scholarly journals In vitro maintaining of CD4+ central and effector memory cells in normal and inflammatory conditions

2020 ◽  
Vol 22 (5) ◽  
pp. 837-846
Author(s):  
E. A. Blinova ◽  
A. V. Kolerova ◽  
V. E. Balyasnikov ◽  
V. A. Kozlov

IL-7 is a key factor for the survival and maintenance of CD4+ central (Tcm) and effector (Tem) memory cells in the whole body. In many autoimmune diseases, an elevated level of IL-7 is detected in blood serum and at the site of inflammation, thus suggesting participation of this homeostatic factor in the survival of memory T cells, including auto-reactive clones, in inflammatory disorders. The aim of the study was to investigate the mechanisms of maintaining CD4+ memory T cells under normal and inflammatory conditions. We developed an in vitro model of inflammation, based on induction of pro-inflammatory cytokines, and then evaluated the effects of IL-7 upon purified sorted populations of CD4+Tcm and Tem under normal conditions and in vitro inflammatory model. IL-7 treatment promoted maintenance of CD4+Tcm phenotype in all variants of cultures. In the absence of contact with adherent cell fraction, the IL-7-induced proliferation of Tcm and Tem was slightly reduced, both under normal and inflammatory conditions, thus suggesting low sensitivity of memory T cells to contacts with MHC, and, probably, a requirement for additional signals to provide complete stimulation with IL-7. The last suggestion is also supported by data about CD127 and CD132 expression, i.e., in the absence of contact with MHC, the proportion of CD127+CD132+ cells was decreased in both subpopulations of CD4+ memory cells. Upon in vitro cultures, IL-7 contributed to decreased expression of CD127, and increased expression of CD132 on CD4+Tcm and Tem. We have evaluated the CD4+Tcm and Tem populations by affinity of T cell receptor (TCR), using the level of CD5 expression. Т cells with high TCR affinity for self-antigens are known to have higher expression of CD5. In comparison to Tem, the Tcm contained more CD5high cells. In cultures, IL-7 promoted a high level of CD5 expression on Tcm, which was comparable to levels observed in peripheral blood cells. High CD5 expression on Tem was observed after stimulation with IL-7 in the in vitro inflammatory model. In the absence of contact with MHC, the number of CD5high cells decreased among CD4+Tem and Tcm. Thus, CD4+Tcm cells with high affinity for autologous antigens are probably dependent on the presence of homeostatic factors, in particular, IL-7, and contacts with antigen-presenting cells (APCs). Under conditions of inflammation, no changes were revealed in the mechanism of maintaining CD4+Tcm, in contrast to CD4+Tem. Being less dependent on IL-7 under normal conditions, CD4+CD5highTem are accumulated in the presence of IL-7 under in vitro inflammatory conditions.

2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A19.2-A20
Author(s):  
C Ripamonti ◽  
C Steinkuhler ◽  
G Fossati

