| 1. |
|
|
| 2. |
|
|
| 3. |
- Kapur, Rick, et al.
(author)
-
Gastrointestinal microbiota contributes to the development of murine transfusion-related acute lung injury
- 2018
-
In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 2:13, s. 1651-1663
-
Journal article (peer-reviewed)abstract
- Transfusion-related acute lung injury (TRALI) is a syndrome of respiratory distress upon blood transfusion and is the leading cause of transfusion-related fatalities. Whether the gut microbiota plays any role in the development of TRALI is currently unknown. We observed that untreated barrier-free (BF) mice suffered from severe antibody-mediated acute lung injury, whereas the more sterile housed specific pathogen-free (SPF) mice and gut flora-depleted BF mice were both protected from lung injury. The prevention of TRALI in the SPF mice and gut flora-depleted BF mice was associated with decreased plasma macrophage inflammatory protein-2 levels as well as decreased pulmonary neutrophil accumulation. DNA sequencing of amplicons of the 16S ribosomal RNA gene revealed a varying gastrointestinal bacterial composition between BF and SPF mice. BF fecal matter transferred into SPF mice significantly restored TRALI susceptibility in SPF mice. These data reveal a link between the gut flora composition and the development of antibody-mediated TRALI in mice. Assessment of gut microbial composition may help in TRALI risk assessment before transfusion.
|
|
| 4. |
- Kapur, Rick, et al.
(author)
-
T regulatory cells and dendritic cells protect against transfusion-related acute lung injury via IL-10
- 2017
-
In: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 129:18, s. 2557-2569
-
Journal article (peer-reviewed)abstract
- Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related fatalities and is characterized by acute respiratory distress following blood transfusion. Donor antibodies are frequently involved; however, the pathogenesis and protective mechanisms in the recipient are poorly understood, and specific therapies are lacking. Using newly developed murine TRALI models based on injection of anti-major histocompatibility complex class I antibodies, we found CD4+CD25+FoxP3+ T regulatory cells (Tregs) and CD11c+ dendritic cells (DCs) to be critical effectors that protect against TRALI. Treg or DC depletion in vivo resulted in aggravated antibody-mediated acute lung injury within 90 minutes with 60% mortality upon DC depletion. In addition, resistance to antibody-mediated TRALI was associated with increased interleukin-10 (IL-10) levels, and IL-10 levels were found to be decreased in mice suffering from TRALI. Importantly, IL-10 injection completely prevented and rescued the development of TRALI in mice and may prove to be a promising new therapeutic approach for alleviating lung injury in this serious complication of transfusion.
|
|
| 5. |
- McVey, Mark J., et al.
(author)
-
Platelet extracellular vesicles mediate transfusion-related acute lung injury by imbalancing the sphingolipid rheostat
- 2021
-
In: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 137:5, s. 690-701
-
Journal article (peer-reviewed)abstract
- Transfusion-related acute lung injury (TRALI) is a hazardous transfusion complication with an associated mortality of 5% to 15%. We previously showed that stored (5 days) but not fresh platelets (1 day) cause TRALI via ceramide-mediated endothelial barrier dysfunction. As biological ceramides are hydrophobic, extracellular vesicles (EVs) may be required to shuttle these sphingolipids from platelets to endothelial cells. Adding to complexity, EV formation in turn requires ceramide. We hypothesized that ceramide-dependent EV formation from stored platelets and EV-dependent sphingolipid shuttling induces TRALI. EVs formed during storage of murine platelets were enumerated, characterized for sphingolipids, and applied in a murine TRALI model in vivo and for endothelial barrier assessment in vitro. Five-day EVs were more abundant, had higher long-chain ceramide (C16:0, C18:0, C20:0), and lower sphingosine-1-phosphate (S1P) content than 1-day EVs. Transfusion of 5-day, but not 1-day, EVs induced characteristic signs of lung injury in vivo and endothelial barrier disruption in vitro. Inhibition or supplementation of ceramide-forming sphingomyelinase reduced or enhanced the formation of EVs, respectively, but did not alter the injuriousness per individual EV. Barrier failure was attenuated when EVs were abundant in or supplemented with S1P. Stored human platelet 4-day EVs were more numerous compared with 2-day EVs, contained more long-chain ceramide and less S1P, and caused more endothelial cell barrier leak. Hence, platelet-derived EVs become more numerous and more injurious (more long-chain ceramide, less S1P) during storage. Blockade of sphingomyelinase, EV elimination, or supplementation of S1P during platelet storage may present promising strategies for TRALI prevention. Key Points: • EVs derived from stored platelets cause TRALI as a function of their elevated ceramide and decreased S1P content. • Inhibiting ceramide formation, supplementing S1P, or washing stored platelets could potentially reduce TRALI incidence and severity.
|
|
| 6. |
- Zufferey, Anne, et al.
(author)
-
Mature murine megakaryocytes present antigen-MHC class I molecules to T cells and transfer them to platelets
- 2017
-
In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 1:20, s. 1773-1785
-
Journal article (peer-reviewed)abstract
- Megakaryocytes (MKs) are bone marrow-derived cells that are primarily responsible for generating platelets for the maintenance of hemostasis. Although MK can variably express major histocompatibility complex (MHC) class I and II molecules during their differentiation, little is known whether they can elicit nonhemostatic immune functions such as T-cell activation. Here, we demonstrate that mature CD342 MHC class II2 CD411 MKs can endocytose exogenous ovalbumin (OVA) and proteolytically generate its immunogenic peptide ligand, which is crosspresented on their surface in association with MHC class I molecules. This crosspresentation triggered in vitro and in vivo OVA-specific CD81 T-cell activation and proliferation. In addition, the OVA-MHC class I complexes were transferred from MK to pro-platelets upon thrombopoiesis in vitro. MK could also present endogenous MK-associated (CD61) peptides to activate CD61-specific CD81 T cells and mediate immune thrombocytopenia in vivo. These results suggest that, in addition to their hemostatic role, mature MKs can significantly affect antigen-specific CD81 T-cell responses via antigen presentation and are able to spread this immunogenic information through platelets.
|
|
