The Macrophage αMβ2 Integrin αM Lectin Domain Mediates the Phagocytosis of Chilled Platelets

Abstract

αMβ2 integrin receptors on myeloid cells mediate the adhesion or uptake of diverse ligands. Ligand binding occurs in the αM chain, which is composed of an I domain and a lectin domain. The αM I domain binds iC3b, fibrinogen, intercellular adhesion molecule-1, and other ligands and mediates the adhesion of neutrophils to platelet glycoprotein Ibα (GPIbα). αMβ2 also recognizes β-GlcNAc residues on GPIbα that are clustered on platelets after cooling. The phagocytosis of chilled platelets could be reconstituted when Chinese hamster ovary cells were transfected with αMβ2. Replacement of the I domain or the lectin domain of the αM chain with the corresponding domain from the αX chain (p150) revealed that the activity of the αMβ2 integrin toward chilled platelets resides within the lectin domain and does not require the I domain. Additional evidences for this conclusion are: 1) Sf9 cells expressing solely the αM lectin domain bound chilled platelets, and 2) soluble recombinant αM lectin domain inhibited the phagocytosis of chilled platelets by αMβ2-expressing THP-1 cells, whereas I domain substrates showed no inhibitory effect. Therefore chilled platelets are removed from blood by an interaction between β-GlcNAc residues on clustered GPIbα and the lectin domain of αM chain of the αMβ2 integrin, distinguishing this interaction from those mediated by the αM I domain. αMβ2 integrin receptors on myeloid cells mediate the adhesion or uptake of diverse ligands. Ligand binding occurs in the αM chain, which is composed of an I domain and a lectin domain. The αM I domain binds iC3b, fibrinogen, intercellular adhesion molecule-1, and other ligands and mediates the adhesion of neutrophils to platelet glycoprotein Ibα (GPIbα). αMβ2 also recognizes β-GlcNAc residues on GPIbα that are clustered on platelets after cooling. The phagocytosis of chilled platelets could be reconstituted when Chinese hamster ovary cells were transfected with αMβ2. Replacement of the I domain or the lectin domain of the αM chain with the corresponding domain from the αX chain (p150) revealed that the activity of the αMβ2 integrin toward chilled platelets resides within the lectin domain and does not require the I domain. Additional evidences for this conclusion are: 1) Sf9 cells expressing solely the αM lectin domain bound chilled platelets, and 2) soluble recombinant αM lectin domain inhibited the phagocytosis of chilled platelets by αMβ2-expressing THP-1 cells, whereas I domain substrates showed no inhibitory effect. Therefore chilled platelets are removed from blood by an interaction between β-GlcNAc residues on clustered GPIbα and the lectin domain of αM chain of the αMβ2 integrin, distinguishing this interaction from those mediated by the αM I domain. The demand for platelet transfusions continues to increase due to the intensive treatment of hematologic and oncologic diseases. The estimated total number of platelet units collected in 2003 in the United States was over 5.9 million, and the fact that refrigerated platelets do not circulate after transfusion, therefore requiring storage at room temperature, complicates this potentially life-saving procedure. Platelets stored at room temperature (RT) 1The abbreviations used are: RT, room temperature; αMβ2, Mac-1, CR3, CD11b/CD18; iC3b, opsonic fragment of C3 that binds to αMβ2 and αXβ2; GPIbα, glycoprotein Ibα; β-d-GlcNAc-1-Me, methylated β-N-acetylglucosamine; CHO, Chinese hamster ovary; Sf9 cells, Spodoptera frugiperda cells; THP-1 cells, human monocytic cell line; αXβ2, p150,95, CR4, CD11c/CD18; CMFDA, 5-chloromethylfluorescein diacetate; CM-Green, CellTracker Green CMFDA fluorescent dye; CMTMR, (5-(and-6)-(((4-chloromethyl)benzoyl)amino)tetramethylrhodamine); CM-Orange, CellTracker Orange CMTMR fluorescent dye; GST, glutathione S-transferase; FLNa, filamin A; MOC, mocarhagin; BSA, bovine serum albumin; HBSS, Hanks' balanced salt solution; s-lectin, soluble αM lectin domain; sWGA, succinyl wheat germ agglutinin; FITC, fluorescein isothiocyanate; Ab, antibody; mAb, monoclonal Ab. 1The abbreviations used are: RT, room temperature; αMβ2, Mac-1, CR3, CD11b/CD18; iC3b, opsonic fragment of C3 that binds to αMβ2 and αXβ2; GPIbα, glycoprotein Ibα; β-d-GlcNAc-1-Me, methylated β-N-acetylglucosamine; CHO, Chinese hamster ovary; Sf9 cells, Spodoptera frugiperda cells; THP-1 cells, human monocytic cell line; αXβ2, p150,95, CR4, CD11c/CD18; CMFDA, 5-chloromethylfluorescein diacetate; CM-Green, CellTracker Green CMFDA fluorescent