scholarly journals Variability of ex-vivo stimulated T-cells secretory profile in healthy subjects

2020 ◽  
Vol 28 (1) ◽  
pp. 75-89
Author(s):  
Ion Bogdan Manescu ◽  
Doina Ramona Manu ◽  
Georgiana Mihaela Serban ◽  
Minodora Dobreanu
Keyword(s):  
T Cells ◽  
Peripheral Blood ◽  
Healthy Subjects ◽  
Ex Vivo ◽  
Intracellular Cytokine Staining ◽  
Interleukin 2 ◽  
Cd8 Cells ◽  
Tnf Α ◽  
Ifn Γ ◽  
Synthetic Capacity

AbstractPeripheral blood lymphocytes (PBL) are able to synthesize various cytokines that play key roles in the immune response and intercellular signaling. Since alterations in cytokine production and/or activity occur in many pathological processes, the study of cytokine synthetic capacity of PBL is a valuable tool for assessing the immune profile. In this paper, we aimed to investigate the variability of interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-α) and interferon gamma (IFN-γ) synthetic capacity of CD4+/CD8+ T-cells stimulated ex-vivo in healthy subjects, by means of a commercial intracellular cytokine staining (ICS) protocol. Peripheral blood mononuclear cells were isolated from 16 healthy subjects by Ficoll gradient centrifugation and activated ex-vivo with PMA/Ionomycin/Brefeldin-A for 4 hours. Activated PBL were surface-stained for CD3/CD4/CD8, fixed and permeabilized. ICS was performed using anti-human IL-2/TNF-α/IFN-γ and samples were analyzed on a BD-FACSAria-III flow cytometer. We recorded high post-isolation and post-activation mean viabilities: 82.1% and 82.4% respectively, p=0.84. Both CD4+/CD8+ subpopulations were found to partially produce each of the three cytokines, but in different proportions. On average, a significantly greater percentage of CD4+ cells was shown to produce IL-2 and TNF-α, compared with CD8+ cells (61.5%+/-5.8 vs. 25%+/-5.6 and 26.9%+/-11 vs. 7.5%+/-3.3 respectively, p---lt---0.0001 for both). Contrarily, IFN-γ was produced by a higher proportion of CD8+ cells (8.4%+/-3.9 vs. 6.8%+/-3.2, p=0.01). These results show that the employed ICS protocol elicits a satisfactory and consistent cytokine response from PBL of healthy subjects. The collected data may be used to outline a preliminary reference range for future studies on both healthy/pathological subjects.

scholarly journals Cytokine production in ex-vivo stimulated fresh and cryopreserved T-cells

2021 ◽  
Vol 67 (2) ◽  
pp. 95-101
Author(s):  
Monica Vuță ◽  
Ionela-Maria Cotoi ◽  
Ion Bogdan Mănescu ◽  
Doina Ramona Manu ◽  
Minodora Dobreanu
Keyword(s):  
T Cells ◽  
Peripheral Blood ◽  
Cd4 T Cells ◽  
Mononuclear Cells ◽  
Cytokine Production ◽  
Ex Vivo ◽  
Gradient Centrifugation ◽  
Intracellular Cytokine Staining ◽  
Interleukin 2 ◽  
Middle Aged

