scholarly journals Successful Protection against Tularemia in C57BL/6 Mice Is Correlated with Expansion of Francisella tularensis-Specific Effector T Cells

2014 ◽  
Vol 22 (1) ◽  
pp. 119-128 ◽  
Author(s):  
Amanda J. Griffin ◽  
Deborah D. Crane ◽  
Tara D. Wehrly ◽  
Catharine M. Bosio
Keyword(s):  
T Cells ◽  
Francisella Tularensis ◽  
Effector T Cells ◽  
Lung Cells ◽  
Content Type ◽  
Specific Effector ◽  
Different Strains ◽  
Protection Against Infection ◽  
Induced Immunity

ABSTRACTFrancisella tularensisis an intracellular, Gram-negative bacterium that causes the fatal disease tularemia. Currently, there are no licensed vaccines for tularemia and the requirements for protection against infection are poorly defined. To identify correlates of vaccine-induced immunity against tularemia, we compared different strains of the live vaccine strain (LVS) for their relative levels of virulence and ability to protect C57BL/6 mice against challenge with virulentF. tularensisstrain SchuS4. Successful vaccination, as defined by survival of C57BL/6 mice, was correlated with significantly greater numbers of effector T cells in the spleen and lung. Further, lung cells and splenocytes from fully protected animals were more effective than lung cells and splenocytes from vaccinated but nonimmune animals in limiting intracellular replication of SchuS4in vitro. Together, our data provide a unique model to compare efficacious vaccines to nonefficacious vaccines, which will enable comprehensive identification of host and bacterial components required for immunization against tularemia.

Escape from Suppression: Tumor-Specific Effector Cells Out-Compete Regulatory T Cells Following Stem Cell Transplantation.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 69-69
Author(s):  
Paria Mirmonsef ◽  
Gladys Tan ◽  
Gang Zhou ◽  
Tricia Pyhel ◽  
Ivan M. Borrello ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
Tumor Antigen ◽  
Immune Reconstitution ◽  
Effector T Cells ◽  
Transplant Recipients ◽  
Tumor Bearing ◽  
Established Tumor ◽  
Specific Effector

Abstract Autologous hematopoietic stem cell (HSC) transplantation is an accepted therapy for many hematological malignancies. High dose chemo-radiation reduces tumor burden but also ablates lymphohematopoiesis. Subsequent infusion of cellular grafts containing HSC and mature lymphocytes “rescues” the host from this otherwise lethal ablation, and initiates immune reconstitution. In many systems, tumor-specific T cells are functionally tolerant in the presence of established tumor. Paradoxically, however, the infusion of these lymphocytes into irradiated tumor-bearing syngeneic recipients unmasks effector function manifested as prolonged progression-free survival when compared to recipients treated with lymphocytes from non-tumor bearing donors. We have recently demonstrated that this tolerant tumor-specific T cell population from mice with established tumor is in fact a heterogeneous mixture of naive, effector, and regulatory T cells (Tregs), which as a whole are rendered functionally unresponsive through dominant suppression. The apparent reversal of tolerance in the post-transplant setting prompted a more detailed examination of the fate of these individual components during immune reconstitution. Here, we show that CD4+ T cells specific for a model tumor antigen are hyporesponsive to antigen when isolated from mice harboring an established systemic B cell lymphoma. Upon transfer into irradiated lymphoma-bearing mice, however, these cells undergo robust antigen-driven clonal expansion, and their ability to produce interferon gamma (IFNγ) is restored. Notably, in spite of the presence of tumor in the transplant recipients, tolerance to tumor antigen was not established in the early post-transplant period, even for mice receiving naive T cells in the graft. Tumor-specific CD4+CD25+Foxp3+ Tregs isolated from the donors were found to undergo a modest tumor-antigen-driven expansion in transplant recipients. When isolated from recipients, such cells maintained expression of Foxp3 and their capacity to suppress naive T cells when cultured in vitro. However, the presence of tumor-specific Tregs failed to significantly inhibit the expansion of naive or effector T cells specific for tumor in vivo, when examined 2 weeks post BMT. Indeed, the expansion of tumor-specific effector T cells significantly exceeded the expansion of Tregs, resulting in a nearly five-fold increase in the effector:Treg ratio. At the ratios present during this phase of immune reconstitution, the frequency of Tregs was insufficient to suppress effector cell function (proliferation and IFNγ production) when studied in vitro. This accounts for the reversal of tolerance identified in the population as a whole and its capacity to mediate tumor rejection.

