scholarly journals Platelets in ITP: Victims in Charge of Their Own Fate?

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3235
Author(s):  
Vivianne S. Nelson ◽  
Anne-Tess C. Jolink ◽  
Sufia N. Amini ◽  
Jaap Jan Zwaginga ◽  
Tanja Netelenbos ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Immune Responses ◽  
Immune Thrombocytopenia ◽  
T Regulatory Cells ◽  
Cytotoxic T Cell ◽  
Regulatory Cells ◽  
The Past ◽  
Immune Balance ◽  
Platelet Microparticles

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder. The pathophysiological mechanisms leading to low platelet levels in ITP have not been resolved, but at least involve autoantibody-dependent and/or cytotoxic T cell mediated platelet clearance and impaired megakaryopoiesis. In addition, T cell imbalances involving T regulatory cells (Tregs) also appear to play an important role. Intriguingly, over the past years it has become evident that platelets not only mediate hemostasis, but are able to modulate inflammatory and immunological processes upon activation. Platelets, therefore, might play an immuno-modulatory role in the pathogenesis and pathophysiology of ITP. In this respect, we propose several possible pathways in which platelets themselves may participate in the immune response in ITP. First, we will elaborate on how platelets might directly promote inflammation or stimulate immune responses in ITP. Second, we will discuss two ways in which platelet microparticles (PMPs) might contribute to the disrupted immune balance and impaired thrombopoiesis by megakaryocytes in ITP. Importantly, from these insights, new starting points for further research and for the design of potential future therapies for ITP can be envisioned.

scholarly journals The Effect of Citrus Peel Extracts on Cytokines Levels and T Regulatory Cells in Acute Liver Injury

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Ia Pantsulaia ◽  
Manana Iobadze ◽  
Nato Pantsulaia ◽  
Tinatin Chikovani
Keyword(s):  
T Cell ◽  
Liver Injury ◽  
Immune Responses ◽  
Autoimmune Hepatitis ◽  
T Regulatory Cells ◽  
Regulatory Cells ◽  
Hepatocellular Injury ◽  
Citrus Peel ◽  
Anti Inflammatory

Background. T cell-mediated immune responses contribute to the hepatocellular injury during autoimmune hepatitis, viral infection, and hepatotoxins. Pharmacological compounds regulating immune responses are suitable candidates for prevention/treatment of this pathology. Therefore, the main aim of this study was to define the effects of antioxidant, anti-inflammatory mixture of citrus peel extract (CPE) on the immune-mediated liver injury.Methods. The influence of CPE on liver injury was determined by the activity of transaminases in plasma and the histological changes. Anti-inflammatory and antioxidant effects were studied by measuring frequency of T regulatory cells (Tregs), cytokines (TNF-α, IL-10, and IFN-γ), and nitric oxide levels.Results. The CPE application notably prevents development of liver injury through decreasing levels of both cytokines (TNF-alpha, INF) and regulatory T cells and increasing levels of IL-10. CPE injection also diminished the serum NO, which in turn resulted in evident reduction of the liver damage.Conclusion. Our findings represent the primary preclinical data indicating that the CPEin vivocould ameliorate Con A induced hepatitis. The low dose of CPE most likely can be used for the treatment of the T cell-mediated liver injury as in autoimmune hepatitis, alcoholic hepatitis, and chronic viral hepatitis.

scholarly journals Proinsulin-specific T regulatory cells may control immune responses in type 1 diabetes: implications for adoptive therapy

2020 ◽  
Vol 8 (1) ◽  
pp. e000873 ◽  
Author(s):  
Mateusz Gliwiński ◽  
Dorota Iwaszkiewicz-Grześ ◽  
Anna Wołoszyn-Durkiewicz ◽  
Monika Tarnowska ◽  
Magdalena Żalińska ◽  
...  
Keyword(s):  
T Cells ◽  
Type 1 Diabetes ◽  
T Cell ◽  
Immune Responses ◽  
T Regulatory Cells ◽  
Cell Receptor ◽  
Regulatory Cells ◽  
Antigen Specificity ◽  
Adoptive Therapy

