scholarly journals Critical role of CD4 T cells in maintaining lymphoid tissue structure for immune cell homeostasis and reconstitution

Blood ◽  
2012 ◽  
Vol 120 (9) ◽  
pp. 1856-1867 ◽  
Author(s):  
Ming Zeng ◽  
Mirko Paiardini ◽  
Jessica C. Engram ◽  
Greg J. Beilman ◽  
Jeffrey G. Chipman ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Cd4 T Cells ◽  
Lymphoid Tissue ◽  
T Cell Subsets ◽  
Tissue Structure ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Hiv 1

Abstract Loss of the fibroblastic reticular cell (FRC) network in lymphoid tissues during HIV-1 infection has been shown to impair the survival of naive T cells and limit immune reconstitution after antiretroviral therapy. What causes this FRC loss is unknown. Because FRC loss correlates with loss of both naive CD4 and CD8 T-cell subsets and decreased lymphotoxin-β, a key factor for maintenance of FRC network, we hypothesized that loss of naive T cells is responsible for loss of the FRC network. To test this hypothesis, we assessed the consequences of antibody-mediated depletion of CD4 and CD8 T cells in rhesus macaques and sooty mangabeys. We found that only CD4 T-cell depletion resulted in FRC loss in both species and that this loss was caused by decreased lymphotoxin-β mainly produced by the CD4 T cells. We further found the same dependence of the FRC network on CD4 T cells in HIV-1–infected patients before and after antiretroviral therapy and in other immunodeficiency conditions, such as CD4 depletion in cancer patients induced by chemotherapy and irradiation. CD4 T cells thus play a central role in the maintenance of lymphoid tissue structure necessary for their own homeostasis and reconstitution.

scholarly journals Lymphoid Tissue Damage in HIV-1 Infection Depletes Naïve T Cells and Limits T Cell Reconstitution after Antiretroviral Therapy

2012 ◽  
Vol 8 (1) ◽  
pp. e1002437 ◽  
Author(s):  
Ming Zeng ◽  
Peter J. Southern ◽  
Cavan S. Reilly ◽  
Greg J. Beilman ◽  
Jeffrey G. Chipman ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Tissue Damage ◽  
Lymphoid Tissue ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
T Cell Reconstitution ◽  
Hiv 1

scholarly journals CRTAM determines the CD4+ cytotoxic T lymphocyte lineage

2015 ◽  
Vol 213 (1) ◽  
pp. 123-138 ◽  
Author(s):  
Arata Takeuchi ◽  
Mohamed El Sherif Gadelhaq Badr ◽  
Kosuke Miyauchi ◽  
Chitose Ishihara ◽  
Reiko Onishi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cytotoxic Activity ◽  
Cd4 T Cells ◽  
Intracellular Signaling ◽  
Ectopic Expression ◽  
T Cell Subsets ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Ifn Γ

Naive T cells differentiate into various effector T cells, including CD4+ helper T cell subsets and CD8+ cytotoxic T cells (CTL). Although cytotoxic CD4+ T cells (CD4+CTL) also develop from naive T cells, the mechanism of development is elusive. We found that a small fraction of CD4+ T cells that express class I–restricted T cell–associated molecule (CRTAM) upon activation possesses the characteristics of both CD4+ and CD8+ T cells. CRTAM+ CD4+ T cells secrete IFN-γ, express CTL-related genes, such as eomesodermin (Eomes), Granzyme B, and perforin, after cultivation, and exhibit cytotoxic function, suggesting that CRTAM+ T cells are the precursor of CD4+CTL. Indeed, ectopic expression of CRTAM in T cells induced the production of IFN-γ, expression of CTL-related genes, and cytotoxic activity. The induction of CD4+CTL and IFN-γ production requires CRTAM-mediated intracellular signaling. CRTAM+ T cells traffic to mucosal tissues and inflammatory sites and developed into CD4+CTL, which are involved in mediating protection against infection as well as inducing inflammatory response, depending on the circumstances, through IFN-γ secretion and cytotoxic activity. These results reveal that CRTAM is critical to instruct the differentiation of CD4+CTL through the induction of Eomes and CTL-related gene.

