scholarly journals T cells expressing specific V beta elements regulate immunoglobulin E production and airways responsiveness in vivo.

1993 ◽  
Vol 177 (4) ◽  
pp. 1175-1180 ◽  
Author(s):  
H Renz ◽  
K Bradley ◽  
J Saloga ◽  
J Loader ◽  
G L Larsen ◽  
...  
Keyword(s):  
T Cells ◽  
Immunoglobulin E ◽  
Critical Role ◽  
Specific Ige ◽  
Specific Immunoglobulin ◽  
Cutaneous Hypersensitivity ◽  
First Time ◽  
Draining Lymph Nodes

The role of T cells expressing specific V beta elements was examined in the regulation of allergen-specific immunoglobulin (Ig)E production and airways responsiveness (AR). In BALB/c mice, inhalation of the allergen ovalbumin (OVA) induced an IgE anti-OVA response, immediate cutaneous reactivity, and increased AR. These results were associated with an expansion of V beta 8.1/8.2 T cells in local draining lymph nodes of the airways and the lung. Transfer of V beta 8.1/8.2 T cells from sensitized mice stimulated an IgE anti-OVA response, immediate cutaneous hypersensitivity, and increased AR in naive syngeneic recipients. In contrast, OVA-reactive V beta 2 T cells inhibited these effects. These data demonstrate for the first time that T cells with different V beta specificities play a critical role in the in vivo regulation of allergen-specific IgE production and AR.

Allogeneic Environment and Tissue Damage Provide Critical Stimuli for Regulatory T Cell Expansion and Survival In Vivo after Hematopoietic Cell Transplantation.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1731-1731
Author(s):  
Vu H. Nguyen ◽  
Daisy Chang ◽  
Robert S. Negrin
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Tissue Damage ◽  
Hematopoietic Cell Transplantation ◽  
Critical Role ◽  
Lymphoid Organs ◽  
Gamma Chain ◽  
Secondary Lymphoid Organs

Abstract CD4+CD25+ regulatory T cells (Treg) mediate alloresponses in murine models of bone marrow transplantation (BMT), leading to protection from graft-versus-host disease (GvHD). However, in vivo migration and tissue localization of Treg during this inflammatory response remain unclear. We previously demonstrated co-localization of Treg with effector T cells (Tcon) with initial expansion in secondary lymphoid organs prior to migration into inflamed tissues in a major MHC-mismatched BMT model. To explore the stimuli for Treg proliferation, we evaluated the role of the allogeneic environment by transferring FVB donor luciferase-expressing (luc+) Treg into lethally-irradiated syngeneic recipients. Unlike the allogeneic irradiated setting where Treg expand in the presence or absence of Tcon, adoptively transferred luc+ Treg were not detected in secondary lymphoid organs of syngeneic lethally-irradiated BMT recipients by in vivo bioluminescence imaging (BLI). Syngeneic luc+ Tcon also had significantly different in vivo dynamics, with a 4 day delay and only moderate expansion in lymph nodes. Proliferation was not detected in the spleen, unlike their allogeneic Tcon counterparts, nor in the bone marrow compartments, as seen in lymphopenic models. To assess whether irradiation induced the observed in vivo dynamics of Treg in the allogeneic setting, we transferred FVB luc+ Treg or luc+ Tcon into unirradiated Balb/c Rag2−/−gamma chain (γC) −/− recipients, which lack T, B, and NK cells. After adoptive transfer into Rag2−/−γC−/− recipients, robust Tcon proliferation was observed in secondary lymphoid organs and the bone marrow compartments; however, Treg expansion was weak, and specific localization to lymphoid or nonlymphoid tissues was not observed. Treg were stimulated to localize to and expand in secondary lymphoid organs by the co-transfer of Tcon in unirradiated Rag2−/− (γC) −/− or by conditioning Rag2−/− (γC) −/− recipients with irradiation. Exogenous IL2 administration two weeks following luc+ Treg transfer into unirradiated Rag2−/− (γC) −/− recipients similarly led to localization and expansion of Treg in secondary lymphoid organs. These studies indicate the critical role of proinflammatory cytokines, such as IL2, generated either by irradiation-induced tissue damage or donor Tcon, in the expansion and localization of Treg. Differences between Tcon and Treg expansion in syngeneic or unconditioned allogeneic Rag2−/− γC−/− hosts suggest an important role of conditioning with irradiation alone or in concert with the allogeneic environment, in providing distinct signals for Tcon versus Treg activation, proliferation, and localization.

