In this task, you are given an abstract of article. Your task is to generate title for this article. Preferred titles are under thirty words.
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Question: The autoimmune regulator (Aire) plays a critical role in central tolerance by promoting the display of tissue-specific antigens in the thymus. To study the influence of Aire on thymic selection in a physiological setting, we used tetramer reagents to detect autoreactive T cells specific for the Aire-dependent tissue-specific antigen interphotoreceptor retinoid-binding protein (IRBP), in the polyclonal repertoire. Two class II tetramer reagents were designed to identify T cells specific for two different peptide epitopes of IRBP. Analyses of the polyclonal T-cell repertoire showed a high frequency of activated T cells specific for both IRBP tetramers in Aire(-/-) mice, but not in Aire(+/+) mice. Surprisingly, although one tetramer-binding T-cell population was efficiently deleted in the thymus in an Aire-dependent manner, the second tetramer-binding population was not deleted and could be detected in both the Aire(-/-) and Aire(+/+) T-cell repertoires. We found that Aire-dependent thymic deletion of IRBP-specific T cells relies on intercellular transfer of IRBP between thymic stroma and bone marrow-derived antigen-presenting cells. Furthermore, our data suggest that Aire-mediated deletion relies not only on thymic expression of IRBP, but also on proper antigen processing and presentation of IRBP by thymic antigen-presenting cells.

Answer: Detection of an autoreactive T-cell population within the polyclonal repertoire that undergoes distinct autoimmune regulator (Aire)-mediated selection.

Question: Tumour-associated cell cycle defects are often mediated by alterations in cyclin-dependent kinase (CDK) activity. Misregulated CDKs induce unscheduled proliferation as well as genomic and chromosomal instability. According to current models, mammalian CDKs are essential for driving each cell cycle phase, so therapeutic strategies that block CDK activity are unlikely to selectively target tumour cells. However, recent genetic evidence has revealed that, whereas CDK1 is required for the cell cycle, interphase CDKs are only essential for proliferation of specialized cells. Emerging evidence suggests that tumour cells may also require specific interphase CDKs for proliferation. Thus, selective CDK inhibition may provide therapeutic benefit against certain human neoplasias.

Answer: Cell cycle, CDKs and cancer: a changing paradigm

Question: BACKGROUND Exacerbations of COPD (ECOPD) remain a major cause of mortality and morbidity. Despite advances in the understanding of their pathophysiology, their assessment relies primarily on clinical presentation, which can be variable and difficult to predict. A large number of biomarkers already have been assessed in this context, and some appear to be promising.
METHODS An online search for articles published until December 2010 was conducted using three terms for ECOPD, five terms for biomarkers, and five terms for the sampling method. Biomarkers were evaluated for their potential role in the establishment and confirmation of the diagnosis of ECOPD, the evaluation of etiology and severity, the prediction of prognosis, and the guidance of treatment decisions.
RESULTS Several systemic biomarkers have been measured in the context of ECOPD, and most have been found to increase at ECOPD onset and to subside during the course of exacerbations. Correlations have been reported among these biomarkers, but direct associations with clinical variables have been more difficult to establish. Although there are several limitations yet to be addressed, some of the biomarkers, most notably C-reactive protein for the identification of an ECOPD and procalcitonin for antibiotic guidance, may provide clinically relevant information.
CONCLUSIONS So far , no single biomarker has been able to gain wide acceptance, but some provide clinically useful information. The evaluation of such biomarkers in large decision-making studies is expected to become an area of intense investigation in the near future.

Answer:
Systemic biomarkers in exacerbations of COPD: the evolving clinical challenge.