scholarly journals Effective Cytotoxic T Lymphocyte Targeting of Persistent HIV-1 during Antiretroviral Therapy Requires Priming of Naive CD8+T Cells

mBio ◽  
2016 ◽  
Vol 7 (3) ◽  
Author(s):  
Kellie N. Smith ◽  
Robbie B. Mailliard ◽  
Paolo A. Piazza ◽  
Will Fischer ◽  
Bette T. Korber ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Memory T Cells ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Infected Cells ◽  
Ifn Γ ◽  
Hiv 1

ABSTRACTCuring HIV-1 infection will require elimination of persistent cellular reservoirs that harbor latent virus in the face of combination antiretroviral therapy (cART). Proposed immunotherapeutic strategies to cure HIV-1 infection include enhancing lysis of these infected cells by cytotoxic T lymphocytes (CTL). A major challenge in this strategy is overcoming viral immune escape variants that have evaded host immune control. Here we report that naive CD8+T cells from chronic HIV-1-infected participants on long-term cART can be primed by dendritic cells (DC). These DC must be mature, produce high levels of interleukin 12p70 (IL-12p70), be responsive to CD40 ligand (CD40L), and be loaded with inactivated, autologous HIV-1. These DC-primed CD8+T cell responders produced high levels of gamma interferon (IFN-γ) in response to a broad range of both conserved and variable regions of Gag and effectively killed CD4+T cell targets that were either infected with the autologous latent reservoir-associated virus or loaded with autologous Gag peptides. In contrast, HIV-1-specific memory CD8+T cells stimulated with autologous HIV-1-loaded DC produced IFN-γ in response to a narrow range of conserved and variable Gag peptides compared to the primed T cells and most notably, displayed significantly lower cytolytic function. Our findings highlight the need to selectively induce new HIV-1-specific CTL from naive precursors while avoiding activation of existing, dysfunctional memory T cells in potential curative immunotherapeutic strategies for HIV-1 infection.IMPORTANCECurrent immunotherapeutic approaches aim to enhance antiviral immunity against the HIV-1 reservoir; however, it has yet to be shown whether T cells from persons on cART can recognize and eliminate virus-infected cells. We show that in persons on cART a personalized medicine approach using their dendritic cells to stimulate their naive T cells induces potent effector CTLin vitrothat recognize and eradicate HIV-1-infected CD4+T cells. Additionally, we show that the same stimulation of existing memory T cells results in cytokine secretion but limited effector function. Our study demonstrates that the naive T cell repertoire can recognize persistent HIV-1 during cART and supports immunotherapy strategies for an HIV-1 cure that targets naive T cells, rather than existing, dysfunctional, memory T cells.

Life after the thymus: CD31+ and CD31− human naive CD4+ T-cell subsets

Blood ◽  
2009 ◽  
Vol 113 (4) ◽  
pp. 769-774 ◽  
Author(s):  
Siegfried Kohler ◽  
Andreas Thiel
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
T Cell Subsets ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Cell Pool ◽  
The Impact ◽  
Naïve T Cell ◽  
Naive T Cell

Abstract Early in life, thymic export establishes the size and the diversity of the human naive T-cell pool. Yet, on puberty thymic activity drastically decreases. Because the overall size of the naive T-cell pool decreases only marginally during ageing, peripheral postthymic expansion of naive T cells has been postulated to account partly for the maintenance of T-cell immunity in adults. So far, the analysis of these processes had been hampered by the inability to distinguish recent thymic emigrants from proliferated, peripheral, naive T cells. However, recently, CD31 has been introduced as a marker to distinguish 2 subsets of naive CD4+ T cells with distinct T-cell receptor excision circle (TREC) content in the peripheral blood of healthy humans. Here, we review studies that have characterized TREChi CD31+ thymicnaive CD4+ T cells and have accordingly used the assessment of this distinct subset of naive CD4+ T cells as a correlate of thymic activity. We will discuss further potential clinical applications and how more research on CD31+ thymicnaive and CD31− centralnaive CD4+ T cells may foster our knowledge of the impact of thymic involution on immune competence.

scholarly journals Immune Reconstitution During the First Year of Antiretroviral Therapy of HIV-1-Infected Adults in Rural Burkina Faso

