scholarly journals Increase of CD4+CD25highFoxP3+ cells impairs in vitro human microbicidal activity against Mycobacterium tuberculosis during latent and acute pulmonary tuberculosis

2021 ◽  
Vol 15 (7) ◽  
pp. e0009605
Author(s):  
Lorenzzo Lyrio Stringari ◽  
Luciana Polaco Covre ◽  
Flávia Dias Coelho da Silva ◽  
Vivian Leite de Oliveira ◽  
Maria Carolina Campana ◽  
...  
Keyword(s):  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
Mononuclear Cells ◽  
Critical Role ◽  
Latent Tuberculosis ◽  
Treg Cells ◽  
Host Responses ◽  
Peripheral Blood Mononuclear ◽  
Microbicidal Activity

Background Regulatory T cells (Tregs) play a critical role during Mycobacterium tuberculosis (Mtb) infection, modulating host responses while neutralizing excessive inflammation. However, their impact on regulating host protective immunity is not completely understood. Here, we demonstrate that Treg cells abrogate the in vitro microbicidal activity against Mtb. Methods We evaluated the in vitro microbicidal activity of peripheral blood mononuclear cells (PBMCs) from patients with active tuberculosis (TB), individuals with latent tuberculosis infection (LTBI, TST+/IGRA+) and healthy control (HC, TST-/IGRA-) volunteers. PBMCs, depleted or not of CD4+CD25+ T-cells, were analyzed to determine frequency and influence on microbicidal activity during in vitro Mtb infection with four clinical isolates (S1, S5, R3, and R6) and one reference strain (H37Rv). Results The frequency of CD4+CD25highFoxP3+ cells were significantly higher in Mtb infected whole blood cultures from both TB patients and LTBI individuals when compared to HC. Data from CD4+CD25+ T-cells depletion demonstrate that increase of CD4+CD25highFoxP3+ is associated with an impairment of Th-1 responses and a diminished in vitro microbicidal activity of LTBI and TB groups. Conclusions Tregs restrict host anti-mycobacterial immunity during active disease and latent infection and thereby may contribute to both disease progression and pathogen persistence.

scholarly journals Differential control of human Treg and effector T cells in tumor immunity by Fc-engineered anti–CTLA-4 antibody

2018 ◽  
Vol 116 (2) ◽  
pp. 609-618 ◽  
Author(s):  
Danbee Ha ◽  
Atsushi Tanaka ◽  
Tatsuya Kibayashi ◽  
Atsushi Tanemura ◽  
Daisuke Sugiyama ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Immunity ◽  
Tumor Antigen ◽  
Mononuclear Cells ◽  
Treg Cells ◽  
Effector T Cells ◽  
Antibody Treatment ◽  
Peripheral Blood Mononuclear ◽  
Antigen Stimulation

Anti–CTLA-4 mAb is efficacious in enhancing tumor immunity in humans. CTLA-4 is expressed by conventional T cells upon activation and by naturally occurring FOXP3+CD4+ Treg cells constitutively, raising a question of how anti–CTLA-4 mAb can differentially control these functionally opposing T cell populations in tumor immunity. Here we show that FOXP3high potently suppressive effector Treg cells were abundant in melanoma tissues, expressing CTLA-4 at higher levels than tumor-infiltrating CD8+ T cells. Upon in vitro tumor-antigen stimulation of peripheral blood mononuclear cells from healthy individuals or melanoma patients, Fc-region–modified anti–CTLA-4 mAb with high antibody-dependent cell-mediated cytotoxicity (ADCC) and cellular phagocytosis (ADCP) activity selectively depleted CTLA-4+FOXP3+ Treg cells and consequently expanded tumor-antigen–specific CD8+T cells. Importantly, the expansion occurred only when antigen stimulation was delayed several days from the antibody treatment to spare CTLA-4+ activated effector CD8+T cells from mAb-mediated killing. Similarly, in tumor-bearing mice, high-ADCC/ADCP anti–CTLA-4 mAb treatment with delayed tumor-antigen vaccination significantly prolonged their survival and markedly elevated cytokine production by tumor-infiltrating CD8+ T cells, whereas antibody treatment concurrent with vaccination did not. Anti–CTLA-4 mAb modified to exhibit a lesser or no Fc-binding activity failed to show such timing-dependent in vitro and in vivo immune enhancement. Thus, high ADCC anti–CTLA-4 mAb is able to selectively deplete effector Treg cells and evoke tumor immunity depending on the CTLA-4–expressing status of effector CD8+ T cells. These findings are instrumental in designing cancer immunotherapy with mAbs targeting the molecules commonly expressed by FOXP3+ Treg cells and tumor-reactive effector T cells.

