scholarly journals Identification of Novel Yellow Fever Class II Epitopes in YF-17D Vaccinees

Viruses ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1300
Author(s):  
Jose Mateus ◽  
Alba Grifoni ◽  
Hannah Voic ◽  
Michael A. Angelo ◽  
Elizabeth Phillips ◽  
...  
Keyword(s):  
T Cells ◽  
Yellow Fever ◽  
Cd4 T Cells ◽  
Mononuclear Cells ◽  
Yellow Fever Virus ◽  
Ex Vivo ◽  
Class Ii ◽  
Small Sample ◽  
Peripheral Blood Mononuclear

Yellow fever virus (YFV) is a mosquito-borne member of the genus flavivirus, including other important human-pathogenic viruses, such as dengue, Japanese encephalitis, and Zika. Herein, we report identifying 129 YFV Class II epitopes in donors vaccinated with the live attenuated YFV vaccine (YFV-17D). A total of 1156 peptides predicted to bind 17 different common HLA-DRB1 allelic variants were tested using IFNγ ELISPOT assays in vitro re-stimulated peripheral blood mononuclear cells from twenty-six vaccinees. Overall, we detected responses against 215 YFV epitopes. We found that the capsid and envelope proteins, as well as the non-structural (NS) proteins NS3 and NS5, were the most targeted proteins by CD4+ T cells from YF-VAX vaccinated donors. In addition, we designed and validated by flow cytometry a CD4+ mega pool (MP) composed of structural and non-structural epitopes in an independent cohort of vaccinated donors. Overall, this study provides a comprehensive prediction and validation of YFV epitopes in a cohort of YF-17D vaccinated individuals. With the design of a CD4 epitope MP, we further provide a useful tool to detect ex vivo responses of YFV-specific CD4 T cells in small sample volumes.

scholarly journals 7-oxo-DHEA enhances impaired M. tuberculosis-specific T cell responses during HIV-TB coinfection

2020 ◽  
Vol 27 (1) ◽  
Author(s):  
María Belén Vecchione ◽  
Natalia Laufer ◽  
Omar Sued ◽  
Marcelo Corti ◽  
Horacio Salomon ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Cross Sectional Study ◽  
Peripheral Blood Mononuclear ◽  
Cross Sectional ◽  
Cytokine Balance ◽  
Ifn Γ

Abstract Background Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis (TB), affecting approximately one third of the world’s population. Development of an adequate immune response will determine disease progression or progress to chronic infection. Risk of developing TB among human immunodeficiency virus (HIV)-coinfected patients (HIV-TB) is 20–30 times higher than those without HIV infection, and a synergistic interplay between these two pathogens accelerates the decline in immunological functions. TB treatment in HIV-TB coinfected persons is challenging and it has a prolonged duration, mainly due to the immune system failure to provide an adequate support for the therapy. Therefore, we aimed to study the role of the hormone 7-oxo-dehydroepiandrosterone (7-OD) as a modulator of anti-tuberculosis immune responses in the context of HIV-TB coinfection. Methods A cross-sectional study was conducted among HIV-TB patients and healthy donors (HD). We characterized the ex vivo phenotype of CD4 + T cells and also evaluated in vitro antigen-specific responses by Mtb stimulation of peripheral blood mononuclear cells (PBMCs) in the presence or absence of 7-OD. We assessed lymphoproliferative activity, cytokine production and master transcription factor profiles. Results Our results show that HIV-TB patients were not able to generate successful anti-tubercular responses in vitro compared to HD, as reduced IFN-γ/IL-10 and IFN-γ/IL-17A ratios were observed. Interestingly, treatment with 7-OD enhanced Th1 responses by increasing Mtb-induced proliferation and the production of IFN-γ and TNF-α over IL-10 levels. Additionally, in vitro Mtb stimulation augmented the frequency of cells with a regulatory phenotype, while 7-OD reduced the proportion of these subsets and induced an increase in CD4 + T-bet+ (Th1) subpopulation, which is associated with clinical data linked to an improved disease outcome. Conclusions We conclude that 7-OD modifies the cytokine balance and the phenotype of CD4 + T cells towards a more favorable profile for mycobacteria control. These results provide new data to delineate novel treatment approaches as co-adjuvant for the treatment of TB.

