scholarly journals p53 Isoform D133p53a: A Novel Transcriptional Enhancer of T-Cell Effector Function to Improve T-Cell Based Cancer Immunotherapy

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3489-3489
Author(s):  
Kevin Jan Legscha ◽  
Edite Antunes ◽  
Borhane Guezguez ◽  
Matthias Theobald ◽  
Hakim Echchannaoui
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
T Cell ◽  
Cancer Immunotherapy ◽  
Tumor Antigen ◽  
Human T Cells ◽  
P53 Isoforms ◽  
Inhibitory Molecules ◽  
T Cell Senescence

Abstract Background: Adoptive transfer of genetically modified T lymphocytes with tumor antigen-specific receptor has proven efficacy in cancer immunotherapy. However, in many patients the overall benefit is still limited due to various tumor escape mechanisms. Cell damage and metabolic/hypoxic stress in the tumor microenvironment (TME) can lead to a dysfunctional anti-tumor T cell response called T cell senescence. The tumor suppressor TP53 is a master molecule in the regulation of cell cycle and senescence. Few studies have demonstrated the critical role of p53 isoforms in the regulation of cellular senescence mainly in tumor cells. However, their role in tumor infiltrating lymphocytes (TILs) remains largely unexplored. Aims: Strategies to prevent T cell senescence in the TME could improve T cell function and thus anti-tumor response. To better understand the role of D133p53 isoform in regulating the cell cycle and senescence we studied the cellular and metabolic/energetic phenotype as well as the effector function of the D133p53-modified tumor-antigen (TA) specific human T cells. We further aimed at identifying the mechanism that may regulate this phenotype. Methods: T cells form healthy donors were retrovirally co-transduced with a TA-specific T cell receptor (TCR) together with the D133p53 isoform or an empty control vector. Modified T cells were characterized for the expression of key activating/inhibitory molecules, homing markers and for their proliferation capacity by flow cytometry. Additionally, we determined the metabolic and energetic phenotype of the cells with an Agilent Seahorse XFp Analyzer. The effector functions i.e. cytokine secretion and antigen-specific killing capacity were assessed by Luminex immunoassay and long-term tumor colony-forming assay, respectively. In an attempt to identify molecules/pathway contributing to this phenotype we performed quantitative proteomic-based analysis. Results: Our analyses of human T cells simultaneously engineered with D133p53a-isoform and a TA-specific TCR revealed reduced cell surface expression of T-cell inhibitory molecules (i.e. PD-1 or TIGIT), senescence markers (CD57, CD160) and increased expression of the homing receptor CD62L upon TA stimulation. First comparative analyses between D133p53a-modified and control T-cells revealed changes in the cell's metabolic and energetic program similar to quiescent/naïve T cells. D133p53a-T cells exhibited lower ATP production, oxygen consumption as well as lower glucose utilization. Upon antigen-specific stimulation, however, they increased their metabolic activity up to the levels of control cells. Importantly, while control T cells exhibited replicative senescence after chronic antigen stimulation, D133p53a-expressing T cells remained highly proliferative, showed superior cytokine secretion and enhanced tumor-specific killing capacity. Comparative proteomic analysis revealed significant differences in more than 100 proteins. Detailed pathway and network analysis as well as validation of the most significantly changing proteins is currently performed. Conclusion: By providing insights in the regulation of T cell metabolic changes and underlying mechanisms that limit immunosenescence, genetic modification with p53 isoforms could be a promising strategy to circumvent tumor-mediated T cell dysfunction and represents a novel approach with high potential for cancer immunotherapy. Disclosures No relevant conflicts of interest to declare.

scholarly journals Splicing factor SRSF1 limits IFN-γ production via RhoH and ameliorates experimental nephritis

Rheumatology ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 420-429
Author(s):  
Takayuki Katsuyama ◽  
Hao Li ◽  
Suzanne M Krishfield ◽  
Vasileios C Kyttaris ◽  
Vaishali R Moulton
Keyword(s):  
T Cells ◽  
T Cell ◽  
Molecular Mechanisms ◽  
Elevated Serum ◽  
Splicing Factor ◽  
Type I ◽  
Human T Cells ◽  
Experimental Nephritis ◽  
Ifn Γ