scholarly journals Kuijieling-Containing Serum Regulates Th17 and Treg Cell Differentiation by Inhibiting STAT3 Signaling In Vitro

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Yu Long ◽  
Yuqing He ◽  
Fengming Jie ◽  
Sixin Li ◽  
Yanli Wu ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
Mononuclear Cells ◽  
Transforming Growth Factor ◽  
Treg Cells ◽  
Orphan Receptor ◽  
Cell Culture Supernatant ◽  
T Helper 17 ◽  
Peripheral Blood Mononuclear

Object. To investigate the effect of Kuijieling (KJL) on the balance between T helper 17 (Th17) and regulatory T (Treg) cells in peripheral blood mononuclear cells (PBMC) in vitro and explore the underlying mechanism. Materials and Methods. PBMCs isolated from rats were stimulated with transforming growth factor-β, interleukin (IL)-6, and IL-23 to induce the imbalance of Th17 and Treg cells and were treated with 10, 5, or 2.5% KJL-containing serum. The proportion of Th17 or Treg cells in CD4+ T cells was analyzed by flow cytometry, the concentrations of IL-17, IL-21, and IL-10 were assayed by ELISA, mRNA expressions of retinoic acid-related orphan receptor γt (RORγt), forkhead box protein 3 (Foxp3), and signal transducer and activator of transcription 3 (STAT3) were quantified by PCR, and phosphorylated STAT3 (p-STAT3) was analyzed by flow cytometry. Results. KJL-containing serum decreased the proportion of Th17 cells and increased the proportion of Treg cells in CD4+ T cells, decreased the concentration of IL-17 and IL-21, enhanced the level of IL-10 in the cell culture supernatant, promoted the expression of Foxp3, and inhibited the levels of RORγt, STAT3, and p-STAT3. Conclusion. KJL suppresses the STAT3 pathway to remedy the imbalance between Th17 and Treg cells.

scholarly journals The effect of serum on monocyte tissue factor generation

Blood ◽  
1984 ◽  
Vol 64 (3) ◽  
pp. 707-714 ◽  
Author(s):  
RL Edwards ◽  
D Perla
Keyword(s):  
T Cells ◽  
Tissue Factor ◽  
Mononuclear Cells ◽  
High Serum ◽  
Peripheral Blood Mononuclear ◽  
Serum Factors ◽  
Normal Peripheral Blood ◽  
Stimulatory Activity ◽  
Normal Hemostasis

Abstract Human monocytes generate the procoagulant tissue factor (MTF) following exposure to a variety of immune stimuli in vitro. The generation of MTF is modified by T cells, lymphokines, and immunoregulatory lipoproteins, and recent studies have shown that MTF can be activated in an immune- specific manner following exposure to antigen. We have examined the role of serum factors in the regulation of MTF generation. Low concentrations (less than 1%) of heat-inactivated normal human serum greatly enhanced MTF generation in cultures of normal peripheral blood mononuclear cells. The stimulatory effect was observed in cultures of both unstimulated cells and cells exposed to bacterial lipopolysaccharide. Stimulation was not observed at high serum concentrations (greater than 10%) and could not be explained by endotoxin contamination or activation of the assay system. Stimulatory activity was present in plasma and BaSO4-adsorbed plasma as well as autologous and allogeneic serum, was not abolished by removal of serum lipoproteins, and did not require the presence of T cells for its expression. Sera from 28 different normal volunteers were screened for stimulatory activity and demonstrated a wide variation in potency. These results suggest that a potent factor is present in sera that enhances the expression of MTF activity in vitro. This factor is distinct from previously described lipoprotein regulators and may play a role in the initiation of coagulation in both normal hemostasis and pathologic states.