BackgroundCentral memory T cells show superior persistence and antitumor immunity compared to effector memory and effector T cells. T effector cells respond quickly to tumors, but they are terminally differentiated and undergo apoptosis upon killing activity. T memory differentiate rapidly into T effector cells and maintain a pool of cells that can continuously differentiate thus sustaining a more lasting response. In adoptive cell therapy (ACT), T cells infused into patients may have a limited time of activity if they are terminally differentiated, and may rapidly undergo exhaustion and apoptosis. The development of new strategies based on novel agents able to generate memory T cells ex-vivo is important for a successful clinical application of ACT.We have studied the effect of a potent and selective HDAC6 inhibitor, ITF3756, on CD8 T cells differentiation during an in vitro induced exhaustion process.Materials and MethodsTo induce exhaustion purified human CD8+ cells were stimulated twice with anti-CD3/CD28 beads (1:2) during 5 days, with or without ITF3756 1μM or 2μM added at all times of stimulation. At day 3 and 5 the expression of exhaustion, memory and effector T cells markers were analyzed by flow cytometry. Cells were also collected at day 5 for genes expression analysis. Expression of exhaustion, T phenotype, metabolic pathway and inflammatory cytokines were investigated by qPCR. Paired two-tailed t-tests was used to determine statistical significance between control versus treatment group at day 3 and 5 in 10 different donors. P-values ≤ 0.05 were considered significant.ResultsITF3756 1μM increased significantly the T central memory phenotype (CD45RO+CD62L+CCR7+) and decreased significantly the T effector phenotype (CD45RO+CD62L-CCR7-). The expression of CD62L in T central memory cells was significantly increased in agreement with the high expression of this marker in naïve and memory T cells. ITF3756 treatment decreased significantly the expression of exhaustion markers PD-1 and LAG-3. No effect was observed on TIM-3 expression. In agreement with the data obtained with protein analysis, treatment with ITF3756 reduced the mRNA level of Pd-1 and Lag-3. Gene expression of Tim-3 was also downmodulated, but this effect did not result in reduction of protein expression at the time of detection. ITF3756 reduced the expression of t-bet (Tbx21) driving T effector differentiation and increased genes related to T memory phenotype (Eomes, Lef-1 and albeit slightly, Tcf-7). T cell activation requires a metabolic reprogramming that supports highly proliferative phenotype and T effector differentiation. ITF3756 treatment decreased both Hif-1α and Glut-1 gene expression that are associated with TCR activation during the exhaustion process. T central memory cells produce less cytokines compared to T effector and effector memory cells. ITF3756 treatment decreased the genes expression of Il-2, Ifn-γ and Tnf-α. All these effects resulted dose dependent.ConclusionsThe selective inhibitor of HDAC6 ITF3756 delays the terminal differentiation of CD8 T cells and increases the percentage of memory T cells with a reduced expression of exhaustion markers in vitro. These results are the basis to further explore the possible use of ITF3756 as a safe ex vivo treatment of CD8 T cells for adoptive cell transfer.Disclosure InformationC. Ripamonti: A. Employment (full or part-time); Significant; Italfarmaco SpA. C. Steinkuhler: A. Employment (full or part-time); Significant; Italfarmaco SpA. G. Fossati: A. Employment (full or part-time); Significant; Italfarmaco SpA.


Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 147 ◽  
Author(s):  
Retamal-Díaz ◽  
Covián ◽  
Pacheco ◽  
Castiglione-Matamala ◽  
Bueno ◽  
...  

Worldwide, human respiratory syncytial virus (RSV) is the most common etiological agent for acute lower respiratory tract infections (ALRI). RSV-ALRI is the major cause of hospital admissions in young children, and it can cause in-hospital deaths in children younger than six months old. Therefore, RSV remains one of the pathogens deemed most important for the generation of a vaccine. On the other hand, the effectiveness of a vaccine depends on the development of immunological memory against the pathogenic agent of interest. This memory is achieved by long-lived memory T cells, based on the establishment of an effective immune response to viral infections when subsequent exposures to the pathogen take place. Memory T cells can be classified into three subsets according to their expression of lymphoid homing receptors: central memory cells (TCM), effector memory cells (TEM) and resident memory T cells (TRM). The latter subset consists of cells that are permanently found in non-lymphoid tissues and are capable of recognizing antigens and mounting an effective immune response at those sites. TRM cells activate both innate and adaptive immune responses, thus establishing a robust and rapid response characterized by the production of large amounts of effector molecules. TRM cells can also recognize antigenically unrelated pathogens and trigger an innate-like alarm with the recruitment of other immune cells. It is noteworthy that this rapid and effective immune response induced by TRM cells make these cells an interesting aim in the design of vaccination strategies in order to establish TRM cell populations to prevent respiratory infectious diseases. Here, we discuss the biogenesis of TRM cells, their contribution to the resolution of respiratory viral infections and the induction of TRM cells, which should be considered for the rational design of new vaccines against RSV.


Blood ◽  
2005 ◽  
Vol 106 (1) ◽  
pp. 144-149 ◽  
Author(s):  
Karin Schilbach ◽  
Gunter Kerst ◽  
Steffen Walter ◽  
Matthias Eyrich ◽  
Dorothee Wernet ◽  
...  