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 Ex Vivo Expanded Human Vγ9Vδ2 T-Cells Can Suppress Epithelial Ovarian Cancer Cell Growth

2019 ◽  
Vol 20 (5) ◽  
pp. 1139 ◽  
Author(s):  
Tsui Mao ◽  
Carol Miao ◽  
Yi Liao ◽  
Ying Chen ◽  
Chia Yeh ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
T Cells ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Γδ T Cells ◽  
Ovarian Cancer Cells ◽  
Cytotoxic Activities ◽  
Antitumor Effects ◽  
Peripheral Blood Mononuclear

γδ-T-cells have attracted attention because of their potent cytotoxicity towards tumors. Most γδ-T-cells become activated via a major histocompatibility complex (MHC)-independent pathway by the interaction of their receptor, Natural Killer Group 2 Member D (NKG2D) with the tumor-specific NKG2D ligands, including MHC class I-related chain A/B (MICA/B) and UL16-binding proteins (ULBPs), to kill tumor cells. However, despite their potent antitumor effects, the treatment protocols specifically targeting ovarian tumors require further improvements. Ovarian cancer is one of the most lethal and challenging female malignancies worldwide because of delayed diagnoses and resistance to traditional chemotherapy. In this study, we successfully enriched and expanded γδ-T-cells up to ~78% from peripheral blood mononuclear cells (PBMCs) with mostly the Vγ9Vδ2-T-cell subtype in the circulation. We showed that expanded γδ-T-cells alone exerted significant cytotoxic activities towards specific epithelial-type OVCAR3 and HTB75 cells, whereas the combination of γδ-T cells and pamidronate (PAM), a kind of aminobisphosphonates (NBPs), showed significantly enhanced cytotoxic activities towards all types of ovarian cancer cells in vitro. Furthermore, in tumor xenografts of immunodeficient NSG mice, γδ-T-cells not only suppressed tumor growth but also completely eradicated preexisting tumors with an initial size of ~5 mm. Thus, we concluded that γδ-T-cells alone possess dramatic cytotoxic activities towards epithelial ovarian cancers both in vitro and in vivo. These results strongly support the potential of clinical immunotherapeutic application of γδ-T-cells to treat this serious female malignancy.

CD70 Expression on HTLV-1 Infected T Cells of Carriers and ATL Patients and Its Clinical Significance

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1730-1730
Author(s):  
Izumi Masamoto ◽  
Sawako Horai ◽  
Tomohiro Kozako ◽  
Makoto Yoshimitsu ◽  
Junko Niimoto ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Mononuclear Cells ◽  
Conflicts Of Interest ◽  
Surveillance Systems ◽  
Peripheral Blood Mononuclear ◽  
Tax Protein ◽  
Infected Cells

Abstract Abstract 1730 Human T-lymphotropic virus type-1(HTLV-1) is the causative agent of adult T cell leukemia/lymphoma (ATL). HTLV-1 infected T cell growth or leukemogenesis in ATL is controlled by various host immune surveillance systems. Among them, CD70 on HTLV-1 infected T cells coupled with CD27 on virus specific cytotoxic T cells has been suggested to play an important role in ATL leukemogenesis. The CD70 molecule is the only known ligand for CD27, a member of the tumor necrosis factor (TNF) receptor superfamily 7. This negative immunoregulatory pathway downregulates cytotoxic T lymphocyte activity against CD70-expressing virus infected cells. In the present study, we examined CD70 expression on primary lymphocytes of HTLV-1 carriers and ATL patients, its relationship with HTLV-1 Tax protein expression, and the effect on CTL induction. CD70 expression was higher on peripheral blood mononuclear cells (PBMCs) of HTLV-1 infected carriers compared with healthy donors (p = 0.021, n = 21, Mann-Whitney U test), and higher in ATL patients compared to carriers (p = 0.045, n = 38, Mann-Whitney U test). CD70 expression may be observed in CD4 T cells, as well as B cells, but not in CD8 T cells or monocytes. CD70 expression in CD4 T cells is related to HTLV-1 infection, because of increased detection of HTLV-1 Tax protein during over night culture of CD70-expressing cells. Experiments using an ATL cell line, in which Tax expression is inducible by doxycycline stimulation, demonstrated enhanced CD70 expression when Tax protein was induced in HTLV-1 infected cells. Anti-CD70 antibody enhanced CD107a mobilization, a marker of recent cytotoxic degranulation, in HTLV-1 Tax specific CTLs in PBMCs from asymptomatic carriers in vitro, suggesting that the CD70/CD27 pathway plays an important role in the immune response to HTLV-1 infection in carriers, as well as ATL patients. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Immunomodulatory Effects of Canine Adipose Tissue Mesenchymal Stem Cell-Derived Extracellular Vesicles on Stimulated CD4+ T Cells Isolated from Peripheral Blood Mononuclear Cells

