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

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.

Blood ◽  
2005 ◽  
Vol 106 (1) ◽  
pp. 216-223 ◽  
Author(s):  
Elodie Segura ◽  
Carole Nicco ◽  
Bérangère Lombard ◽  
Philippe Véron ◽  
Graça Raposo ◽  
...  

Exosomes are secreted vesicles formed in late endocytic compartments. Immature dendritic cells (DCs) secrete exosomes, which transfer functional major histocompatibility complex (MHC)–peptide complexes to other DCs. Since immature and mature DCs induce different functional T-cell responses (ie, tolerance versus priming), we asked whether DC maturation also influenced the priming abilities of their exosomes. We show that exosomes secreted by lipopolysaccharide (LPS)–treated mature DCs are 50- to 100-fold more potent to induce antigen-specific T-cell activation in vitro than exosomes from immature DCs. In vitro, exosomes from mature DCs transfer to B lymphocytes the ability to prime naive T cells. In vivo, only mature exosomes trigger effector T-cell responses, leading to fast skin graft rejection. Proteomic and biochemical analyses revealed that mature exosomes are enriched in MHC class II, B7.2, intercellular adhesion molecule 1 (ICAM-1), and bear little milk-fat globule–epidermal growth factor–factor VIII (MFG-E8) as compared with immature exosomes. Functional analysis using DC-derived exosomes from knock-out mice showed that MHC class II and ICAM-1 are required for mature exosomes to prime naive T cells, whereas B7.2 and MFG-E8 are dispensable. Therefore, changes in protein composition and priming abilities of exosomes reflect the maturation signals received by DCs.


1998 ◽  
Vol 188 (12) ◽  
pp. 2289-2299 ◽  
Author(s):  
Mark Bix ◽  
Zhi-En Wang ◽  
Bonnie Thiel ◽  
Nicholas J. Schork ◽  
Richard M. Locksley

The dysregulated expression of interleukin 4 (IL-4) can have deleterious effects on the outcome of infectious and allergic diseases. Despite this, the mechanisms by which naive T cells commit to IL-4 expression during differentiation into mature effector cells remain incompletely defined. As compared to cells from most strains of mice, activated CD4+ T cells from BALB mice show a bias towards IL-4 production and T helper 2 commitment in vitro and in vivo. Here, we show that this bias arises not from an increase in the amount of IL-4 produced per cell, but rather from an increase in the proportion of CD4+ T cells that commit to IL-4 expression. This strain-specific difference in commitment was independent of signals mediated via the IL-4 receptor and hence occurred upstream of potential autoregulatory effects of IL-4. Segregation analysis of the phenotype in an experimental backcross cohort implicated a polymorphic locus on chromosome 16. Consistent with a role in differentiation, expression of the phenotype was CD4+ T cell intrinsic and was evident as early as 16 h after the activation of naive T cells. Probabilistic gene activation is proposed as a T cell–intrinsic mechanism capable of modulating the proportion of naive T cells that commit to IL-4 production.


2015 ◽  
Vol 213 (1) ◽  
pp. 123-138 ◽  
Author(s):  
Arata Takeuchi ◽  
Mohamed El Sherif Gadelhaq Badr ◽  
Kosuke Miyauchi ◽  
Chitose Ishihara ◽  
Reiko Onishi ◽  
...  

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.


1997 ◽  
Vol 27 (9) ◽  
pp. 2383-2390 ◽  
Author(s):  
Joyce L. Young ◽  
Judith M. Ramage ◽  
J. S. Hill Gaston ◽  
Peter C. L. Beverley

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2233-2233
Author(s):  
Monera Al Rukhayes ◽  
Victoria T Potter ◽  
Pilar Perez-Abellan ◽  
Jesus Feliu ◽  
Lajos Floro ◽  
...  