dye; CMTMR, (5-(and-6)-(((4-chloromethyl)benzoyl)amino)tetramethylrhodamine); CM-Orange, CellTracker Orange CMTMR fluorescent dye; GST, glutathione S-transferase; FLNa, filamin A; MOC, mocarhagin; BSA, bovine serum albumin; HBSS, Hanks' balanced salt solution; s-lectin, soluble αM lectin domain; sWGA, succinyl wheat germ agglutinin; FITC, fluorescein isothiocyanate; Ab, antibody; mAb, monoclonal Ab. lose hemostatic function. Furthermore the risk of bacterial infections transmitted through RT platelet concentrate transfusion is 50 times higher than through transfusion of refrigerated red blood cell products. Thus, regulatory agencies limit platelet storage to 5 days, a limitation that severely compromises platelet inventories and creates chronic shortages (1Center National Blood Data Resource Comprehensive Report on Blood Collection and Transfusion in the United States in 2001. National Blood Data Resource Center, Bethesda, MD2003: 3Google Scholar, 2McCullough J. Handin R. Lux S. Stossel T. Transfusion Medicine in Blood, Principles and Practice of Hematology. 2nd Ed. Lippincott Williams & Wilkins, Philadelphia, PA2003: 2011-2068Google Scholar). We recently defined the clearance mechanism of refrigerated platelets. Cooled platelets irreversibly reorganize von Willebrand factor receptors (the (GPIbαβIX)2V complex) into clusters on the platelet surface. The hepatic macrophage integrin receptors, αMβ2 (complement receptor type 3, Mac-1, or CD11b/CD18), recognize clustered GPIbα, leading to ingestion of cooled platelets (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google Scholar). Previously we provided indirect evidence that αMβ2 recognizes GPIbα on cooled platelets through exposed β-GlcNAc residues on N-linked oligosaccharides and proposed that this interaction is mediated by the αM lectin domain (4Hoffmeister K.M. Josefsson E.C. Isaac N.A. Clausen H. Hartwig J.H. Stossel T.P. Science. 2003; 301: 1531-1534Crossref PubMed Scopus (213) Google Scholar). Other investigators have also shown that the C terminus of platelet GPIbα, via its flanking and leucine-rich repeat region, binds to the neutrophil αM I domain of αMβ2 (5Simon D.I. Chen Z. Xu H. Li C.Q. Dong J.F. McIntire L.V. Ballantyne C.M. Zhang L. Furman M.I. Berndt M.C. Lopez J.A. J. Exp. Med. 2000; 192: 193-204Crossref PubMed Scopus (509) Google Scholar). αMβ2 was initially described an opsonic receptor that binds to the fragment and the phagocytosis of I J. PubMed Scopus Google Scholar, J. PubMed Scopus Google Scholar, J. in the Scholar). The αM of an I a binding and a lectin domain. iC3b, intercellular adhesion molecule-1, or in a within the αM I domain Cell. Full Text PDF PubMed Scopus Google Scholar, T. Full Text PDF PubMed Scopus Google Scholar, S. PubMed Scopus Google Scholar, R. J. PubMed Scopus Google Scholar). The lectin to the I domain and to the J. Google is of its in with cell phagocytosis in the of the J.A. PubMed Scopus Google Scholar). αMβ2 is also of phagocytosis of that is mediated by the binding of the cell to the αM lectin domain J. J. PubMed Scopus Google Scholar). The fact that residues on GPIbα on chilled platelets by αMβ2 receptors the αM lectin domain in this platelet GPIbα also mediates adhesion to neutrophil αMβ2 through the αM I domain (5Simon D.I. Chen Z. Xu H. Li C.Q. Dong J.F. McIntire L.V. Ballantyne C.M. Zhang L. Furman M.I. Berndt M.C. Lopez J.A. J. Exp. Med. 2000; 192: 193-204Crossref PubMed Scopus (509) Google Scholar). this we the of the αM for the and ingestion of chilled platelets. platelets not by serum (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google are by the αMβ2 We that chilled platelet phagocytosis by THP-1 cells could be in Chinese cells expressing αMβ2 on J. J. PubMed Scopus Google Scholar). cells expressing the αM lectin domain in which of the αMβ2 were with of CR4, and chilled platelets. Sf9 cells expressing the αM to chilled platelets times than to room temperature platelets. Furthermore a αM lectin domain inhibited chilled platelet phagocytosis by THP-1 αM I fibrinogen, a I domain R. Chen Z. Zhang R. Lopez J. D.I. J. Exp. Med. 2003; PubMed Scopus Google or an I domain not chilled platelet that the αM lectin domain mediates the phagocytosis of chilled platelets by myeloid and αM from & αM mAb, were from αX was from was from was from GPIbα was from was from αM methylated β-GlcNAc with were from Green and CellTracker Orange CMTMR were from was from was from was from αM J. Full Text PDF PubMed Google into and αM binding human were provided by T. for Blood cells expressing and J. J. PubMed Scopus Google were provided by Center, of The the human αM I domain a soluble Cell. Full Text PDF PubMed Scopus