Induction of cytotoxic T lymphocytes (CTLs) for treatment of relapsed leukemia after allogeneic stem-cell transplantation is hindered by the laborious and time-consuming procedure of generating dendritic cells for antigen presentation. Artificial antigen-presenting cells (aAPCs) offer the advantage of being readily available in sufficient numbers, thus allowing for a highly standardized in vitro induction of CTLs. We generated aAPCs coated with anti-CD28 antibody (Ab) and either high-density (HD) or low-density (LD) major histocompatibility complex (MHC) class I molecules loaded with HA-1H, a nonapeptide derived from the hematopoiesis-restricted minor histocompatibility antigen HA-1. HD- and LD-aAPCs potently induced HA-1H–specific CD8+ CTLs from untouched CD8+ T cells of healthy donors. CTLs were subsequently purified by magnetic-activated cell sorting. HD- as well as LD-aAPC–induced CTLs exerted high HA-1H–specific cytotoxicity, resembled Tc1 effector memory cells, survived a long time in vitro, and were expanded by a factor varying between 8.2 × 104 and 51 × 104. The T-cell receptor (TCR) repertoire of HA-1H tetramer–positive CTLs was oligoclonal with a prominent usage of Vβ6. The TCR repertoire of tetramer-positive CTLs was distinct from and more restricted than that of tetramer-negative cells. These findings indicate that aAPCs are attractive tools for the ex vivo generation of HA-1H–specific CTLs suitable for immunotherapy of relapsed leukemia.


2008 ◽  
Vol 205 (11) ◽  
pp. 2561-2574 ◽  
Author(s):  
Alfonso Martín-Fontecha ◽  
Dirk Baumjohann ◽  
Greta Guarda ◽  
Andrea Reboldi ◽  
Miroslav Hons ◽  
...  

There is growing evidence that the maturation state of dendritic cells (DCs) is a critical parameter determining the balance between tolerance and immunity. We report that mouse CD4+ effector memory T (TEM) cells, but not naive or central memory T cells, constitutively expressed CD40L at levels sufficient to induce DC maturation in vitro and in vivo in the absence of antigenic stimulation. CD4+ TEM cells were excluded from resting lymph nodes but migrated in a CD62P-dependent fashion into reactive lymph nodes that were induced to express CD62P, in a transient or sustained fashion, on high endothelial venules. Trafficking of CD4+ TEM cells into chronic reactive lymph nodes maintained resident DCs in a mature state and promoted naive T cell responses and experimental autoimmune encephalomyelitis (EAE) to antigens administered in the absence of adjuvants. Antibodies to CD62P, which blocked CD4+ TEM cell migration into reactive lymph nodes, inhibited DC maturation, T cell priming, and induction of EAE. These results show that TEM cells can behave as endogenous adjuvants and suggest a mechanistic link between lymphocyte traffic in lymph nodes and induction of autoimmunity.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 190-190
Author(s):  
Elizabeth O. Hexner ◽  
Dale Frank ◽  
Stephen G. Emerson ◽  
Yi Zhang

