scholarly journals Reciprocal Changes in Tumor Antigenicity and Antigen-specific T Cell Function during Tumor Progression

2004 ◽  
Vol 200 (12) ◽  
pp. 1581-1592 ◽  
Author(s):  
Gang Zhou ◽  
Zhengbin Lu ◽  
John D. McCadden ◽  
Hyam I. Levitsky ◽  
Aimee L. Marson
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cancer Progression ◽  
Tumor Antigens ◽  
Cell Function ◽  
Early Recognition ◽  
Antigen Expression ◽  
Cell Repertoire ◽  
Antigen Loss

Two seemingly incompatible models exist to explain the progression of cancers in immunocompetent hosts. The cancer immunosurveillance hypothesis posits that recognition of transformed cells by the immune system results in the generation of an effector response that may impede tumor growth. Clinically detectable cancer results from the emergence of tumor variants that escape this selective pressure. Alternatively, induction of immune tolerance to tumor antigens may enable cancer progression. We established a model where changes in the function of tumor-specific T cells and in tumor antigen expression could be followed during cancer progression. Early recognition of antigen led to activation, expansion, and effector function in tumor-specific CD4+ T cells resulting in the outgrowth of tumors expressing substantially reduced levels of antigen. Antigen loss was not complete, however, and levels remained above the threshold required for tumor-specific T cell recognition in vivo. In the face of persisting antigen, T cell tolerance ensued, leading to an impaired ability to mediate further antigen loss. Together, these studies establish that the processes of immunosurveillance and tumor editing coexist with a process in which the functional tumor-specific T cell repertoire is also “edited,” reconciling two hypotheses historically central to our attempts to understand host antitumor immunity.

scholarly journals 751 Neo-X-Prime bispecific antibodies targeting CD40 and tumor antigens promote cross-presentation of tumor exosome-derived neoantigen and induce superior anti-tumor responses compared to CD40 mAb

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A785-A785
Author(s):  
Karin Hagerbrand ◽  
Mattias Levin ◽  
Laura Von Schantz ◽  
Laura Varas ◽  
Anna Säll ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Antigens ◽  
Antigen Presenting Cells ◽  
Immunological Memory ◽  
Cell Repertoire ◽  
Cross Presentation ◽  
Antigen Presenting

BackgroundAlligator's Neo-X-Prime platform aims to enable antigen presenting cells to efficiently enhance priming of tumor neoantigen-specific T cells with the goal of overcoming PD-1 resistance in certain tumor types. We hypothesize that binding of a CD40 x TAA bispecific antibody (bsAb) to CD40 on dendritic cells (DCs) and a tumor-associated antigen (TAA) on tumor exosomes or tumor debris leads to (i) activation of the DC, (ii) uptake of the tumor material, (iii) cross-presentation of tumor-derived neoantigen (present in exosomes or debris) and, iv) priming of tumor neoantigen-specific T cells, resulting in an increased quantity and/or quality of the tumor-targeting T cell pool.MethodsFunctionality was evaluated in vitro using CD40 reporter cells and monocyte-derived DCs, co-cultured with cells expressing TAA. Further, co-localization of TAA-expressing cellular debris with a CD40-expressing human B cell line in the presence of bsAbs was assessed using live cell imaging. In vivo, anti-tumor efficacy and immunological memory were assessed in human CD40 transgenic (hCD40tg) mice bearing MB49 bladder carcinoma tumors transfected with human TAA or controls. T cells isolated from OVA-specific TCR-transgenic mice were used to evaluate the effect of Neo-X-Prime bsAbs on antigen-specific T cell expansion in the presence of hCD40tg DCs and exosomes from MB49 tumors transfected with both human TAA and OVA using flow cytometry.ResultsUsing CEA as a highly expressed TAA, we have developed lead Neo-X-Prime CD40-CEA bsAbs engineered to achieve an optimal profile. Further, using Neo-X-Prime concept molecules targeting EpCAM, we have demonstrated the ability to mediate co-localization of tumor debris and CD40 expressing antigen presenting cells that is dependent on the receptor density of the TAA. We have further shown that addition of Neo-X-Prime bsAbs to a co-culture of murine DCs, T cells and tumor-derived exosomes induces increased expansion of model neoantigen-specific T cells. In vivo, Neo-X-Prime bsAbs display a potent, TAA-dependent anti-tumor effect that is superior to CD40 mAbs. Cured mice develop a broad immunological memory that is not dependent on expression of the TAA. The tumor-localizing property of Neo-X-Prime bsAbs also shows potential for improved safety compared to CD40 monospecific antibodies.ConclusionsNeo-X-Prime bsAbs have the potential to tumor-selectively target CD40-expressing antigen-presenting cells to mediate an expansion of the tumor-specific T cell repertoire, resulting in increased T cell infiltration and potent anti-tumor effects.Ethics ApprovalAll experiments were performed after approval from the Malmö/Lund Animal Ethics Committee.

