scholarly journals Cellular and humoral peritoneal immunity to Mesocestoides vogae metacestodes infection in mice.

2020 ◽  
Author(s):  
Terézia Mačák Kubašková ◽  
Dagmar Mudroňová ◽  
Miroslava Vargová ◽  
Katarína Reiterová ◽  
Gabriela Hrckova
Keyword(s):  
T Cells ◽  
Cell Population ◽  
Peritoneal Cavity ◽  
Post Infection ◽  
Cell Activation ◽  
Suppressor Cells ◽  
Initial Increase ◽  
Cell Functions ◽  
Peritoneal Cells ◽  
Immunosuppressive Cell

Abstract BackgroundHere, Mesocestoides (M.) vogae infection in mice is proposed as a suitable experimental model for studying the immunity in the peritoneal cavity of mice. MethodsTo investigate the kinetics of immune parameters in M. vogae-infected mice, we detected, using flow cytometry, the expression of selected lymphoid and myeloid markers within the peritoneal cell population at day 0, 3, 6, 10, 14, 19, 25, 30 and 35 post-infection. Then, using ELISA, we analyzed the cytokine IFN-γ, TGF-β, IL-4 and IL-10 responses and the levels of anti-M. vogae IgG and IgM antibodies in the peritoneal lavage fluid. Cells isolated from peritoneal cavity were subjected to further molecular analysis. To assess cell activation, peritoneal cells were exposed to LPS, and culture supernatants were collected and assayed for the level of cytokines and production of nitrite. Ly6C+ and Ly6G+ cells were isolated using MACS from the peritoneal cells at day 35 post-infection. Both MACS-isolated subsets were co-cultured with preactivated T cells to measure their suppressive capacity. Next, the role of parasite excretory-secretory antigens on induction of CD11b+ myeloid cells with the suppressive phenotype and the production of IL-10 was examined.ResultsIn the peritoneal cavity an initial increase of CD11b+Gr-1+F4/80highMHCIIhigh cells, NK, NKT cells and CD8+ cytotoxic T cells was observed in the first week of infection. At day 14 post-infection, an increase in the number of myeloid CD11b+Gr-1+ cells was detected, and most of this cell population expressed low levels of F4/80 and MHC II in later stages of infection, suggesting the impairment of antigen-presenting cell functions, probably through the excretory-secretory molecules. Moreover, we confirmed that peritoneal Gr1+ cells (Ly6C+ and Ly6G+ population) are phenotypically and functionally consistent with myeloid-derived suppressor cells. Metacestode infection elicited high levels of IL-10 and up-regulated of STAT-3 in peritoneal cells. A higher level of IgM suggests that this isotype may be predominant and is involved in the host protection.ConclusionsM. vogae tetrathyridia induced the recruitment of immunosuppressive cell subsets, which may play a key role in the down-regulation of immune response in long-term parasitic diseases, and excretory-secretory antigens seem to be the main regulatory factor.

scholarly journals Cellular And Humoral Peritoneal Immunity To Mesocestoides Vogae Metacestodes Infection In Mice.

2020 ◽  
Author(s):  
Terézia Mačák Kubašková ◽  
Dagmar Mudroňová ◽  
Miroslava Vargová ◽  
Katarína Reiterová ◽  
Gabriele Hrčková
Keyword(s):  
T Cells ◽  
Cell Population ◽  
Peritoneal Cavity ◽  
Post Infection ◽  
Cell Activation ◽  
Suppressor Cells ◽  
Initial Increase ◽  
Cell Functions ◽  
Peritoneal Cells ◽  
Immunosuppressive Cell