Abstract Objective: In vitro cytokine production by peripheral blood mononuclear cells (PBMCs) is an important and reliable measure of immunocompetence. PBMC can be stimulated directly after isolation or frozen for later use. However, cryopreservation may affect cell recovery, viability and functionality. This study aims to investigate cytokine synthesis in ex-vivo stimulated fresh and cryopreserved CD4+ and CD4- T cells. Methods: PBMCs were obtained by Ficoll gradient centrifugation from heparinized peripheral blood of 6 middle-aged clinically healthy subjects. Half of these cells (labeled “Fresh”) was further processed and the other half (labeled “Cryo”) was cryopreserved at -140°C for up to 3 months. Fresh-PBMCs were activated with Phorbol-Myristate-Acetate/Ionomycin/Monensin for 5 hours immediately after isolation while Cryo-PBMCs were identically activated after thawing and cell resting. Activated cells were fixed, permeabilized and intracellular cytokine staining was performed using Phycoerythrin (PE)-conjugated antibodies for Interleukin-2 (IL-2), Tumor Necrosis Factor-alpha (TNF-a), and Interferon-gamma (IFN-g). All samples were analyzed within 24 hours by flow cytometry. Results: Both Fresh and Cryo CD3+CD4+/CD3+CD4- sub-populations partially produced each of the three cytokines. A higher percentage of CD4+ T cells produced IL-2 and TNF-a and a greater percentage of CD4- T cells were found to produce IFN-g. A significantly higher percentage of Cryo-lymphocytes was shown to produce TNF-a in both CD3+CD4+ (31.4% vs 24.9%, p=0.031) and CD3+CD4- (22.7% vs 17.9%, p=0.031) subpopulations. No notable difference was found for IL-2 and IFN-g production between Fresh and Cryo T cells. Conclusion: Cryopreservation for up to 3 months significantly increases TNF-a production of T-cells in clinically healthy middle-aged subjects.

scholarly journals Spontaneous Cytokine Production and Its Effect on Induced Production

2002 ◽  
Vol 9 (5) ◽  
pp. 1049-1056 ◽  
Author(s):  
Derrick Walker ◽  
Janine Jason ◽  
Kelly Wallace ◽  
Justin Slaughter ◽  
Virginia Whatley ◽  
...  
Keyword(s):  
T Cells ◽  
Cytokine Production ◽  
Ex Vivo ◽  
Interleukin 2 ◽  
Healthy Adults ◽  
Multiparameter Flow Cytometry ◽  
Parasitic Infections ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Ifn Γ

ABSTRACT Cytokines regulate cellular immune activity and are produced by a variety of cells, especially lymphocytes, monocytes, and macrophages. Multiparameter flow cytometry is often used to examine cell-specific cytokine production after in vitro phorbol 12-myristate 13-acetate and ionomycin induction, with brefeldin A or other agents added to inhibit protein secretion. Spontaneous ex vivo production reportedly rarely occurs. We examined the spontaneous production of interleukin 2 (IL-2), IL-4, IL-6, IL-8, IL-10, tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ) by peripheral-blood B lymphocytes, T cells, CD8− T cells, CD8+ T cells, CD3− CD16/56+ lymphocytes (natural killer [NK] cells), CD3+ CD16/56+ lymphocytes (natural T [NT] cells), and/or monocytes of 316 acutely ill hospitalized persons and 62 healthy adults in Malawi, Africa. We also evaluated the relationship between spontaneous and induced cytokine production. In patients, spontaneous TNF-α production occurred most frequently, followed in descending order by IFN-γ, IL-8, IL-4, IL-10, IL-6, and IL-2. Various cells of 60 patients spontaneously produced TNF-α; for 12 of these patients, TNF-α was the only cytokine produced spontaneously. Spontaneous cytokine production was most frequent in the immunoregulatory cells, NK and NT. For IL-2, IL-4, IL-6, IL-8, and IL-10, spontaneous cytokine production was associated with greater induced production. For TNF-α and IFN-γ, the relationships varied by cell type. For healthy adults, IL-6 was the cytokine most often produced spontaneously. Spontaneous cytokine production was not unusual in these acutely ill and healthy persons living in an area where human immunodeficiency virus, mycobacterial, malaria, and assorted parasitic infections are endemic. In such populations, spontaneous, as well as induced, cell-specific cytokine production should be measured and evaluated in relation to various disease states.

scholarly journals Ex Vivo Kinetics of Early and Long-Term Multifunctional Human Leukocyte Antigen E-Specific CD8+ Cells in Volunteers Immunized with the Ty21a Typhoid Vaccine