Abstract Lymphocyte-depletion effectively reduces risk of graft versus host disease (GvHD) after allogeneic haematopoietic stem cell transplantation (allo-HSCT), but risk of infections and malignant disease relapse remains high. We have previously reported that pre-emptive donor lymphocyte infusions (pDLI) given to patients after allo-HSCT for myeloid malignancies to reverse falling donor T-cell chimerism improve overall and relapse-free survival. GvHD rates after pDLI were not high and grade rarely severe. To investigate the basis for better outcome after pDLI, we have assessed recovery of lymphocyte subsets, T-cell receptor (TCR) diversity and T-cell functional competence after allo-HSCT with fludarabine and busulphan in cohorts of 59 patients (median age 59) given alemtuzumab for lymphocyte-depletion and 34 patients (median age 58) given anti-thymocyte globulin (ATG). Lymphocytes were significantly less depleted with ATG compared to alemtuzumab (Day 30: Median 3.9 x 108/liter versus 2.3x108/liter, P=0.03) but numbers for both ATG and alemtuzumab remained significantly below the normal range (median 2.34x109/liter for 11 aged-matched healthy volunteers) for at least one year (Day 360 P<0.005: Median 8.35 x 108/liter after ATG; median 1.04 x 109/liter after alemtuzumab). Lymphocyte subset composition was similar after ATG or alemtuzumab, and abnormal. Notable, the T-cell population comprised only memory and effector T cells early after HSCT. These cells expressed significantly higher levels of Ki67 than T cells from healthy volunteers (Day 30 P<0.005: Median CD4 T cells 41.3% Ki67+ after ATG, 66% after alemtuzumab compared to 2.51% for healthy volunteers; median CD8 T cells 18.5% Ki67+ after ATG, 50.8% after alemtuzumab compared to 2.58% for healthy volunteers). This marker is indicative of homeostatic proliferation likely driven by increased levels of IL7 and IL15 detected in the serum of patients early after HSCT compared to healthy volunteers (Day 30 P=0.066 and P<0.005 respectively). Higher frequency of T cells expressing the proliferation marker in patients treated with alemtuzumab was associated with high frequencies of T cells expressing the PD1 marker, indicative of exhaustion (Day 30 P<0.005: Median CD4 T cells 84.0% PD1+ after alemtuzumab compared to 6.35% for healthy volunteers; median CD8 T cells 49.1% PD1+ after alemtuzumab compared to 12.3% for healthy volunteers). Expression of PD1 by T cells was near normal in patients treated with ATG. Naïve T cells were typically absent for at least six months after HSCT following lymphocyte depletion with ATG or alemtuzumab, and any subsequent recovery was poor. In contrast, the naïve T-cell population increased rapidly in patients after pDLI (n=18). Six of these patients received pDLI early after HSCT (at 3-5 months) and naïve T-cell recovery was significantly enhanced at six months compared to patients that did not receive pDLI (Day 180 P<0.005: Median 19.25% naïve CD4 T cells compared to 1.36%; median 23.5% naïve CD8 T cells compared to 3.48%). Naïve T cells are the main source of repertoire diversity and responsible for responses to antigens not previously encountered. Analysis of the TCR β chain repertoire of five patients by deep sequencing revealed that pDLI boosts repertoire diversity. For example, unique TCR β chain sequences increased 31-fold in 150 days after pDLI compared to a 2-fold increase during a similar period for another patient that did not receive DLI. Furthermore, instances of emergence of public clonotypes specific for CMV or EBV that were not detected before DLI were seen in virus-positive patients whose donors were virus-negative. Emergence and rapid expansion of donor-derived clonotypes to frequencies up to 6.75% suggests that naïve T cells present in the DLI had been primed upon encounter with virus in the patient. In vitro stimulation with overlapping 15-mer peptide libraries for CMV antigens and EBV antigens followed by assessment of activation marker expression and interferon-γ, MIP-1β, and TNF-α production showed that virus-specific T-cell responses increased in magnitude and poly-functionality after DLI. These findings show that DLI replenishes naïve T cells and restores ability to respond to viral antigens previously unseen. By inference, this may extend to leukaemia antigens and underlie the reduced rate of malignant disease relapse seen in patients given pDLI. Disclosures No relevant conflicts of interest to declare.


2020 ◽  
Vol 4 (8) ◽  
pp. 475-484
Author(s):  
Ana Lustig ◽  
Ty’Keemi Manor ◽  
Guixin Shi ◽  
Jiangyuan Li ◽  
Ying-Ting Wang ◽  
...  

