards antigens not expressed in professional APCs. Although in vitro experiments have shown that dendritic cells (DCs) and macrophages are capable of presenting exogenous antigens in association with MHC class I, the cross-presenting cell in vivo has not been identified. We have isolated splenic DCs after in vivo priming with ovalbumin-loaded β2-microglobulin–deficient splenocytes and show that they indeed present cell-associated antigens in the context of MHC class I molecules. This process is transporter associated with antigen presentation (TAP) dependent, suggesting an endosome to cytosol transport. To determine whether a specific subset of splenic DCs is involved in this cross-presentation, we negatively and positively selected for CD8− and CD8+ DCs. Only the CD8+, and not the CD8−, DC subset demonstrates cross-priming ability. FACS® studies after injection of splenocytes loaded with fluorescent beads showed that 1 and 0.6% of the CD8+ and the CD8− DC subsets, respectively, had one or more associated beads. These results indicate that CD8+ DCs play an important role in the generation of cytotoxic T lymphocyte responses specific for cell-associated antigens.


1987 ◽  
Vol 166 (6) ◽  
pp. 1716-1733 ◽  
Author(s):  
J S Weber ◽  
G Jay ◽  
K Tanaka ◽  
S A Rosenberg

We have shown that two weakly immunogenic MCA sarcomas developed in our laboratory that are sensitive to high-dose IL-2 immunotherapy express class I MHC in vivo and in vitro. Two nonimmunogenic MCA sarcomas are relatively insensitive to IL-2 therapy and express minimal or no class I MHC molecules in vivo and in vitro. To study the role of MHC in the therapy of tumors with IL-2, a class I-deficient murine melanoma, B16BL6, was transfected with the Kb class I gene. Expression of class I MHC rendered B16BL6 advanced pulmonary macrometastases sensitive to IL-2 immunotherapy. 3-d micrometastases of CL8-2, a class I transfected clone of B16BL6, were significantly more sensitive to IL-2 therapy than a control nontransfected line. Expression of Iak, a class II MHC molecule, had no effect on IL-2 therapy of transfectant pulmonary micrometastases in F1 mice. By using lymphocyte subset depletion with mAbs directed against Lyt-2, therapy of class I transfectant macrometastases with high-dose IL-2 was shown to involve an Lyt-2 cell. In contrast, regression of micrometastases treated with low-dose IL-2 involved Lyt-2+ cells, but regression mediated by high doses of IL-2 did not. We hypothesize that both LAK and Lyt-2+ T cells effect IL-2-mediated elimination of micrometastases, but only Lyt-2+ T cells are involved in macrometastatic regression. Low doses of IL-2 stimulate Lyt-2+ cells to eliminate class I-expressing micrometastases, but high doses of IL-2 can recruit LAK cells to mediate regression of micrometastases independent of class I expression. Only high-dose IL-2, mediating its effect predominantly via Lyt-2+ cells, is capable of impacting on MHC class I-expressing macrometastases. Macrometastases devoid of class I MHC antigens appear to be resistant to IL-2 therapy.


1990 ◽  
Vol 172 (4) ◽  
pp. 1083-1090 ◽  
Author(s):  
A Aggarwal ◽  
S Kumar ◽  
R Jaffe ◽  
D Hone ◽  
M Gross ◽  
...  