ObjectiveHere we looked for possible mechanisms regulating the progression of type 1 diabetes mellitus (T1DM). In this disease, autoaggressive T cells (T conventional cells, Tconvs) not properly controlled by T regulatory cells (Tregs) destroy pancreatic islets.Research design and methodsWe compared the T-cell compartment of patients with newly diagnosed T1DM (NDT1DM) with long-duration T1DM (LDT1DM) ones. The third group consisted of patients with LDT1DM treated previously with polyclonal Tregs (LDT1DM with Tregs). We have also looked if the differences might be dependent on the antigen specificity of Tregs expanded for clinical use and autologous sentinel Tconvs.ResultsPatients with LDT1DM were characterized by T-cell immunosenescence-like changes and expansion of similar vβ/T-cell receptor (TCR) clones in Tconvs and Tregs. The treatment with Tregs was associated with some inhibition of these effects. Patients with LDT1DM possessed an increased percentage of various proinsulin-specific T cells but not GAD65-specific ones. The percentages of all antigen-specific subsets were higher in the expansion cultures than in the peripheral blood. The proliferation was more intense in proinsulin-specific Tconvs than in specific Tregs but the levels of some proinsulin-specific Tregs were exceptionally high at baseline and remained higher in the expanded clinical product than the levels of respective Tconvs in sentinel cultures.ConclusionsT1DM is associated with immunosenescence-like changes and reduced diversity of T-cell clones. Preferential expansion of the same TCR families in both Tconvs and Tregs suggests a common trigger/autoantigen responsible. Interestingly, the therapy with polyclonal Tregs was associated with some inhibition of these effects. Proinsulin-specific Tregs appeared to be dominant in the immune responses in patients with T1DM and probably associated with better control over respective autoimmune Tconvs.Trial registration numberEudraCT 2014-004319-35.

scholarly journals Modelling the interplay between the CD4$$^{+}$$/CD8$$^{+}$$ T-cell ratio and the expression of MHC-I in tumours

2021 ◽  
Vol 83 (1) ◽  
Author(s):  
Christian John Hurry ◽  
Alexander Mozeika ◽  
Alessia Annibale
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Critical Level ◽  
Cell Infiltration ◽  
Cytotoxic T Cell ◽  
Mhc I ◽  
Cell Ratio ◽  
T Cell Infiltration ◽  
Immunological Mechanisms ◽  
Tcr Repertoire

AbstractDescribing the anti-tumour immune response as a series of cellular kinetic reactions from known immunological mechanisms, we create a mathematical model that shows the CD4$$^{+}$$ + /CD8$$^{+}$$ + T-cell ratio, T-cell infiltration and the expression of MHC-I to be interacting factors in tumour elimination. Methods from dynamical systems theory and non-equilibrium statistical mechanics are used to model the T-cell dependent anti-tumour immune response. Our model predicts a critical level of MHC-I expression which determines whether or not the tumour escapes the immune response. This critical level of MHC-I depends on the helper/cytotoxic T-cell ratio. However, our model also suggests that the immune system is robust against small changes in this ratio. We also find that T-cell infiltration and the specificity of the intra-tumour TCR repertoire will affect the critical MHC-I expression. Our work suggests that the functional form of the time evolution of MHC-I expression may explain the qualitative behaviour of tumour growth seen in patients.

scholarly journals TAMI-07. THE IMMUNE MICROENVIRONMENT IN LOWER GRADE GLIOMAS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii214-ii214
Author(s):  
Anupam Kumar ◽  
Katharine Chen ◽  
Claudia Petritsch ◽  
Theodore Nicolaides ◽  
Mariarita Santi-Vicini ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Cd8 T Cells ◽  
Molecular Mechanisms ◽  
T Regulatory Cells ◽  
Immune Cell ◽  
T Cell Response ◽  
Cytotoxic T Cell ◽  
Lower Grade ◽  
Functional Relationships