ADF/n-cofilin–dependent actin turnover determines platelet formation and sizing

Blood ◽  
2010 ◽  
Vol 116 (10) ◽  
pp. 1767-1775 ◽  
Author(s):  
Markus Bender ◽  
Anita Eckly ◽  
John H. Hartwig ◽  
Margitta Elvers ◽  
Irina Pleines ◽  
...  
Keyword(s):  
Actin Filament ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Actin Dynamics ◽  
Complex Process ◽  
First Time ◽  
Late Stages ◽  
Platelet Formation

Abstract The cellular and molecular mechanisms orchestrating the complex process by which bone marrow megakaryocytes form and release platelets remain poorly understood. Mature megakaryocytes generate long cytoplasmic extensions, proplatelets, which have the capacity to generate platelets. Although microtubules are the main structural component of proplatelets and microtubule sliding is known to drive proplatelet elongation, the role of actin dynamics in the process of platelet formation has remained elusive. Here, we tailored a mouse model lacking all ADF/n-cofilin–mediated actin dynamics in megakaryocytes to specifically elucidate the role of actin filament turnover in platelet formation. We demonstrate, for the first time, that in vivo actin filament turnover plays a critical role in the late stages of platelet formation from megakaryocytes and the proper sizing of platelets in the periphery. Our results provide the genetic proof that platelet production from megakaryocytes strictly requires dynamic changes in the actin cytoskeleton.

scholarly journals Critical role of EBNA1-specific CD4+ T cells in the control of mouse Burkitt lymphoma in vivo

2004 ◽  
Vol 114 (4) ◽  
pp. 542-550 ◽  
Author(s):  
Tihui Fu ◽  
Kui Shin Voo ◽  
Rong-Fu Wang
Keyword(s):  
T Cells ◽  
Burkitt Lymphoma ◽  
Cd4 T Cells ◽  
Critical Role

scholarly journals Siderophore-Mediated Iron Acquisition Plays a Critical Role in Biofilm Formation and Survival of Staphylococcus epidermidis Within the Host

2021 ◽  
Vol 8 ◽  
Author(s):  
Fernando Oliveira ◽  
Tânia Lima ◽  
Alexandra Correia ◽  
Ana Margarida Silva ◽  
Cristina Soares ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Iron Acquisition ◽  
Critical Role ◽  
Siderophore Production ◽  
Restricted Environment ◽  
Underlying Mechanisms ◽  
First Time ◽  
Comprehensive Study

Iron acquisition through siderophores, a class of small, potent iron-chelating organic molecules, is a widely spread strategy among pathogens to survive in the iron-restricted environment found in the host. Although these molecules have been implicated in the pathogenesis of several species, there is currently no comprehensive study addressing siderophore production in Staphylococcus epidermidis. Staphylococcus epidermidis is an innocuous skin commensal bacterium. The species, though, has emerged as a leading cause of implant-associated infections, significantly supported by an inherent ability to form biofilms. The process of adaptation from skin niche environments to the hostile conditions during invasion is yet not fully understood. Herein, we addressed the possible role of siderophore production in S. epidermidis virulence. We first identified and deleted a siderophore homolog locus, sfaABCD, and provided evidence for its involvement in iron acquisition. Our findings further suggested the involvement of siderophores in the protection against oxidative stress-induced damage and demonstrated the in vivo relevance of a siderophore-mediated iron acquisition during S. epidermidis infections. Conclusively, this study addressed, for the first time in this species, the underlying mechanisms of siderophore production, highlighting the importance of a siderophore-mediated iron acquisition under host relevant conditions and, most importantly, its contribution to survival within the host.

scholarly journals Critical Contribution of Ox40 Ligand to T Helper Cell Type 2 Differentiation in Experimental Leishmaniasis

2000 ◽  
Vol 191 (2) ◽  
pp. 375-380 ◽  
Author(s):  
Hisaya Akiba ◽  
Yasushi Miyahira ◽  
Machiko Atsuta ◽  
Kazuyoshi Takeda ◽  
Chiyoko Nohara ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Leishmania Major ◽  
Critical Role ◽  
Flow Cytometric Analysis ◽  
Th2 Cells ◽  
Mouse Strains ◽  
T Helper