scholarly journals The Anthrax Vaccine Adsorbed Vaccine Generates Protective Antigen (PA)-Specific CD4+ T Cells with a Phenotype Distinct from That of Naïve PA T Cells

2008 ◽  
Vol 76 (10) ◽  
pp. 4538-4545 ◽  
Author(s):  
William W. Kwok ◽  
Junbao Yang ◽  
Eddie James ◽  
John Bui ◽  
Laurie Huston ◽  
...  
Keyword(s):  
T Cells ◽  
Mononuclear Cells ◽  
Protective Antigen ◽  
Ex Vivo ◽  
Cytokine Profile ◽  
T Cell Epitopes ◽  
Peripheral Blood Mononuclear ◽  
Anthrax Vaccine ◽  
Cellular Immune

ABSTRACT Cellular immune responses against protective antigen (PA) of Bacillus anthracis in subjects that received the anthrax vaccine adsorbed (AVA) vaccine were examined. Multiple CD4+ T-cell epitopes within PA were identified by using tetramer-guided epitope mapping. PA-reactive CD4+ T cells with a CD45RA− phenotype were also detected by direct ex vivo staining of peripheral blood mononuclear cells (PBMC) with PA-specific tetramers. Surprisingly, PA-specific T cells were also detected in PBMC of nonvaccinees after a single cycle of in vitro PA stimulation. However, PA-reactive CD4+ T cells in nonvaccinees occurred at lower frequencies than those in vaccinees. The majority of PA-reactive T cells from nonvaccinees were CD45RA+ and exhibited a Th0/Th1 cytokine profile. In contrast, phenotyping and cytokine profile analyses of PA-reactive CD4+ T cells from vaccinees indicated that vaccination leads to commitment of PA-reactive T cells to a Th2 lineage, including generation of PA-specific, pre-Th2 central memory T cells. These results demonstrate that the current AVA vaccine is effective in skewing the development of PA CD4+ T cells to the Th2 lineage. The data also demonstrated the feasibility of using class II tetramers to analyze CD4+ cell responses and lineage development after vaccination.

scholarly journals Role of T cells in intrauterine administration of activated peripheral blood mononuclear cells in recurrent implantation failure.

2021 ◽  
Author(s):  
Guillaume Ricaud ◽  
Cathy Vaillancourt ◽  
Veronique Blais ◽  
Marjorie Disdier ◽  
Fabien Joao ◽  
...  
Keyword(s):  
T Cells ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Treg Cells ◽  
Implantation Failure ◽  
Recurrent Implantation Failure ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells

Intrauterine administration of autologous peripheral blood mononuclear cells (PBMC) has been recently proposed as new immunotherapy for patients with unexplained recurrent implantation failure (RIF). In these patients, administration of activated PBMC 24-h or 72-h before embryo transfer resulted in a 3-fold increase in biochemical pregnancy rate. In this study we evaluated the role of T cells to promotes human endometrial receptivity. On the day of ovulation, PBMC were isolated from and activated with T cells mitogen, the phytohemagglutinin (PHA) and hCG for 48-h in a conditioned culture medium. Distributions of CD4+ T cells were characterized in 157 patients by flow cytometry before and after PHA/hCG activation. Cytokine production was analyzed by cytometric beads array. We observed in RIF patients a significant decrease in Th2 and natural Treg cells before activation with PHA/hCG and an increase of Th17 cells after activation compared to intrauterine sperm insemination (IUI) and in vitro fertilization (IVF) groups. Furthermore, the hCG/PHA treatment increases anti-inflammatory T cells (Th2 and Treg cells) compared to non-treated T cells. Principal component analysis (PCA) performed on CD4 T cell subtypes revealed a different cellular profile in the RIF compared to the IUI and IVF groups. This inflammatory state change could explain how endometrium immunomodulation by hCG-activated PBMC helps patients with unexplained RIF to reach implantation.

scholarly journals Precision engineering of an anti-HLA-A2 chimeric antigen receptor in regulatory T cells for transplant immune tolerance

2021 ◽  
Author(s):  
Yannick D. Muller ◽  
Leonardo M.R. Ferreira ◽  
Emilie Ronin ◽  
Patrick Ho ◽  
Vinh Nguyen ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Chimeric Antigen Receptor ◽  
Mononuclear Cells ◽  
Antigen Receptor ◽  
Single Chain ◽  
Transplant Tolerance ◽  
Peripheral Blood Mononuclear