Abstract Background: Here, Mesocestoides (M.) vogae infection in mice is proposed as a suitable experimental model for studying the immunity in the peritoneal cavity of mice. Methods: To investigate the kinetics of immune parameters in M. vogae-infected mice, we detected, using flow cytometry, the expression of selected lymphoid and myeloid markers within the peritoneal cell population at day 0, 3, 6, 10, 14, 19, 25, 30 and 35 post-infection. Then, using ELISA, we analyzed the cytokine IFN-γ, TGF-β, IL-4 and IL-10 responses and the levels of anti-M. vogae IgG and IgM antibodies in the peritoneal lavage fluid. Cells isolated from peritoneal cavity were subjected to further molecular analysis. To assess cell activation, peritoneal cells were exposed to LPS, and culture supernatants were collected and assayed for the level of cytokines and production of nitrite. Ly6C+ and Ly6G+ cells were isolated using MACS from the peritoneal cells at day 35 post-infection. Both MACS-isolated subsets were co-cultured with preactivated T cells to measure their suppressive capacity. Next, the role of parasite excretory-secretory antigens on induction of CD11b+ myeloid cells with the suppressive phenotype and the production of IL-10 was examined.Results: In the peritoneal cavity an initial increase of CD11b+Gr-1+F4/80highMHCIIhigh cells, NK, NKT cells and CD8+ cytotoxic T cells was observed in the first week of infection. At day 14 post-infection, an increase in the number of myeloid CD11b+Gr-1+ cells was detected, and most of this cell population expressed low levels of F4/80 and MHC II in later stages of infection, suggesting the impairment of antigen-presenting cell functions, probably through the excretory-secretory molecules. Moreover, we confirmed that peritoneal Gr1+ cells (Ly6C+ and Ly6G+ population) are phenotypically and functionally consistent with myeloid-derived suppressor cells. Metacestode infection elicited high levels of IL-10 and up-regulated of STAT-3 in peritoneal cells. A higher level of IgM suggests that this isotype may be predominant and involved in host protection.Conclusions: M. vogae tetrathyridia induced the recruitment of immunosuppressive cell subsets, which may play a key role in the down-regulation of immune response in long-term parasitic diseases, and excretory-secretory antigens seem to be the main regulatory factor.

scholarly journals Cellular and humoral peritoneal immunity to Mesocestoides vogae metacestodes infection in mice.

2020 ◽  
Author(s):  
Terézia Mačák Kubašková ◽  
Dagmar Mudroňová ◽  
Miroslava Vargová ◽  
Katarína Reiterová ◽  
Gabriela Hrckova
Keyword(s):  
T Cells ◽  
Cell Population ◽  
Peritoneal Cavity ◽  
Post Infection ◽  
Cell Activation ◽  
Suppressor Cells ◽  
Initial Increase ◽  
Cell Functions ◽  
Peritoneal Cells ◽  
Immunosuppressive Cell

Abstract Background Here, Mesocestoides (M.) vogae infection in mice is proposed as a suitable experimental model for studying the immunity in the peritoneal cavity of mice. Methods To investigate the kinetics of immune parameters in M. vogae-infected mice, we detected, using flow cytometry, the expression of selected lymphoid and myeloid markers within the peritoneal cell population at day 0, 3, 6, 10, 14, 19, 25, 30 and 35 post-infection. Then, using ELISA, we analyzed the cytokine IFN-γ, TGF-β, IL-4 and IL-10 responses and the levels of anti-M. vogae IgG and IgM antibodies in the peritoneal lavage fluid. Cells isolated from peritoneal cavity were subjected to further molecular analysis. To assess cell activation, peritoneal cells were exposed to LPS, and culture supernatants were collected and assayed for the level of cytokines and production of nitrite. Ly6C+ and Ly6G+ cells were isolated using MACS from the peritoneal cells at day 35 post-infection. Both MACS-isolated subsets were co-cultured with preactivated T cells to measure their suppressive capacity. Next, the role of parasite excretory-secretory antigens on induction of CD11b+ myeloid cells with the suppressive phenotype and the production of IL-10 was examined.Results In the peritoneal cavity an initial increase of CD11b+Gr-1+F4/80highMHCIIhigh cells, NK, NKT cells and CD8+ cytotoxic T cells was observed in the first week of infection. At day 14 post-infection, an increase in the number of myeloid CD11b+Gr-1+ cells was detected, and most of this cell population expressed low levels of F4/80 and MHC II in later stages of infection, suggesting the impairment of antigen-presenting cell functions, probably through the excretory-secretory molecules. Moreover, we confirmed that peritoneal Gr1+ cells (Ly6C+ and Ly6G+ population) are phenotypically and functionally consistent with myeloid-derived suppressor cells. Metacestode infection elicited high levels of IL-10 and up-regulated of STAT-3 in peritoneal cells. A higher level of IgM suggests that this isotype may be predominant and is involved in the host protection.Conclusions M. vogae tetrathyridia induced the recruitment of immunosuppressive cell subsets, which may play a key role in the down-regulation of immune response in long-term parasitic diseases, and excretory-secretory antigens seem to be the main regulatory factor.

scholarly journals Cellular and humoral peritoneal immunity to Mesocestoides vogae metacestode infection in mice