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Takahiro Teshima ◽  
Yunosuke Yuchi ◽  
Ryohei Suzuki ◽  
Hirotaka Matsumoto ◽  
Hidekazu Koyama
Keyword(s):  
T Cells ◽  
Extracellular Vesicles ◽  
Cd8 T Cells ◽  
Immune Cells ◽  
Cd4 T Cells ◽  
Mononuclear Cells ◽  
Immunomodulatory Effects ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells

Adipose tissue-derived mesenchymal stem cells (ADSCs) have anti-inflammatory and immunomodulatory characteristics. Many studies have suggested that the immunomodulation of ADSCs is largely mediated by secreted paracrine factors. Various factors are secreted from ADSCs, among which extracellular vesicles are considered to play a major role in the communication between ADSCs and target cells. Several studies have reported the function of canine ADSC-derived extracellular vesicles (cADSC-EVs), but few studies have reported the immunomodulatory effects of cADSC-EVs on immune cells. The purpose of this study was to investigate the effects of cADSC-EVs on in vitro-stimulated CD4+ T cells isolated from peripheral blood mononuclear cells (PBMCs). cADSC-EVs were isolated from cADSCs under naive conditions or primed conditions by tumor necrosis factor-α (TNFα) and interferon-γ (IFNγ). The expression levels of several microRNAs in cADSC-EVs were altered by priming with TNFα and IFNγ. Culturing PBMCs stimulated with concanavalin A in the presence of naive or primed cADSC-EVs inhibited the differentiation of PBMCs and CD4+ T cells and promoted apoptosis of PBMCs. CD4+, CD8+, and CD4+CD8+ T cells were decreased, while CD3+CD4-CD8- T cells were increased. T helper (Th) 1, Th2, Th17, and regulatory T (Treg) cells were analyzed by flow cytometry. cADSC-EVs inhibited the proliferation of Th1 and Th17 cells and enhanced Th2 and Treg cell proliferation. However, CD4+ T cells that had incorporated labeled cADSC-EVs comprised only a few percent of all cells. Therefore, these responses of stimulated CD4+ T cells may be due to not only direct effects of cADSC-EVs but also to indirect effects through interactions between cADSC-EVs and other immune cells. In conclusion, cADSC-EVs exert immunosuppressive effects on stimulated CD4+ T cells in vitro. These findings may be useful for further studies of immune diseases.

Association of changes in T regulatory cells (Treg) during nivolumab treatment with melanoma outcome.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 3031-3031 ◽  
Author(s):  
Jeffrey S. Weber ◽  
Rupal Ramakrishnan ◽  
Andressa Laino ◽  
Anders E. Berglund ◽  
David Woods
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Cd4 T Cells ◽  
T Regulatory Cells ◽  
Mononuclear Cells ◽  
In Vitro Assays ◽  
Peripheral Blood Mononuclear ◽  
Suppressive Function ◽  
Blocking Antibodies

3031 Background: PD-1 blocking antibodies have significant efficacy in the treatment of melanoma; however, many patients fail to respond and resistance mechanisms remain unknown. We addressed the role of Tregs, an immunosuppressive T-cell population, in patient outcome after treatment with nivolumab. Methods: Peripheral blood mononuclear cells (PBMC) were obtained from patients on trials with nivolumab as adjuvant therapy for resected disease or as treatment for metastatic melanoma. To measure suppression, Tregs were flow-sorted from PBMC and evaluated in allogeneic mixed lymphocyte reactions. Tregs and conventional CD4 T-cells were evaluated for gene expression changes by RNA-sequencing. Treg percentages and phosphorylated STAT3 (pSTAT3) expression were evaluated by flow cytometry. The effects of PD-1 blockade with nivolumab were evaluated in vitro using T-cells from baseline patient PBMC samples. Results: Tregs from responding patients or adjuvant patients without evidence of disease (NED) had reduced suppressive function post-nivolumab (p < 0.05), but no changes were observed in relapsing/non-responding patients; their Tregs were more suppressive than NED/responding Tregs (p < 0.001). NED Tregs had unique gene expression changes and associated pathways post-nivolumab compared to relapsing patient Tregs and conventional CD4 T-cells, including up-regulation of proliferation pathways (q < 8e-19) and downregulation of oxidative phosphorylation (q < 7e-5). NED Tregs had upregulation of pSTAT3 expression post-nivolumab (p < 0.05), which was not observed in relapsing patients. Evaluation of Tregs from patients with active disease also showed upregulation of pSTAT3 in responders (p < 0.05) but not non-responders. The relative increase in Treg pSTAT3 was associated with increased overall survival (R2= 0.49, p < 0.05). In vitro assays using PD-1 blocking antibodies recapitulated the increase in pSTAT3 (p < 0.05) and Treg percentages (p < 0.001), which were diminished with the addition of a STAT3 inhibitor (p < 0.01). Conclusions: These results demonstrate previously unknown roles of decreased Treg suppressive function and induction of STAT3 as biomarkers of patient’s outcome to nivolumab therapy.

