Helper Cell Population Research Articles

MicroRNA-155 plays a critical role in the establishment of latency in murine γ-herpesvirus infection (VIR1P.1148)

Abstract Gammaherpesvirus infection in immunosuppressed populations is associated with severe disease. MicroRNA-155 (miR155) has been shown to play significant roles in the immune response, including in the formation of germinal centers (GC) and the development and maturation of T follicular helper cells (Tfh). We sought to determine the relative contribution of miR-155 in the T and B cell compartments to latent murine gammaherpesvirus infection. Mice deficient in miR-155 had a 100-fold decrease in latent viral load, measured by qPCR, and exhibited decreases in both follicular helper cells and germinal center B cells. However, infection of mixed bone marrow chimeric mice showed a similar latent viral burden in both WT and miR-155 deficient B cells. Therefore the role of miR-155 may not be B cell intrinsic, but is likely mediated in part due to the regulation that miR155 exerts on the T follicular helper cell population. Studies using a YFP marker virus also address roles for miR-155 in virus reactivation and maintenance of latency. Further elucidating the relative role of miR155 on these cell populations will provide key insights into the development of latency in this model system.

Modulatory Effects of Astragalus Polysaccharides on T-Cell Polarization in Mice with Polymicrobial Sepsis.

Background. This study evaluated the impact of different doses of Astragalus polysaccharides (APS) on the functional status and phenotype of T cells during polymicrobial sepsis. Methods. On day 1 after cecal ligation and puncture, mice were treated with either saline, 100 (A100), 200 (A200), or 400 mg APS/kg body weight (BW) (A400) by an intraperitoneal injection daily for 4 days. All mice were sacrificed 5 days after the operation. Results. APS treatment reversed the sepsis-induced decrement in the T helper (Th) cell population, and the percentage of activated Th cells also increased in the spleen and Peyer's patches. APS administration downregulated the percentages of circulating Th2 cells and regulatory T cells (Treg), and the percentage of Th17 cells in blood was upregulated in the A400 group. Weight loss and kidney injury were attenuated in the A100 and A200 groups but not in the A400 group at the end of the study. Conclusions. Treatments with 100 and 200 mg APS/kg BW reduced Treg populations and elicited a more-balanced Th1/Th2 response that consequently attenuated immunosuppression in polymicrobial sepsis. High-dose APS administration led to excessive responses of Th17 cells which may have adverse effects in sepsis-induced organ injury.

Individual T Helper Cells Have a Quantitative Cytokine Memory

The probabilistic expression of cytokine genes in differentiated T helper (Th) cell populations remains ill defined. By single-cell analyses and mathematical modeling, we show that one stimulation featured stable cytokine nonproducers as well as stable producers with wide cell-to-cell variability in the magnitude of expression. Focusing on interferon-γ (IFN-γ) expression by Th1 cells, mathematical modeling predicted that this behavior reflected different cell-intrinsic capacities and not mere gene-expression noise. In vivo, Th1 cells sort purified by secreted IFN-γ amounts preserved a quantitative memory for both probability and magnitude of IFN-γ re-expression for at least 1 month. Mechanistically, this memory resulted from quantitatively distinct transcription of individual alleles and was controlled by stable expression differences of the Th1 cell lineage-specifying transcription factor T-bet. Functionally, Th1 cells with graded IFN-γ production competence differentially activated Salmonella-infected macrophages for bacterial killing. Thus, individual Th cells commit to produce distinct amounts of a given cytokine, thereby generating functional intrapopulation heterogeneity.

Maternal and postnatal dietary probiotic supplementation enhances splenic regulatory T helper cell population and reduces peanut allergen-induced hypersensitivity responses in mice