2012 ◽  
Vol 6 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Fabrice Tiba ◽  
Frans Nauwelaers ◽  
Siaka Traoré ◽  
Boubacar Coulibaly ◽  
Thierry Ouedraogo ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Burkina Faso ◽  
T Cell Activation ◽  
Cell Activation ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Cell Counts ◽  
Hiv 1

There are no data on the outcome of highly active antiretroviral therapy (HAART) in HIV-infected adults in rural Burkina Faso. We therefore assessed CD4+ T-cell counts and HIV-1 plasma viral load (VL), the proportion of naive T-cells (co-expressing CCR7 and CD45RA) and T-cell activation (expression of CD95 or CD38) in 61 previously untreated adult patients from Nouna, Burkina Faso, at baseline and 2 weeks, 1, 3, 6, 9 and 12 months after starting therapy. Median CD4+ T-cell counts increased from 174 (10th-90th percentile: 33-314) cells/µl at baseline to 300 (114- 505) cells/µl after 3 months and 360 (169-562) cells/µl after 12 months of HAART. Median VL decreased from 5.8 (4.6- 6.6) log10 copies/ml at baseline to 1.6 (1.6-2.3) log10 copies/ml after 12 months. Early CD4+ T-cell recovery was accompanied by a reduction of the expression levels of CD95 and CD38 on T-cells. Out of 42 patients with complete virological follow-up under HAART, 19 (45%) achieved concordant good immunological (gain of ≥100 CD4+ T-cells/µl above baseline) and virological (undetectable VL) responses after 12 months of treatment (intention-to-treat analysis). Neither a decreased expression of the T-cell activation markers CD38 and CD95, nor an increase in the percentage of naive T-cells reliably predicted good virological treatment responses in patients with good CD4+ T-cell reconstitution. Repeated measurement of CD4+ T-cell counts during HAART remains the most important parameter for immunologic monitoring. Substitution of repeated VL testing by determination of T-cell activation levels (e.g., CD38 expression on CD8+ T-cells) should be applied with caution.

scholarly journals Long-Term Depletion of Naive T Cells in Patients Treated for Hodgkin's Disease

Blood ◽  
1997 ◽  
Vol 90 (9) ◽  
pp. 3662-3672 ◽  
Author(s):  
Nobukazu Watanabe ◽  
Stephen C. De Rosa ◽  
Anthony Cmelak ◽  
Richard Hoppe ◽  
Leonore A. Herzenberg ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Hodgkin's Disease ◽  
Hodgkin’S Disease ◽  
Cell Subset ◽  
T Cell Subsets ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Cell Counts

Abstract We investigated the representation of T cells in patients who had been treated for Hodgkin's disease (HD). We found a marked depletion in both CD4 and CD8 naive T-cell counts that persists up to 30 years after completion of treatment. In contrast, CD4 and CD8 memory T-cell subsets recovered to normal or above normal levels by 5 years posttreatment. Thus, the previously-reported long-term deficit in total CD4 T-cell counts after treatment for HD is due to specific depletion of naive T cells. Similarly, total CD8 T-cell counts return to normal by 5 years only because CD8 memory T cells expand to higher than normal levels. These findings suggest that the treatment (mediastinal irradiation) results in a longterm dysregulation of T-cell subset homeostasis. The profound depletion of naive T cells may explain the altered T-cell function in treated patients, including the poor response to immunization after treatment for HD. Further, in some individuals, we identified expansions of unusual subsets expressing low levels of CD8. Eight-color fluorescence-activated cell sorting analyses showed that these cells largely express CD8αα homodimers and CD57, consistent with the phenotype of potentially extrathymically derived T cells. In addition, these cells, both CD4+ and CD4−, are probably cytotoxic lymphocytes, as they express high levels of intracellular perforin. In adults treated for HD, an increased activity of extrathymic T-cell differentiation may partially compensate for the loss of thymic-derived T cells.

scholarly journals Response of naive antigen-specific CD4+ T cells in vitro: characteristics and antigen-presenting cell requirements.