2010 ◽  
Vol 17 (9) ◽  
pp. 1305-1314 ◽  
Author(s):  
Rosângela Salerno-Goncalves ◽  
Rezwanul Wahid ◽  
Marcelo B. Sztein
Keyword(s):  
T Cells ◽  
Ex Vivo ◽  
Interleukin 2 ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Typhoid Vaccine ◽  
Tnf Α ◽  
Ifn Γ ◽  
Kinetics Of

ABSTRACT T cells are likely to play an important role in the host defense against Salmonella enterica serovar Typhi, the causative agent of typhoid fever. We have shown that HLA-E can function as a restriction element for S. Typhi-specific CD8+ T cells. Because of the potential importance of HLA-E-restricted CD8+ responses in resistance to Salmonella infection, we characterized these responses and investigated their kinetics of appearance and persistence in volunteers immunized orally with the licensed attenuated Ty21a strain typhoid vaccine. Cells were obtained from volunteers before and at days 2, 4, 7, 10, 14, 28, 42, 56, 120, 180, 360, and 720 after immunization. An ex vivo multicolor staining panel including antibodies to CD107a and -b, interleukin-2, gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α) was used to functionally assess memory T-cell subsets by flow cytometry. Increases in cytokine-secreting CD8+ cells were observed in the T effector/memory (TEM) and CD45RA+ TEM (TEMRA) subsets as early as 4 days after immunization and persisted, particularly in the TEMRA subset, up to 2 years after immunization. The majority of HLA-E-restricted CD8+ cells 28 to 56 days after immunization coexpressed CD107, IFN-γ, and TNF-α, showing characteristic features of multifunctional T cells. In summary, the multifunctionality and longevity of the HLA-E-restricted CD8 responses observed in this study highlight their significance in adaptive immunity to S. Typhi. Finally, this is the first demonstration, in either animals or humans, of the presence of long-term multifunctional HLA-E-restricted CD8+ cells after immunization.

scholarly journals Persistent High Frequencies of Varicella-Zoster Virus ORF4 Protein-Specific CD4+ T Cells after Primary Infection

2006 ◽  
Vol 80 (19) ◽  
pp. 9772-9778 ◽  
Author(s):  
Louise Jones ◽  
Antony P. Black ◽  
Gathsaurie N. Malavige ◽  
Graham S. Ogg
Keyword(s):  
T Cells ◽  
Varicella Zoster Virus ◽  
Peripheral Blood ◽  
Primary Infection ◽  
Ex Vivo ◽  
High Frequencies ◽  
Varicella Zoster ◽  
Early Protein ◽  
Orf4 Protein ◽  
Ifn Γ

ABSTRACT Open reading frame 4 (ORF4) of varicella-zoster virus (VZV) encodes an immediate-early protein that is believed to be important for viral infectivity and establishing latency. Evidence suggests that VZV-specific T cells are crucial in the control of viral replication, but there are no data addressing the existence of potential ORF4 protein-specific CD4+ T cells. We tested the hypothesis that VZV ORF4 protein-specific CD4+ T cells could be identified and characterized within the peripheral blood of healthy immune donors following primary infection. Gamma interferon (IFN-γ) immunosorbent assays were used to screen peripheral blood mononuclear cells obtained from healthy seropositive donors for responses to overlapping ORF4 peptides, viral lysate, and live vaccine. High frequencies of ORF4 protein-specific T cells were detected ex vivo in individuals up to 52 years after primary infection. Several immunogenic regions of the ORF4 protein were identified, including a commonly recognized epitope which was restricted through HLA-DRB1*07. Total ORF4 protein-specific responses comprised 19.7% and 20.7% of the total lysate and vaccine responses, respectively, and were dominated by CD4+ T cells. Indeed, CD4+ T cells were found to dominate the overall virus-specific IFN-γ cellular immune response both ex vivo and after expansion in vitro. In summary, we have identified an ORF4 protein as a novel target antigen for persistent VZV-specific CD4+ T cells, with implications for disease pathogenesis and future vaccine development.