Neonatal to early childhood is the critical period for establishing a balance of T helper 1 (Th1) versus T helper 2 (Th2) cellular immunity within the gut, which is strongly influenced by the source and establishment of gut microflora. Probiotic administration has been shown to attenuate Th2-biased cellular immunity and predisposition to food allergies. To test this hypothesis we provided ad libitum a probiotic-supplemented (Primalac 454 Feed Grade Microbials) or control diet to lactating dams with suckling pups and weaned pups until 10 weeks of age. Weaned mice were sensitized/challenged with peanut extract, saline or adjuvant at 6, 8 and 10 weeks of age. At 3, 6, 8 and 10 weeks, fecal samples were collected for microbial analysis, while blood samples were analyzed for total plasma IgE levels. At termination (10 weeks of age), splenic T lymphocyte population subtypes were determined using FACS analysis and Th1/Th2/Th17 gene expression by PCR array. Mice given the probiotic-supplemented diet had significantly enhanced probiotic fecal counts compared to controls at 3, 6, 8 and 10 weeks. Moreover, mice fed the probiotic-supplemented diet had enhanced splenic naturally occurring T regulatory cell populations, and reduced splenic gene expression of allergic mediator IL-13 compared to controls. These results provide evidence that early probiotic supplementation may provide host protection to hypersensitivity reactions to food allergens by attenuating food allergen inflammatory responses.

Maternal and postnatal dietary probiotic supplementation enhances splenic regulatory T helper cell population and reduces ovalbumin allergen-induced hypersensitivity responses in mice (HYP7P.305)

Abstract Neonatal to early childhood is the critical period for establishing a balance of T helper 1 (Th1) versus T helper 2 (Th2) mucosal immunity, which is strongly influenced by the source and establishment of gut microflora. Probiotic administration has been shown to attenuate Th2-biased cellular immunity and predisposition to food allergies. To test this hypothesis we fed a probiotic-supplemented or control diet to lactating dams with suckling pups and weaned pups until 10 weeks of age. Weaned mice were sensitized with egg allergen ovalbumin, saline or adjuvant at 6, 8 and 10 weeks of age. At 3, 6, 8 and 10 weeks, fecal samples were collected for microbial analysis, while blood samples were analyzed for ovalbumin and total plasma IgE levels. At termination, splenic T helper population subtypes were determined by FACS analysis and gene expression by PCR array. At 21 days of age, pups suckled by lactating dams fed the probiotic supplemented diet had significantly enhanced Lactobacillus acidophilus fecal counts compared to controls. Moreover, mice fed the probiotic supplemented diet had enhanced splenic naturally occurring and induced regulatory T cell populations, enhanced TGFβ gene expression and reduced expression of allergic mediator IL13 compared to controls. These results provide evidence that early probiotic supplementation may provide host protection from hypersensitivity reactions to food allergens by attenuating food allergen inflammatory responses.

Maternal and postnatal dietary probiotic supplementation enhances splenic regulatory T helper cell population and reduces ovalbumin allergen-induced hypersensitivity responses in mice

Neonatal to early childhood is the critical period for establishing a balance of T helper 1 (Th1) versus T helper 2 (Th2) cellular immunity within the gut, which is strongly influenced by the source and establishment of gut microflora. Probiotic administration has been shown to attenuate Th2-biased cellular immunity and predisposition to food allergies. To test this hypothesis we provided ad libitum a probiotic-supplemented (Primalac 454 Feed Grade Microbials) or control diet to lactating dams with suckling pups and weaned pups until 10 weeks of age. Weaned mice were sensitized/challenged with egg allergen ovalbumin, saline or adjuvant at 6, 8 and 10 weeks of age. At 3, 6, 8 and 10 weeks, fecal samples were collected for microbial analysis, while blood samples were analyzed for ovalbumin-IgE and total plasma IgE levels. At termination, splenic T helper cell lymphocyte population subtypes were determined using FACS analysis and Th1/Th2/Th17 gene expression by PCR array. At 21 days of age, pups suckled by lactating dams fed the probiotic supplemented diet had significantly enhanced Lactobacillus acidophilus fecal counts compared to controls. Moreover, mice fed the probiotic supplemented diet had enhanced splenic naturally occurring and induced regulatory T cell populations, enhanced TGFβ gene expression and reduced expression of allergic mediator IL13 compared to controls. These results provide evidence that early probiotic supplementation may provide host protection from hypersensitivity reactions to food allergens by attenuating food allergen inflammatory responses.