1992 ◽  
Vol 176 (5) ◽  
pp. 1431-1437 ◽  
Author(s):  
M Croft ◽  
D D Duncan ◽  
S L Swain
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Cd4 Cells ◽  
Peptide Antigen ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Antigen Presenting

Because of the low frequency of T cells for any particular soluble protein antigen in unprimed animals, the requirements for naive T cell responses in specific antigens have not been clearly delineated and they have been difficult to study in vitro. We have taken advantage of mice transgenic for the V beta 3/V alpha 11 T cell receptor (TCR), which can recognize a peptide of cytochrome c presented by IEk. 85-90% of CD4+ T cells in these mice express the transgenic TCR, and we show that almost all such V beta 3/V alpha 11 receptor-positive cells have a phenotype characteristic of naive T cells, including expression of high levels of CD45RB, high levels of L-selectin (Mel-14), low levels of CD44 (Pgp-1), and secretion of interleukin 2 (IL-2) as the major cytokine. Naive T cells, separated on the basis of CD45RB high expression, gave vigorous responses (proliferation and IL-2 secretion) to peptide antigen presented in vitro by a mixed antigen-presenting cell population. At least 50% of the T cell population appeared to respond, as assessed by blast transformation, entry into G1, and expression of increased levels of CD44 by 24 h. Significant contributions to the response by contaminating memory CD4+ cells were ruled out by demonstrating that the majority of the CD45RB low, L-selectin low, CD44 high cells did not express the V beta 3/V alpha 11 TCR and responded poorly to antigen. We find that proliferation and IL-2 secretion of the naive CD4 cells is minimal when resting B cells present peptide antigen, and that both splenic and bone marrow-derived macrophages are weak stimulators. Naive T cells did respond well to high numbers of activated B cells. However, dendritic cells were the most potent stimulators of proliferation and IL-2 secretion at low cell numbers, and were far superior inducers of IL-2 at higher numbers. These studies establish that naive CD4 T cells can respond vigorously to soluble antigen and indicate that maximal stimulation can be achieved by presentation of antigen on dendritic cells. This model should prove very useful in further investigations of activation requirements and functional characteristics of naive helper T cells.

Abstract 424: Effector T Cells Induce Cardiac Fibroblasts Transition to Myofibroblasts & Contribute to Pressure Overload Induced Cardiac Fibrosis

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Tania A Nevers ◽  
Ane Salvador ◽  
Francisco Velazquez ◽  
Mark Aronovitz ◽  
Robert Blanton
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Pressure Overload ◽  
Effector T Cells ◽  
T Cell Subsets ◽  
Naive T Cells ◽  
Effector T Cell ◽  
Naïve T Cells

Background: Cardiac fibrogenesis is a major pathogenic factor that occurs in heart failure (HF) and results in contractile dysfunction and ventricular dilation. Recently, we showed that T cell deficient mice (TCRα -/- ) do not develop cardiac fibrosis (CF) and have preserved cardiac function in the thoracic aortic constriction (TAC) mouse model of pressure overload (PO). Specifically, CD4 + T cells are activated in the cardiac draining lymph nodes and infiltrate the LV, where the Th1 and Th17 effector T cell signature transcription factors are significantly upregulated as compared with control mice. However, the T cell subsets involved and the mechanisms by which they contribute to CF and pathogenesis of non-ischemic HF remains to be determined. Thus, we hypothesize that heart infiltrated effector T cells perpetuate the fibrotic response by regulating the differentiation and activation of extracellular matrix-producing cardiac myofibroblasts. Methods and Results: Naïve or effector T cells differentiated in vitro or isolated from mice undergoing TAC or Sham surgery were co-cultured with adult C57BL/6 cardiac fibroblasts (CFB). In contrast with naïve T cells, effector T cells and PO activated T cells strongly adhered to CFB and mediated fibroblast to myofibroblasts transition as depicted by immunofluorescence expression of SMAα. Effector T cell supernatants only slightly mediated this transition, indicating that effector T cells direct contact with CFB, rather than cytokine release is required to mediate CFB transformation. Adoptive transfer of effector, but not naïve T cells, into TCRα -/- recipient mice in the onset of TAC resulted in T cells infiltration into the left ventricle and increased CF. Conclusions: Our data indicate that CD4+ effector T cells directly interact with CFB to induce CF in response to PO induced CF. Future studies will determine the adhesion mechanisms regulating this crosstalk and evaluate the pro-fibrotic mechanisms induced and whether this is a T effector cell specific subset. These results will provide an attractive tool to counteract the inflammatory/fibrotic process as an alternative option for the treatment of CF in non- ischemic HF.

Sign in / Sign up

Export Citation Format

Share Document