scholarly journals Central memory CD4 T cells are associated with incomplete restoration of the CD4 T cell pool after treatment-induced long-term undetectable HIV viraemia

2013 ◽  
Vol 68 (11) ◽  
pp. 2616-2625 ◽  
Author(s):  
N. Rallon ◽  
J. M. Sempere-Ortells ◽  
V. Soriano ◽  
J. M. Benito
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Central Memory ◽  
Cd4 T Cell ◽  
Cell Pool ◽  
Memory Cd4 T Cells

scholarly journals HIV-1 Viremia Prevents the Establishment of Interleukin 2–producing HIV-specific Memory CD4+ T Cells Endowed with Proliferative Capacity

2003 ◽  
Vol 198 (12) ◽  
pp. 1909-1922 ◽  
Author(s):  
Souheil-Antoine Younes ◽  
Bader Yassine-Diab ◽  
Alain R. Dumont ◽  
Mohamed-Rachid Boulassel ◽  
Zvi Grossman ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
Memory Cells ◽  
Cell Responses ◽  
Specific Memory ◽  
Ifn Γ ◽  
Memory Cd4 T Cells

CD4+ T cell responses are associated with disease control in chronic viral infections. We analyzed human immunodeficiency virus (HIV)-specific responses in ten aviremic and eight viremic patients treated during primary HIV-1 infection and for up to 6 yr thereafter. Using a highly sensitive 5-(and-6)-carboxyfluorescein diacetate-succinimidyl ester–based proliferation assay, we observed that proliferative Gag and Nef peptide-specific CD4+ T cell responses were 30-fold higher in the aviremic patients. Two subsets of HIV-specific memory CD4+ T cells were identified in aviremic patients, CD45RA− CCR7+ central memory cells (Tcm) producing exclusively interleukin (IL)-2, and CD45RA− CCR7− effector memory cells (Tem) that produced both IL-2 and interferon (IFN)-γ. In contrast, in viremic, therapy-failing patients, we found significant frequencies of Tem that unexpectedly produced exclusively IFN-γ. Longitudinal analysis of HIV epitope–specific CD4+ T cells revealed that only cells that had the capacity to produce IL-2 persisted as long-term memory cells. In viremic patients the presence of IFN-γ–producing cells was restricted to periods of elevated viremia. These findings suggest that long-term CD4+ T cell memory depends on IL-2–producing CD4+ T cells and that IFN-γ only–producing cells are short lived. Our data favor a model whereby competent HIV-specific Tcm continuously arise in small numbers but under persistent antigenemia are rapidly induced to differentiate into IFN-γ only–producing cells that lack self-renewal capacity.

scholarly journals Age-Associated Change in the Frequency of Memory CD4+ T Cells Impairs Long Term CD4+ T Cell Responses to Influenza Vaccine

2004 ◽  
Vol 173 (1) ◽  
pp. 673-681 ◽  
Author(s):  
Insoo Kang ◽  
Myung Sun Hong ◽  
Helena Nolasco ◽  
Sung Hwan Park ◽  
Jin Myung Dan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Influenza Vaccine ◽  
Cd4 T Cells ◽  
T Cell Responses ◽  
Cd4 T Cell ◽  
Cell Responses ◽  
Memory Cd4 T Cells

scholarly journals Comparison of the Development of SARS-Coronavirus-2-Specific Cellular Immunity, and Central Memory CD4+ T-Cell Responses Following Infection versus Vaccination

Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1439
Author(s):  
Kevin M. Dennehy ◽  
Eva Löll ◽  
Christine Dhillon ◽  
Johanna-Maria Classen ◽  
Tobias D. Warm ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
T Cell Responses ◽  
Central Memory ◽  
Cd4 T Cell ◽  
Memory T Cell ◽  
Cell Responses ◽  
Specific Effector ◽  
Memory Cd4 T Cells