Activation-Dependent Expression of an Interleukin-2 Transgene Mediated by Transduction with a Lentiviral Vector Enhances T Cell Functions.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 5273-5273
Author(s):  
Qi Sun ◽  
Karen Chorney ◽  
Carol Stine ◽  
Kenneth G. Lucas
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Lentiviral Vector ◽  
Ex Vivo ◽  
Interleukin 2 ◽  
Immune Functions ◽  
Cell Functions ◽  
Genetically Engineer ◽  
Ifn Γ

Abstract Adoptive T cell immunotherapy (ATCI) is an evolving strategy that explores antigen-specific T cells manipulated ex vivo as therapeutic agents. Although the concept of ATCI has been tested clinically, with success in the treatment of post-transplant EBV induced lymphoproliferative disease, one of the major obstacles hindering its application to other malignancies is the procurement of tumor-specific T cells that possess potent anti-tumor functions even in the inhibitory environment at the tumor sites. This study aims to genetically engineer enriched viral specific T cells for improved immune functions. A self-inactivating lentiviral vector (SIN) CD69p-IL2 was constructed to encode the transgene interleukin-2 (IL2) under the control of a human CD69 promoter (CD69p), and this vector was tested in ex vivo cultivated EBV-specific T cells. SIN vector allows a high degree of autonomy for the internal promoter, and CD69 expression in the T cells is closely associated with T cell activation. Experiments showed that the SIN vectors efficiently transduced EBV-specific T cells, both CD4 and CD8. Furthermore, the newly cloned CD69p exhibited a higher degree of responsiveness to physiological antigen stimulation than the early promoter from the cytomegalovirus (CMVp). In response to stimulation by EBV-infected B cells, the percentage of IL2 expressing cells was 2 fold higher for the activated CD69p-IL2 transduced T cells than the non-transduced, or the CMVp-IL2 transduced, counterparts. In correlation with the stronger IL2 expression, 3 fold more T cells expressed the anti-viral cytokine interferon-γ (IFN-γ) in the CD69p-IL2 transduced T cells than the CMVp-IL2 transduced, and the IFN-γ expression at the single cell level was 2 fold higher in the former, indicating an enhanced functionality. While the culture supernatant from the CMVp-IL2 transduced T cells contained IL2 at a concentration 2000 fold higher than the non-transduced T cells, the IL2 level in the media from the CD69p-IL2 transduced T cells was comparable to that in the control, suggesting the IL2 expression mediated by the CD69p more relevant to T cell functions than the CMVp. These results may serve as a foundation for the further development and clinical application of specific T cells engineered for enhanced immune functions.

Preliminary biomarker and pharmacodynamic data from a phase I study of single-agent bispecific antibody T-cell engager GBR 1302 in subjects with HER2-positive cancers.

2018 ◽  
Vol 36 (5_suppl) ◽  
pp. 69-69 ◽  
Author(s):  
Martin Wermke ◽  
Juergen Alt ◽  
John S. Kauh ◽  
Jonathan Back ◽  
Yacine Salhi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Solid Tumors ◽  
Peripheral Blood ◽  
Bispecific Antibody ◽  
Cell Populations ◽  
Single Subject ◽  
Her2 Positive ◽  
Tnf Α ◽  
Ifn Γ

