51 research outputs found
Heterologous CD8 T Cell Immune Response to HSV Induced by Toll Like Receptor Ligands
No full textA memory response is established following primary antigen exposure that stays more or less constant. It appears to adopt a set-point in magnitude but upon re-exposure the response is quicker and better and there is an upward shift in memory frequency that varies with individuals based on the exposure pattern to other microbes or its components. Our investigations were designed to test such differences of non-specific stimulation by PAMPs in lowering the threshold of activation. Neonatal mice were pre-exposed to TLR-ligands intermittently and later analyzed for its resilience to challenge with virus during adult-life. Secondly, adult mice with pre-existing memory to virus were exposed to various TLR-ligands and analyzed for their quality of memory response. The TLR-ligands exposed animals were better responders to a new agent exposure compared to the animals kept in sterile surroundings. Moreover, immune memory recall and the viral specific CD8+ T cells response with TLR-ligands were comparable to the recall response with the cognate antigen. The results provide insights into the role of hyper-sanitized environment versus PAMPs mediated signaling in adaptive immunity and long-term immune memory
PLoS One
No full textMycobacterium bovis bacille Calmette-Gu\ue9rin (BCG) is the most widely used live attenuated vaccine. However, the correlates of protection and waning of its immunity against tuberculosis is poorly understood. In this study, we correlated the longitudinal changes in the magnitude and functional quality of CD4+ and CD8+ T-cell response over a period of two years after mucosal or parenteral BCG vaccination with the strength of protection against Mycobacterium tuberculosis in mice. The BCG vaccination-induced CD4+ and CD8+ T cells exhibited comparable response kinetics but distinct functional attributes in-terms of IFN-\u3b3, IL-2 and TNF-\u3b1 co-production and CD62L memory marker expression. Despite a near life-long BCG persistence and the induction of enduring CD4+ T-cell responses characterized by IFN-\u3b3 and/or TNF-\u3b1 production with comparable protection, the protective efficacy waned regardless of the route of vaccination. The progressive decline in the multifactorial functional abilities of CD4+ and CD8+ T cells in-terms of type-1 cytokine production, proliferation and cytolytic potential corresponded with the waning of protection against M. tuberculosis infection. In addition, simultaneous increase in the dysfunctional and terminally-differentiated T cells expressing CTLA-4, KLRG-1 and IL-10 during the contraction phase of BCG-induced response coincided with the loss of protection. Our results question the empirical development of BCG-booster vaccines and emphasize the pursuit of strategies that maintain superior T-cell functional capacity. Furthermore, our results underscore the importance of understanding the comprehensive functional dynamics of antigen-specific T-cell responses in addition to cytokine polyfunctionality in BCG-vaccinated hosts while optimizing novel vaccination strategies against tuberculosis.20141023
T regulatory cells: an overview and intervention techniques to modulate allergy outcome
No full textAbstract Dysregulated immune response results in inflammatory symptoms in the respiratory mucosa leading to asthma and allergy in susceptible individuals. The T helper type 2 (Th2) subsets are primarily involved in this disease process. Nevertheless, there is growing evidence in support of T cells with regulatory potential that operates in non-allergic individuals. These regulatory T cells occur naturally are called natural T regulatory cells (nTregs) and express the transcription factor Foxp3. They are selected in the thymus and move to the periphery. The CD4 Th cells in the periphery can be induced to become regulatory T cells and hence called induced or adaptive T regulatory cells. These cells can make IL-10 or TGF-b or both, by which they attain most of their suppressive activity. This review gives an overview of the regulatory T cells, their role in allergic diseases and explores possible interventionist approaches to manipulate Tregs for achieving therapeutic goals.</p
Employability Skills Development Through Collaborative Learning in Business Math: An Onward Journey
No full textThis paper reflects upon the journey of the author in facilitating collaborative teaching and learning practices for developing employability skills in General Education Mathematics courses at the undergraduate level. The paper discusses similar experiences of STEM faculty members who have experimented with collaborative learning and teaching for enhancing student experience. The research also discusses how specific employability skills can be developed during various stages of the collaborative teaching and learning model designed for the purpose of the study. Team formation and work in teams are discussed in detail. Finally, the paper concludes with the possibilities of future SoTL research for employability purposes
PLoS One
No full textBackgroundThe identification of Mycobacterium tuberculosis vaccines that elicit a protective immune response in the lungs is important for the development of an effective vaccine against tuberculosis.Methods and Principal FindingsIn this study, a comparison of intranasal (i.n.) and subcutaneous (s.c.) vaccination with the BCG vaccine demonstrated that a single moderate dose delivered intranasally induced a stronger and sustained M. tuberculosis-specific T-cell response in lung parenchyma and cervical lymph nodes of BALB/c mice than vaccine delivered subcutaneously. Both BCG and a multicomponent subunit vaccine composed of nine M. tuberculosis recombinant proteins induced strong antigen-specific T-cell responses in various local and peripheral immune compartments. Among the nine recombinant proteins evaluated, the alanine proline rich antigen (Apa, Rv1860) was highly antigenic following i.n. BCG and immunogenic after vaccination with a combination of the nine recombinant antigens. The Apa-induced responses included induction of both type 1 and type 2 cytokines in the lungs as evaluated by ELISPOT and a multiplexed microsphere-based cytokine immunoassay. Of importance, i.n. subunit vaccination with Apa imparted significant protection in the lungs and spleen of mice against M. tuberculosis challenge. Despite observed differences in the frequencies and location of specific cytokine secreting T cells both BCG vaccination routes afforded comparable levels of protection in our study.Conclusion and SignificanceOverall, our findings support consideration and further evaluation of an intranasally targeted Apa-based vaccine to prevent tuberculosis