Memory T-cell responses following infection with coronaviruses are reportedly long-lived and provide long-term protection against severe disease. Whether vaccination induces similar long-lived responses is not yet clear since, to date, there are limited data comparing memory CD4+ T-cell responses induced after SARS-CoV-2 infection versus following vaccination with BioNTech/Pfizer BNT162b2. We compared T-cell immune responses over time after infection or vaccination using ELISpot, and memory CD4+ T-cell responses three months after infection/vaccination using activation-induced marker flow cytometric assays. Levels of cytokine-producing T-cells were remarkably stable between three and twelve months after infection, and were comparable to IFNγ+ and IFNγ+IL-2+ T-cell responses but lower than IL-2+ T-cell responses at three months after vaccination. Consistent with this finding, vaccination and infection elicited comparable levels of SARS-CoV-2 specific CD4+ T-cells after three months in addition to comparable proportions of specific central memory CD4+ T-cells. By contrast, the proportions of specific effector memory CD4+ T-cells were significantly lower, whereas specific effector CD4+ T-cells were higher after infection than after vaccination. Our results suggest that T-cell responses—as measured by cytokine expression—and the frequencies of SARS-CoV-2-specific central memory CD4+T-cells—indicative of the formation of the long-lived memory T-cell compartment—are comparably induced after infection and vaccination.

scholarly journals Multiple developmental pathways lead to the generation of CD4 T-cell memory

2020 ◽  
Vol 32 (9) ◽  
pp. 589-595 ◽  
Author(s):  
Shintaro Hojyo ◽  
Damon Tumes ◽  
Akihiko Murata ◽  
Koji Tokoyoda
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Memory Cell ◽  
Cd4 T Cell ◽  
Developmental Pathways ◽  
T Cell Memory ◽  
Cell Memory ◽  
Memory Cd4 T Cells

Abstract Long-term immunological memory mediated by CD4 T cells provides a rapid protection against previously encountered pathogens or antigens. However, it is still controversial how memory CD4 T cells are generated and maintained. Unclear definitions of T-cell memory may be partially responsible for this controversy. It is becoming clear that diverse pathways are responsible for the differentiation and long-term persistence of memory T cells. We herein discuss the diversity of memory cell generation, describing a novel population of resting memory CD4 T cells and their precursors.

scholarly journals Reduced immune-regulatory molecule expression on human colonic memory CD4 T cells in older adults

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Stephanie M. Dillon ◽  
Tezha A. Thompson ◽  
Allison J. Christians ◽  
Martin D. McCarter ◽  
Cara C. Wilson
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Older Persons ◽  
Age Groups ◽  
T Cell Immunity ◽  
Cd4 T Cell ◽  
Cell Immunity ◽  
Memory Cd4 T Cells

Abstract Background The etiology of the low-level chronic inflammatory state associated with aging is likely multifactorial, but a number of animal and human studies have implicated a functional decline of the gastrointestinal immune system as a potential driver. Gut tissue-resident memory T cells play critical roles in mediating protective immunity and in maintaining gut homeostasis, yet few studies have investigated the effect of aging on human gut T cell immunity. To determine if aging impacted CD4 T cell immunity in the human large intestine, we utilized multi-color flow cytometry to measure colonic lamina propria (LP) CD4 T cell frequencies and immune-modulatory marker expression in younger (mean ± SEM: 38 ± 1.5 yrs) and older (77 ± 1.6 yrs) adults. To determine cellular specificity, we evaluated colon LP CD8 T cell frequency and phenotype in the same donors. To probe tissue specificity, we evaluated the same panel of markers in peripheral blood (PB) CD4 T cells in a separate cohort of similarly aged persons. Results Frequencies of colonic CD4 T cells as a fraction of total LP mononuclear cells were higher in older persons whereas absolute numbers of colonic LP CD4 T cells per gram of tissue were similar in both age groups. LP CD4 T cells from older versus younger persons exhibited reduced CTLA-4, PD-1 and Ki67 expression. Levels of Bcl-2, CD57, CD25 and percentages of activated CD38+HLA-DR+ CD4 T cells were similar in both age groups. In memory PB CD4 T cells, older age was only associated with increased CD57 expression. Significant age effects for LP CD8 T cells were only observed for CTLA-4 expression, with lower levels of expression observed on cells from older adults. Conclusions Greater age was associated with reduced expression of the co-inhibitory receptors CTLA-4 and PD-1 on LP CD4 T cells. Colonic LP CD8 T cells from older persons also displayed reduced CTLA-4 expression. These age-associated profiles were not observed in older PB memory CD4 T cells. The decline in co-inhibitory receptor expression on colonic LP T cells may contribute to local and systemic inflammation via a reduced ability to limit ongoing T cell responses to enteric microbial challenge.