Requirements for Retroviral Targeting of a Suicide Gene to Alloreactive Memory Stem T Cells for Adoptive Immunotherapy of Leukemia.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2176-2176
Author(s):  
Attilio Bondanza ◽  
Lothar Hambach ◽  
Shin Kaneko ◽  
Sara Mastaglio ◽  
Bart Nijmeijer ◽  
...  
Keyword(s):  
T Cells ◽  
Memory T Cells ◽  
Suicide Gene ◽  
Effector T Cells ◽  
Donor T Cells ◽  
Specific Effector ◽  
Ifn Γ ◽  
Homeostatic Cytokines

Abstract In a phase I/II clinical trial investigating the prophylactic infusion of suicide gene-modified donor T cells in the context of haploidentical hemopoietic cell transplantation (haplo-HCT) for the treatment of high-risk leukemia, we observed a rapid and effective immune reconstitution. After activation with anti-CD3 antibodies, genetic modification of donor T cells was accomplished with a retroviral vector encoding for the Herpes Simplex thymidine kinase (TK). In vitro before infusion and in vivo at immune reconstitution, TK+ cells displayed an effector memory (EM) phenotype (CD45RA–CD62L−, CD28±CD27+, IL-2±IFN–γ+). The graft-versus-leukemia (GvL) effect was substantial in patients transplanted in remission, but failed to cure patients in relapse. Gene targeting with retroviral vectors is limited to memory T cells. Central memory (CM) T cells (CD45RA–CD62L+, CD28+CD27+, IL-2+IFN-γ±) share many characteristics with stem cells, namely the ability to self-renew and to differentiate into a progeny of effector cells. EM TK+ cells have a reduced alloreactivity. Recently, it has been proposed that alloreactivity may be confined to memory T cells with stem cell-features. Since alloantigens are the target not only of graft-versus-host disease (GvHD), but also of the GvL effect, crucial to the success of the strategy is the suicide gene-modification of this subset of memory T cells. We found that addition of CD28 costimulation on cell-sized beads and the use of homeostatic cytokines, such as IL-7 and IL-15, generates central memory (CM) TK+ cells. CM TK+ cells are highly alloreactive, both in vitro and in vivo in a humanized animal model of GvHD based on the grafting of human skin onto NOD/scid mice. Interestingly, CM TK+ cells express the IL7Rα, a marker associated with the stem cell-features of memory T cells. Moreover, IL7Rα expression is maintained after stimulation with alloantigens. Stimulation of CM, but not of EM TK+ cells with autologous dendritic cells pulsed with restricted peptides from the minor histocompatibility alloantigen (mHag) HA-1 or H-Y efficiently induces mHag-specific effector T cells that lyse natural ligand expressing HLA-A2+ targets. TK+ mHag-specific effector T cells also lysed mHag+HLA-A2+ leukemic cells and, when infused in conditioned NOD/scid mice harboring human leukemia, significantly delayed disease progression. Altogether, these data suggest that optimal T-cell receptor triggering and homeostatic cytokines are required for retroviral targeting of a suicide gene to alloreactive memory stem T cells and warrant their use for a safe and powerful GvL effect.

scholarly journals Regulation of specific cell-mediated cytotoxic response against SV40-induced tumor associated antigens by depletion of suppressor T cells with cyclophosphamide in mice.

