scholarly journals Cytokine Secretion by CD4+ T Cells at the Immunological Synapse Requires Cdc42-Dependent Local Actin Remodeling but Not Microtubule Organizing Center Polarity

2012 ◽  
Vol 189 (5) ◽  
pp. 2159-2168 ◽  
Author(s):  
Karine Chemin ◽  
Armelle Bohineust ◽  
Stéphanie Dogniaux ◽  
Marie Tourret ◽  
Sarah Guégan ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Immunological Synapse ◽  
Cytokine Secretion ◽  
Microtubule Organizing Center ◽  
Actin Remodeling ◽  
Organizing Center

scholarly journals Cdc42-interacting protein–4 functionally links actin and microtubule networks at the cytolytic NK cell immunological synapse

2007 ◽  
Vol 204 (10) ◽  
pp. 2305-2320 ◽  
Author(s):  
Pinaki P. Banerjee ◽  
Rahul Pandey ◽  
Rena Zheng ◽  
Megan M. Suhoski ◽  
Linda Monaco-Shawver ◽  
...  
Keyword(s):  
Actin Filament ◽  
Cell Activation ◽  
Immunological Synapse ◽  
Nk Cell ◽  
Filamentous Actin ◽  
Microtubule Organizing Center ◽  
Interacting Protein ◽  
Lytic Granules ◽  
Organizing Center ◽  
Microtubule Networks

An essential function of the immunological synapse (IS) is directed secretion. NK cells are especially adept at this activity, as they direct lytic granules to the synapse for secretion, which enables cytotoxicity and facilitates host defense. This initially requires rearrangement of the actin cytoskeleton and, subsequently, microtubule-dependent trafficking of the lytic granules. As these two steps are sequential, specific linkages between them are likely to serve as critical regulators of cytotoxicity. We studied Cdc42-interacting protein–4 (CIP4), which constitutively interacts with tubulin and microtubules but focuses to the microtubule organizing center (MTOC) after NK cell activation, when it is able to associate with Wiskott-Aldrich syndrome protein (WASp) and the actin filament–rich IS. WASp deficiency, overexpression of CIP4, or parts of CIP4 interfere with this union and block normal CIP4 localization, MTOC polarization to the IS, and cytotoxicity. Reduction of endogenous CIP4 expression using small interfering RNA similarly inhibits MTOC polarization and cytotoxic activity but does not impair actin filament accumulation at the IS, or Cdc42 activation. Thus, CIP4 is an important cytoskeletal adaptor that functions after filamentous actin accumulation and Cdc42 activation to enable MTOC polarization and NK cell cytotoxicity.

scholarly journals Stathmin Regulates Microtubule Dynamics and Microtubule Organizing Center Polarization in Activated T Cells

2012 ◽  
Vol 188 (11) ◽  
pp. 5421-5427 ◽  
Author(s):  
Erin L. Filbert ◽  
Marie Le Borgne ◽  
Joseph Lin ◽  
John E. Heuser ◽  
Andrey S. Shaw
Keyword(s):  
T Cells ◽  
Microtubule Dynamics ◽  
Microtubule Organizing Center ◽  
Activated T Cells ◽  
Organizing Center

Imaging of plasmacytoid dendritic cell interactions with T cells

Blood ◽  
2009 ◽  
Vol 113 (1) ◽  
pp. 75-84 ◽  
Author(s):  
María Mittelbrunn ◽  
Gloria Martínez del Hoyo ◽  
María López-Bravo ◽  
Noa B. Martín-Cofreces ◽  
Alix Scholer ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Plasmacytoid Dendritic Cell ◽  
Time Lapse ◽  
Cell Interactions ◽  
Type I ◽  
Microtubule Organizing Center ◽  
Immune Synapse ◽  
Organizing Center

Abstract Plasmacytoid dendritic cells (pDCs) efficiently produce type I interferon and participate in adaptive immune responses, although the molecular interactions between pDCs and antigen-specific T cells remain unknown. This study examines immune synapse (IS) formation between murine pDCs and CD4+ T cells. Mature pDCs formed canonical ISs, involving relocation to the contact site of the microtubule-organizing center, F-actin, protein kinase C-θ, and pVav, and activation of early signaling molecules in T cells. However, immature pDCs were less efficient at forming conjugates with T cells and inducing IS formation, microtubule-organizing center translocation, and T-cell signaling and activation. Time-lapse videomicroscopy and 2-photon in vivo imaging of pDC–T-cell interactions revealed that immature pDCs preferentially mediated transient interactions, whereas mature pDCs promoted more stable contacts. Our data indicate that, under steady-state conditions, pDCs preferentially establish transient contacts with naive T cells and show a very modest immunogenic capability, whereas on maturation, pDCs are able to form long-lived contacts with T cells and significantly enhance their capacity to activate these lymphocytes.