Oral immunization with an attenuated Salmonella typhimurium recombinant containing the full-length Plasmodium berghei circumsporozoite (CS) gene induces protective immunity against P. berghei sporozoite challenge in the absence of antibody. We found that this immunity was mediated through the induction of specific CD8+ T cells since in vivo elimination of CD8+ cells abrogated protection. In vitro studies revealed that this Salmonella-P. berghei CS recombinant induced class I-restricted CD8+ cytotoxic T cells that are directed against the P. berghei CS peptide epitope spanning amino acids 242-253. This is the same peptide that previously was identified as the target of cytotoxic T lymphocytes (CTL) induced by sporozoite immunization. Salmonella-P. falciparum CS recombinants were constructed that contained either the full-length CS gene or a repeatless gene consisting of CS flanking sequences. Both of these vaccines were able to induce CD8+ CTL directed against P. falciparum CS peptide 371-390, which is identical to the target of CTL induced by sporozoites and vaccinia CS recombinants. These results directly demonstrate the ability of an intracellular bacteria such as Salmonella to induce class I-restricted CD8+ CTL and illustrate the importance of CD8+ CTL in immunity to malaria.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3152-3152
Author(s):  
Benjamin J Uttenthal ◽  
Emma Nicholson ◽  
Ben Carpenter ◽  
Sara Ghorashian ◽  
Graham P Wright ◽  
...  

Abstract Abstract 3152 Alloreactive immune responses directed against malignant cells in recipients of allogeneic hematopoietic stem cell transplants are able to cure patients with hematological cancers. However, such immune responses may cause severe morbidity when directed against healthy recipient tissue, resulting in graft-versus-host disease (GvHD). Naturally occurring regulatory T cells (Tregs) are CD4+ T cells characterized by their expression of the transcription factor Foxp3. Whilst adoptively transferred polyclonal Tregs suppress GvHD in several murine models, their lack of specificity may compromise beneficial immunity against malignancy or infection. The generation of MHC class I-restricted, alloantigen-specific Tregs would allow them to recognize antigen presented directly on GvHD target tissues, concentrating their sites of activation at these tissues and possibly reducing the potential for non-specific immune suppression. We have generated ‘converted’ Tregs through retroviral transfer of genes encoding Foxp3 and specific MHC class I-restricted T cell receptors (TCRs) into polyclonal conventional CD4+ T cells. We used the 2C-TCR, which recognizes the MHC class I molecule H-2Ld, expressed in Balb/c and other H-2d mice, in complex with the ubiquitously expressed peptide p2Ca; and the MH-TCR, which recognizes the MHC class I molecule H-2Db, expressed in B6 and other H-2b mice, in complex with the male peptide WMHHNMDLI. In vitro, Foxp3 2C-TCR-transduced B6 polyclonal CD4+ T cells were hyporesponsive to stimulation and suppressed the alloreactive proliferative response of B6 CD4+ and CD8+ T cells to Balb/c splenocytes, consistent with the acquisition of regulatory function. When adoptively transferred to lethally irradiated Balb/c recipients of MHC-mismatched B6 bone marrow and conventional T cells, Foxp3 2C-TCR-transduced B6 polyclonal CD4+ T cells significantly reduced early proliferation of donor T cells, weight loss and GvHD score in the recipients. Similarly, polyclonal CD4+ T cells transduced with Foxp3 and the MH-TCR caused marked suppression of allogeneic responses both in vitro and in vivo. However, while both the 2C-TCR and the MH-TCR conferred specificity to their cognate antigens in vitro, the potent suppression in these in vivo models was independent of the cognate antigen for the transduced TCRs. This non-specific suppression was markedly reduced when class I-restricted TCRs were transduced into OT-II Rag1-/- CD4+ T cells that are transgenic for a single endogenous TCR. These findings demonstrate an important role for the endogenous TCRs in driving non-specific suppression by polyclonal CD4+ T cells transduced with Foxp3 and class I-restricted TCRs, and suggest that strategies to downregulate endogenous TCRs will be required to achieve antigen-specific suppression in TCR gene-modified regulatory T cells. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A239-A239
Author(s):  
Ioannis Gavvovidis ◽  
Matthias Leisegang ◽  
Vivian Scheuplein ◽  
Matthias Obenaus ◽  
Thomas Blankenstein ◽  
...  