1979 ◽  
Vol 149 (3) ◽  
pp. 774-779 ◽  
Author(s):  
M Glaser
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Effector T Cells ◽  
Specific Cell ◽  
51Cr Release ◽  
Tumor Associated Antigens ◽  
Specific Effector ◽  
Release Assay

When cyclophosphamide was administered to mice before immunization with syngeneic SV40 transformed cells, the specific immune response elicited, as was measured by in vitro 51Cr release assay was stronger and lasted longer when compared to the response generated in noncyclophosphamide-treated mice. The augmentation effect of the drug was dependent on cyclophosphamide concentration being optimal at 100 mg/kg and on the time of drug administration in relation to antigen immunization being optimal at 2 d before antigen administration. Transfer of T cells from normal syngeneic mice to drug-treated animals abolished the cyclophosphamide-induced augmentation of immune response. These results implied that cyclophosphamide sensitive T cells suppressed the in vivo generation of specific effector T cells against SV40-induced tumor-associated antigens.

scholarly journals Needle-Free Delivery of Acetalated Dextran-Encapsulated AR-12 Protects Mice from Francisella tularensis Lethal Challenge

2016 ◽  
Vol 60 (4) ◽  
pp. 2052-2062 ◽  
Author(s):  
Ky V. Hoang ◽  
Heather Curry ◽  
Michael A. Collier ◽  
Hassan Borteh ◽  
Eric M. Bachelder ◽  
...  
Keyword(s):  
Francisella Tularensis ◽  
Lethal Challenge ◽  
Content Type ◽  
Human Macrophages ◽  
Gentamicin Treatment ◽  
Significant Toxicity ◽  
Serovar Typhimurium ◽  
Spectrum Activity

ABSTRACTFrancisella tularensiscauses tularemia and is a potential biothreat. Given the limited antibiotics for treating tularemia and the possible use of antibiotic-resistant strains as a biowarfare agent, new antibacterial agents are needed. AR-12 is an FDA-approved investigational new drug (IND) compound that induces autophagy and has shown host-directed, broad-spectrum activityin vitroagainstSalmonella entericaserovar Typhimurium andF. tularensis. We have shown that AR-12 encapsulated within acetalated dextran (Ace-DEX) microparticles (AR-12/MPs) significantly reduces host cell cytotoxicity compared to that with free AR-12, while retaining the ability to controlS.Typhimurium within infected human macrophages. In the present study, the toxicity and efficacy of AR-12/MPs in controlling virulent type AF. tularensisSchuS4 infection were examinedin vitroandin vivo. No significant toxicity of blank MPs or AR-12/MPs was observed in lung histology sections when the formulations were given intranasally to uninfected mice. In histology sections from the lungs of intranasally infected mice treated with the formulations, increased macrophage infiltration was observed for AR-12/MPs, with or without suboptimal gentamicin treatment, but not for blank MPs, soluble AR-12, or suboptimal gentamicin alone. AR-12/MPs dramatically reduced the burden ofF. tularensisin infected human macrophages, in a manner similar to that of free AR-12. However,in vivo, AR-12/MPs significantly enhanced the survival ofF. tularensisSchuS4-infected mice compared to that seen with free AR-12. In combination with suboptimal gentamicin treatment, AR-12/MPs further improved the survival ofF. tularensisSchuS4-infected mice. These studies provide support for Ace-DEX-encapsulated AR-12 as a promising new therapeutic agent for tularemia.

scholarly journals Regulatory T Cells Contribute to Resistance against Lyme Arthritis

2020 ◽  
Vol 88 (11) ◽  
Author(s):  
Emily M. Siebers ◽  
Elizabeth S. Liedhegner ◽  
Michael W. Lawlor ◽  
Ronald F. Schell ◽  
Dean T. Nardelli
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lyme Disease ◽  
Regulatory T Cells ◽  
Regulatory T Cell ◽  
Interleukin 10 ◽  
Lyme Arthritis ◽  
Interleukin 17 ◽  
Content Type

ABSTRACT The symptoms of Lyme disease are caused by inflammation induced by species of the Borrelia burgdorferi sensu lato complex. The various presentations of Lyme disease in the population suggest that differences exist in the intensity and regulation of the host response to the spirochete. Previous work has described correlations between the presence of regulatory T cells and recovery from Lyme arthritis. However, the effects of Foxp3-expressing CD4+ T cells existing prior to, and during, B. burgdorferi infection have not been well characterized. Here, we used C57BL/6 “depletion of regulatory T cell” mice to assess the effects these cells have on the arthritis-resistant phenotype characteristic of this mouse strain. We showed that depletion of regulatory T cells prior to infection with B. burgdorferi resulted in sustained swelling, as well as histopathological changes, of the tibiotarsal joints that were not observed in infected control mice. Additionally, in vitro stimulation of splenocytes from these regulatory T cell-depleted mice resulted in increases in gamma interferon and interleukin-17 production and decreases in interleukin-10 production that were not evident among splenocytes of infected mice in which Treg cells were not depleted. Depletion of regulatory T cells at various times after infection also induced rapid joint swelling. Collectively, these findings provide evidence that regulatory T cells existing at the time of, and possibly after, B. burgdorferi infection may play an important role in limiting the development of arthritis.