Potential TH9402-Based ECP Treatment for cGvHD Patients.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 5119-5119
Author(s):  
Annie Levesque ◽  
Ann-Louise Savard ◽  
Denis-Claude Roy ◽  
Francine Foss ◽  
Christian Scotto
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Chronic Phase ◽  
Dose Effect ◽  
Peripheral Blood Mononuclear ◽  
Hematopoietic Stem

Abstract Although the risk of graft versus host disease (GvHD) can be reduced by improved donor-recipient matching and by the depletion of T cells before transplantation, GvHD still develops in 30–70% of allogeneic hematopoietic stem cell transplantation (HSCT) patients. The chronic phase of the disease (cGvHD), for which the pathogenesis is similar to autoimmune diseases, involves profound immune dysregulation leading to both immunodeficiency and autoimmunity. Standard therapies for cGvHD such as corticosteroids and immunosuppressants are associated with high toxicity and have demonstrated limited efficacy in patients with extensive disease. Extracorporeal photopheresis (ECP) has been shown by others in the clinic as a non-aggressive and beneficial alternative treatment for cGvHD, inducing Th1/Th2 immunomodulation that restores immunological tolerance. Celmed has developed an alternative approach to eliminate immunoreactive T cells using the Theralux™ photodynamic cell therapy (PDT) system based on the use of the rhodamine-123 derivative TH9402 illuminated ex vivo with a visible light source (λ =514nm). It has been suggested that the apoptotic cells, when returned to the patient, may be able to modulate the immune system as seen with other ECP methods. We aimed to evaluate in vivo and in vitro the possibility of also using the Theralux™ system in the ECP setting. A preliminary mouse model suggested that splenic T cells pre-treated with the Theralux™ system were able to induce an improvement of overall survival (p&lt;0.05) in mice with acute GvHD. Additionally, we developed a simplified PDT process and conducted a series of experiments with peripheral blood mononuclear cells (PBMCs) isolated from healthy volunteers. These studies have shown that the intra- and inter-donor variability in TH9402 incorporation are very low (~5% and 10%, respectively). A dose-effect study has shown a relationship of the PDT conditions with the levels of cell death, allowing significant control of the level of apoptosis induced. Phenotypic analyses have shown that this process results in an increase of AnnexinV positive cells as well as a decrease in the absolute number of CD3+ cells, CD19+/CD20+ cells and CD14+ cells and an increase in CD11c+ cells. This would suggest that apoptosis could be induced in both autoreactive T and B cells which could potentially stimulate an immune response against them. Moreover, the increase in CD11c+ cells combined with the decrease in CD14+ cells could reflect the maturation of macrophages into dendritic cells that are very potent antigen presenting cells. The mechanism by which these specific PDT conditions induce cell death is still under investigation but preliminary studies have shown that the cell death in unselected resting PBMCs may be caspase-independent. Finally, the evaluation of the effect of PDT on samples from cGvHD patients also demonstrated the capacity of this treatment strategy to induce apoptosis in these cells. Based on these data, we intend to begin a pilot clinical study evaluating two controlled PDT conditions inducing different levels of apoptosis in order to assess the safety and biological effect of the Theralux™ ECP system to treat patients with cGvHD.