Myor/ABF-1 Mrna Expression Marks Follicular Helper T Cells but Is Dispensable for Tfh Cell Differentiation and Function In Vivo

Follicular T helper cells (Tfh) are crucial for effective antibody responses and long term T cell-dependent humoral immunity. Although many studies are devoted to this novel T helper cell population, the molecular mechanisms governing Tfh cell differentiation have yet to be characterized. MyoR/ABF-1 is a basic helix-loop-helix transcription factor that plays a role in the differentiation of the skeletal muscle and Hodgkin lymphoma. Here we show that MyoR mRNA is progressively induced during the course of Tfh-like cell differentiation in vitro and is expressed in Tfh responding to Alum-precipitated antigens in vivo. This expression pattern suggests that MyoR could play a role in the differentiation and/or function of Tfh cells. We tested this hypothesis using MyoR-deficient mice and found this deficiency had no impact on Tfh differentiation. Hence, MyoR-deficient mice developed optimal T-dependent humoral responses to Alum-precipitated antigens. In conclusion, MyoR is a transcription factor selectively up-regulated in CD4 T cells during Tfh cell differentiation in vitro and upon response to alum-protein vaccines in vivo, but the functional significance of this up-regulation remains uncertain.

48: Immunophenotyping innate lymphoid and T helper cell populations in human asthma

Asthma is a heterogeneous disease driven by T-helper type 2 (Th2) cell-driven airway inflammation, due to the production of the pro-inflammatory cytokines IL-13, IL-5 and IL-4. Many cell types in the allergic lung produce IL-13, including T cells and type 2 innate lymphoid cells (ILC2). To identify the T helper cell subsets that contribute to disease, we immunophenotyped blood, bronchoalveolar lavage fluid (BAL) and induced sputum cells from asthmatic patients. Using 10–12 color flow cytometry, we characterized innate cells and T helper cell populations in two separate immunophenotyping panels, and correlated cell surface markers with intracellular cytokine production. To incorporate a larger number of parameters into a single immunophenotyping panel, we have started to use the cytometry by time-of-flight mass spectrometry (CyTOF) platform as an alternative for airway biospecimens. CyTOF allows us to look at upwards of 30–40 markers on every cell in each sample, including both cell surface and intracellular markers, and will help us determine the interplay among the different cell types that contribute to allergic airway disease.

Quantifying the Cluster of Differentiation 4 Receptor Density on Human T Lymphocytes Using Multiple Reaction Monitoring Mass Spectrometry

Cluster of differentiation 4 (CD4) is an important glycoprotein containing four extracellular domains, a transmembrane portion and a short intracellular tail. It locates on the surface of various types of immune cells and performs a critical role in multiple cellular functions such as signal amplification and activation of T cells. It is well-known as a clinical cell surface protein marker for study of HIV progression and for defining the T helper cell population in immunological applications. Moreover, CD4 protein has been used as a biological calibrator for quantification of other surface and intracellular proteins. However, flow cytometry, the conventional method of quantification of the CD4 density on the T cell surface depends on antibodies and has suffered from variables such as antibody clones, the fluorophore and conjugation chemistries, the fixation conditions, and the flow cytometric quantification methods used. In this study, we report the development of a highly reproducible nano liquid chromatography-multiple reaction monitoring mass spectrometry-based quantitative method to quantify the CD4 receptor density in units of copy number per cell on human CD4+ T cells. The method utilizes stable isotope-labeled full-length standard CD4 as an internal standard to measure endogenous CD4 directly, without the use of antibodies. The development of the mass spectrometry-based approach of CD4 protein quantification is important as a complementary strategy to validate the analysis from the cytometry-based conventional method. It also provides new support for quantitative understanding and advanced characterization of CD4 on CD4+ T cells.