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Terézia Mačak Kubašková ◽  
Dagmar Mudroňová ◽  
Miroslava Vargová ◽  
Katarína Reiterová ◽  
Gabriela Hrčková
Keyword(s):  
T Cells ◽  
Cell Population ◽  
Peritoneal Cavity ◽  
Post Infection ◽  
Initial Increase ◽  
Mhc Ii ◽  
Cell Functions ◽  
Peritoneal Cells ◽  
Immunosuppressive Cell ◽  
Mesocestoides Vogae

Abstract Background Here, Mesocestoides (M.) vogae infection in mice is proposed as a suitable experimental model for studying the immunity in the peritoneal cavity of mice. Methods To investigate the kinetics of immune parameters in M. vogae-infected mice, we detected, using flow cytometry, the expression of selected lymphoid and myeloid markers within the peritoneal cell population at day 0, 3, 6, 10, 14, 19, 25, 30 and 35 post-infection. Then, using ELISA, we analyzed the cytokine IFN-γ, TGF-β, IL-4 and IL-10 responses and the levels of anti-M. vogae IgG and IgM antibodies in the peritoneal lavage fluid. Cells isolated from the peritoneal cavity were subjected to further molecular analysis. To assess cell activation, peritoneal cells were exposed to LPS, and culture supernatants were collected and assayed for the level of cytokines and production of nitrite. Ly6C+ and Ly6G+ cells were isolated using MACS from the peritoneal cells at day 35 post-infection. Both MACS-isolated subsets were co-cultured with preactivated T cells to measure their suppressive capacity. Next, the role of parasite excretory-secretory antigens in induction of CD11b+ myeloid cells with the suppressive phenotype and the production of IL-10 was examined. Results In the peritoneal cavity an initial increase of CD11b+Gr-1+F4/80highMHC IIhigh cells, NK, NKT cells and CD8+ cytotoxic T cells was observed in the first week of infection. At day 14 post-infection, an increase in the number of myeloid CD11b+Gr-1+ cells was detected, and most of this cell population expressed low levels of F4/80 and MHC II in later stages of infection, suggesting the impairment of antigen-presenting cell functions, probably through the excretory-secretory molecules. Moreover, we confirmed that peritoneal Gr1+ cells (Ly6C+ and Ly6G+ population) are phenotypically and functionally consistent with myeloid-derived suppressor cells. Metacestode infection elicited high levels of IL-10 and upregulated STAT-3 in peritoneal cells. A higher level of IgM suggests that this isotype may be predominant and is involved in the host protection. Conclusions Mesocestoides vogae tetrathyridia induced the recruitment of immunosuppressive cell subsets, which may play a key role in the downregulation of immune response in long-term parasitic diseases, and excretory-secretory antigens seem to be the main regulatory factor.

Modulation of T-Cell Functions in KIR2DL3 (CD158b) Transgenic Mice

Blood ◽  
1999 ◽  
Vol 94 (7) ◽  
pp. 2396-2402 ◽  
Author(s):  
Anna Cambiaggi ◽  
Sylvie Darche ◽  
Sophie Guia ◽  
Philippe Kourilsky ◽  
Jean-Pierre Abastado ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Transgenic Mice ◽  
T Cell Activation ◽  
Cell Activation ◽  
Killer Cell ◽  
In Vitro Proliferation ◽  
Cell Functions ◽  
Double Transgenic Mice

In humans, a minor subset of T cells express killer cell Ig-like receptors (KIRs) at their surface. In vitro data obtained with KIR+ β and γδ T-cell clones showed that engagement of KIR molecules can extinguish T-cell activation signals induced via the CD3/T-cell receptor (TCR) complex. We analyzed the T-cell compartment in mice transgenic for KIR2DL3 (Tg-KIR2DL3), an inhibitory receptor for HLA-Cw3. As expected, mixed lymphocyte reaction and anti-CD3 monoclonal antibody (MoAb)-redirected cytotoxicity exerted by freshly isolated splenocytes can be inhibited by engagement of transgenic KIR2DL3 molecules. In contrast, antigen and anti-CD3 MoAb-induced cytotoxicity exerted by alloreactive cytotoxic T lymphocytes cannot be inhibited by KIR2DL3 engagement. In double transgenic mice, Tg-KIR2DL3 × Tg-HLA-Cw3, no alteration of thymic differentiation could be documented. Immunization of double transgenic mice with Hen egg white lysozime (HEL) or Pigeon Cytochrome-C (PCC) was indistinguishable from immunization of control mice, as judged by recall antigen-induced in vitro proliferation and TCR repertoire analysis. These results indicate that KIR effect on T cells varies upon cell activation stage and show unexpected complexity in the biological function of KIRs in vivo.