T-Rapa Cell Clinical Products Contain a Balance of Minimally Differentiated Th2/Th1 Effector Cells Depleted of Treg Cells

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 352-352 ◽  
Author(s):  
Miriam E. Mossoba ◽  
Jacopo Mariotti ◽  
Xiao-Yi Yan ◽  
Anu Gangopadhyay ◽  
Mathew Winterton ◽  
...  
Keyword(s):  
T Cells ◽  
Transcription Factor ◽  
Cd4 T Cells ◽  
Treg Cells ◽  
Cytokine Secretion ◽  
Th2 Cells ◽  
Th1 Cells ◽  
Cell Secretion ◽  
Th2 Cytokine ◽  
Low Levels

Abstract Abstract 352 Ex-vivo expansion of murine donor CD4+ T cells using co-stimulation, IL-4, and rapamycin generated a T cell population (T-rapa cells) that beneficially modulated GVHD, graft rejection, and GVT effects. We thus conducted a clinical trial to evaluate T-rapa cell infusion after HLA-matched sibling allogeneic HCT. In one trial arm, T-rapa cell infusion (2.5 × 107 cells/kg; d 14 post-HCT) safely accelerated alloengraftment after low-intensity host conditioning, as evidenced by: conversion of mixed chimerism to predominant donor chimerism in the majority of patients by d 100 post-HCT and a low rate of grade II to IV acute GVHD (10%; 4/40 cases). This abstract characterizes the T-rapa clinical products (n=48), particularly with respect to the balance of Th1, Th2, and Treg cells and the magnitude of effector function (cytokine secretion); this latter aspect is relevant because in animal models, T cells of limited differentiation mediate increased in vivo effects upon adoptive transfer. Transplant donors underwent steady-state leukapheresis. CD4+ T cells were then purified (Miltenyi.. CliniMACS) and expanded in Lifecell.. bags for 12 days using co-stimulation (anti-CD3, anti-CD28 coated magnetic beads) and media containing rhIL-2, rhIL-4, and rapamycin. T-rapa products contained minimal cells of naive phenotype (CD45RA+ cells: 2 ± 0.4%) and were comprised of both central memory cells (CCR7+: 28 ± 2%) and effector memory cells (CCR7−: 67 ± 2%). Phenotyping assays were performed on T-rapa clinical products at d 12 of culture (time of cell product infusion); in addition, to assess phenotype stability, assays were performed after an additional 6 days of culture after co-stimulation without IL-4 and rapamycin (“day 18”). For comparison, four separate CD4+ T cell culture conditions were established from each of n=8 normal donors. For these control cultures, CD4+ T cells were co-stimulated and propagated for 12 days in tissue culture flasks using: (1) IL-2, IL-4 (“Th2”); (2) IL-2, IL-4 plus rapamycin (“T-rapa”); (3) IL-2, IFN-a (“Th1”); and (4) IL-2, IFN-a plus rapamycin (“Th1-rapa”). Phenotyping results are shown in Fig. 1. In the four flask cultures, there was modest skewing of the Th2/Th1 balance, as indicated by relatively comparable expression of the Th2 transcription factor GATA-3 and the Th1 transcription factor T-bet by intra-cellular flow cytometry (Fig. 1A). In marked contrast, day 12 T-rapa clinical products expressed a highly polarized Th2/Th1 balance (GATA-3/T-bet ratio of 28 ± 9 [mean ± SEM]); this Th2/Th1 balance was relatively stable after additional culture without IL-4 and rapamycin (“Day 18”). The median frequency of transcription factor expression was 11.5% for GATA-3 (range: 3–37%), 5.1% for T-bet (range: 0–18%), and < 1% expression of the Treg transcription factor FoxP3 (range: 0–0.7%). T-rapa clinical products were evaluated for cytokine secretion in response to co-stimulation at day 12 and day 18 of culture; supernatants were tested for Th2 cytokines (Fig. 1B) and Th1/Th17 cytokines (Fig. 1C). Day 12 T-rapa clinical products secreted each Th2 cytokine measured. The magnitude (pg/ml) of T-rapa cell Th2 cytokine secretion was approximately 2-log reduced relative to control Th2 cells; day 18 T-rapa cell secretion of Th2 cytokines was increased relative to day 12 values, but still reduced relative to control Th2 cells. Day 12 T-rapa clinical products did not secrete IL-17 and secreted low levels of IFN-g, IL-2, and TNF-a (1-3 log reduced relative to Th1 control cells). Day 18 T-rapa cell secretion of IFN-g and TNF-a was increased relative to day 12 values, but still reduced relative to control Th1 cells. Remarkably, day 18 T-rapa cell secretion of IL-2 was greatly diminished relative to day 12 values, and IL-17 secretion remained at minimal levels. In conclusion, T-rapa cell clinical products are comprised of a balance of Th2 and Th1 effector CD4+ T cells, with minimal contamination from Treg or Th17 cells. The T-rapa cell clinical products possessed limited differentiation plasticity and secreted low levels of Th2 and Th1 cytokines. Adoptive transfer of a balance of minimally differentiated and fixed polarity donor Th2/Th1 cells represents a novel approach to safely accelerate alloengraftment after low-intensity conditioning. Disclosures: No relevant conflicts of interest to declare.

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