Identifying the T helper cell population involved in class-switching to IgE

Event Abstract Back to Event Identifying the T helper cell population involved in class-switching to IgE Sharrada Subramaniam1, 2*, Jinshu He1, Leigh A. Jones1 and Maria A. Curotto De Lafaille1 1 Singapore Immunology Network, Singapore 2 Nanyang Technological University, Singapore IgE antibodies are key players in allergic diseases and can be generated by direct switching of IgM/IgD cells, or by sequential switching of IgG1 cells to IgE. The characteristics of the IgG1 cells involved in the switching to IgE and the nature of IL-4 producing T cells involved in direct and sequential switching are not known. The goal of this work is to identify the T cell populations that help naïve and IgG1 cells to switch to IgE. When comparing the memory/activated population of cells in the lymphoid organs of immunized TBmc 4get mice, we found at least 2 types of IL-4 producing cells identified based on PD1 expression, in agreement with published work. Real-time PCR analysis of the GFP+PD1+ cells in the lymphoid organs showed expression of IL-4, IL-21, CXCR5 and Bcl6, confirming its Tfh nature. Conversely, the GFP+PD1- population lacked Tfh markers, representing a Th2-like population. Using this system, we found that the Th2-like cells were the best helpers to induce naïve B cells to class-switch to IgE both in an in-vitro and an in vivo model. We are also investigating the specific characteristics of IL-4 Tfh populations found in systemic and mucosal lymph nodes, to correlate with their differential ability to promote immunoglobulin class switching to IgE. Supported by SIgN-A*STAR core funding to M.A.C.L. Keywords: T cells, Tfh cells, class-switching, IgE, Th2 Cells, IgG1 Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Adaptive Immunity Citation: Subramaniam S, He J, Jones LA and Curotto De Lafaille MA (2013). Identifying the T helper cell population involved in class-switching to IgE. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00385 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 20 Mar 2013; Published Online: 22 Aug 2013. * Correspondence: Miss. Sharrada Subramaniam, Singapore Immunology Network, Singapore, 138648, Singapore, sharrada_subramaniam@immunol.a-star.edu.sg Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Sharrada Subramaniam Jinshu He Leigh A Jones Maria A Curotto De Lafaille Google Sharrada Subramaniam Jinshu He Leigh A Jones Maria A Curotto De Lafaille Google Scholar Sharrada Subramaniam Jinshu He Leigh A Jones Maria A Curotto De Lafaille PubMed Sharrada Subramaniam Jinshu He Leigh A Jones Maria A Curotto De Lafaille Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Follicular helper T cells serve as the major CD4 T cell compartment for HIV-1 infection, replication, and production

In the present study, we have investigated the distribution of HIV-specific and HIV-infected CD4 T cells within different populations of memory CD4 T cells isolated from lymph nodes of viremic HIV-infected subjects. Four memory CD4 T cell populations were identified on the basis of the expression of CXCR5, PD-1, and Bcl-6: CXCR5(-)PD-1(-)Bcl-6(-), CXCR5(+)PD-1(-)Bcl-6(-), CXCR5(-)PD-1(+)Bcl-6(-), and CXCR5(+)PD-1(+)Bcl-6(+). On the basis of Bcl-6 expression and functional properties (IL-21 production and B cell help), the CXCR5(+)PD-1(+)Bcl-6(+) cell population was considered to correspond to the T follicular helper (Tfh) cell population. We show that Tfh and CXCR5(-)PD-1(+) cell populations are enriched in HIV-specific CD4 T cells, and these populations are significantly increased in viremic HIV-infected subjects as compared with healthy subjects. The Tfh cell population contained the highest percentage of CD4 T cells harboring HIV DNA and was the most efficient in supporting productive infection in vitro. Replication competent HIV was also readily isolated from Tfh cells in subjects with nonprogressive infection and low viremia (<1,000 HIV RNA copies). However, only the percentage of Tfh cells correlated with the levels of plasma viremia. These results demonstrate that Tfh cells serve as the major CD4 T cell compartment for HIV infection, replication, and production.

Reprogramming Aberrant B Cell-Subsets to Improve Immune Function in Multiple Myeloma