Abstract Objective CD4 T helper 1 (Th1) cells producing IFN-γ contribute to inflammatory responses in the pathogenesis of SLE and lupus nephritis. Moreover, elevated serum type II IFN levels precede the appearance of type I IFNs and autoantibodies in patient years before clinical diagnosis. However, the molecules and mechanisms that control this inflammatory response in SLE remain unclear. Serine/arginine-rich splicing factor 1 (SRSF1) is decreased in T cells from SLE patients, and restrains T cell hyperactivity and systemic autoimmunity. Our objective here was to evaluate the role of SRSF1 in IFN-γ production, Th1 differentiation and experimental nephritis. Methods T cell-conditional Srsf1-knockout mice were used to study nephrotoxic serum-induced nephritis and evaluate IFN-γ production and Th1 differentiation by flow cytometry. RNA sequencing was used to assess transcriptomics profiles. RhoH was silenced by siRNA transfections in human T cells by electroporation. RhoH and SRSF1 protein levels were assessed by immunoblots. Results Deletion of Srsf1 in T cells led to increased Th1 differentiation and exacerbated nephrotoxic serum nephritis. The expression levels of RhoH are decreased in Srsf1-deficient T cells, and silencing RhoH in human T cells leads to increased production of IFN-γ. Furthermore, RhoH expression was decreased and directly correlated with SRSF1 in T cells from SLE patients. Conclusion Our study uncovers a previously unrecognized role of SRSF1 in restraining IFN-γ production and Th1 differentiation through the control of RhoH. Reduced expression of SRSF1 may contribute to pathogenesis of autoimmune-related nephritis through these molecular mechanisms.

Constitutive Activation of Toll like Receptor Signaling in Adult T-Cell Leukemia Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2291-2291
Author(s):  
Takamitsu Mizobe ◽  
Junichi Tsukada ◽  
Takehiro Higashi ◽  
Fumihiko Mouri ◽  
Ai Matsuura ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Adaptor Protein ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Constitutive Activation ◽  
Adult T Cell Leukemia ◽  
Human T Cells

Abstract Human T-cell leukemia virus type I (HTLV-I) is etiologically associated with the development of an aggressive and fatal malignancy of CD4+ T lymphocytes called adult T-cell leukemia (ATL). Constitutive activation of nuclear factor-κB (NF-κB) is a common feature of ATL. Although the mechanism by which NF-κB is spontaneously activated in ATL cells still remains unclear, inhibition of NF-κB activity induces apoptosis, suggesting a central role of NF-κB in their proliferation. Toll like receptors (TLRs) are involved in innate cell activation by conserved structures expressed by microorganisms. Engagement of IL-1R or TLR with their cognate ligands causes an adaptor protein MyD88 to be recruited to the receptor complex, which in turn promotes its association with the IL-1R-associated kinase (IRAK) via an interaction between the respective death domains of each molecule. Several recent reports have indicated unique expression profiles of TLRs on different subsets of human T cells, and that some TLR ligands modulate the function of human T cells. We examined expression of the TLR mRNAs in primary ATL cells and ATL cell lines, MT2, MT4 and HUT102 by RT-PCR. Expression of TLR mRNAs, except of TLR7 and TLR8, was detected in all cell samples examined. We further demonstrated constitutive association of MyD88, an adaptor protein for the TLR signaling, with the IL-1R-associated kinase 1 (IRAK1) in ATL cell lines, MT2, MT4 and HUT102. In MT2 cells, constitutive activation of NF-κB and NF-IL6, but not Stat3 was significantly inhibited by expression of a dominant negative form of MyD88 protein (MyD88dn). Spontaneous transcriptional activation of IL-1α, IFN-γ and TNF-α gene promoters in MT2 cells was also suppressed by MyD88dn expression. MyD88dn inhibited cell proliferation and induced apoptosis of MT2 cells. In addition, overexpression of wild-type MyD88 and HTLV-I Tax induces synergistically transcriptional activity of NF-κB in 293T cells, showing interaction of Tax with MyD88. Thus, our results show a critical role of MyD88 in dysregulated gene activation and cell proliferation in HTLV-I-transformed T-cells, and further suggest the involvement of MyD88 in Tax-mediated intracellular signal transduction in HTLV-I-infected cells. Considering the fact that blocking NF-κB is a potential strategy to treat ATL, our argument raises a possibility that we may be able to find new treatment targets against ATL.