scholarly journals Sunitinib Exerts In Vitro Immunomodulatory Activity on Sarcomas via Dendritic Cells and Synergizes With PD-1 Blockade

2021 ◽  
Vol 12 ◽  
Author(s):  
Darina Ocadlikova ◽  
Mariangela Lecciso ◽  
Javier Martin Broto ◽  
Katia Scotlandi ◽  
Michele Cavo ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Cell Lines ◽  
Effector T Cells ◽  
Sarcoma Cell ◽  
Ifn Γ ◽  
Sarcoma Cells

BackgroundHigh-grade sarcomas are a heterogeneous group of aggressive tumors arising in bone and soft tissues. After relapse, treatment options are limited. The multi-targeted receptor tyrosine kinase inhibitors (TKIs) sunitinib and inhibitor of PD-1 (anti-PD-1) nivolumab have shown antitumor activity in selected subtypes. In this study, we examine the role of TKIs and PD-1 based therapy in in vitro cocultures of sarcoma.MethodsThe human osteosarcoma (SaOS-2) and synovial sarcoma (SYO-1) cell lines were treated with sunitinib. After cell death and proliferation assessment, expression of PD-L1 was analyzed by flow cytometry. Sunitinib-treated sarcoma cells were cocultured with dendritic cells (DCs), and the phenotype of mature DCs was determined by flow cytometry. Mature DCs were cultured with autologous T cells. PD-1 expression on T cells, their proliferation, T regulatory cell (Tregs) induction and IFN-γ production, before and after nivolumab exposure, were analyzed.ResultsAlong with its anti-proliferative and direct pro-apoptotic effect on sarcoma cell lines, sunitinib prompted PD-L1 upregulation on sarcoma cells. Interestingly, sunitinib-treated sarcoma cells drive DCs to full maturation and increase their capacity to induce sarcoma-reactive T cells to produce IFN-γ. Conversely, no effect on T cell proliferation and T cell subpopulation composition was observed. Moreover, both bone and synovial sarcoma cell lines induced Tregs through DCs but sunitinib treatment completely abrogated Treg induction. Finally, sarcoma cell lines induced PD-1 upregulation on both effector T cells and Tregs when loaded into DCs, providing a rationale for using PD-1 blockade. Indeed, PD-1 blockade by nivolumab synergized with sunitinib in inducing IFN-γ-producing effector T cells.ConclusionsTaken together, our in vitro data indicate that the treatment of sarcoma cells with sunitinib can exert significant changes on immune cell subsets toward immune activation, leading to DC-based cross-priming of IFN-γ-producing effector T cells and reduced Treg induction. PD-1 blockade with nivolumab has a synergistic effect with sunitinib, supporting the use of TKI and anti-PD-1 approach in sarcomas, and perhaps in other cancers. DC-targeted drugs, including toll-like receptor 3 inhibitors and CD47 inhibitors, are under development and our preclinical model might help to better design their clinical application.

scholarly journals Tim-3 Induces Th2-Biased Immunity and Alternative Macrophage Activation during Schistosoma japonicum Infection

2015 ◽  
Vol 83 (8) ◽  
pp. 3074-3082 ◽  
Author(s):  
Nan Hou ◽  
Xianyu Piao ◽  
Shuai Liu ◽  
Chuang Wu ◽  
Qijun Chen
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Schistosoma Japonicum ◽  
Immune Cell ◽  
Nk Cell ◽  
Alternative Activation ◽  
Interleukin 12 ◽  
Content Type