Infection of inbred mouse strains with Leishmania major is a well characterized model for analysis of T helper (Th)1 and Th2 cell development in vivo. In this study, to address the role of costimulatory molecules CD27, CD30, 4-1BB, and OX40, which belong to the tumor necrosis factor receptor superfamily, in the development of Th1 and Th2 cells in vivo, we administered monoclonal antibody (mAb) against their ligands, CD70, CD30 ligand (L), 4-1BBL, and OX40L, to mice infected with L. major. Whereas anti-CD70, anti-CD30L, and anti–4-1BBL mAb exhibited no effect in either susceptible BALB/c or resistant C57BL/6 mice, the administration of anti-OX40L mAb abrogated progressive disease in BALB/c mice. Flow cytometric analysis indicated that OX40 was expressed on CD4+ T cells and OX40L was expressed on CD11c+ dendritic cells in the popliteal lymph nodes of L. major–infected BALB/c mice. In vitro stimulation of these CD4+ T cells showed that anti-OX40L mAb treatment resulted in substantially reduced production of Th2 cytokines. Moreover, this change in cytokine levels was associated with reduced levels of anti–L. major immunoglobulin (Ig)G1 and serum IgE. These results indicate that anti-OX40L mAb abrogated progressive leishmaniasis in BALB/c mice by suppressing the development of Th2 responses, substantiating a critical role of OX40–OX40L interaction in Th2 development in vivo.

scholarly journals Immune Cells in Cancer Therapy and Drug Delivery

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Ceren Eyileten ◽  
Kinga Majchrzak ◽  
Zofia Pilch ◽  
Katarzyna Tonecka ◽  
Joanna Mucha ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Cell Proliferation ◽  
T Cells ◽  
Dendritic Cells ◽  
Immune Cells ◽  
Critical Role ◽  
Tumour Microenvironment ◽  
Cytokines And Chemokines

Recent studies indicate the critical role of tumour associated macrophages, tumour associated neutrophils, dendritic cells, T lymphocytes, and natural killer cells in tumourigenesis. These cells can have a significant impact on the tumour microenvironment via their production of cytokines and chemokines. Additionally, products secreted from all these cells have defined specific roles in regulating tumour cell proliferation, angiogenesis, and metastasis. They act in a protumour capacityin vivoas evidenced by the recent studies indicating that macrophages, T cells, and neutrophils may be manipulated to exhibit cytotoxic activity against tumours. Therefore therapy targeting these cells may be promising, or they may constitute drug or anticancer particles delivery systems to the tumours. Herein, we discussed all these possibilities that may be used in cancer treatment.

scholarly journals Critical Role of the Interleukin-17/Interleukin-17 Receptor Axis in Regulating Host Susceptibility to Respiratory Infection with Chlamydia Species

2009 ◽  
Vol 77 (11) ◽  
pp. 5059-5070 ◽  
Author(s):  
Xiaohui Zhou ◽  
Qiangwei Chen ◽  
Jessica Moore ◽  
Jay K. Kolls ◽  
Scott Halperin ◽  
...  
Keyword(s):  
Respiratory Infection ◽  
Critical Role ◽  
Lung Parenchyma ◽  
Host Susceptibility ◽  
Interleukin 17 ◽  
Chlamydia Muridarum ◽  
Inflammatory Protein ◽  
First Time

ABSTRACT The specific contribution of interleukin-17/interleukin-17 receptor (IL-17/IL-17R)-mediated responses in regulating host susceptibility against obligatory intracellular Chlamydia infection was investigated in C57BL/6 and C3H/HeN mice during Chlamydia muridarum respiratory infection. We demonstrated that Chlamydia stimulated IL-17/IL-17R-associated responses in both Chlamydia-resistant C57BL/6 and Chlamydia-susceptible C3H/HeN mice. However, C3H/HeN mice developed a significantly greater IL-17/IL-17R-associated response than C57BL/6 mice did. This was reflected by an increase in IL-17 mRNA expression, a higher recall IL-17 production from splenocytes upon antigen restimulation, and higher production of Th17-related cytokines (IL-23 and IL-6) and chemokines (chemokine [C-X-C motif] ligand 2 [CXCL1]/keratinocyte-derived chemokine [KC] and CXCL2/macrophage inflammatory protein 1 [MIP2]) in C3H/HeN mice than in C57BL/6 mice. Furthermore, C3H/HeN mice displayed a massive accumulation of activated and preactivated neutrophils in the airway and lung parenchyma compared to their C57BL/6 counterparts. We further demonstrated that the skewed IL-17/Th17 profile in C3H/HeN mice was predisposed by a higher basal level of IL-17 receptor C (IL-17RC) expression and then further amplified by a higher inducible IL-17RA expression in lungs. Most importantly, in vivo delivery of IL-17RA antagonist that resulted in a 50% reduction in the neutrophilic infiltration in lungs was able to reverse the susceptible phenotype of C3H/HeN mice to respiratory Chlamydia infection. Thus, our data for the first time have demonstrated a critical role for the IL-17/IL-17R axis in regulating host susceptibility to Chlamydia infection in mice.