scholarly journals CD4+ regulatory T cells require CTLA-4 for the maintenance of systemic tolerance

2009 ◽  
Vol 206 (2) ◽  
pp. 421-434 ◽  
Author(s):  
Randall H. Friedline ◽  
David S. Brown ◽  
Hai Nguyen ◽  
Hardy Kornfeld ◽  
JinHee Lee ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Cell Function ◽  
Cytotoxic T Lymphocyte ◽  
Critical Role ◽  
Lymphoproliferative Disease ◽  
In Trans ◽  
And Function

Cytotoxic T lymphocyte antigen-4 (CTLA-4) plays a critical role in negatively regulating T cell responses and has also been implicated in the development and function of natural FOXP3+ regulatory T cells. CTLA-4–deficient mice develop fatal, early onset lymphoproliferative disease. However, chimeric mice containing both CTLA-4–deficient and –sufficient bone marrow (BM)–derived cells do not develop disease, indicating that CTLA-4 can act in trans to maintain T cell self-tolerance. Using genetically mixed blastocyst and BM chimaeras as well as in vivo T cell transfer systems, we demonstrate that in vivo regulation of Ctla4−/− T cells in trans by CTLA-4–sufficient T cells is a reversible process that requires the persistent presence of FOXP3+ regulatory T cells with a diverse TCR repertoire. Based on gene expression studies, the regulatory T cells do not appear to act directly on T cells, suggesting they may instead modulate the stimulatory activities of antigen-presenting cells. These results demonstrate that CTLA-4 is absolutely required for FOXP3+ regulatory T cell function in vivo.

scholarly journals T-cell lineage commitment and cytokine responses of thymic progenitors

Blood ◽  
1995 ◽  
Vol 86 (5) ◽  
pp. 1850-1860 ◽  
Author(s):  
TA Moore ◽  
A Zlotnik
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Cultured Cells ◽  
Critical Role ◽  
Cell Lineage ◽  
Lineage Commitment ◽  
Organ Cultures ◽  
Cell Commitment

The earliest steps of intrathymic differentiation recently have been elucidated. It has been reported that both CD4lo (CD44+ CD25- c-kit+ CD3- CD4lo CD8-) and pro-T cells (CD44+ CD25+ c-kit+ CD3- CD4- CD8-, representing the next step in maturation) exhibit germline T-cell receptor beta and gamma loci, suggesting that neither population is exclusively committed to the T-cell lineage. Several groups have shown that CD4lo cells retain the capacity to generate multiple lymphoid lineages in vivo; however, the lineage commitment status of pro-T cells is unknown. To determine when T-cell lineage commitment occurs, we examined the ability of sorted CD4lo and pro-T cells to generate lymphoid lineage cells in vivo or in fetal thymic organ cultures (FTOCs). When intravenously injected into scid mice, CD4lo cells generated both T and B cells, whereas the progeny of pro-T cells contained T cells exclusively. Fetal thymic organ cultures repopulated with CD4lo cells contained both T and natural killer (NK) cells, whereas cultures repopulated with pro-T cells contained T cells almost exclusively. These observations strongly suggest that T-cell lineage commitment occurs during the transition of CD4lo to pro-T cells. Because it is likely that the thymic microenvironment plays a critical role in T-cell commitment, we compared the responses of CD4lo and pro-T cells to various cytokine combinations in vitro, as well as the ability of the cultured cells to repopulate organ cultures. Cytokine combinations that maintained T-cell repopulation potential for both CD4lo and pro-T cells were found. CD4lo cells proliferated best in response to the combination containing interleukin-1 (IL-1), IL-3, IL- 6, IL-7, and stem cell factor (SCF). Unlike CD4lo cells, pro-T cells were much more dependent upon IL-7 for proliferation and FTOC repopulation. However, combinations of cytokines lacking IL-7 were found that maintained the T-cell repopulating potential of pro-T cells, suggesting that, whereas this cytokine is clearly very important for normal pro-T cell function, it is not an absolute necessity during early T-cell expansion and differentiation.

scholarly journals Structures suggest an approach for converting weak self-peptide tumor antigens into superagonists for CD8 T cells in cancer