Abstract The potent ability of allogeneic hematopoietic stem cell transplantation (Allo-HSCT) and donor leukocyte infusion (DLI) to cure leukemia remains the most striking example of the ability of the immune system to recognize and destroy tumors. Unfortunately, both allo-HSCT and DLI are often complicated by graft-versus-host disease (GVHD). In addition, durable responses to conventional DLI for acute leukemias have been disappointing. A better understanding of the mechanisms of alloreactive T cell-mediated anti-leukemia activity will be important for separating the GVL effect from GVHD. Adoptive transfer of selected subsets of T cells specific for miHA- or leukemia associated antigens might offer the chance to maximize GVL while minimizing GVHD. Using mouse models of human GVHD directed against miHAs, we recently demonstrated that antigen-experienced CD44loCD62LhiCD8+ T cells contain T memory stem cells that have greater ability than naïve T cells and mature memory T cells to proliferate and generate alloreactive effector cells and all memory T cell subsets (Nature Medicine, 2005, 11:1299). Using the same mouse model, we have now found that although B6/SJL mice receiving donor CD44hiCD8+ T cells (mature memory cells) primed against B6 mouse-derived myeloid leukemia C1498 cells do not develop clinical GVHD, most will die from C1498 leukemia by day 45 following injection of C1498 cells. Adoptive transfer of CD44loCD8+ T cells primed against C1498 leukemic cells caused clinical GVHD, but the majority of recipients (75%) survived long term free of C1498 leukemia. Surprisingly, the GVL effect of donor CD44loCD8+ T cells primed against C1498 leukemia cells was significantly inhibited when C1498 leukemia cell-primed CD44hiCD8+ T cells and CD44loCD8+ T cells were co-injected into B6/SJL mice, with only 25% of the mice surviving without leukemia. These results suggest that while the GVL effect is clearly mediated by antigen experienced CD44loCD8+ T cells, CD44hiCD8+ T memory cells primed against tumor cells are not only functionally defective in eliminating leukemia cells but are also potent inhibitors of alloreactive T cell-mediated GVL activity. We found that host-reactive effector memory CD8+ T cells produced 10-fold higher IL-10 than unstimulated naïve T cells and T memory stem cells, while CD8+ T memory stem cells expressed upregulated IL-10 receptors. These findings suggest that the inhibitory effect of mature memory T cells on alloreactive T cell-mediated GVL effect may be associated with increased production of IL-10 by mature memory cells and/or enhanced susceptibility of T memory stem cells to IL-10 secreted by mature memory cells. In addition, host dendritic cell activation of donor CD8+ naïve T cells progressively induced the generation of memory stem cells (CD44loCD62LhiSca-1hi), central memory cells (CD44hiCD62Lhi) and effector memory cells (CD44hiCD62Llo). CD8+ T memory stem cells displayed a TCR V-beta repertoire similar to that of unstimulated naive T cells. In contrast, both central memory and effector memory T cells showed a skewed TCR V-beta repertoire. Thus, selective elimination of suppressive CD44hiCD8+ T cells may represent an approach to augmenting GVL activity while preserving a diverse TCR V-beta repertoire.


2006 ◽  
Vol 203 (4) ◽  
pp. 897-906 ◽  
Author(s):  
Megan MacLeod ◽  
Mark J. Kwakkenbos ◽  
Alison Crawford ◽  
Sheila Brown ◽  
Brigitta Stockinger ◽  
...  

Secondary T cell responses are enhanced because of an expansion in numbers of antigen-specific (memory) cells. Using major histocompatibility complex class II tetramers we have tracked peptide-specific endogenous (non–T cell receptor transgenic) CD4 memory T cells in normal and in costimulation-deficient mice. CD4 memory T cells were detectable after immunization for more than 200 days, although decay was apparent. Memory cells generated in CD40 knockout mice by immunization with peptide-pulsed wild-type dendritic cells survived in the absence of CD40 and proliferated when boosted with peptide (plus adjuvant) in a CD40-independent fashion. However, differentiation of the memory cells into cytokine-producing effector cells did not occur in the absence of CD40. The data indicate that memory cells can be generated without passing through the effector cell stage.


2006 ◽  
Vol 204 (1) ◽  
pp. 79-91 ◽  
Author(s):  
Catherine Riou ◽  
Bader Yassine-Diab ◽  
Julien Van grevenynghe ◽  
Roland Somogyi ◽  
Larry D. Greller ◽  
...  

The molecular events involved in the establishment and maintenance of CD4+ central memory and effector memory T cells (TCM and TEM, respectively) are poorly understood. In this study, we demonstrate that ex vivo isolated TCM are more resistant to both spontaneous and Fas-induced apoptosis than TEM and have an increased capacity to proliferate and persist in vitro. Using global gene expression profiling, single cell proteomics, and functional assays, we show that the survival of CD4+ TCM depends, at least in part, on the activation and phosphorylation of signal transducer and activator of transcription 5a (STAT5a) and forkhead box O3a (FOXO3a). TCM showed a significant increase in the levels of phosphorylation of STAT5a compared with TEM in response to both IL-2 (P < 0.04) and IL-7 (P < 0.002); the latter is well known for its capacity to enhance T cell survival. Moreover, ex vivo TCM express higher levels of the transcriptionally inactive phosphorylated forms of FOXO3a and concomitantly lower levels of the proapoptotic FOXO3a target, Bim. Experiments aimed at blocking FOXO3a phosphorylation confirmed the role of this phosphoprotein in protecting TCM from apoptosis. Our results provide, for the first time in humans, an insight into molecular mechanisms that could be responsible for the longevity and persistence of CD4+ TCM.


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