Abstract The determinants of the tumor-associated immune response in brain tumors are poorly understood. Using tumor samples from two molecularly distinct subtypes of lower grade glioma, MAPK-driven glioma with biallelic inactivation of CDKN2A (n=30) and IDH-mutant, 1p/19q-intact astrocytoma (n=29), we demonstrate qualitative and quantitative differences in the tumor-associated immune response and we investigate the molecular mechanisms involved. Histologically the MAPK-driven gliomas were comprised of pleomorphic xanthoastrocytoma (PXA) (n=11) and anaplastic PXA (n=19). Seven patients had paired samples from two sequential surgeries. Immune cell populations and their activity were determined by quantitative multiplex immunostaining and Digital Spatial Profiling and gene expression was analyzed by Nanostring. Functional studies were performed using established cell lines and two new patient-derived lines from MAPK-driven LGGs. MAPK-driven tumors exhibited an increased number of CD8+ T cells and tumor-associated microglial/macrophage (TAMs), including CD163+ TAMs, as compared to IDH-mutant astrocytoma. In contrast, IDH-mutant tumors had increased FOXP3+ immunosuppressive T regulatory cells. Transcriptional and protein level analyses in MAPK-driven tumors suggested an active cytotoxic T cell response with robust expression of granzyme B, present on 27% of CD8+ T cells, increased MHC class I expression, and altered cytokine profiles. Interestingly, MAPK-driven tumors also had increased expression of immunosuppressive molecules, including CXCR4, PD-L1, and VEGFA. Expression differences for cell surface and secreted proteins were confirmed in patient-derived tumor lines and functional relationships between altered chemokine expression and immune cell infiltration was investigated. Our data provide novel insights into the immune contexture of MAPK driven LGGs and suggest MAPK driven gliomas with biallelic inactivation of CDKN2A may be particularly vulnerable to immunotherapeutic modulation

scholarly journals Optimized Adenovirus-Antibody Complexes Stimulate Strong Cellular and Humoral Immune Responses against an Encoded Antigen in Naïve Mice and Those with Preexisting Immunity

2011 ◽  
Vol 19 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Jin Huk Choi ◽  
Joe Dekker ◽  
Stephen C. Schafer ◽  
Jobby John ◽  
Craig E. Whitfill ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
T Cell Responses ◽  
Transduction Efficiency ◽  
Virus Antibody ◽  
Cell Responses

ABSTRACTThe immune response to recombinant adenoviruses is the most significant impediment to their clinical use for immunization. We test the hypothesis that specific virus-antibody combinations dictate the type of immune response generated against the adenovirus and its transgene cassette under certain physiological conditions while minimizing vector-induced toxicity.In vitroandin vivoassays were used to characterize the transduction efficiency, the T and B cell responses to the encoded transgene, and the toxicity of 1 × 1011adenovirus particles mixed with different concentrations of neutralizing antibodies. Complexes formed at concentrations of 500 to 0.05 times the 50% neutralizing dose (ND50) elicited strong virus- and transgene-specific T cell responses. The 0.05-ND50formulation elicited measurable anti-transgene antibodies that were similar to those of virus alone (P= 0.07). This preparation also elicited very strong transgene-specific memory T cell responses (28.6 ± 5.2% proliferation versus 7.7 ± 1.4% for virus alone). Preexisting immunity significantly reduced all responses elicited by these formulations. Although lower concentrations (0.005 and 0.0005 ND50) of antibody did not improve cellular and humoral responses in naïve animals, they did promote strong cellular (0.005 ND50) and humoral (0.0005 ND50) responses in mice with preexisting immunity. Some virus-antibody complexes may improve the potency of adenovirus-based vaccines in naïve individuals, while others can sway the immune response in those with preexisting immunity. Additional studies with these and other virus-antibody ratios may be useful to predict and model the type of immune responses generated against a transgene in those with different levels of exposure to adenovirus.

Distinct regulatory CD4+T cell subsets; differences between naïve and antigen specific T regulatory cells

2011 ◽  
Vol 23 (5) ◽  
pp. 641-647 ◽  
Author(s):  
Bruce M Hall ◽  
Nirupama D Verma ◽  
Giang T Tran ◽  
Suzanne J Hodgkinson
Keyword(s):  
T Cell ◽  
T Regulatory Cells ◽  
T Cell Subsets ◽  
Cd4 T Cell ◽  
Regulatory Cells

scholarly journals Clearance of Staphylococcus aureus Nasal Carriage Is T Cell Dependent and Mediated through Interleukin-17A Expression and Neutrophil Influx

2013 ◽  
Vol 81 (6) ◽  
pp. 2070-2075 ◽  
Author(s):  
Nathan K. Archer ◽  
Janette M. Harro ◽  
Mark E. Shirtliff
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Response ◽  
T Cell ◽  
Immune Responses ◽  
Neutrophil Migration ◽  
Nasal Carriage ◽  
Causal Connection ◽  
Content Type ◽  
Neutrophil Influx ◽  
Increased Risk

