Contribution of Chondroitin Sulfate A to the Binding of Complement Proteins to Activated Platelets

Exposure of chondroitin sulfate A (CS-A) on the surface of activated platelets is well established. The aim of the present study was to investigate to what extent CS-A contributes to the binding of the complement recognition molecule C1q and the complement regulators C1 inhibitor (C1INH), C4b-binding protein (C4BP), and factor H to platelets.Human blood serum was passed over Sepharose conjugated with CS-A, and CS-A-specific binding proteins were identified by Western blotting and mass spectrometric analysis. C1q was shown to be the main protein that specifically bound to CS-A, but C4BP and factor H were also shown to interact. Binding of C1INH was dependent of the presence of C1q and then not bound to CS-A from C1q-depleted serum. The specific interactions observed of these proteins with CS-A were subsequently confirmed by surface plasmon resonance analysis using purified proteins. Importantly, C1q, C4BP, and factor H were also shown to bind to activated platelets and this interaction was inhibited by a CS-A-specific monoclonal antibody, thereby linking the binding of C1q, C4BP, and factor H to exposure of CS-A on activated platelets. CS-A-bound C1q was also shown to amplify the binding of model immune complexes to both microtiter plate-bound CS-A and to activated platelets.This study supports the concept that CS-A contributes to the binding of C1q, C4BP, and factor H to platelets, thereby adding CS-A to the previously reported binding sites for these proteins on the platelet surface. CS-A-bound C1q also seems to amplify the binding of immune complexes to activated platelets, suggesting a role for this molecule in immune complex diseases

BOSE-EINSTEIN CORRELATIONS IN NEUTRINO AND ANTINEUTRINO INTERACTIONS IN DEUTERIUM

none33siBose-Einstein correlations between pions of equal charge have been observed in Charged Current and Neutral Current (anti)neutrino-deuterium interactions in the BEBC bubble chamber exposed to the SPS wide band beam. The pion emission region is found to be essentially spherical with a mean radius of (0.48±0.07) fm; the chaoticity parameter is 0.36±0.04. © 1988 Springer-Verlag.noneAllasia D.; Angelini C.; Baldini A.; Bertanza L.; Bianchi F.; Bigi A.; Bobisut F.; Borg A.; Capiluppi P.; Cirio R.; Derkaoui J.; Faccini-Turluer M.L.; Frodesen A.G.; Gamba D.; Giacomelli G.; Jongejans B.; Mandrioli G.; Margiotta-Neri A.; Marzari-Chiesa A.; Pazzi R.; Patrizii L.; Petri C.; Predieri F.; Romero A.; Rossi A.M.; Sconza A.; Serra-Lugaresi P.; Spurio M.; Tenner A.G.; van Apeldoorn G.W.; van Dam P.H.A.; van Eijndoven N.A.M.; Vignaud D.Allasia D.; Angelini C.; Baldini A.; Bertanza L.; Bianchi F.; Bigi A.; Bobisut F.; Borg A.; Capiluppi P.; Cirio R.; Derkaoui J.; Faccini-Turluer M.L.; Frodesen A.G.; Gamba D.; Giacomelli G.; Jongejans B.; Mandrioli G.; Margiotta-Neri A.; Marzari-Chiesa A.; Pazzi R.; Patrizii L.; Petri C.; Predieri F.; Romero A.; Rossi A.M.; Sconza A.; Serra-Lugaresi P.; Spurio M.; Tenner A.G.; van Apeldoorn G.W.; van Dam P.H.A.; van Eijndoven N.A.M.; Vignaud D

SEARCH FOR FRACTIONALLY CHARGED-PARTICLES IN (ANTI)NEUTRINO-DEUTERIUM INTERACTIONS

A search for relativistic fractionally charged particles in (anti)neutrino-deuterium interactions was performed using the CERN SPS wide-band neutrino beam and the Big European Bubble Chamber. The experiment established the following upper limit: quark/event <5×10-5 (90% confidence level) for charged particles with 0.3e<0.7e, interaction length >0.02, and mass mq<0.5 GeV. Other limits are quoted in the text. © 1988 The American Physical Society