scholarly journals Interleukin-2-dependent phosphorylation of the retinoblastoma-susceptibility-gene product p110-115RB in human T-cells

1992 ◽  
Vol 282 (3) ◽  
pp. 759-764 ◽  
Author(s):  
G A Evans ◽  
L M Wahl ◽  
W L Farrar
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
T Cell ◽  
Gene Transcription ◽  
T Cell Activation ◽  
Cell Activation ◽  
Susceptibility Gene ◽  
Interleukin 2 ◽  
Human T Cells ◽  
Rb Phosphorylation

The state of phosphorylation of the retinoblastoma-susceptibility gene product, p110-115RB, is thought to have fundamental importance in controlling the progression of the cell through the cell cycle. We have studied RB phosphorylation in human T-cells in the context of T-cell activation, stimulated by phytohaemagglutinin (PHA) and interleukin-2 (IL-2). We show that, of the signals associated with T-cell activation, only signals that directly lead to movement into S phase of the cell cycle are capable of stimulating RB phosphorylation. Cyclosporin A (CsA), a potent inhibitor of IL-2 synthesis and cellular proliferation, blocked RB phosphorylation, and this was recovered with exogenous IL-2, indicating a direct involvement of IL-2 in controlling RB phosphorylation. We found that PHA did not stimulate RB phosphorylation within 10 h of treatment, but IL-2 could effectively stimulate RB phosphorylation within 2 h, and this approached a maximum within 8-10 h of IL-2 treatment. Further, by using actinomycin D to inhibit new gene transcription following IL-2 stimulation, we found that early-cell-cycle phosphorylation of RB required IL-2-stimulated gene transcription. From these data we conclude that, in human T-cells, RB phosphorylation is not directly associated with T-cell receptor-mediated events, but requires the interaction of IL-2 and new gene transcription following IL-2 stimulation.

scholarly journals Telomerase regulation during entry into the cell cycle in normal human T cells.

1996 ◽  
Vol 7 (9) ◽  
pp. 1443-1454 ◽  
Author(s):  
K J Buchkovich ◽  
C W Greider
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
T Cell ◽  
Cell Receptor ◽  
Telomerase Activity ◽  
Quiescent Cells ◽  
Human T Cells ◽  
Somatic Tissues ◽  
Normal Human Cell ◽  
Normal Human

Telomerase activity is involved in telomere length maintenance. Leukocytes, unlike many human somatic tissues, have detectable telomerase activity. These cells provide a normal human cell type in which to study telomerase. We studied the regulation of telomerase activity and the telomerase RNA component as leukocytes were stimulated to enter the cell cycle. In primary human leukocytes stimulated with phytohemagglutinin, telomerase activity increased > 10-fold as naturally quiescent cells entered the cell cycle. Antibodies to the T cell receptor (TCR)/CD3 complex and the costimulatory CD28 receptor induced telomerase activity in a T cell-enriched population of cells. Rapamycin, an immunosuppressant that blocks TCR/CD3 signal transduction pathways and cdk2 activation, blocked telomerase induction. Hydroxyurea, an inhibitor of S phase, did not block cdk2 kinase activity or telomerase activation. In summary, telomerase is regulated in G1 phase as normal human T cells enter the cell cycle.

scholarly journals Conventional CD4+CD25- and Regulatory CDCD4+25+ t Cells Have Opposite Effects on Progenitor Cells and Hematopoietic Reconstitution Following Stem Cell Transplantation

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 654-654
Author(s):  
Antonia MS Mueller ◽  
Jessica Poyser ◽  
Holbrook E Kohrt ◽  
Judith A Shizuru
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
T Cell ◽  
Cell Transplantation ◽  
Immune Cells ◽  
T Cell Subsets ◽  
Mixed Chimerism ◽  
Allogeneic Hct ◽  
Hematopoietic Reconstitution