69 Background: HER2 is overexpressed in many solid tumors and is a validated therapeutic target. GBR 1302 is a HER2xCD3 bispecific antibody engineered (using Glenmark’s BEAT® platform) to direct T-cells to HER2-expressing tumor cells. GBR1302-101 (NCT02829372) is an ongoing, multicenter, open-label, first-in-human study of GBR 1302 in subjects with HER2-positive cancers to evaluate the safety, tolerability, and preliminary efficacy of GBR 1302, and to elucidate the mechanism(s) by which it redirects T-cells to tumor and enhances cytolytic activity of cytotoxic T-cells. Methods: Adults with progressive HER2-positive solid tumors with no available standard or curative treatment receive intravenous GBR 1302 on Day 1 and Day 15 in 28-day treatment cycles at escalating dose levels, starting at 1 ng/kg. The first 4 cohorts consist of a single subject; subsequent cohorts enroll using a 3+3 design. The primary and secondary efficacy and safety endpoints of this trial will be reported at the end of the study. Preliminary pharmacodynamic (PD) data are reported for cellular biomarkers and cytokines as assessed by FACS and ELISA in peripheral blood. Results: Beginning at 30 ng/kg dosing of GBR 1302 (Cohort 4), numbers of peripheral blood CD3, CD4, and CD8 positive T-cell populations decreased within 6 hours of initiating administration, but recovered to levels at or above baseline by 48 hours. A parallel, transient increase was observed in peripheral blood cytokines (IL-2, IL-6, IL-10, IFN-γ, TNF-α). At doses greater than 30 ng/kg, more pronounced cytokine increases were observed, which normalized at 12 hours. At the highest dose level for which data are available (n = 8 subjects; Cohort 5), changes from baseline in cytokine expression at ~340 hours were greater by ~60-fold for IL-6, ~30-fold for IL-2, ~3-fold for IFN-γ, ~5-fold for TNF-α, and ~18-fold for IL-10. Two subjects treated at 100 ng/kg experienced Grade 1 cytokine release syndrome, evidenced by short-lived fever spikes. Dose escalation is ongoing. Conclusions: Preliminary PD data indicate changes in peripheral T-cell populations and inflammatory cytokines following GBR 1302 treatment. Clinical trial information: NCT02829372.

scholarly journals Clinical and Immunological Insights on Severe, Adverse Neurotropic and Viscerotropic Disease following 17D Yellow Fever Vaccination

2009 ◽  
Vol 17 (1) ◽  
pp. 118-126 ◽  
Author(s):  
Maria Luiza Silva ◽  
Luçandra Ramos Espírito-Santo ◽  
Marina Angela Martins ◽  
Denise Silveira-Lemos ◽  
Vanessa Peruhype-Magalhães ◽  
...  
Keyword(s):  
T Cells ◽  
B Lymphocytes ◽  
Yellow Fever ◽  
Ex Vivo ◽  
Present Report ◽  
Suspected Case ◽  
Activated T Cells ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Ifn Γ

ABSTRACT Yellow fever (YF) vaccines (17D-204 and 17DD) are well tolerated and cause very low rates of severe adverse events (YEL-SAE), such as serious allergic reactions, neurotropic adverse diseases (YEL-AND), and viscerotropic diseases (YEL-AVD). Viral and host factors have been postulated to explain the basis of YEL-SAE. However, the mechanisms underlying the occurrence of YEL-SAE remain unknown. The present report provides a detailed immunological analysis of a 23-year-old female patient. The patient developed a suspected case of severe YEL-AVD with encephalitis, as well as with pancreatitis and myositis, following receipt of a 17D-204 YF vaccination. The patient exhibited a decreased level of expression of Fc-γR in monocytes (CD16, CD32, and CD64), along with increased levels of NK T cells (an increased CD3+ CD16+/− CD56+/−/CD3+ ratio), activated T cells (CD4+ and CD8+ cells), and B lymphocytes. Enhanced levels of plasmatic cytokines (interleukin-6 [IL-6], IL-17, IL-4, IL-5, and IL-10) as well as an exacerbated ex vivo intracytoplasmic cytokine pattern, mainly observed within NK cells (gamma interferon positive [IFN-γ+], tumor necrosis factor alpha positive [TNF-α+], and IL-4 positive [IL-4+]), CD8+ T cells (IL-4+ and IL-5+), and B lymphocytes (TNF-α+, IL-4+, and IL-10+). The analysis of CD4+ T cells revealed a complex profile that consisted of an increased frequency of IL-12+ and IFN-γ+ cells and a decreased percentage of TNF-α+, IL-4+, and IL-5+ cells. Depressed cytokine synthesis was observed in monocytes (TNF-α+) following the provision of antigenic stimuli in vitro. These results support the hypothesis that a strong adaptive response and abnormalities in the innate immune system may be involved in the establishment of YEL-AND and YEL-AVD.