scholarly journals Physiological strength electric fields modulate human T cell activation and polarisation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Christina E. Arnold ◽  
Ann M. Rajnicek ◽  
Joseph I. Hoare ◽  
Swechha Mainali Pokharel ◽  
Colin D. Mccaig ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Electric Fields ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Activity ◽  
Research Area ◽  
Functional Changes ◽  
Cell Functions ◽  
Human T Cell

AbstractThe factors and signals driving T cell activation and polarisation during immune responses have been studied mainly at the level of cells and chemical mediators. Here we describe a physical driver of these processes in the form of physiological-strength electric fields (EFs). EFs are generated at sites where epithelium is disrupted (e.g. wounded skin/bronchial epithelia) and where T cells frequently are present. Using live-cell imaging, we show human primary T cells migrate directionally to the cathode in low strength (50/150 mV/mm) EFs. Strikingly, we show for the first time that EFs significantly downregulate T cell activation following stimulation with antigen-activated APCs or anti-CD3/CD28 antibodies, as demonstrated by decreased IL-2 secretion and proliferation. These EF-induced functional changes were accompanied by a significant dampening of CD4+ T cell polarisation. Expression of critical markers of the Th17 lineage, RORγt and IL-17, and the Th17 polarisation mediator phospho-STAT3 were reduced significantly, while STAT1, ERK and c-Jun phosphorylation were comparatively unaffected suggesting STAT3 modulation by EFs as one mechanism driving effects. Overall, we identify electrical signals as important contributors to the co-ordination and regulation of human T cell functions, paving the way for a new research area into effects of naturally occurring and clinically-applied EFs in conditions where control of T cell activity is paramount.

scholarly journals Role of Phosphodiesterase 7 (PDE7) in T Cell Activity. Effects of Selective PDE7 Inhibitors and Dual PDE4/7 Inhibitors on T Cell Functions

2020 ◽  
Vol 21 (17) ◽  
pp. 6118 ◽  
Author(s):  
Marianna Szczypka
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Splice Variants ◽  
Cell Activity ◽  
Cell Functions ◽  
Simultaneous Inhibition ◽  
And Function

Phosphodiesterase 7 (PDE7), a cAMP-specific PDE family, insensitive to rolipram, is present in many immune cells, including T lymphocytes. Two genes of PDE7 have been identified: PDE7A and PDE7B with three or four splice variants, respectively. Both PDE7A and PDE7B are expressed in T cells, and the predominant splice variant in these cells is PDE7A1. PDE7 is one of several PDE families that terminates biological functions of cAMP—a major regulating intracellular factor. However, the precise role of PDE7 in T cell activation and function is still ambiguous. Some authors reported its crucial role in T cell activation, while according to other studies PDE7 activity was not pivotal to T cells. Several studies showed that inhibition of PDE7 by its selective or dual PDE4/7 inhibitors suppresses T cell activity, and consequently T-mediated immune response. Taken together, it seems quite likely that simultaneous inhibition of PDE4 and PDE7 by dual PDE4/7 inhibitors or a combination of selective PDE4 and PDE7 remains the most interesting therapeutic target for the treatment of some immune-related disorders, such as autoimmune diseases, or selected respiratory diseases. An interesting direction of future studies could also be using a combination of selective PDE7 and PDE3 inhibitors.

scholarly journals T cell regulation of B cell activation. Lyt-1+,2-T cells modify the MHC-restricted function of heterogeneous and cloned T suppressor cells.

1985 ◽  
Vol 162 (2) ◽  
pp. 413-426 ◽  
Author(s):  
Y Asano ◽  
R J Hodes
Keyword(s):  
T Cells ◽  
B Cells ◽  
Cell Activation ◽  
Cell Function ◽  
Suppressor Cells ◽  
Effector Function ◽  
B Cell Activation ◽  
Experimental Conditions ◽  
Th Cells ◽  
Mhc Restriction