Abstract The bone marrow (BM) is a complex microsystem to support lifelong blood production. At steady-state most hematopoietic stem cells (HSC) are quiescent. However, in situations of increased demand, their activation is triggered by an array of signals, such as cytokines. Following hematopoietic cell transplantation (HCT) in the phase of hematopoietic reconstitution maximal blood production is needed. In an HCT donor HSC are given together with immune cells in the belief that T cells support HSC engraftment and regeneration of the blood system. Yet, states of immune mediated BM insufficiency, hypoplasia, and cytopenias are often observed. Moreover, with increased use of reduced intensity conditioning (RIC) engraftment failure has reemerged as a serious problem. Here, we studied the effects of distinct T cell subsets on hematopoietic reconstitution following HCT; specifically, we examined how conventional CD4+CD25- T cells (CD4conv) vs regulatory T cells (CD4+CD25+, Treg) modify the BM environment and influence donor-HSC activity and engraftment. We used minor-mismatched mouse models, non-myeloablative total body irradiation (TBI) conditioning and transplantations of purified HSC (KTLS; cKit+Thy1.1loLin–Sca-1+) plus selected T cell subsets. Recipients of HSC, HSC+Treg or HSC+CD8+ - but not HSC+CD4conv- demonstrated prompt donor engraftment with mixed chimerism in all lineages. Transplantation of HSC+Treg resulted in significantly faster lymphocyte recovery and higher levels of donor chimerism compared with recipients of HSC, HSC+CD8+ or HSC+CD4conv. Particularly B-cell regeneration was markedly higher in HSC+Treg-recipients compared with all other groups. In contrast, (B-) lymphopoiesis was severely impaired in recipients of HSC+CD4conv; when lymphocytes recovered eventually they were of host type. Moreover, in BM and spleens of HSC+CD4conv recipients pronounced hypocellularity was observed. This suppression of hematopoiesis was due to IFNg secretion of donor CD4conv cells, which were activated by dendritic cells via IL-12. High cytokine levels (of both IL-12 and IFNg) were only detectable in the BM (and not the spleen) of HSC+CD4conv recipients, where they resulted in an arrest of early hematopoiesis at the stage of short-term HSC and decreased cell-cycle activity within the progenitor compartment. As a consequence more mature multipotent progenitors were lacking. The key role of IFNg in halting hematopoietic maturation was confirmed by using CD4conv cells from IFNg-/- mice, which had no suppressive effects on BM cellularity and maturation of blood cells; rather, recipients of HSC+IFNg-/-CD4conv cells had equivalent cell numbers and subset distributions as mice given HSC alone. We hypothesized that differences of hematopoietic regeneration and donor engraftment relate to cell cycle activity of HSC in presence of CD4conv vs Tregs. To study the influence of these CD4-subsets on HSC cycling in more detail FACS-purified Treg vs CD4conv cells were infused into congenic mice following low-dose TBI-stimulation. In fact, on d+8 post-infusion HSC in the BM of Treg-recipients had increased cell-cycling activity in long-term-HSC and multipotent-progenitor fractions compared with mice given CD4conv cells or radiation only. These data lead us to speculate that Tregs promote, directly or indirectly, HSC proliferation; in the context of an allogeneic HCT this increased cycling of host HSC my open-up the niche space required to allow donor HSC to engraft. In contrast, CD4convinhibited HSC cycling activity, resulting in BM hypoplasia and cytopenias; at the same time donor HSC engraftment was impaired due to HSC-niche occupation by quiescent host HSC. Our findings underscore the critical role of T cells in regulating hematopoiesis under physiologic conditions and even more following allogeneic HCT. While donor T cells are generally believed to improve regeneration of the blood post-HCT and to be required to overcome host barriers, our data suggest Treg facilitate engraftment and hematopoiesis by increasing HSC cycling-activity and thereby making marrow sites available. CD4conv appear to have the opposite effect, resulting in decreased HSC proliferation and maturation - thus occupation of HSC niches. Our studies are of particular relevance to allogeneic HCT settings using RIC, where host HSC persist and grafts can be rejected by residual host immune cells. Disclosures No relevant conflicts of interest to declare.

scholarly journals Somatic mutagenesis studies of NF-κB signaling in human T cells: evidence for an essential role of IKKγ in NF-κB activation by T-cell costimulatory signals and HTLV-I Tax protein