AbstractAbstract 3986B cell-malignancies exhibit considerable immune dysfunction particularly in multiple myeloma (MM). We have previously demonstrated that in T cell-compartment, regulatory T helper cells are dysfunctional in multiple myeloma (MM) while Th17 cells are significantly elevated and IL-17 produced by them is associated with MM cell growth and survival as well as suppressed immune responses and bone disease. We have here investigated the B cell-subsets and their ability to re-program anti-tumor immunity in MM. We have first characterised four different B cell-subsets (B1a, B1b, B2 and regulatory B cells) using 10-color flow cytometric analysis in both peripheral blood and bone-marrow (BM) samples from MM patients compared with normal healthy donors. We observe that CD5+ B1a-B cells are significantly elevated in peripheral blood of MM patients (N=7) compared to healthy donor (N=15) (42±8% vs 13±3%, respectively, p<0.05); while normal B cells (B2 cells) are significantly reduced in peripheral blood (29.8±6.5, p<0.05) and in the BM samples (11±4.8, N=4, p<0.05) of MM patients compared to healthy donors (59±3, and 60.2±2, N=10, respectively). We also observed that both B1b (47.9±18 vs. 22.8±4) and regulatory B cells (7.1±4.5 vs. 1.54±0.3) are elevated in BM samples of MM compared to healthy donors, however there were no differences in B1b and regulatory B cells in the peripheral blood of MM compared to healthy donor samples. Interestingly, in myeloma we observe higher levels of activated B cell subsets but lower levels of memory B cell subsets compared to healthy donors. These results, particularly very low levels of normal B cells in MM patients, may explain the decreased levels of uninvolved immunoglobulin in MM.As removal of B cell population has been shown to re-program T helper cell populations, we next investigated impact of B cell population on T cell activation. We activated normal PBMC via the anti-CD3 antibody, in the presence or absence of B or CD25+ cells and measured intra-cellular IFN-γ levels in CD69+ cells. We found that the absence of B cells significantly inhibited interferon-producing T cells compared to PBMC (by 43%; p<0.05). Importantly, following removal of CD25+ cells, which consists of both Tregs and activated memory T cells, with or without B cells, we did not observe any difference in the inhibition of IFN-γ, indicating that B cells are influencing memory T cells rather than naïve T cells for the production of IFN-γ. This prompted us to identify the phenotypic signature of regulatory T cell populations when purified memory T cells are polarized with the regulatory T cell cocktail in presence or absence of B cells. We observed that B cells reduce FOXP3 expression by 18 %(N=5) and establish cognitive interactions with T cells. This occurred by increasing the expression of GITR (154%) and CTLA4 (54%); while reducing PD1 (−24%) and OX40 (−21%) expression on T cells without affecting HLA expression. We have also observed these improvements by B cell modulation on T cells in MM. Our results indicate that targeting these re-programmable capabilities of B cells to modulate T helper cell populations may enable us to improve T cell function in MM; and may improve immune function in MM and also allow us to enhance responses to vaccinations. Disclosures:Ghobrial:Millennium: Advisory Board Other; Novartis: Advisory Board, Advisory Board Other. Richardson:Novartis: Membership on an entity’s Board of Directors or advisory committees; Celgene: Membership on an entity’s Board of Directors or advisory committees; Millennium: Membership on an entity’s Board of Directors or advisory committees; Johnson & Johnson: Membership on an entity’s Board of Directors or advisory committees. Treon:Onyx: Research Funding; Celgene: Research Funding; Pharmacyclics: Research Funding; Cephalon: Consultancy; Avila: Consultancy. Anderson:Celgene, Millennium, BMS, Onyx: Membership on an entity’s Board of Directors or advisory committees; Acetylon, Oncopep: Scientific Founder, Scientific Founder Other.

Identification of a human Th1-like IFNγ-secreting Treg subtype deriving from effector T cells

Characteristics and function of effector T-cells with regulatory properties (induced Treg, “iTreg”) in humans are ill defined. Here we report that a proportion of activated, initially CD4(+)CD25(−)CD127(+) effector T-cells from human peripheral blood can convert into T-cells with regulatory activity while concomitantly secreting IFNγ. Upon short-term culture in vitro these cells expressed a panel of common Treg markers, including FOXP3, CD25, GITR, HLA-DR and CTLA-4 in parallel with the Th1-specific transcription factor T-bet. Despite their own IFNγ secretion they effectively suppressed IFNγ secretion in effector T cells in parallel with inhibition of their proliferation. Highly purified IFNγ(+)iTreg shared many functional properties with nTreg: Their suppressive activity was antigen-independent, contact-mediated and cytokine-independent. Of note, in contrast to nTreg an inhibitor of TGF-β1 signalling promoted the proliferation of IFNγ(+)iTreg, without abrogating their suppressive function. In addition in vivo in tonsils of patients with chronic tonsillitis an IFNγ-secreting subpopulation of the CD4(+)CD25(−)CD127(+)CD45RA(−) memory T helper cell population was detected, which exhibited regulatory properties as well.Our results support the existence of Th1-like adaptive Tregs in humans that express a robust regulatory phenotype, comparable to nTreg and at the same time share characteristics of Th1 cells. According to our in vitro data IFNγ(+)iTreg can emerge from activated effector T cells and downregulate Th1-mediated immune responses, supporting the hypothesis of effector T cell plasticity as a means for proper initiation and self regulation of inflammatory processes.This report characterizes a new subpopulation of human adaptive regulatory T-cells that derive from effector Th-cells and concomitantly express Th1-specific T-bet and IFNγ with Foxp3.