Infusion of regulatory T cells (Tregs) engineered with a chimeric antigen receptor (CAR) targeting donor-derived human leukocyte antigen (HLA) is a promising strategy to promote transplant tolerance. Here, we describe an anti-HLA-A2 CAR (A2-CAR) generated by grafting the complementarity-determining regions (CDRs) of a human monoclonal anti-HLA-A2 antibody into the framework regions of the Herceptin 4D5 single-chain variable fragment and fusing it with a CD28-zeta signaling domain. The CDR-grafted A2-CAR maintained the specificity of the original antibody. We then generated HLA-A2 mono-specific human CAR Tregs either by deleting the endogenous T-cell receptor (TCR) via CRISPR/Cas9 and introducing the A2-CAR using lentiviral transduction or by directly integrating the CAR construct into the TCR alpha constant locus using homology-directed repair. These A2-CAR+TCRdeficient human Tregs maintained both Treg phenotype and function in vitro. Moreover, they selectively accumulated in HLA-A2-expressing islets transplanted from either HLA-A2 transgenic mice or deceased human donors. A2-CAR+TCRdeficient Tregs did not impair the function of these HLA-A2+ islets, whereas similarly engineered A2-CAR+TCRdeficientCD4+ conventional T cells rejected the islets in less than 2 weeks. A2-CAR+TCRdeficient Tregs delayed graft-versus-host disease only in the presence of HLA-A2, expressed either by co-transferred peripheral blood mononuclear cells or by the recipient mice. Altogether, we demonstrate that genome-engineered mono-antigen-specific A2-CAR Tregs localize to HLA-A2-expressing grafts and exhibit antigen-dependent in vivo suppression, independent of TCR expression. These approaches may be applied towards developing precision Treg cell therapies for transplant tolerance.

scholarly journals Spontaneous secretion of interferon γ and interleukin 4 by human intraepithelial and lamina propria gut lymphocytes

Gut ◽  
1998 ◽  
Vol 42 (5) ◽  
pp. 643-649 ◽  
Author(s):  
M Carol ◽  
A Lambrechts ◽  
A Van Gossum ◽  
M Libin ◽  
M Goldman ◽  
...  
Keyword(s):  
Lamina Propria ◽  
Intestinal Mucosa ◽  
Mononuclear Cells ◽  
Critical Role ◽  
Gastrointestinal Diseases ◽  
Interferon Γ ◽  
Interleukin 4 ◽  
Peripheral Blood Mononuclear ◽  
Ifn Γ

Background—Cytokines secreted by intestinal T lymphocytes probably play a critical role in regulation of the gut associated immune responses.Aims—To quantify interferon γ (IFN-γ) and interleukin 4 (IL-4) secreting cells (SC) among human intraepithelial (IEL) and lamina propria (LPL) lymphocytes from the duodenum and right colon in non-pathological situations and in the absence of in vitro stimulation.Patients—Duodenal and right colonic biopsy specimens were obtained from patients with no inflammation of the intestinal mucosa.Methods—Intraepithelial and lamina propria cell suspensions were assayed for numbers of cells spontaneously secreting IFN-γ and IL-4 by a two site reverse enzyme linked immunospot technique (ELISPOT).Results—The relatively high proportion of duodenal lymphocytes spontaneously secreting IFN-γ (IEL 3.6%; LPL 1.9%) and IL-4 (IEL 1.3%; LPL 0.7%) contrasted with the very low numbers of spontaneously IFN-γ SC and the absence of spontaneously IL-4 SC among peripheral blood mononuclear cells. In the basal state, both IFN-γ and IL-4 were mainly produced by CD4+ cells. Within the colon, only 0.2% of IEL and LPL secreted IFN-γ in the basal state, and 0.1% secreted IL-4.Conclusions—Compared with peripheral lymphocytes substantial proportions of intestinal epithelial and lamina propria lymphocytes spontaneously secrete IFN-γ and/or IL-4. These cytokines are probably involved in the normal homoeostasis of the human intestinal mucosa. Disturbances in their secretion could play a role in the pathogenesis of gastrointestinal diseases.