2021 ◽  
Vol 118 (23) ◽  
pp. e2100588118
Author(s):  
Pengcheng Wei ◽  
Kimberly R. Jordan ◽  
Jonathan D. Buhrman ◽  
Jun Lei ◽  
Hexiang Deng ◽  
...  
Keyword(s):  
T Cells ◽  
Amino Acid ◽  
T Cell ◽  
Amino Acid Substitution ◽  
Cd8 T Cells ◽  
Tumor Antigens ◽  
Vaccine Development ◽  
Single Amino Acid ◽  
Cell Repertoire ◽  
Subtle Change

Tumors frequently express unmutated self-tumor–associated antigens (self-TAAs). However, trial results using self-TAAs as vaccine targets against cancer are mixed, often attributed to deletion of T cells with high-affinity receptors (TCRs) for self-TAAs during T cell development. Mutating these weak self-TAAs to produce higher affinity, effective vaccines is challenging, since the mutations may not benefit all members of the broad self-TAA–specific T cell repertoire. We previously identified a common weak murine self-TAA that we converted to a highly effective antitumor vaccine by a single amino acid substitution. In this case the modified and natural self-TAAs still raised very similar sets of CD8 T cells. Our structural studies herein show that the modification of the self-TAA resulted in a subtle change in the major histocompatibility complex I–TAA structure. This amino acid substitution allowed a dramatic conformational change in the peptide during subsequent TCR engagement, creating a large increase in TCR affinity and accounting for the efficacy of the modified self-TAA as a vaccine. These results show that carefully selected, well-characterized modifications to a poorly immunogenic self-TAA can rescue the immune response of the large repertoire of weakly responding natural self-TAA–specific CD8 T cells, driving them to proliferate and differentiate into functional effectors. Subsequently, the unmodified self-TAA on the tumor cells, while unable to drive this response, is nevertheless a sufficient target for the CD8 cytotoxic effectors. Our results suggest a pathway for more efficiently identifying variants of common self-TAAs, which could be useful in vaccine development, complementing other current nonantigen-specific immunotherapies.

scholarly journals TRPM2 Is Not Required for T-Cell Activation and Differentiation

2022 ◽  
Vol 12 ◽  
Author(s):  
Niels C. Lory ◽  
Mikolaj Nawrocki ◽  
Martina Corazza ◽  
Joanna Schmid ◽  
Valéa Schumacher ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Transient Receptor Potential ◽  
Cell Function ◽  
Intestinal Inflammation ◽  
Activation Markers

Antigen recognition by the T-cell receptor induces a cytosolic Ca2+ signal that is crucial for T-cell function. The Ca2+ channel TRPM2 (transient receptor potential cation channel subfamily M member 2) has been shown to facilitate influx of extracellular Ca2+ through the plasma membrane of T cells. Therefore, it was suggested that TRPM2 is involved in T-cell activation and differentiation. However, these results are largely derived from in vitro studies using T-cell lines and non-physiologic means of TRPM2 activation. Thus, the relevance of TRPM2-mediated Ca2+ signaling in T cells remains unclear. Here, we use TRPM2-deficient mice to investigate the function of TRPM2 in T-cell activation and differentiation. In response to TCR stimulation in vitro, Trpm2-/- and WT CD4+ and CD8+ T cells similarly upregulated the early activation markers NUR77, IRF4, and CD69. We also observed regular proliferation of Trpm2-/- CD8+ T cells and unimpaired differentiation of CD4+ T cells into Th1, Th17, and Treg cells under specific polarizing conditions. In vivo, Trpm2-/- and WT CD8+ T cells showed equal specific responses to Listeria monocytogenes after infection of WT and Trpm2-/- mice and after transfer of WT and Trpm2-/- CD8+ T cells into infected recipients. CD4+ T-cell responses were investigated in the model of anti-CD3 mAb-induced intestinal inflammation, which allows analysis of Th1, Th17, Treg, and Tr1-cell differentiation. Here again, we detected similar responses of WT and Trpm2-/- CD4+ T cells. In conclusion, our results argue against a major function of TRPM2 in T-cell activation and differentiation.

scholarly journals Dynamics of TCR repertoire and T cell function in COVID-19 convalescent individuals

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Lingjie Luo ◽  
Wenhua Liang ◽  
Jianfeng Pang ◽  
Gang Xu ◽  
Yingying Chen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Critical Role ◽  
World Health ◽  
Cell Repertoire ◽  
Metabolic Functions ◽  
Tcr Repertoire ◽  
Discharged Patients ◽  
Health Organization