T cell immunoglobulin- and mucin-domain-containing molecule 3 (Tim-3) has been regarded as an important regulatory factor in both adaptive and innate immunity. Recently, Tim-3 was reported to be involved in Th2-biased immune responses in mice infected withSchistosoma japonicum, but the exact mechanism behind the involvement of Tim-3 remains unknown. The present study aims to understand the role of Tim-3 in the immune response againstS. japonicuminfection. Tim-3 expression was determined by flow cytometry, and increased Tim-3 expression was observed on CD4+and CD8+T cells, NK1.1+cells, and CD11b+cells from the livers ofS. japonicum-infected mice. However, the increased level of Tim-3 was lower in the spleen than in the liver, and no increase in Tim-3 expression was observed on splenic CD8+T cells or CD11b+cells. The schistosome-induced upregulation of Tim-3 on natural killer (NK) cells was accompanied by reduced NK cell numbersin vitroandin vivo. Tim-3 antibody blockade led to upregulation of inducible nitric oxide synthase and interleukin-12 (IL-12) mRNA in CD11b+cells cocultured with soluble egg antigen and downregulation of Arg1 and IL-10, which are markers of M2 macrophages. In summary, we observed schistosome-induced expression of Tim-3 on critical immune cell populations, which may be involved in the Th2-biased immune response and alternative activation of macrophages during infection.

scholarly journals Publisher Correction: Clonal analysis of Salmonella-specific effector T cells reveals serovar-specific and cross-reactive T cell responses

2019 ◽  
Vol 20 (4) ◽  
pp. 514-514
Author(s):  
Giorgio Napolitani ◽  
Prathiba Kurupati ◽  
Karen Wei Weng Teng ◽  
Malick M. Gibani ◽  
Margarida Rei ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Responses ◽  
Clonal Analysis ◽  
Effector T Cells ◽  
Cell Responses ◽  
Specific Effector

scholarly journals Global Analysis of Genes Essential forFrancisella tularensisSchu S4 GrowthIn Vitroand for Fitness during Competitive Infection of Fischer 344 Rats

2019 ◽  
Vol 201 (7) ◽  
Author(s):  
Philip M. Ireland ◽  
Helen L. Bullifent ◽  
Nicola J. Senior ◽  
Stephanie J. Southern ◽  
Zheng Rong Yang ◽  
...  
Keyword(s):  
Francisella Tularensis ◽  
Insertion Site ◽  
Therapeutic Drug ◽  
Content Type ◽  
Fischer 344 ◽  
A Genome ◽  
Fischer 344 Rat ◽  
Schu S4

ABSTRACTThe highly virulent intracellular pathogenFrancisella tularensisis a Gram-negative bacterium that has a wide host range, including humans, and is the causative agent of tularemia. To identify new therapeutic drug targets and vaccine candidates and investigate the genetic basis ofFrancisellavirulence in the Fischer 344 rat, we have constructed anF. tularensisSchu S4 transposon library. This library consists of more than 300,000 unique transposon mutants and represents a transposon insertion for every 6 bp of the genome. A transposon-directed insertion site sequencing (TraDIS) approach was used to identify 453 genes essential for growthin vitro. Many of these essential genes were mapped to key metabolic pathways, including glycolysis/gluconeogenesis, peptidoglycan synthesis, fatty acid biosynthesis, and the tricarboxylic acid (TCA) cycle. Additionally, 163 genes were identified as required for fitness during colonization of the Fischer 344 rat spleen. Thisin vivoselection screen was validated through the generation of marked deletion mutants that were individually assessed within a competitive index study against the wild-typeF. tularensisSchu S4 strain.IMPORTANCEThe intracellular bacterial pathogenFrancisella tularensiscauses a disease in humans characterized by the rapid onset of nonspecific symptoms such as swollen lymph glands, fever, and headaches.F. tularensisis one of the most infectious bacteria known and following pulmonary exposure can have a mortality rate exceeding 50% if left untreated. The low infectious dose of this organism and concerns surrounding its potential as a biological weapon have heightened the need for effective and safe therapies. To expand the repertoire of targets for therapeutic development, we initiated a genome-wide analysis. This study has identified genes that are important forF. tularensisunderin vitroandin vivoconditions, providing candidates that can be evaluated for vaccine or antibacterial development.

Sign in / Sign up

Export Citation Format

Share Document