Oncogene ◽  
2000 ◽  
Vol 19 (11) ◽  
pp. 1448-1456 ◽  
Author(s):  
Edward W Harhaj ◽  
LiFeng Good ◽  
Gutian Xiao ◽  
Mark Uhlik ◽  
Mary Ellen Cvijic ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Essential Role ◽  
Tax Protein ◽  
Human T Cells ◽  
Costimulatory Signals ◽  
Somatic Mutagenesis

scholarly journals Δ133p53α enhances metabolic and cellular fitness of TCR-engineered T cells and promotes superior antitumor immunity

2021 ◽  
Vol 9 (6) ◽  
pp. e001846
Author(s):  
Kevin Jan Legscha ◽  
Edite Antunes Ferreira ◽  
Antonios Chamoun ◽  
Alexander Lang ◽  
Mohamed Hemaid Sayed Awwad ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cancer Immunotherapy ◽  
Critical Role ◽  
Limiting Factor ◽  
Mouse Tumor ◽  
Lymphocyte Function ◽  
Phenotypic Analysis ◽  
Effector Functions ◽  
P53 Isoforms

BackgroundTumor microenvironment-associated T cell senescence is a key limiting factor for durable effective cancer immunotherapy. A few studies have demonstrated the critical role of the tumor suppressor TP53-derived p53 isoforms in cellular senescence process of non-immune cells. However, their role in lymphocytes, in particular tumor-antigen (TA) specific T cells remain largely unexplored.MethodsHuman T cells from peripheral blood were retrovirally engineered to coexpress a TA-specific T cell receptor and the Δ133p53α-isoform, and characterized for their cellular phenotype, metabolic profile and effector functions.ResultsPhenotypic analysis of Δ133p53α-modified T cells revealed a marked reduction of the T-cell inhibitory molecules (ie, CD160 and TIGIT), a lower frequency of senescent-like CD57+ and CD160+ CD8+ T cell populations, and an increased number of less differentiated CD28+ T cells. Consistently, we demonstrated changes in the cellular metabolic program toward a quiescent T cell state. On a functional level, Δ133p53α-expressing T cells acquired a long-term proliferative capacity, showed superior cytokine secretion and enhanced tumor-specific killing in vitro and in mouse tumor model. Finally, we demonstrated the capacity of Δ133p53α to restore the antitumor response of senescent T cells isolated from multiple myeloma patients.ConclusionThis study uncovered a broad effect of Δ133p53α isoform in regulating T lymphocyte function. Enhancing fitness and effector functions of senescent T cells by modulation of p53 isoforms could be exploited for future translational research to improve cancer immunotherapy and immunosenescence-related diseases.

scholarly journals 474 Phase 1 study of SEA-TGT, a human, nonfucosylated anti-TIGIT monoclonal antibody with enhanced immune-effector function, in patients with advanced malignancies (SGNTGT-001, trial in progress)

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A503-A503
Author(s):  
Diwakar Davar ◽  
Vincent Ribrag ◽  
Clementine Sarkozy ◽  
Elena Garralda ◽  
Honey Kumar Oberoi ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
T Cells ◽  
T Cell ◽  
Antitumor Activity ◽  
Cancer Immunotherapy ◽  
Tumor Antigen ◽  
Cutaneous Melanoma ◽  
Phase 1 ◽  
Cd8 T Cell ◽  
Part C