T helper cell populations: As flexible as the skin?

T helper cells can be defined by the cytokines they produce and are divided into Th1, Th2, Th17, T(FH) or regulatory T cells. Th17 cells have been shown to produce, in addition to IL-17, IL-22. In the current issue of the European Journal of Immunology, an article by Larsen et al. (Eur. J. Immunol. 2011. 41: 2596-2605) provides evidence that human T helper cells, like murine cells, can also express IL-22 in the absence of the other T helper cell signature cytokines. Moreover, they show that these IL-22-producing cells, namely Th22 cells, can be found in the skin of psoriasis patients, where they might contribute to the pathogenesis of this inflammatory skin disease. Finally, they show that, molecularly, Th22 cells are related to Th17 cells, and might therefore be derived from the latter. In this Commentary, the development of the pro-inflammatory T helper populations in the skin are discussed and a model that explains the development of Th22 cells found in the skin of psoriasis patients is proposed.

The Current Concept of T H 17 Cells and Their Expanding Role in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a multifaceted range of symptoms affecting almost every organ system. The prototypical pathology of SLE involves the production of antinuclear antibodies and the deposition of immune complexes in basement membranes throughout the body where they induce inflammatory responses. The genetic and environmental etiologies of this process are being intensively sought, and recently, T H 17 cells have been implicated in the pathogenesis of SLE. T H 17 cells are CD4+ memory T cells that behave as both helper and effector cell populations functioning through their signature IL-17 cytokines. Their differentiation is distinct to either the T H 1 or T H 2 cell lineage, but strongly influences development of adaptive responses, including autoimmunity. This paper details the biological functions and regulation of T H 17 cells, followed by an update of their expanding role in SLE.

STAT proteins in cancerogenesis and therapy of malignancies

Signal transducers and activators of transcription (STAT) proteins are a 7-member family of cytoplasmic transcription factors that participate in signal transduction by cytokines, hormones, and growth factors. STAT proteins control the most important cellular processes, including survival, proliferation and differentiation. A great number of cytokines and other factors in different cell types activate STAT1, STAT3 and STAT5 and in this manner regulate processes such as cellular proliferation, differentiation and survival. STATs such as STAT4 and STAT6 have a more specific effect and are engaged in the differentiation of T helper cell populations. Given the critical roles of STAT proteins it has been established in many studies that STAT3 and STAT5 are oncogenes that can contribute to cellular transformation by increasing proliferation and slowing-down apoptosis. On the other hand, STAT1 is a tumour suppressor gene and its inactivation contributes to malignant transformation. Initially STAT proteins were extensively studied in leukaemias, but later their role in the development of different solid tumours has been also shown. Aside from their role in the development of tumours, STAT1, STAT3 and STAT5 can be considered as molecular markers for early detection of certain types of tumours, as well as prognostic factors in the determination of tumour aggressiveness and predictors of response to various types of therapy. Evidence of the deregulation of STAT signalling pathway can serve as a basis for designing novel targeted molecular therapeutic strategies that carry a great potential in the therapy of solid tumours and leukaemias.

Evaluation of a rapid microbial detection method via phage lytic amplification assay coupled with Live/Dead fluorochromic stains

To develop a method for rapid detection of bacteria via bacteriophage amplification coupled with exogenous fluorochromic stains. A method for the rapid detection of bacteria was developed which consisted of exposing the sample suspected to contain target cells to host-specific phage. After at least one infection cycle, bacteria known to be infected by the phage (helper cells) were added and the number of nascent phage particles was estimated using the Live/Dead BacLight Bacterial Viability kit. Using Pseudomonas aeruginosa, it was shown that the dead helper cell population following phage infection was proportional to the initial number of target cells present in the original sample. Approximately 1 x 10(1) CFU per ml of P. aeruginosa could be detected within 4 h without the need for enrichment. The phage lytic amplification assay coupled with exogenous fluorochromic stains was able to detect approx. 1 x 10(1) CFU per ml of the target bacterium within 4 h. A method to detect low number of bacterial cells in a sample within 4 h without the need for enrichment was developed.