ABSTRACTThe anterior nares of humans are the major reservoir forStaphylococcus aureuscolonization. Approximately 20% of the healthy human population is persistently and 80% is intermittently colonized withS. aureusin the nasal cavity. Previous studies have shown a strong causal connection betweenS. aureusnasal carriage and increased risk of nosocomial infection, as well as increased carriage due to immune dysfunction. However, the immune responses that permit persistence or mediate clearance ofS. aureuson the nasal mucosa are fundamentally undefined. In this study, we developed a carriage model in C57BL/6J mice and showed that clearance begins 14 days postinoculation. In contrast, SCID mice that have a deficient adaptive immune response are unable to eliminateS. aureuseven after 28 days postinoculation. Furthermore, decolonization was found to be T cell mediated but B cell independent by evaluating carriage clearance in T-cell receptor β/δ (TCR-β/δ) knockout (KO) and IgH-μ KO mice, respectively. Upregulation of the cytokines interleukin 1β (IL-1β), KC (also termed CXC ligand 1 [CXCL1]), and IL-17A occurred following inoculation with intranasalS. aureus. IL-17A production was crucial for clearance, since IL-17A-deficient mice were unable to effectively eliminateS. aureuscarriage. Subsequently, cell differential counts were evaluated from nasal lavage fluid obtained from wild-type and IL-17A-deficient colonized mice. These counts displayed IL-17A-dependent neutrophil migration. Antibody-mediated depletion of neutrophils in colonized mice caused reduced clearance compared to that in isotype-treated controls. Our data suggest that the Th17-associated immune response is required for nasal decolonization. This response is T cell dependent and mediated via IL-17A production and neutrophil influx. Th17-associated immune responses may be targeted for strategies to mitigate distal infections originating from persistentS. aureuscarriage in humans.

scholarly journals EFFICIENCY OF THE FORMATION OF ANTITUMOR IMMUNE RESPONSES IN THE SYSTEM OF PREVENTIVE VACCINATION OF MICE WITH TESTICULAR ANTIGENS

2021 ◽  
Vol 23 (4) ◽  
pp. 665-670
Author(s):  
A. B. Dorzhieva ◽  
T. S. Khabalova ◽  
Yu. E. Androsova ◽  
E. A. Kaschenko ◽  
I. P. Ivanova ◽  
...  
Keyword(s):  
Immune Responses ◽  
Tumor Cells ◽  
T Regulatory Cells ◽  
Specific Method ◽  
Large Set ◽  
Chemotherapeutic Drugs ◽  
Regulatory Cells ◽  
Biochemical Processes ◽  
Preventive Vaccination ◽  
Experimental Group

Аppearance of a malignant tumor is associated with impaired mechanisms of proliferation, differentiation, apoptosis ability. However, these changes are not enough for immune system to recognize and destroy mutated cells. Weak immunogenicity of tumor-associated antigens (TAA) and the insufficiency of co-stimulating molecules on the surface of tumor cells is a reason for this phenomenon Since biochemical processes of tumor cells and healthy tissue cells are identical, therefore creation of effective chemotherapeutic drugs is limited not by selectivity of their action. So antitumor vaccination is the most effective specific method for both preventing recurrence of a disease and a therapeutic treatment tool in oncology. Xenogeneic proteins are highly immunogenic and effective in breaking immune tolerance to human analogs. In our work, we used sheep testicular AG as a source xenogenic TAAs. Sheep testicles contain a large set of TAAs. Experimental mice were immunized with type liposomal testicular vaccine from sheep, one month after vaccination, to induce tumor growth, cells of carcinoma LLC were implanted in mouse. The life expectancy of the experimental group of mice was 2 times higher compared to the syngenetic control and 20% of them did not develop the tumor at all. In the spleen of mice who did not have tumors after pre-vaccination sheep liposomal testicular AG, T-regulatory cells and T-memory cells were measured. We found a credible decrease in both naive Treg (CD4+CD25+), activated (CD4+CD25+FoxP3+) and both T-memory (CD4+CD44+) and central memory (CD4+CD44+CD62L+) in spleen pre-vaccination mice with compared to the contral intact spleen. Content of IFNg and IL-10 in supernatants of mouse slenocytes derived from vaccinated mice with no tumors was investigated and showed a reliable decrease in the amount of IL-10, but not IFNg. We believe that immunization with xenogenic tumor AGs can lead to the formation of a protective antitumor response. 

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