Previous studies have shown the existence of both heterogeneous Lyt-1-,2+ suppressor (Ts) cells and cloned Lyt-1+,2- Ts cells which, despite the difference in their Lyt phenotypes, functioned in a similar antigen-specific and major histocompatibility complex (MHC)-restricted fashion to suppress the antibody responses generated by cloned helper T (Th) cells and hapten-primed B cells. Our studies were carried out to assess in further detail the genetically restricted cell interactions that mediate this immune response suppression. We show that the activation of both heterogeneous and cloned Ts cells is antigen-specific and MHC-restricted under our experimental conditions. After appropriate activation, the effector function of both cloned Lyt-1+,2-Ts cells and heterogeneous Lyt-1-,2+ Ts cells was also antigen-specific. In contrast, once activated, Ts cells suppressed the responses generated by cloned Th cells and hapten-primed B cells in an MHC-unrestricted fashion. We also showed, however, that a population of unprimed Lyt-1+,2-T cells was able to significantly alter the genetic restriction requirements for Ts cell function. The activity of this population was itself MHC-restricted, and was observed only when the unprimed Lyt-1+,2-T cells shared the MHC restriction specificity of the cloned Th cells functioning in a given response. When these requirements were satisfied, Lyt-1+,2- T cells significantly modified the suppression mediated by both heterogeneous and cloned Ts cells, resulting in suppression that was then MHC restricted in its effector function as well as in its activation requirements. Thus, our findings suggest that the observed MHC restriction in Ts function is the result of a complex interaction involving Ts cells, Th cells, and an additional population of MHC-restricted Lyt-1+,2- T cells. This newly characterized activity of Lyt-1+,2- T cells functionally resembles that of an MHC-restricted contrasuppressor population that selectively blocks a pathway of MHC-unrestricted Ts activity, while leaving intact susceptibility to MHC-restricted Ts effects.

scholarly journals Expansion of myeloid-derived suppressor cells in patients with severe coronavirus disease (COVID-19)

2020 ◽  
Vol 27 (11) ◽  
pp. 3196-3207 ◽  
Author(s):  
Chiara Agrati ◽  
Alessandra Sacchi ◽  
Veronica Bordoni ◽  
Eleonora Cimini ◽  
Stefania Notari ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Mononuclear Cells ◽  
Severe Disease ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Cell Functions ◽  
Convalescent Phase

Abstract SARS-CoV-2 is associated with a 3.4% mortality rate in patients with severe disease. The pathogenesis of severe cases remains unknown. We performed an in-depth prospective analysis of immune and inflammation markers in two patients with severe COVID-19 disease from presentation to convalescence. Peripheral blood from 18 SARS-CoV-2-infected patients, 9 with severe and 9 with mild COVID-19 disease, was obtained at admission and analyzed for T-cell activation profile, myeloid-derived suppressor cells (MDSCs) and cytokine profiles. MDSC functionality was tested in vitro. In four severe and in four mild patients, a longitudinal analysis was performed daily from the day of admission to the early convalescent phase. Early after admission severe patients showed neutrophilia, lymphopenia, increase in effector T cells, a persisting higher expression of CD95 on T cells, higher serum concentration of IL-6 and TGF-β, and a cytotoxic profile of NK and T cells compared with mild patients, suggesting a highly engaged immune response. Massive expansion of MDSCs was observed, up to 90% of total circulating mononuclear cells in patients with severe disease, and up to 25% in the patients with mild disease; the frequency decreasing with recovery. MDSCs suppressed T-cell functions, dampening excessive immune response. MDSCs decline at convalescent phase was associated to a reduction in TGF-β and to an increase of inflammatory cytokines in plasma samples. Substantial expansion of suppressor cells is seen in patients with severe COVID-19. Further studies are required to define their roles in reducing the excessive activation/inflammation, protection, influencing disease progression, potential to serve as biomarkers of disease severity, and new targets for immune and host-directed therapeutic approaches.

The Inflammation Signaling Molecule ATP Regulates Human CD4+ T Cell Functions

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3901-3901
Author(s):  
Sara Trabanelli ◽  
Darina Očadlíková ◽  
Sara Gulinelli ◽  
Antonio Curti ◽  
Francesco di Virgilio ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Extracellular Atp ◽  
Cd4 T Cell ◽  
Cell Functions ◽  
Atp Concentration ◽  
High Concentrations