scholarly journals ID:3002 Notch-mediated control of memory T cells against cancer cells

2017 ◽  
Vol 4 (S) ◽  
pp. 12
Author(s):  
Koji Yasutomo
Keyword(s):  
T Cells ◽  
T Cell ◽  
Notch Signaling ◽  
Cancer Cells ◽  
Cd4 T Cells ◽  
Memory T Cells ◽  
Term Survival ◽  
Long Term Survival ◽  
Memory Cd4 T Cells

T cells recognize an antigen presented by self-MHC, and the part of initially activated T cells differentiate toward memory T cells. T cells also recognize cancer cells leading to generation of memory T cells against cancer-derived antigens although the activity of T cells are frequently suppressed by various factors. The release from T cell inhibitory factors could allow T cells to respond to cancer cells. However, it remains unclear which molecules are required for long-term survival of memory T cells and generation of memory T cells against cancer cells. Notch functions as a regulator for fate decision, activation and survival of immune cells. We have demonstrated the roles of Notch in mature T cell differentiation and found that Notch signaling is essential for the maintenance of memory CD4 T cells. The inhibition of Notch disturbs the survival of memory CD4 T cells. The effect of Notch on T cell survival depended on glucose uptake through cell surface Glut1 expression. We revealed that Notch is crucial for the long-term survival of memory T cells against cancer cells and suppression of Notch signaling reduced the tumor antigen-specific killing of cancer cells. Those data demonstrate that Notch is pivotal for the maintenance of memory T cells against cancer cells and suggest that activation of Notch signaling might be advantageous to cancer immunotherapy.

scholarly journals Plasmacytoid dendritic cells have divergent effects on HIV infection of initial target cells and induce a pro-retention phenotype

2021 ◽  
Vol 17 (4) ◽  
pp. e1009522
Author(s):  
Orion Tong ◽  
Gabriel Duette ◽  
Thomas Ray O’Neil ◽  
Caroline M. Royle ◽  
Hafsa Rana ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Hiv Infection ◽  
Reverse Transcriptase ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
Target Cells ◽  
Ccr5 Expression ◽  
Memory Cd4 T Cells

Although HIV infection inhibits interferon responses in its target cells in vitro, interferon signatures can be detected in vivo soon after sexual transmission, mainly attributed to plasmacytoid dendritic cells (pDCs). In this study, we examined the physiological contributions of pDCs to early HIV acquisition using coculture models of pDCs with myeloid DCs, macrophages and the resting central, transitional and effector memory CD4 T cell subsets. pDCs impacted infection in a cell-specific manner. In myeloid cells, HIV infection was decreased via antiviral effects, cell maturation and downregulation of CCR5 expression. In contrast, in resting memory CD4 T cells, pDCs induced a subset-specific increase in intracellular HIV p24 protein expression without any activation or increase in CCR5 expression, as measured by flow cytometry. This increase was due to reactivation rather than enhanced viral spread, as blocking HIV entry via CCR5 did not alter the increased intracellular p24 expression. Furthermore, the load and proportion of cells expressing HIV DNA were restricted in the presence of pDCs while reverse transcriptase and p24 ELISA assays showed no increase in particle associated reverse transcriptase or extracellular p24 production. In addition, PDCs also markedly induced the expression of CD69 on infected CD4 T cells and other markers of CD4 T cell tissue retention. These phenotypic changes showed marked parallels with resident memory CD4 T cells isolated from anogenital tissue using enzymatic digestion. Production of IFNα by pDCs was the main driving factor for all these results. Thus, pDCs may reduce HIV spread during initial mucosal acquisition by inhibiting replication in myeloid cells while reactivating latent virus in resting memory CD4 T cells and retaining them for immune clearance.