scholarly journals Sex differences in morphofunctional changes in the immune system in Wistar rats of different age groups with experimental endotoxinemia

2020 ◽  
pp. 65-73
Author(s):  
Anna M. Kosyreva ◽  
Olga V. Makarova
Keyword(s):  
Gender Differences ◽  
Sex Differences ◽  
Immune System ◽  
Peripheral Blood ◽  
Wistar Rats ◽  
Ex Vivo ◽  
Age Groups ◽  
Mature Adult ◽  
Tnf Α ◽  
Ifn Γ

Objective. The aim was revealing gender differences in morphological and functional changes of lymphoid organs (thymus and spleen), changes of cytokine production and subpopulation composition of peripheral blood lymphocytes in Wistar rats of three age groups with endotoxemia. Materials and methods. We used male and female Wistar rats of three age groups: newborns, prepubertal and sexually mature adult rats. A day after the injection of 15 mg/kg of O26:B6 E. coli lipopolysaccharide (LPS), the volume fraction of the functional zones of the thymus and spleen, the number of AnnexinV + apoptotically dying cells in the thymus, the relative and absolute number of lymphocyte subpopulations (CD3+CD4+, CD3+CD8a+, CD4+CD25+Foxp3+, CD3-CD45R+) in peripheral blood and ex vivo production of IL-2, IL-4, IFN-γ and TNF-α were estimated. Results. Sex differences in the response of the immune system after the LPS injection in different age periods are expressed differently: in the neonatal period, there is immunosuppression in females (decrease in the ex vivo production of IL-2, TNF-α and IFN-γ), and there is activation of pro-inflammatory reactions in males (increase in ex vivo production of IL-2 and TNF-α). As compared with other age periods at prepubertal age, LPS-induced immunological disorders are more pronounced, and gender differences are minimal and related only to the number of T-regulatory and B-lymphocytes. In the adults, the LPS-induced immunosuppression is most pronounced in males - they have a decrease in the production of all the cytokines studied and a decrease in the number of cytotoxic and regulatory T-lymphocytes and B-cells. Conclusion. Thus, in each of the studied age periods - newborn, prepubertal and adult, the sexual differences in the immune system reactions are expressed differently and, apparently, these differences are determined by the content of sex steroid hormones, the concentration of which varies with age.

CD8+CD28− T cells: key cytotoxic players impacting disease pathogenesis in chronic HBV infection

2019 ◽  
Vol 133 (17) ◽  
pp. 1917-1934
Author(s):  
Madhuparna Nandi ◽  
Sourina Pal ◽  
Sumantra Ghosh ◽  
Bidhan Chandra Chakraborty ◽  
Debangana Dey ◽  
...  
Keyword(s):  
T Cells ◽  
Chronic Hepatitis ◽  
T Cell ◽  
Hepatitis B ◽  
Chronic Hepatitis B ◽  
Peripheral Blood ◽  
Cd4 T Cells ◽  
Hepatitis B E Antigen ◽  
Tnf Α ◽  
Ifn Γ