AbstractSARS-CoV-2 outbreak has been declared by World Health Organization as a worldwide pandemic. However, there are many unknowns about the antigen-specific T-cell-mediated immune responses to SARS-CoV-2 infection. Here, we present both single-cell TCR-seq and RNA-seq to analyze the dynamics of TCR repertoire and immune metabolic functions of blood T cells collected from recently discharged COVID-19 patients. We found that while the diversity of TCR repertoire was increased in discharged patients, it returned to basal level ~1 week after becoming virus-free. The dynamics of T cell repertoire correlated with a profound shift of gene signatures from antiviral response to metabolism adaptation. We also demonstrated that the top expanded T cell clones (~10% of total T cells) display the key anti-viral features in CD8+ T cells, confirming a critical role of antigen-specific T cells in fighting against SARS-CoV-2. Our work provides a basis for further analysis of adaptive immunity in COVID-19 patients, and also has implications in developing a T-cell-based vaccine for SARS-CoV-2.

Anatomic location and T-cell stimulatory functions of mouse dendritic cell subsets defined by CD4 and CD8 expression

Blood ◽  
2002 ◽  
Vol 99 (6) ◽  
pp. 2084-2093 ◽  
Author(s):  
Alexander D. McLellan ◽  
Michaela Kapp ◽  
Andreas Eggert ◽  
Christian Linden ◽  
Ursula Bommhardt ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Antigen Expression ◽  
Cell Receptor ◽  
In Vitro Assays ◽  
Peptide Complexes ◽  
Marginal Zones

Abstract Mouse spleen contains CD4+, CD8α+, and CD4−/CD8α− dendritic cells (DCs) in a 2:1:1 ratio. An analysis of 70 surface and cytoplasmic antigens revealed several differences in antigen expression between the 3 subsets. Notably, the Birbeck granule–associated Langerin antigen, as well as CD103 (the mouse homologue of the rat DC marker OX62), were specifically expressed by the CD8α+ DC subset. All DC types were apparent in the T-cell areas as well as in the splenic marginal zones and showed similar migratory capacity in collagen lattices. The 3 DC subtypes stimulated allogeneic CD4+ T cells comparably. However, CD8α+ DCs were very weak stimulators of resting or activated allogeneic CD8+ T cells, even at high stimulator-to-responder ratios, although this defect could be overcome under optimal DC/T cell ratios and peptide concentrations using CD8+ F5 T-cell receptor (TCR)–transgenic T cells. CD8α− or CD8α+DCs presented alloantigens with the same efficiency for lysis by cytotoxic T lymphocytes (CTLs), and their turnover rate of class I–peptide complexes was similar, thus neither an inability to present, nor rapid loss of antigenic complexes from CD8α DCs was responsible for the low allostimulatory capacity of CD8α+ DCs in vitro. Surprisingly, both CD8α+ DCs and CD4−/CD8− DCs efficiently primed minor histocompatibility (H-Y male antigen) cytotoxicity following intravenous injection, whereas CD4+ DCs were weak inducers of CTLs. Thus, the inability of CD8α+ DCs to stimulate CD8+ T cells is limited to certain in vitro assays that must lack certain enhancing signals present during in vivo interaction between CD8α+ DCs and CD8+ T cells.

Thymomas alter the T-cell subset composition in the blood: a potential mechanism for thymoma-associated autoimmune disease

Blood ◽  
2000 ◽  
Vol 96 (12) ◽  
pp. 3872-3879 ◽  
Author(s):  
Viola Hoffacker ◽  
Anja Schultz ◽  
James J. Tiesinga ◽  
Ralf Gold ◽  
Berthold Schalke ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Autoimmune Disease ◽  
Cd8 T Cells ◽  
Cell Function ◽  
Cell Subset ◽  
Cell Repertoire ◽  
T Cell Subset ◽  
Functional Studies ◽  
Circulating T Cells

Abstract Thymomas are the only tumors that are proven to generate mature T cells from immature precursors. It is unknown, however, whether intratumorous thymopoiesis has an impact on the peripheral T-cell pool and might thus be related to the high frequency of thymoma-associated myasthenia gravis. This study shows, using fluorescence-activated cell sorting-based analyses and T-cell proliferation assays, that thymopoiesis and T-cell function in thymomas correspond with immunologic alterations in the blood. Specifically, the proportion of circulating CD45RA+CD8+ T cells is significantly increased in patients with thymoma compared with normal controls, in accordance with intratumorous T-cell development that is abnormally skewed toward the CD8+ phenotype. Moreover, it is primarily the proportion of circulating CD45RA+CD8+ T cells that decreases after thymectomy. The results also demonstrate that T cells reactive toward recombinant autoantigens are distributed equally between thymomas and blood, whereas T-cell responses to foreign antigen (ie, tetanus toxoid) are seen only among circulating T cells and not among thymoma-derived T cells. These functional studies support the hypothesis that thymopoiesis occurring within thymomas alters the peripheral T-cell repertoire. Because many thymomas are enriched with autoantigen-specific T cells, a disturbance of circulating T-cell subset composition by export of intratumorous T cells may contribute to paraneoplastic autoimmune disease arising in patients with thymoma.

