Neutrophil Microvesicles from Healthy Control and Rheumatoid Arthritis Patients Prevent the Inflammatory Activation of Macrophages

Abstract

Microvesicles (MVs) are emerging as a novel means to enact cell-to-cell communication in inflammation. Here, we aimed to ascertain the ability of neutrophil-derived MVs to modulate target cell behaviour, the focus being the macrophage.MVs were generated in response to tumour necrosis factor-α, from healthy control neutrophils or those from rheumatoid arthritis patients. MVs were used to stimulate human monocyte-derived macrophages in vitro, or administered intra-articularly in the K/BxN mouse model of arthritis. A macrophage/fibroblast-like synoviocyte co-culture system was used to study the effects of vesicles on the crosstalk between these cells.We demonstrate a direct role for phosphatidylserine and annexin-A1 exposed by the MVs to counteract classical activation of the macrophages, and promote the release of transforming growth factor-β, respectively. Classically-activated macrophages exposed to neutrophil MVs no longer activated fibroblast-like synoviocytes in subsequent co-culture settings. Finally, intra-articular administration of neutrophil MVs from rheumatoid arthritis patients in arthritic mice affected the phenotype of joint macrophages.Altogether these data, with the identification of specific MV determinants, open new opportunities to modulate on-going inflammation in the synovia – mainly by affecting macrophage polarization and potentially also fibroblast-like synoviocytes - through the delivery of autologous or heterologous MVs produced from neutrophils.

Neutrophil–macrophage cooperation and its impact on tissue repair

“…In addition, apoptotic neutrophils release annexin‐1 which can enhance the phagocytic activity of macrophages . In addition, both phosphatidylserine and annexin‐1 can suppress the ability of interferon‐gamma to elicit an inflammatory phenotype in macrophages . Furthermore, molecules released by neutrophils such as neutrophil gelatinase‐associated lipocalin can enhance efferocytosis by increasing the expression of the phosphatidylserine receptor MER proto‐oncogene, tyrosine kinase on macrophages .…”

Extracellular vesicles, news about their role in immune cells: physiology, pathology and diseases

“…Considered together, the EVs released from immune cells modulate ample aspects of the system by either enhancing or suppressing its various activities [22,23]. This role of EVs has been confirmed by in-vitro studies, where the cells employed for their release are often of a single type, and target cells are known.…”

“…EVs are often important for animals and humans, especially when afflicted by infectious diseases. It appears, therefore, that the EV cocktails from the blood or other origin can induce apparently opposite effects, programmed towards pro-or antiinflammatory cell phenotypes [23,[27][28][29][30][31][32]. The EVs most effective for intervention in the latter responses are those derived from mesenchymal stromal cells (MSCs) [26].…”

“…However, effects induced by miscellaneous EVs have also been of antiinflammatory type. It appears, therefore, that the EV cocktails from the blood or other origin can induce apparently opposite effects, programmed towards pro-or antiinflammatory cell phenotypes [23,[27][28][29][30][31][32].…”

Annexin A1 drives macrophage skewing towards a resolving phenotype to accelerate the regeneration of muscle injury through AMPK activation

“…The protein annexin A1 (ANXA1) (Lim and Pervaiz, 2007;Perretti and D'Acquisto, 2009), is a major driver of inflammatory resolution, promoting neutrophil apoptosis (Solito et al, 2003), nonphlogistic monocyte recruitment (McArthur et al, 2015) and macrophage efferocytosis (Dalli et al, 2012;Scannell et al, 2007). Moreover, we and others have recently provided evidence showing ANXA1 to promote an anti-inflammatory macrophage phenotype in in vitro models of rheumatoid arthritis (Rhys et al, 2018) and tumour growth (Moraes et al, 2017), but how this translates to an in vivo situation is less clear. Against this background, we applied a well-characterised model of skeletal muscle injury (Arnold et al, 2007;Varga et al, 2013;Varga et al, 2016a) to test the hypothesis that ANXA1 and its receptor FPR2/ALX could be the upstream trigger of AMPK activation, and hence be a major driver of the pro-to anti-inflammatory macrophage phenotype shift, promoting inflammatory resolution and the restoration of skeletal muscle tissue homeostasis.…”