Abstract During chronic hepatitis B (CHB), CD8+ T cells down-regulate CD28, the primary co-stimulation molecule for T-cell activation. Diverse functional attributes of CD8+CD28− T cells are suggested in various disease contexts. The present study aimed to characterize CD8+CD28− T cells in different phases of chronic Hepatitis B virus (HBV) infection (CHI)- Immune-tolerance (IT), Hepatitis B e-antigen-positive CHB (EP-CHB), Inactive carriers (IC) and Hepatitis B e-antigen-negative CHB (EN-CHB), to appraise their contribution in HBV-related disease pathophysiology. Flow cytometry analysis of T cells in peripheral blood of study subjects revealed enhanced CD8+CD28− T-cell accumulation in EP-/EN-CHB, compared with IT/IC and they expanded equivalently in HBV-specific and non-specific CD8+ T-cell compartments. Profound increase in CD8+CD28− T cells expressing perforin/granzyme-B/CD57/IFN-γ/TNF-α and markers of terminal differentiation were observed exclusively in EP-/EN-CHB. Further, activation with anti-NKG2D resulted in heightened IFN-γ/TNF-α production selectively from CD8+CD28− T cells, suggesting NKG2D-mediated alternative co-stimulation. CD8+CD28− T cells sorted from CHB patients induced enhanced apoptosis of peripheral blood mononuclear cells (PBMC), including CD4+ T cells. However, NKG2D-ligand (major histocompatibility complex class I chain-related molecule A/B (MICA/B)) was preferentially expressed by HBV-specific CD4+ T cells of CHB patients, making these cells a potential target to NKG2D-dependent CD8+CD28− T-cell killing. Both CD28+ and CD28− T cells in CHB expressed CXCR3 at similar levels and thus capable of homing to the liver. A positive correlation was seen between CD8+CD28− T-cell frequency and serum-alanine transaminase (ALT) levels and CHB-derived CD8+CD28− T cells caused pronounced cell death in HBV-transfected Huh7 cells. Immunofluorescence staining identified greater intrahepatic incidence of CD8+CD28− T cells but decline in CD4+ T cells in CHB than IC. Collectively, CD8+CD28− T cells demonstrated differential distribution and phenotypic/functional skewing in different CHI phases and contribute to disease progression by Perforin-Granzyme- or IFN-γ-TNF-α-mediated cytotoxicity while restraining antiviral immunity through NKG2D-dependent HBV-specific CD4+ T-cell depletion.

scholarly journals Differential Regulation of Cytokine Production by CD1d-Restricted NKT Cells in Response to Superantigen Staphylococcal Enterotoxin B Exposure

2006 ◽  
Vol 74 (1) ◽  
pp. 282-288 ◽  
Author(s):  
Melanie J. Ragin ◽  
Nisebita Sahu ◽  
Avery August
Keyword(s):  
T Cells ◽  
T Cell ◽  
Interleukin 2 ◽  
Nkt Cells ◽  
Staphylococcal Enterotoxin ◽  
Cytokine Secretion ◽  
Staphylococcal Enterotoxin B ◽  
Tnf Α ◽  
Ifn Γ ◽  
Enterotoxin B

ABSTRACT NKT cells are a heterogeneous population characterized by the ability to rapidly produce cytokines, such as interleukin 2 (IL-2), IL-4, and gamma interferon (IFN-γ) in response to infections by viruses, bacteria, and parasites. The bacterial superantigen staphylococcal enterotoxin B (SEB) interacts with T cells bearing the Vβ3, -7, or -8 T-cell receptors, inducing their expansion and cytokine secretion, leading to death in some cases due to cytokine poisoning. The majority of NKT cells bear the Vβ7 or -8 T-cell receptor, suggesting that they may play a role in regulating this response. Using mice lacking NKT cells (CD1d−/− and Jα18−/− mice), we set out to identify the role of these cells in T-cell expansion, cytokine secretion, and toxicity induced by exposure to SEB. We find that Vβ8+ CD4+ T-cell populations similarly expand in wild-type (WT) and NKT cell-null mice and that NKT cells did not regulate the secretion of IL-2. By contrast, these cells positively regulated the secretion of IL-4 and IFN-γ production and negatively regulated the secretion of tumor necrosis factor alpha (TNF-α). However, this negative regulation of TNF-α secretion by NKT cells provides only a minor protective effect on SEB-mediated shock in WT mice compared to mice lacking NKT cells. These data suggest that NKT cells may regulate the nature of the cytokine response to exposure to the superantigen SEB and may act as regulatory T cells during exposure to this superantigen.

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