scholarly journals The Cysteine-Containing Cell-Penetrating Peptide AP Enables Efficient Macromolecule Delivery to T Cells and Controls Autoimmune Encephalomyelitis

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1134
Author(s):  
Won-Ju Kim ◽  
Gil-Ran Kim ◽  
Hyun-Jung Cho ◽  
Je-Min Choi
Keyword(s):  
Drug Delivery ◽  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Fluorescent Protein ◽  
Autoimmune Encephalomyelitis ◽  
Optimal Sequence ◽  
T Cell Function

T cells are key immune cells involved in the pathogenesis of several diseases, rendering them important therapeutic targets. Although drug delivery to T cells is the subject of continuous research, it remains challenging to deliver drugs to primary T cells. Here, we used a peptide-based drug delivery system, AP, which was previously developed as a transdermal delivery peptide, to modulate T cell function. We first identified that AP-conjugated enhanced green fluorescent protein (EGFP) was efficiently delivered to non-phagocytic human T cells. We also confirmed that a nine-amino acid sequence with one cysteine residue was the optimal sequence for protein delivery to T cells. Next, we identified the biodistribution of AP-dTomato protein in vivo after systemic administration, and transduced it to various tissues, such as the spleen, liver, intestines, and even to the brain across the blood–brain barrier. Next, to confirm AP-based T cell regulation, we synthesized the AP-conjugated cytoplasmic domain of CTLA-4, AP-ctCTLA-4 peptide. AP-ctCTLA-4 reduced IL-17A expression under Th17 differentiation conditions in vitro and ameliorated experimental autoimmune encephalomyelitis, with decreased numbers of pathogenic IL-17A+GM-CSF+ CD4 T cells. These results collectively suggest the AP peptide can be used for the successful intracellular regulation of T cell function, especially in the CNS.

Identification of a Discrete Subpopulation of T-Cells Over-Expressing HDAC11 with a TH17 Phenotype

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 588-588
Author(s):  
Karrune Woan ◽  
Fengdong Cheng ◽  
Hongwei Wang ◽  
Jennifer Rock-Klotz ◽  
Zi Wang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Cell Function ◽  
Conflicts Of Interest ◽  
Negative Regulator ◽  
Egfp Expression ◽  
In Vivo Models

Abstract Abstract 588 We recently defined a novel role of histone deacetylase 11 (HDAC11), the newest member of the HDAC family, as a negative regulator of IL-10 gene transcription in antigen-presenting cells (APCs).1 To better understand the role of HDAC11 gene expression in immune cells in vivo, we have utilized a BAC (Bacterial artificial chromosome) transgenic mouse in which the EGFP reporter gene was inserted downstream of the HDAC11 promoter region but immediately upstream of the HDAC11 coding sequence (TgHDAC11-EGFP mice).2 In the steady-state, macrophages and B-cells isolated from spleen of TgHDAC11-EGFP mice express low levels of HDAC11 as evidenced by a slight shift in EGFP fluorescence from background. In sharp contrast, we identified a discrete population (11.9%) of T-cells over-expressing HDAC11 as demonstrated both by flow cytometry for EGFP and by qRT-PCR for HDAC11, a majority of which were CD4+ T-cells. Sorting of this EGFP+, CD4+ T-cell population confirmed that the increased EGFP expression correlated with an increased HDAC11mRNA expression. Reminiscent of our prior data in APCs, the increased expression of HDAC11 in T-cells was also inversely correlated with IL-10mRNA expression. Further analyses revealed that in the absence of any stimulation or T-cell polarizing conditions, this EGFP positive population expressed significantly elevated levels of ROR-γt and IL-17 mRNA, markers specific for the TH17 subpopulation. Polarization of wild type CD4+ T-cells into functional TH17 cells was associated with reduction of HDAC11 expression, suggesting a potential role for HDAC11 in regulating T-cell function and/or activation, in particular within the TH17 subset. Further support for this regulatory role of HDAC11 has been provided by our additional findings that T-cells devoid of HDAC11 are indeed hyper-reactive in vitro and in in vivo models. 1. Villagra A, et al. Nat Immunol. 2009 Jan;10(1):92-100. 2. Gong S, et al. Nature. 2003 Oct 30;425(6961):917-25. Disclosures: No relevant conflicts of interest to declare.

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