BackgroundAs cancer-testis antigens are self-antigens, T cells expressing high-affinity TCRs against such antigens are eliminated via negative selection. Therefore, human-derived TCRs are typically of low affinity and exhibit reduced anti-tumor activity. Affinity maturation by mutagenesis is a common tool to increase affinity but may result in reduced specificity and off-target toxicity. Using our proprietary HuTCR mouse platform, which consists of mouse lines carrying the full human TCR-a/ß loci and human HLA alleles, we have isolated naturally optimized high-affinity TCRs specific for the cancer-testis antigen MAGE-A1 and compared them in vitro and in vivo to human-derived MAGE-A1-specific TCRs that are currently reported to be in clinical development.MethodsMAGE-A1-specific TCRs were isolated from HuTCR mice immunized with the MAGE-1 antigen using scRNAseq or were synthesized based on publicly available databases of human donor-derived MAGE-A1-specific TCRs. All TCRs were re-expressed in primary human T cells as verified using peptide-MHC-multimer staining. Functional activity of the TCRs was analyzed by coculture with T2 target cells loaded with titrated amounts of epitope and measuring cytokine concentration by ELISA. Reactivity of TCRs to endogenously processed MAGE-A1 protein was assessed by coculture with tumor cell lines with variable MAGE-A1 and/or MHC-class-I expression. Tumor rejection potential of TCRs was evaluated in vivo using a syngeneic mouse model (TNA2 mice) expressing MAGE-A1 and HLA-A*02 on syngeneic tumor cells.ResultsImmunization of HuTCR mice with the MAGE-A1 antigen resulted in robust CD8+ T cell responses and several TCR clonotypes were identified by scRNAseq, with the majority of clonotypes being specific to the MAGE-A1-derived peptide KVLEYVIKV and TCR functional avidities ranging from 0.3nM to 3nM. In sharp contrast, human-derived TCRs of the same epitope specificity exhibited lower functional avidity with EC50 from 3nM to 60nM. In addition, HuTCR-mouse-derived TCRs were more sensitive in recognition of tumor cells expressing low MAGE-A1 and/or MHC-class-I. Adoptive T-cell transfer to TNA2-mice with established tumors resulted in complete rejection without relapse of tumors only in mice treated with HuTCR-mouse-derived TCR but not with human-derived or control TCRs.ConclusionsThe HuTCR mouse platform allows for the generation of high-affinity MAGE-A1-specific human TCRs with increased anti-tumor efficacy as compared to human-derived TCRs against the same cancer antigen. The in vitro and in vivo comparative data presented herein highlight the HuTCR-derived MAGE-A1-specific TCR as the most favorable candidate for clinical translation and a clinical trial evaluating its safety and efficacy in a variety of solid malignancies will be initiated November 2021.Ethics ApprovalAll animal experiments were performed according to institutional and national guidelines, after approval by the responsible authority (Landesamt für Gesundheit und Soziales, Berlin). Blood collection from healthy human donors was done after prior informed consent and experiments were conducted in accordance with the ethical standards of Declaration of Helsinki.


1999 ◽  
Vol 190 (11) ◽  
pp. 1605-1616 ◽  
Author(s):  
Gretchen Bain ◽  
Melanie W. Quong ◽  
Rachel S. Soloff ◽  
Stephen M. Hedrick ◽  
Cornelis Murre

The E2A proteins, E12 and E47, are required for progression through multiple developmental pathways, including early B and T lymphopoiesis. Here, we provide in vitro and in vivo evidence demonstrating that E47 activity regulates double-positive thymocyte maturation. In the absence of E47 activity, positive selection of both major histocompatibility complex (MHC) class I– and class II–restricted T cell receptors (TCRs) is perturbed. Additionally, development of CD8 lineage T cells in an MHC class I–restricted TCR transgenic background is sensitive to the dosage of E47. Mice deficient for E47 display an increase in production of mature CD4 and CD8 lineage T cells. Furthermore, ectopic expression of an E2A inhibitor helix-loop-helix protein, Id3, promotes the in vitro differentiation of an immature T cell line. These results demonstrate that E2A functions as a regulator of thymocyte positive selection.


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