BTK Inhibitors, Irrespective of ITK Inhibition, Increase Efficacy of a CD19/CD3 Bispecific Antibody in CLL

Blood ◽  
2021 ◽  
Author(s):  
Maissa Mhibik ◽  
Erika M. Gaglione ◽  
David Eik ◽  
Ellen K Kendall ◽  
Amy Blackburn ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cytotoxic Activity ◽  
Kinase Inhibitors ◽  
Bispecific Antibody ◽  
Mononuclear Cells ◽  
Cell Function ◽  
Lymphocytic Leukemia ◽  
Peripheral Blood Mononuclear

Bruton Tyrosine Kinase inhibitors (BTKis) are a preferred treatment for patients with chronic lymphocytic leukemia (CLL). Indefinite therapy with BTKis, while effective, presents clinical challenges. Combination therapy can deepen responses, shorten treatment duration, and possibly prevent or overcome drug resistance. We previously reported on a CD19/CD3 bispecific antibody (bsAb) that recruits autologous T cell cytotoxicity against CLL cells in vitro. Compared to observations with samples from treatment-naïve patients, T cells from patients being treated with ibrutinib expanded more rapidly and exerted superior cytotoxic activity in response to the bsAb. In addition to BTK, ibrutinib also inhibits IL2 inducible T cell Kinase (ITK). In contrast, acalabrutinib, does not inhibit ITK. Whether ITK inhibition contributes to the observed immune effects is unknown. To better understand how BTKis modulate T-cell function and cytotoxic activity, we cultured peripheral blood mononuclear cells (PBMCs) from BTKi-naive, and ibrutinib- or acalabrutinib-treated CLL patients with CD19/CD3 bsAb in vitro. T-cell expansion, activation, differentiation, and cytotoxicity were increased in PBMCs from patients on treatment with either BTKi compared to that observed for BKTi-naïve patients. BTKi therapy transcriptionally downregulated immunosuppressive effectors expressed by CLL cells, including CTLA-4 and CD200. CTLA-4 blockade with ipilimumab in vitro increased the cytotoxic activity of the bsAb in BTKi-naïve but not BTKi-treated PBMCS. Taken together, BTKis enhance bsAb induced cytotoxicity by relieving T cells of immunosuppressive restraints imposed by CLL cells. The benefit of combining bsAb immunotherapy with BTKis needs to be confirmed in clinical trials.

scholarly journals Expression Cloning of an Immunodominant Family of Mycobacterium tuberculosis Antigens Using Human Cd4+ T Cells

2000 ◽  
Vol 191 (3) ◽  
pp. 551-560 ◽  
Author(s):  
Mark R. Alderson ◽  
Teresa Bement ◽  
Craig H. Day ◽  
Liqing Zhu ◽  
David Molesh ◽  
...  
Keyword(s):  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
Cd4 T Cells ◽  
Mononuclear Cells ◽  
Genomic Library ◽  
Cell Epitope ◽  
Single Amino Acid ◽  
Expression Cloning ◽  
Peripheral Blood Mononuclear

Development of a subunit vaccine for Mycobacterium tuberculosis (Mtb) is likely to be dependent on the identification of T cell antigens that induce strong proliferation and interferon γ production from healthy purified protein derivative (PPD)+ donors. We have developed a sensitive and rapid technique for screening an Mtb genomic library expressed in Escherichia coli using Mtb-specific CD4+ T cells. Using this technique, we identified a family of highly related Mtb antigens. The gene of one family member encodes a 9.9-kD antigen, termed Mtb9.9A. Recombinant Mtb9.9A protein, expressed and purified from E. coli, elicited strong T cell proliferation and IFN-γ production by peripheral blood mononuclear cells from PPD+ but not PPD− individuals. Southern blot analysis and examination of the Mtb genome sequence revealed a family of highly related genes. A T cell line from a PPD+ donor that failed to react with recombinant Mtb9.9A recognized one of the other family members, Mtb9.9C. Synthetic peptides were used to map the T cell epitope recognized by this line, and revealed a single amino acid substitution in this region when compared with Mtb9.9A. The direct identification of antigens using T cells from immune donors will undoubtedly be critical for the development of vaccines to several intracellular pathogens.

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