scholarly journals Kynurenine Reduces Memory CD4 T-Cell Survival by Interfering with Interleukin-2 Signaling Early during HIV-1 Infection

2016 ◽  
Vol 90 (17) ◽  
pp. 7967-7979 ◽  
Author(s):  
Xavier Dagenais-Lussier ◽  
Mouna Aounallah ◽  
Vikram Mehraj ◽  
Mohamed El-Far ◽  
Cecile Tremblay ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Survival ◽  
Cd4 T Cells ◽  
Interleukin 2 ◽  
Cd4 T Cell ◽  
Tryptophan Catabolism ◽  
T Cell Survival ◽  
Memory Cd4 T Cells ◽  
Hiv 1

ABSTRACTEarly HIV-1 infection is characterized by enhanced tryptophan catabolism, which contributes to immune suppression and disease progression. However, the mechanism by which kynurenine, a tryptophan-related metabolite, induces immune suppression remains poorly understood. Herein, we show that the increased production of kynurenine correlates with defective interleukin-2 (IL-2) signaling in memory CD4 T cells from HIV-infected subjects. Defective IL-2 signaling in these subjects, which drives reduced protection from Fas-mediated apoptosis, was also associated with memory CD4 T-cell loss. Treatment of memory CD4 T cells with the concentration of kynurenine found in plasma inhibited IL-2 signaling through the production of reactive oxygen species. We further show that IL-2 signaling in memory CD4 T cells is improved by the antioxidantN-acetylcysteine. Early initiation of antiretroviral therapy restored the IL-2 response in memory CD4 T cells by reducing reactive oxygen species and kynurenine production. The study findings provide a kynurenine-dependent mechanism through IL-2 signaling for reduced CD4 T-cell survival, which can be reversed by early treatment initiation in HIV-1 infection.IMPORTANCEThe persistence of functional memory CD4 T cells represents the basis for long-lasting immune protection in individuals after exposure to HIV-1. Unfortunately, primary HIV-1 infection results in the massive loss of these cells within weeks of infection, which is mainly driven by inflammation and massive infection by the virus. These new findings show that the enhanced production of kynurenine, a metabolite related to tryptophan catabolism, also impairs memory CD4 T-cell survival and interferes with IL-2 signaling early during HIV-1 infection.

scholarly journals A role for TSLP in the development of inflammation in an asthma model

2005 ◽  
Vol 202 (6) ◽  
pp. 829-839 ◽  
Author(s):  
Amin Al-Shami ◽  
Rosanne Spolski ◽  
John Kelly ◽  
Andrea Keane-Myers ◽  
Warren J. Leonard
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Interferon Γ ◽  
Cd4 T Cell ◽  
T Cell Homeostasis ◽  
Asthma Model ◽  
Memory Cd4 T Cells ◽  
Th2 Differentiation

Thymic stromal lymphopoietin (TSLP) is a cytokine that promotes CD4+ T cell homeostasis. We now demonstrate that TSLP is required to mount a normal CD4+ T cell–mediated inflammatory response. TSLP acts directly on naive, but not, memory CD4+ T cells, and promotes their proliferation in response to antigen. In addition, TSLP exerts an effect indirectly through DCs to promote Th2 differentiation of CD4+ T cells. Correspondingly, TSLP receptor (TSLPR) knockout (KO) mice exhibit strong Th1 responses, with high levels of interleukin (IL)-12, interferon-γ, and immunoglobulin (Ig) G2a, but low production of IL-4, -5, -10, -13, and IgE; moreover, CD4+ T cells from these animals proliferate less well in response to antigen. Furthermore, TSLPR KO mice fail to develop an inflammatory lung response to inhaled antigen unless supplemented with wild-type CD4+ T cells. This underscores an important role for this cytokine in the development of inflammatory and/or allergic responses in vivo.

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