1,721,144 research outputs found
Senescent angiogenic T cells: the use of CD28 makes the difference in endothelial homeostasis
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Detection of circulating endothelial progenitor cells in cardiovascular diseases
No full textIntroduction: Endothelial progenitor cells (EPCs) are bone marrow-derived cells playing a critical role in adult vasculogenesis and endothelial homeostasis, as they are recruited to sites of endothelial injury where they contribute to blood vessel formation and repair. Since their first description in 1997, EPCs have stimulated considerable interest among scientists due to the observation that variations in their number and function are associated with many pathological conditions including cardiovascular, cancer, and metabolic diseases. However, comparative interpretation of clinical studies on EPCs is still hampered by the lack of standardized methods employed for EPC quantification and analysis.
Methods: Two main approaches are currently used to study circulating EPCs. One approach consists in identifying and selecting EPCs by cell surface phenotype using fluorescently labeled antibodies and flow cytometry directly performed on peripheral blood samples. The second approach consists in isolating and expanding EPCs in vitro, starting from peripheral blood samples. Key advantages, limits and critical methodological aspects of each approach will be illustrated.
Results: EPC variations observed in pathological conditions will be shown, mainly focused on the involvement of EPCs in cardiovascular diseases. The behaviour of EPCs during particular physiologic challenges, such as systemic hypoxia exposure and physical exercise, will also be described in order to provide some insight into the role and function of EPCs in human physiopathology.
Conclusions: Changes in the number and function of circulating EPCs may be relevant to the study of a wide range of human diseases. If the methods for studying EPCs will be adequately standardized and adapted for routine use, EPC analysis will likely become a valuable diagnostic and prognostic non-invasive tool useful for patient follow-up
NK cell immune activation in HIV-1 infection : flipping the bad and good side of the same coin
No full textIFN-gamma: a Janus-faced cytokine in dendritic cell programming
No full textDiscussion on dose-dependent bivalent effects of IFN- in association with the acquisition of regulatory features by DCs
Tissue-resident and memory properties of human T-cell and NK-cell subsets
No full textEfficient immune responses to invading pathogens are the result of the complex but coordinated synergy between a variety of cell types from both the innate and adaptive arms of the immune system. While adaptive and innate immune responses are highly complementary, some cells types within these two systems perform similar functions, underscoring the need for redundancy and increased flexibility. In this review, we will discuss the striking shared features of immunological memory and tissue residency recently discovered between T cells, a component of the adaptive immune system, and natural killer (NK) cells, members generally assigned to the innate compartment. Specifically, we will focus on the T-cell and NK-cell diversity at the single cell level, on the discrete function of specific subsets, and on their anatomical location. Finally, we will discuss the implication of such diversity in the generation of long-term memory. This article is protected by copyright
Different combinations of cytokines and activating receptor stimuli are required for human natural killer cell functional diversity
No full textAlthough cytokine induced NK cell activation protocols are commonly used in many laboratories worldwide, a systematic study of the effect of different cytokines either alone or in combination on NK cell function is lacking. In this study we performed a comparative evaluation of several cytokines potentially important for NK cell stimulation, focusing particularly on IL21 because of its promising role in anti-tumor therapy. To simulate in vivo physiological condition, we evaluated cytokine stimulation in total peripheral blood mononuclear cells (PBMCs), as accessory cells are responsible for the secretion of many soluble factors and can simultaneously trigger multiple activation signals through engagement of NK cell activating receptors. We show here that NK cell responses are finely regulated by several incoming stimuli and that combinations of IL21 + IL2 or IL21 + IL15 strongly induced NK cell function. Cytokine stimulation combined with NK receptor engagement can be helpful in the dissection of NK cell responses in health and disease
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