Bcl-XL is up-regulated by HTLV-I and HTLV-II in vitro and in ex vivo ATLL samples

Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 275-281 ◽  
Author(s):  
Christophe Nicot ◽  
Renaud Mahieux ◽  
Shigeki Takemoto ◽  
Genoveffa Franchini
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Biological Significance ◽  
Lymphocytic Leukemia ◽  
Type I ◽  
Peripheral Blood Mononuclear ◽  
Term Survival

Human T lymphotropic virus type I (HTLV-I) is the etiological agent of adult T-cell lymphocytic leukemia (ATLL), whereas HTLV-II has not been associated with hematopoietic malignancies. The control of apoptotic pathways has emerged as a critical step in the development of many cancer types. As a result, the underlying mechanism of long-term survival of HTLV-I and HTLV-II was studied in infected T cells in vitro and in ex vivo ATLL samples. Results indicate that HTLV-I– and HTLV-II–infected T cells in vitro express high levels of the antiapoptotic protein Bcl compared with other human leukemic T cell lines or uninfected peripheral blood mononuclear cells. The levels of proapoptotic proteins Bax, BAD, and Bak were not significantly altered. HTLV-I and HTLV-II viral transactivators, Tax1 and Tax2, are known to increase expression of cellular genes. These proteins were tested for increased transcription from the human Bcl2 and Bcl-XL promoters. Whereas no effect was observed on the Bcl2 promoter, both Tax1 and Tax2 increased transcription of the Bcl-XL promoter in T cells, although Tax1 appeared to be more efficient than Tax2. The biological significance of these observations was validated by the finding of an increased expression of Bcl-XL in ex vivo ATLL cells, especially from patients unresponsive to various chemotherapy regimens. Altogether, these data suggest that overexpression of Bcl-XL in vivomay be in part responsible for the resistance of ATLL cells to chemotherapy. In addition, inefficient activation of the Bcl-XL promoter by Tax2 may result in a shorter survival time of HTLV-II–infected cells in vivo and a diminished risk of leukemia development.

Up-regulation of HIV coreceptors CXCR4 and CCR5 on CD4+ T cells during human endotoxemia and after stimulation with (myco)bacterial antigens: the role of cytokines

Blood ◽  
2000 ◽  
Vol 96 (8) ◽  
pp. 2649-2654 ◽  
Author(s):  
Nicole P. Juffermans ◽  
William A. Paxton ◽  
Pascale E. P. Dekkers ◽  
Annelies Verbon ◽  
Evert de Jonge ◽  
...  
Keyword(s):  
T Cells ◽  
Hiv Infection ◽  
Cd4 T Cells ◽  
Chemokine Receptors ◽  
Mononuclear Cells ◽  
Lipoteichoic Acid ◽  
Interleukin 10 ◽  
Virus Infectivity ◽  
Peripheral Blood Mononuclear

Abstract Concurrent infections in patients with human immunodeficiency virus (HIV) infection stimulate HIV replication. Chemokine receptors CXCR4 and CCR5 can act as HIV coreceptors. The authors hypothesized that concurrent infection increases the HIV load through up-regulation of CXCR4 and CCR5. Using experimental endotoxemia as a model of infection, changes in HIV coreceptor expression were assessed in 8 subjects injected with lipopolysaccharide (LPS, 4 ng/kg). The expression of CXCR4 and CCR5 on CD4+ T cells was increased 2- to 4-fold, 4 to 6 hours after LPS injection. In whole blood in vitro, LPS induced a time- and dose-dependent increase in the expression of CXCR4 and CCR5 on CD4+ T cells. Similar changes were observed after stimulation with cell wall components ofMycobacterium tuberculosis (lipoarabinnomannan) orStaphylococcus aureus (lipoteichoic acid), or with staphylococcal enterotoxin B. LPS increased viral infectivity of CD4-enriched peripheral blood mononuclear cells (PBMCs) with a T-tropic HIV strain. In contrast, M-tropic virus infectivity was reduced, possibly because of elevated levels of the CCR5 ligand cytokines RANTES and MIP-1β. LPS-stimulated up-regulation of CXCR4 and CCR5 in vitro was inhibited by anti-TNF and anti-IFNγ. Incubation with recombinant TNF or IFNγ mimicked the LPS effect. Anti–interleukin 10 (anti–IL-10) reduced CCR5 expression, without influencing CXCR4. In accordance, rIL-10 induced up-regulation of CCR5, but not of CXCR4. Intercurrent infections during HIV infection may up-regulate CXCR4 and CCR5 on CD4+ T cells, at least in part via the action of cytokines. Such infections may favor selectivity of HIV for CD4+ T cells expressing CXCR4.

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