Abstract Abstract 3901 Adenosine 5'-triphosphate (ATP) is emerging as an extracellular signaling molecule playing a pivotal role in several cellular processes, through specific cell membrane purinergic P2 receptors (P2Rs). Under physiological conditions, ATP is present in the extracellular space at low concentrations (1-10 nM), whereas during inflammation and tumor cell growth ATP is present in the extracellular space at high concentrations, when 5–10 mM of ATP are quickly released from cytoplasm following plasma membrane damage or membrane stretching. For these reasons, extracellular ATP, via activation of P2Rs, might be an important regulator of inflammatory and immune response. CD4+ T cells are often exposed to different ATP concentrations in healthy or in injured/inflamed tissues. In the present study, we investigated the expression of purinergic P2 receptors (P2Rs) on human activated and regulatory CD4+ T cells and tested the lymphocyte functions in presence of low (1-10 nM), intermediate (250 nM) and high (1 mM) concentration of extracellular ATP. We assessed CD4+ T cells proliferation, apoptosis, phenotype, cytokine release, migration and matrix/cells adhesion. We show that activated CD4+ T cells express all P2Rs subtypes, whereas Tregs do not express P2X6 and P2Y2. At a functional level, low concentrations of extracellular ATP do not modulate CD4+ T cell functions. An increase in ATP concentration (250 nM) stimulates CD4+ T cells during activation: activated CD4+ T cells enhance their proliferation, the secretion of several cytokines critical for T cell functions (IL-2, IL-1b, IFN-g, IL-8), the expression of adhesion molecules (CD49d and CD54) and the capacity to adhere to cellular matrix or to other cells. Tregs seem to be unaffected by 250 nM of ATP. In contrast, high concentrations of ATP (1 mM) “turn off” activated CD4+ T cells and “turn on” Tregs. 1 mM of ATP inhibits activation of CD4+ T cells, by enhancing apoptosis and diminishing proliferation, cell-adhesion and the release of pro-inflammatory cytokines. Conversely, 1 mM of ATP attracts Tregs and stimulates their proliferation and their capacity to adhere to other cells. Moreover, Tregs cultured in presence of 1 mM of extracellular ATP are more efficient in inhibiting T cell proliferation. In summary, the present data show that the concentration of extracellular ATP regulates CD4+ T cell functions. Low ATP concentrations, as in physiological conditions, do not affect CD4+ T cell functions, whereas any enhancement of ATP concentration alters CD4+ T cell behavior. Specifically, a small increase stimulates CD4+ T cell activation, whereas a high increase inhibits CD4+ T cell activation and promotes the immunosuppression Tregs-mediated. We propose that the present in vitro data might explain how in vivo ATP regulates the behavior of activated CD4+ T cells and Tregs in case of inflammation or tumor cell growth. A small enhancement of ATP concentration occurs at the beginning of an inflammatory state or at the first stages of tumor growth; these ATP concentrations alert CD4+ T cells to the presence of a possible damage, which does not yet require Tregs involvement. In contrast, in case of severe inflammation, high ATP concentrations might prevent a further involvement of activated CD4+ T cells and promotes Tregs recruitment, avoiding hyper-inflammation. In case of advanced stages of tumorigenesis, high ATP concentration might be a tumor-escape mechanism, by killing activated CD4+ T cells and by attracting Tregs to surround the tumor. Disclosures: No relevant conflicts of interest to declare.

Effects of Ca-Containing Phosphate Glasses on T Lymphocytes In Vitro

2005 ◽  
Vol 284-286 ◽  
pp. 597-602 ◽  
Author(s):  
A. Kesisoglou ◽  
Jonathan C. Knowles ◽  
I. Olsen
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Dna Synthesis ◽  
T Cell Activation ◽  
Cell Activation ◽  
Human Peripheral Blood ◽  
Suppressor Cells ◽  
Phosphate Glasses ◽  
Activated T Cells

Calcium phosphate-based glasses (PG) are of interest as both scaffold and delivery materials for tissue rebuilding because of their chemical similarity to bone. Since it is essential that these materials exhibit local and systemic biocompatibility and do not adversely affect host tissues, the present study was undertaken to examine the effects of PG containing different amounts of Ca on human T lymphocytes in vitro. This was carried out by measuring the effects of extracts of the PG on the direct and mitogen-induced activation of T cells from human peripheral blood, as well as assessing CD4 and CD8, surface antigens which define T-helper and T-suppressor cells, respectively. The results showed that DNA synthesis by resting T lymphocytes was unaffected by all the PG. However, extracts of the PG containing 24 mol% of Ca caused a very marked inhibition of mitogen-induced T cell activation. This PG also reduced both the resting CD4+ and CD8+ T cells, as well as activated CD8+ cells. In contrast, high Ca-PG significantly augmented DNA synthesis by mitogen-activated T cells. These experiments show that PG containing differing levels of Ca can have pronounced and differential effects on the activation and function of T lymphocytes in vitro.

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