Eradication of lymphoma by CD8 T cells following anti-CD40 monoclonal antibody therapy is critically dependent on CD27 costimulation

Blood ◽  
2007 ◽  
Vol 109 (11) ◽  
pp. 4810-4815 ◽  
Author(s):  
Ruth R. French ◽  
Vadim Y. Taraban ◽  
Graham R. Crowther ◽  
Tania F. Rowley ◽  
Juliet C. Gray ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Critical Role ◽  
Antibody Therapy ◽  
Cell Immunity ◽  
Tumor Protection ◽  
Tnfr Superfamily ◽  
First Time ◽  
Dc Maturation

AbstractGrowing evidence points to the potential of agonistic anti-CD40 mAbs as adjuvants for vaccination against cancer. These appear to act by maturing dendritic cells (DCs) and allowing them to prime CD8 cytotoxic T lymphocytes (CTLs). Although it is well established that optimal T-cell priming requires costimulation via B7:CD28, recent studies emphasize the contribution of TNF receptors to this process. To understand how anti-CD40 mAbs trigger effective antitumor immunity, we investigated the role of TNFR superfamily members CD27 and 4-1BB in the generation of this immunity and showed that, although partially dependent on 4-1BB:4-1BBL engagement, it is completely reliant on CD27:CD70 interactions. Importantly, blocking CD70, and to some extent 4-1BBL, during anti-CD40 treatment prevented accumulation of tumor-reactive T cells and subsequent tumor protection. However, it did not influence changes in DC number, phenotype, nor the activity of CTLs once immunity was established. We conclude that CD27:CD70 and 4-1BB:4-1BBL interactions are needed for DC-driven accumulation of antitumor CTLs following anti-CD40 mAb treatment. Finally, in support of the critical role for CD70:CD27, we show for the first time that agonistic anti-CD27 mAbs given without a DC maturation signal completely protect tumor-bearing mice and provide a highly potent reagent for boosting antitumor T-cell immunity.

scholarly journals 157 A critical role of CD40 and CD70 signaling in cDC1s in expansion and antitumor efficacy of adoptively transferred tumor-specific T cells

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A171-A171
Author(s):  
Takaaki Oba ◽  
Toshifumi Hoki ◽  
Takayoshi Yamauchi ◽  
Tibor Keler ◽  
Henry Marsh ◽  
...  
Keyword(s):  
T Cells ◽  
Adoptive Cell Therapy ◽  
Critical Role ◽  
Flow Cytometric Analysis ◽  
Antitumor Efficacy ◽  
Tumor Control ◽  
Type I ◽  
Loss Of Function