BackgroundT-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory domains (TIGIT), and costimulatory receptor CD226 competitively bind 2 ligands, CD155 and CD112, which are expressed by tumor cells and antigen-presenting cells in the tumor microenvironment.1 2 Dual TIGIT/programmed cell death protein-1 (PD-1) blockade increased tumor antigen-specific CD8+ T-cell expansion and function in vitro and promoted potent antitumor response in vivo.3 4 TIGIT/PD-1 dual blockade using a TIGIT monoclonal antibody (mAb) with intact Fc produced clinical responses in advanced cancer.5 SEA-TGT is an investigational, human, nonfucosylated mAb directed against TIGIT. SEA-TGT binds to TIGIT, blocking inhibitory checkpoint signals directed at T cells. SEA-TGT enhances binding to activating FcγRIIIa and decreases binding to inhibitory FcγRIIb; this depletes immunosuppressive regulatory T cells and amplifies naive and memory T cells, potentially augmenting PD-1 inhibition effects. Preclinically, at suboptimal doses, SEA-TGT plus anti-PD-1 mAbs had superior antitumor activity than either agent alone.6MethodsSafety and antitumor activity of SEA TGT in ~377 adults (≥18 years) will be evaluated in this phase 1, multicenter, open-label, dose-escalation/expansion study. Part A will assess the safety/tolerability of SEA TGT to determine maximum tolerated and recommended doses. Part B will assess the safety and antitumor activity of the recommended dose in disease-specific expansion cohorts. Part C will assess SEA-TGT plus sasanlimab in dose-expansion cohorts after an initial safety run-in. Patients with histologically/cytologically confirmed relapsed/refractory/progressive metastatic solid tumors including non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC), gastric/gastroesophageal junction carcinoma, cutaneous melanoma, bladder, cervical, ovarian or triple-negative breast cancer, or selected lymphomas will be eligible for Parts A and B. Part C will enroll patients with histologically confirmed advanced NSCLC (high [tumor proportion score (TPS) ≥50%] and low [TPS=1–49%] PD ligand 1 [PD-L1] expression), cutaneous melanoma, and HNSCC without previous anti–PD-1/PD-L1 therapy exposure. SEA TGT will be administered on Day 1 of 21-day cycles.Laboratory abnormalities, adverse events, dose-limiting toxicities, and dose-level safety and activity are primary endpoints. Secondary endpoints are objective response (OR) and complete response (CR) rates, duration of OR/CR, progression-free survival, overall survival, pharmacokinetics (PK), and antidrug antibodies. Exploratory analysis will include pharmacodynamics (PD), PK/PD relationships, biomarkers, and resistance to SEA-TGT. This trial is recruiting in Europe and North America.Trial RegistrationNCT04254107ReferencesBlake SJ, Dougall WC, Miles JJ, et al. Molecular pathways: Targeting CD96 and TIGIT for cancer immunotherapy. Clin Cancer Res 2016;22(21):5183–5188.Chauvin JM, Zarour HM. TIGIT in cancer immunotherapy. J ImmunoTher Cancer 2020;8:e000957.Johnston RJ, Comps-Agrar L, Hackney J, et al. The immunoreceptor TIGIT regulates antitumor and antiviral CD8+ T cell effector function. Cancer Cell 2014;26(6):923–937.Chauvin JM, Pagliano O, Fourcade J, et al. TIGIT and PD-1 impair tumor antigen-specific CD8+ T cells in melanoma patients. J Clin Invest 2015;125(5):2046–2058.Rodriguez-Abreu D, Johnson ML, Hussein MA, et al. Primary analysis of a randomized, double-blind, phase 2 study of the anti-TIGIT antibody tiragolumab (tira) plus atezolizumab (atezo) versus placebo plus atezo as first-line (1L) treatment in patients with PD-L1-selected NSCLC (CITYSCAPE). J Clin Oncol 2020;38(15 suppl):9503.Smith A, Zeng W, Lucas S, et al. Poster 1583. SEA-TGT is an empowered anti-TIGIT antibody that displays superior combinatorial activity with several therapeutic agents. Presented at: American Association for Cancer Research Annual Meeting; April 9–14, 2021; Virtual Meeting.Ethics ApprovalInstitutional review boards or independent ethics committees of participating sites approved the trial, which will be conducted in compliance with the Declaration of Helsinki and International Conference on Harmonisation Guidelines for Good Clinical Practice. All patients will provide written informed consent.

scholarly journals Targeting Pim2 for Improving T-Cell Effector Function and Promoting Cancer Immunotherapy

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1720-1720
Author(s):  
Yongxia Wu ◽  
Linlu Tian ◽  
Corey Mealer ◽  
Hee-Jin Choi ◽  
Xue-Zhong Yu
Keyword(s):  
Breast Cancer ◽  
T Cells ◽  
T Cell ◽  
Cancer Immunotherapy ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Effector Function ◽  
Cell Responses ◽  
Deficient Mice