Neuroprotective Activities of Chrysantheum Indicum L.

We examined the inhibitory activities against monoamine oxidase (MAO) of Chrysantheum indicum L. in vitro and in vivo methods. Methanol extract of C. indicum showed significantly inhibitory activities on MAO-A that were prepared from rat brain in vitro. The inhibitory activities were measured by serotonin as substrates. The ethylacetate fractions of C. indicum exhibited the best activity toward MAO-A with IC50 value of 0.05 mg/ml in vitro tests. The extract of C. indicum slightly decreased MAO-A on the brain of rat administered by oral, while MAO-B activity was increased (p<0.05). And the stress-immune systems of the rat administered the extract of C. indicum by oral were showed the interesting changes. The T helper cell populations in the spleen of rat administered the extract of C. indicum by oral were decreased without other cytokines population’s changes such as, IFN-gamma or IL-4. Consequently, we suggest that C. indicum may have the effects on the inhibitory activities against MAO both in vitro and in vivo. From these results it is indicates that the C. indicum extract has properties indicative of potential neuroprotective ability.

Follicular B helper T cell activity is confined to CXCR5hiICOShi CD4 T cells and is independent of CD57 expression

The generation of high-affinity antibody-secreting plasma cells critically depends on the presence of CD4 T cells during the germinal center (GC) reaction. GC T cells are so far incompletely characterized in terms of phenotype and function. Here, we show that human follicular B helper T (T(FH)) cells are characterized by high expression of the homeostatic chemokine receptor CXCR5 and the costimulatory molecule ICOS, but not CD57 expression. CXCR5(hi)ICOS(hi) CD4 T cells are the most potent inducers of IgG production that also secrete large amounts of the B cell-attracting chemokine CXCL13. CXCR5(hi)ICOS(hi) CD4 T cells differ from other tonsillar CD4 T cell subsets in their stimulatory activity, proliferative capacity and susceptibility to apoptosis. Large-scale gene expression analysis revealed that T(FH) cells are only distantly related to CXCR5(-) and CXCR5(+) central memory T (T(CM)) as well as effector memory T (T(EM)) cells present in the periphery. CXCR5(hi)ICOS(hi) CD4 T cells appear to be terminally differentiated T helper cells that express a unique set of transcription factors related to the Notch signaling pathway and thus differentiate independent of other T helper cell populations.

Magnetic resonance tomography of sacroiliitis: anatomy, histological pathology, MR-morphology, and grading

The diagnosis of spondyloarthropathy is based on radiography of the sacroiliac joints, beside the patient's history and clinical examination. In cases where the clinical examination and radiography yield discrepant findings, contrast-enhanced magnetic resonance imaging (MRI) is a sensitive modality for the diagnosis of early sacroiliitis. Knowledge of the morphologic anatomy of the sacroiliac joints and of their abnormal micro- and macroanatomy in sacroiliitis and enthesitis are helpful for interpreting MR images. Arthritis of the sacroiliac joints is characterized by subchondral sclerosis, erosions, transarticular bone bridges, accumulation of periarticular fat, juxta-articular osteitis, synovtis, capsulitis, and enthesitis. The major histologic finding in active sacroiliitis is the presence of proliferative, pannus-like connective tissue destroying cartilage and bone. This tissue contains fibroblasts and fibrocytes as well as T cells and macrophages with a shift of the CD4/CD8 ratio toward the CD4 T helper cell population. The well-established grading of MRI findings by means of a chronicity and activity index, which are determined quantitatively from dynamic MR images, is supplemented by an alternative, semi-quantitative grading of activity. The following grades were defined for the short tau inversion recovery (STIR) sequence or the T1-weighted, fatsaturated spin-echo sequence for each quadrant (iliac anterior, iliac posterior, sacral anterior, sacral posterior): 0: no signal increase, 1: local increase in the joint cavity or within erosions, 2: small areas of increased juxta-articular signal, 3: moderate sized areas of increased juxta-articular signal, 4: large areas of increased juxta-articular signal. Values of the 4 quadrants are summed to an activity score (range 0-16). The new grading system is proposed to facilitate the examination and shorten image interpretation time.