title: Transforming growth factor-beta1 in supernatants from stored red blood cells inhibits neutrophil locomotion.
abstract: Studies comparing transfusion and nontransfusion patients suggest an increased risk of postoperative infections in transfusion groups. Supernatants of blood components have been shown to affect the function of T lymphocytes and natural killer cells. Here, we found that supernatants from stored red blood cells (RBCs) inhibit human neutrophil migration in response to formyl peptides and stimulate neutrophil locomotion. These effects can be observed with high dilutions of RBC supernatants, such as 1:5 x 106 (vol/vol), able to trigger locomotion as well as desensitization of the cells to alternative chemoattractants. The phenomenon might be mediated by chemoattractants present in the supernatants. As RBC supernatants failed to mobilize intracellular free calcium, the chemoattractants should belong to the group of pure chemoattractants, that is, soluble Fas ligand (sFasL) and transforming growth factor-beta1 (TGF-beta1), known to act without increasing calcium levels. Recombinant TGF-beta1, but not sFasL, was found to reproduce the ability of RBC supernatants to both inhibit neutrophil response to formyl peptides and stimulate neutrophil locomotion. Moreover, TGF-beta1-immunodepleted supernatants did not display neutrophil-directed activities. Finally, RBC supernatants from RBCs stored after depletion of leukocytes were incapable of affecting neutrophil function. With neutrophils acting as a first-line antimicrobial defense, the ability, shown here, of high dilutions of RBC supernatants to inhibit neutrophil chemotaxis through TGF-beta1 may be a relevant determinant of infections in the postoperative period for transfusion patients. Consistently, the neutrophil chemotactic response to formyl peptide was inhibited by the plasma obtained from 5 transfusion patients.
authors.affiliation: Department of Internal Medicine and Center of Excellence for Biomedical Research (CEBR), University of Genoa, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Ghio
authors.forename: Luciano
authors.initials: L
authors.lastname: Ottonello
authors.forename: Paola
authors.initials: P
authors.lastname: Contini
authors.forename: Massimo
authors.initials: M
authors.lastname: Amelotti
authors.forename: Clemente
authors.initials: C
authors.lastname: Mazzei
authors.forename: Francesco
authors.initials: F
authors.lastname: Indiveri
authors.forename: Francesco
authors.initials: F
authors.lastname: Puppo
authors.forename: Franco
authors.initials: F
authors.lastname: Dallegri
mesh_terms: D001793:Blood Preservation / Q000009:adverse effects*; D039481:CD11b Antigen / Q000378:metabolism; D002634:Chemotaxis, Leukocyte / Q000187:drug effects*; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D018375:Neutrophil Activation / Q000187:drug effects; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects*; D016212:Transforming Growth Factor beta / Q000378:metabolism* / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1
chemical_list: D039481:CD11b Antigen; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D009240:N-Formylmethionine Leucyl-Phenylalanine