Abstract The Provirus Integration sites for Moloney murine leukemia virus (Pim) kinases are a highly conserved family of serine/threonine kinases. The Pim kinase family is composed of three different isoforms, Pim1, Pim2, and Pim3, which have been studied extensively in tumorigenesis and as a potential therapeutic target in various cancers. We previously reported an unexpected role of Pim2 in negatively regulates T-cell responses to alloantigen and tumor (JCI, 2015, PMID: 29781812). However, the mechanisms by which Pim2 modulates T-cell responses remain largely undefined. In the current study, using genetic Pim2-deficient mouse, we demonstrated a key role of Pim2 in regulating T-cell hemostatic and anti-tumor responses in aging, hematopoietic cell transplantation (HCT), and antigen-specific adoptive T-cell therapy (ACT). We observed that Pim2 was critical for T cells to retain quiescent in aged mice, as thymic Treg development was impaired while effector T-cell differentiation in lymphoid organs, including Tc1/Th1, Tc17/Th17 and follicular helper T cells, was increased in Pim2-deficient mice, but not in Pim1/Pim3-deficient mice. Furthermore, Pim2-deficient mice were capable to completely eradicate syngeneic breast cancer (NT2.5) growth (Figure A). During antigen specific anti-tumor response, adoptively transferred Pim2 -/- CD8 T cells showed enhanced ability for controlling established NT2.5 breast cancer and B16 melanoma (Figure B, C). Mechanistically, loss of Pim2 promoted G1 to S phase cell-cycle progression while reduced apoptosis in CD8 T cells. Pim2 -/- CD8 T cells exhibited elevated effector cytokine production while maintained higher levels of CD62L expression, leading to superior effector function, persistence and anti-tumor activity. Reduced differentiation of exhausted and suppressive subsets were observed in Pim2 -/- CD8 T cells after being adoptively transferred in tumor-bearing mice. In addition, Pim2 deficiency was associated with a higher metabolic potential, reflected by increased glycolysis and oxidative phosphorylation, which was at least partially attributed to a decreased level of autophagy in Pim2 -/- CD8 T cells. To further evaluate the clinical translation potential, we applied a Pim2-specific inhibitor (JP11646) and found that blocking Pim2 improved graft-versus-leukemia activity after autologous HCT and also enhanced CD8 T-cell mediated anti-melanoma effects after ACT in mice (Figure B, C). Furthermore, blocking Pim2 using JP11646 promoted human CD8 T-cell response during polyclonal stimulation and enhanced expansion, effector function and tumor killing ability of human melanoma antigen-specific CD8 T cells (data not shown) and CD19 CAR-T cells (Figure D). Our work demonstrated that Pim2 is a potent and distinct regulator of differentiation and maintenance of T effector cells through modulating metabolism and autophagy. Specifically target Pim2 can serve as a novel strategy for improving cancer immunotherapy. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

scholarly journals Three-dimensional localization of T-cell receptors in relation to microvilli using a combination of superresolution microscopies

2016 ◽  
Vol 113 (40) ◽  
pp. E5916-E5924 ◽  
Author(s):  
Yunmin Jung ◽  
Inbal Riven ◽  
Sara W. Feigelson ◽  
Elena Kartvelishvily ◽  
Kazuo Tohya ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptors ◽  
Three Dimensional ◽  
Spatial Relation ◽  
Protein Distribution ◽  
Cell Receptors ◽  
Human T Cells ◽  
Antigen Presenting

Leukocyte microvilli are flexible projections enriched with adhesion molecules. The role of these cellular projections in the ability of T cells to probe antigen-presenting cells has been elusive. In this study, we probe the spatial relation of microvilli and T-cell receptors (TCRs), the major molecules responsible for antigen recognition on the T-cell membrane. To this end, an effective and robust methodology for mapping membrane protein distribution in relation to the 3D surface structure of cells is introduced, based on two complementary superresolution microscopies. Strikingly, TCRs are found to be highly localized on microvilli, in both peripheral blood human T cells and differentiated effector T cells, and are barely found on the cell body. This is a decisive demonstration that different types of T cells universally localize their TCRs to microvilli, immediately pointing to these surface projections as effective sensors for antigenic moieties. This finding also suggests how previously reported membrane clusters might form, with microvilli serving as anchors for specific T-cell surface molecules.

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