Sci Rep
No full textHeterologous prime-boosting has emerged as a powerful vaccination approach against tuberculosis. However, optimal timing to boost BCG-immunity using subunit vaccines remains unclear in clinical trials. Here, we followed the adhesin Apa-specific T-cell responses in BCG-primed mice and investigated its BCG-booster potential. The Apa-specific T-cell response peaked 32-52 weeks after parenteral or mucosal BCG-priming but waned significantly by 78 weeks. A subunit-Apa-boost during the contraction-phase of BCG-response had a greater effect on the magnitude and functional quality of specific cellular and humoral responses compared to a boost at the peak of BCG-response. The cellular response increased following mucosal BCG-prime-Apa-subunit-boost strategy compared to Apa-subunit-prime-BCG-boost approach. However, parenteral BCG-prime-Apa-subunit-boost by a homologous route was the most effective strategy in-terms of enhancing specific T-cell responses during waning in the lung and spleen. Two Apa-boosters markedly improved waning BCG-immunity and significantly reduced Mycobacterium tuberculosis burdens post-challenge. Our results highlight the challenges of optimization of prime-boost regimens in mice where BCG drives persistent immune-activation and suggest that boosting with a heterologous vaccine may be ideal once the specific persisting effector responses are contracted. Our results have important implications for design of prime-boost regimens against tuberculosis in humans
Tracking Crossing Targets in Passive Sonars Using NNJPDA
No full textAbstractThis paper presents an effective solution to the problems of multi-target tracking in passive sonar. Since bearing information alone is used, target crossing problems arises in passive sonar. Nearest Neighbor Joint Probabilistic Data Association (NNJPDA) is employed for the information processing. Further a prediction mechanism is used, where the track bearing depends only on the predicted value not on the measurements. This leads to the correct assignment of measurements with the track in the clutter and thereby avoids the track loss. The state estimation is then refined by Kalman filtering based on the corrected measurements from the NNJPDA technique. Thus accurate and continuous track is maintained
La quête identitaire dans l’œuvre romanesque d’Ananda Devi
No full textThis article examines three novels by Ananda Devi, a well‑known francophone novelist from Mauritius, the author of many novels, short stories and poetry books. In her novels, theauthor portrays the lives of women, the roles and norms that have been imposed on them, as well as their place in the conservative and patriarchal society in Mauritius and in India.The protagonists of Pagli, Le Voile de Draupadi and Indian tango, whilst searching for their identity, rebel against the society, their families and religion which marginalise them and deny their right to make decisions about their own lives. The protagonists of Devi’s novels by objecting to such a lifestyle, by violating the social norms and breaching bans, discover their identity. Pagli symbolically rediscovers her true name, Anjali freedom and Subhadra her body/sexuality.Key words: Ananda Devi, francophone novel, woman, identity, freedom, violation of social, religious and moral norm
Cyclostationarity Based Sonar Signal Processing
No full textAbstractThis paper presents a reliable method for target vessel identification in passive sonar by exploiting the underlying periodicity of propeller noise signal, using the principles of cyclostationarity. In conventional signal processing methods, random signals are treated as statistically stationary and the parameters of the underlying physical mechanism that generates the signal would not vary in time. However, for most manmade signals, some parameters vary periodically with time and this requires that random signals be modeled as cyclostationary. In the field of sonar, the propeller noise signal generated by underwater vessels is cyclostationary. As a ship propagates in the sea, noise generated during the collapse of cavitation-induced bubbles are modulated by the rotating propeller shaft and this results in characteristic amplitude modulated random noise signal, which can be detected using passive sonar. Processing these signals, the number of blades and the shaft frequency of the propeller can be identified. In this work, cyclostationary processing technique is introduced for processing propeller noise signal and it is observed to provide better noise immunity. A detailed comparison with the conventional DEMON processing is also presented
La quête identitaire dans l’œuvre romanesque d’Ananda Devi
No full textThis article examines three novels by Ananda Devi, a well‑known francophone novelist from Mauritius, the author of many novels, short stories and poetry books. In her novels, theauthor portrays the lives of women, the roles and norms that have been imposed on them, as well as their place in the conservative and patriarchal society in Mauritius and in India.
The protagonists of Pagli, Le Voile de Draupadi and Indian tango, whilst searching for their identity, rebel against the society, their families and religion which marginalise them and deny their right to make decisions about their own lives. The protagonists of Devi’s novels by objecting to such a lifestyle, by violating the social norms and breaching bans, discover their identity. Pagli symbolically rediscovers her true name, Anjali freedom and Subhadra her body/sexuality.
Key words: Ananda Devi, francophone novel, woman, identity, freedom, violation of social, religious and moral norm
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