2019 ◽  
Vol 11 (2) ◽  
pp. 108-123
Author(s):  
Dan Tong ◽  
Li Zhang ◽  
Fei Ning ◽  
Ying Xu ◽  
Xiaoyu Hu ◽  
...  

Abstract Common γ chain cytokines are important for immune memory formation. Among them, the role of IL-2 remains to be fully explored. It has been suggested that this cytokine is critically needed in the late phase of primary CD4 T cell activation. Lack of IL-2 at this stage sets for a diminished recall response in subsequent challenges. However, as IL-2 peak production is over at this point, the source and the exact mechanism that promotes its production remain elusive. We report here that resting, previously antigen-stimulated CD4 T cells maintain a minimalist response to dendritic cells after their peak activation in vitro. This subtle activation event may be induced by DCs without overt presence of antigen and appears to be stronger if IL-2 comes from the same dendritic cells. This encounter reactivates a miniature IL-2 production and leads a gene expression profile change in these previously activated CD4 T cells. The CD4 T cells so experienced show enhanced reactivation intensity upon secondary challenges later on. Although mostly relying on in vitro evidence, our work may implicate a subtle programing for CD4 T cell survival after primary activation in vivo.


Immunobiology ◽  
2018 ◽  
Vol 223 (3) ◽  
pp. 294-299 ◽  
Author(s):  
Pauline C. Ledur ◽  
Juliana S.M. Tondolo ◽  
Francielli P.K. Jesus ◽  
Camila M. Verdi ◽  
Érico S. Loreto ◽  
...  

Blood ◽  
2008 ◽  
Vol 111 (4) ◽  
pp. 2091-2100 ◽  
Author(s):  
Tony J. Kenna ◽  
Ranjeny Thomas ◽  
Raymond J. Steptoe

Antigen stimulation of naive T cells in conjunction with strong costimulatory signals elicits the generation of effector and memory populations. Such terminal differentiation transforms naive T cells capable of differentiating along several terminal pathways in response to pertinent environmental cues into cells that have lost developmental plasticity and exhibit heightened responsiveness. Because these cells exhibit little or no need for the strong costimulatory signals required for full activation of naive T cells, it is generally considered memory and effector T cells are released from the capacity to be inactivated. Here, we show that steady-state dendritic cells constitutively presenting an endogenously expressed antigen inactivate fully differentiated memory and effector CD8+ T cells in vivo through deletion and inactivation. These findings indicate that fully differentiated effector and memory T cells exhibit a previously unappreciated level of plasticity and provide insight into how memory and effector T-cell populations may be regulated.


Blood ◽  
2004 ◽  
Vol 104 (9) ◽  
pp. 2801-2809 ◽  
Author(s):  
Matthias Gunzer ◽  
Carsten Weishaupt ◽  
Anja Hillmer ◽  
Yasmin Basoglu ◽  
Peter Friedl ◽  
...  

Abstract For activation T cells engage antigen-presenting cells (APCs) in lymphatic tissues. The contact duration and kinetics (static versus dynamic) vary considerably in different model systems; however, it is unclear whether T cells, APCs, or the environment are responsible for the observed discrepancies. Using 3-D collagen matrices as structural scaffold, we directly compared the kinetics of T-cell engagement and activation by functionally major APC types, ie, dendritic cells (DCs) and resting or activated B cells. Resting B cells engaged T cells in long-lived (several hours), adhesive, and leukocyte function-associated antigen-1 (LFA-1)-dependent conjugates in 3-D collagen as well as in intact lymph nodes in vivo. DCs and preactivated B cells, however, supported predominantly dynamic, short-lived (minutes), and sequential contacts to T cells that were dependent on high cytoskeletal activity of the APCs but could not be inhibited by anti-LFA-1 treatment. Naive T cells were most strongly activated by DCs and activated B cells, whereas resting B cells were 100-fold less efficient to induce T-cell proliferation. Thus, in the same 3-D environment, naive T cells respond with a spectrum of different interaction modes dependent on the type and activation state of the APCs. Thereby, more dynamic interaction kinetics is positively correlated with higher T-cell priming efficiency. (Blood. 2004;104: 2801-2809)


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