BackgroundAdoptive cell therapy (ACT) with antigen-specific CD8+ T cells is a promising approach for treating patients with various solid malignancies including melanoma. In vivo expansion of adoptively transferred T cells is one of the major determinants of successful ACT. On the other hand, a frequently overlooked consideration is that the host antigen-presenting cells affect the antitumor efficacy of ACT. Accumulating evidence suggests that tumor-residing Batf3-dependent conventional type I dendritic cells (cDC1s) play an important role in trafficking of adoptively transferred T cells into the tumor by producing chemokines such as CXCL10, and improve antitumor efficacy of ACT. However, a role of cDC1s in expansion of adoptively transferred T cells remains unclear.MethodsWe utilized Pmel-1 T cell receptor transgenic T cells in the B16 melanoma model to investigate the role of cDC1s in expansion of adoptively transferred tumor-specific T cells.ResultsWhile adoptive transfer of in vitro-activated Pmel-1 T cells with vaccination of cognate antigen, hgp100, agonistic anti-CD40 monoclonal antibody (mAb), and Toll-like receptor 7 (TLR7) agonist delayed the tumor growth and survival in wild type C57BL/6 mice (WT), antitumor efficacy of ACT was completely abrogated in Batf3-/- mice. Flow cytometric analysis of peripheral blood showed expansion of adoptively transferred Pmel-1 T cells was significantly compromised in WT mice but not in in Batf3-/- mice. Mechanistically, loss-of-function studies using mixed bone marrow chimera reconstituted with Batf3-/- and CD40-/- (Batf3-/-/CD40-/-), Batf3-/- and CD70-/- (Batf3-/-/CD70-/-), or Batf3-/- and CD80/86-/- (Batf3-/-/CD80/86-/-) revealed CD40-CD70 axis but not CD80/86 signaling in host cDC1s plays an important role in expansion of adoptively transferred T cells. Accordingly, overall survival of Batf3-/-/CD70-/- mixed chimeric was significantly shorter than that of Batf3-/-/WT mice, while survival of Batf3-/-/CD80/86-/- mice was similar to that of Batf3-/-/WT mice. Furthermore, induction of cDC1s by administration of Fms-like tyrosine kinase 3 receptor ligand (gain-of-function) demonstrated significantly enhanced in vivo expansion of adoptively transferred Pmel-1 T cells associated with improved tumor control and survival.ConclusionsThese findings elucidate a role of host cDC1s in expansion of adoptively transferred in vivo restimulated tumor-specific T cells, and identify CD40 and CD70 as key molecules.

scholarly journals TNFα priming through its interaction with TNFR2 enhances Endothelial Progenitor Cell immunosuppressive effect: new hope for their widespread clinical application

2020 ◽  
Author(s):  
Mahsa NOURI BARKESTANI ◽  
Sara SHAMDANI ◽  
Mazdak AFSHAR BAKSHLOO ◽  
Nassim AROUCHE ◽  
Bijan BAMBAI ◽  
...  
Keyword(s):  
T Cells ◽  
Endothelial Progenitor ◽  
Vascular Regeneration ◽  
Endothelial Repair ◽  
Human T Cells ◽  
Anti Inflammatory ◽  
Endothelial Homeostasis ◽  
First Time

Abstract Background: Bone marrow (BM) derived endothelial progenitor cells (EPCs) are immature endothelial cells (ECs) involved in neo-angiogenesis and endothelial homeostasis and are considered as a circulating reservoir for endothelial repair. Many studies showed that EPCs from patients with cardiovascular pathologies are impaired and insufficient; hence, allogenic sources of EPCs from adult or cord blood are considered as good choices for cell therapy applications. However, allogenic condition increases the chance of immune rejection, especially by T cells, before exerting the desired regenerative functions. TNFα is one of the main mediators of EPC activation that recognizes two distinct receptors, TNFR1 and TNFR2. We have recently reported that human EPCs are immunosuppressive and this effect was TNFα-TNFR2 dependent. Here, we aimed to investigate if an adequate TNFα pre-conditioning could increase TNFR2 expression and prime EPCs towards more immunoregulatory functions.Methods: EPCs were pre-treated with several doses of TNFα to find the proper dose to up-regulate TNFR2 while keeping the TNFR1 expression stable. Then, co-cultures of human EPCs and human T cells were performed to assess whether TNFα priming would increase EPC immunosuppressive and immunomodulatory effect.Results: Treating EPCs with 1 ng/ml TNFα significantly up-regulated TNFR2 expression without unrestrained increase of TNFR1 and other endothelial injury markers. Moreover, TNFα priming through its interaction with TNFR2 remarkably enhanced EPC immunosuppressive and anti-inflammatory effects. Conversely, blocking TNFR2 using anti-TNFR2 mAb followed by 1 ng/ml of TNFα treatment led to the TNFα-TNFR1 interaction and polarized EPCs towards pro-inflammatory and immunogenic functions.Conclusions: We report for the first time the crucial impact of inflammation notably the TNFα-TNFR signaling pathway on EPC immunological function. Our work unveils the pro-inflammatory role of the TNFα-TNFR1 axis and, inversely the anti-inflammatory implication of the TNFα-TNFR2 axis in EPC immunoregulatory functions. Priming EPCs with 1 ng/ml of TNFα prior to their administration could boost them toward a more immunosuppressive phenotype. This could potentially lead to EPCs’ longer presence in vivo after their allogenic administration resulting in their better contribution to angiogenesis and vascular regeneration.

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