Honore P.M.,Vrije Universiteit Brussel |
Jacobs R.,Vrije Universiteit Brussel |
Joannes-Boyau O.,University of Bordeaux Segalen |
Boer W.,Hospital East Limburg |
And 4 more authors.
Molecular Medicine | Year: 2012
For almost three decades, researchers have invested in strategies that involved removal of excess inflammatory mediators from the circulation (that is, the "cytotoxic" approach). Blood purification techniques using an extracorporeal device can indeed nonspecifically remove a wide array of inflammatory mediators from the circulation. In animal models, this multimediator targeting or pleiotropic approach was shown to downregulate systemic inflammation and to restore immune homeostasis. In this issue, Namas et al. seriously challenge this cytotoxic hypothesis and propose to replace it by a cytokinic approach. In a rodent model of sepsis, these authors elegantly demonstrate that hemoadsorption using a large surface-area polymer could reduce and, more importantly, relocalize and reprogram sepsis-induced acute inflammation, while simultaneously lowering infectious burden and liver damage. Although challenging, this new theory can be considered complementary to the existing cytotoxic hypotheses by coupling reduced endothelial damage at the interstitial level (cytotoxic approach) with the concept of reprogramming leucocytes and mediators toward infected tissue, thus emptying the bloodstream of important promoters of remote organ damages (cytokinic approach).
Dhaeze T.,Hasselt University |
Dhaeze T.,transnational University of Limburg |
Peelen E.,Hasselt University |
Peelen E.,transnational University of Limburg |
And 17 more authors.
Journal of Immunology | Year: 2015
Follicular regulatory T cells (TFR) have been extensively characterized in mice and participate in germinal center responses by regulating the maturation of B cells and production of (auto)antibodies.We report that circulating TFR are phenotypically distinct from tonsil-derived TFR in humans. They have a lower expression of follicular markers, and display a memory phenotype and lack of high expression of B cell lymphoma 6 and ICOS. However, the suppressive function, expression of regulatory markers, and FOXP3 methylation status of blood TFR is comparable with tonsil-derived TFR. Moreover, we show that circulating TFR frequencies increase after influenza vaccination and correlate with anti-flu Ab responses, indicating a fully functional population. Multiple sclerosis (MS) was used as a model for autoimmune disease to investigate alterations in circulating TFR. MS patients had a significantly lower frequency of circulating TFR compared with healthy control subjects. Furthermore, the circulating TFR compartment of MS patients displayed an increased proportion of Th17-like TFR. Finally, TFR of MS patients had a strongly reduced suppressive function compared with healthy control subjects. We conclude that circulating TFR are a circulating memory population derived from lymphoid resident TFR, making them a valid alternative to investigate alterations in germinal center responses in the context of autoimmune diseases, and TFR impairment is prominent in MS. Copyright © 2015 by The American Association of Immunologists, Inc.