Google was provided by The of the αM I R. Chen Z. Zhang R. Lopez J. D.I. J. Exp. Med. 2003; PubMed Scopus Google and for the αM I domain were from and to soluble in Sf9 cells H. J. J. Clausen H. J. Full Text Full Text PDF PubMed Scopus Google was from H. H. of of and recombinant to filamin in Sf9 cells Stossel T.P. J. Full Text Full Text PDF PubMed Scopus Google was a from and and GPIbα were provided by Berndt of and blood was from human by into of was from the of and and and was to the of was by at for and platelets were from by through a J.H. J. PubMed Scopus Google or by a H. Hartwig J.H. 2000; PubMed Google Scholar). Platelets by were to at for in 5 bovine serum and human platelets were used in for the in platelets were with by and in and described (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google Scholar). the platelet binding to Sf9 cells expressing αM platelets were with for at The platelets were and described for of GPIbα with was described (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google Scholar). the of on platelet human platelets were at RT or at for and for at in and THP-1 cells were in with bovine serum and of THP-1 cells, which is by of αMβ2, was by treatment of the cells with and 50 for D.I. Xu L. L. PubMed Google Scholar). αMβ2 was by a αM were and cells expressing and were in with and with bovine and Sf9 cells were at in with 50 and 50 Sf9 cells were to the of recombinant or in at THP-1 THP-1 cells were by the of for at and human and to for at in (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google Scholar). The cells were and in Hanks' balanced salt or and to the of on platelet the of the the were with αM I domain or for RT or chilled platelets were for at with soluble I soluble lectin I or from Sf9 cells expressing Stossel T.P. J. Full Text Full Text PDF PubMed Scopus Google or H. J. J. Clausen H. J. Full Text Full Text PDF PubMed Scopus Google were used for Sf9 the soluble αM lectin domain. or RT platelets were to THP-1 cells and to for at platelets were removed through with by the of for 5 THP-1 cells were from the and with mAb, which recognizes the ingestion was and by on a (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google Scholar). Data were in The of for when with RT platelets was to to the of the increase for the chilled platelet αMβ2, αXβ2, or for platelets by THP-1 cells was for cells expressing of αM and αX J. J. PubMed Scopus Google Scholar). The were 1) αM I domain was by the αX domain in the αM chain and αM lectin domain J. J. PubMed Scopus Google Scholar). 2) The αM lectin domain and the domain were by the αX and αM I domain J. J. PubMed Scopus Google were with human serum 5 cells were and were to at for The cells were with for at and the cell was and with an of or of platelets by cells was (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google Scholar). or RT platelets were with and to the was by the of into cells by platelets were by the cells after the with for platelets, bound platelets are platelets are were in and Data were in or were used to that were on the of cells and that the of the and were The of cells expressing αMβ2, αXβ2, or for when with RT platelets was to to the of the increase for the chilled platelet by the and platelets or were by the of of PubMed Scopus Google Scholar). were for 5 platelets were by the of of and H. S. PubMed Scopus Google Scholar). was removed by at for and the soluble was with 50 domain bound to lectin was with and the was with soluble were with the soluble were collected and in were by on or and with or were with in and with 5 GPIbα bound to domain on GPIbα bound to soluble lectin on with I and with in Sf9 by a Ab. was with an were with in which cells expressing the and were The cells were to for with for at and or chilled and platelets were to the cells into and with for at The cells were in for at RT, and times for 5 at of platelets by cells was cells are by platelets were by the cells after the with The cells were times for 5 and the were on with were at RT were on a with a an and and red were the were to of αM and in a and J. Google were used to the and lectin domain human αM from the J. Full Text PDF PubMed Google a The was 1) for 2) for for and for to were for and with for The were into the and into the and of the αM fragment was and cells were used to the recombinant into a with the Sf9 cells were transfected with and was Sf9 cells were with a of of of and for The residues and lectin domain at the was by or Sf9 cells were and in and 5 cells were with 5 the mAb, or the at for and by The of the αM lectin domain was by binding Sf9 cells were in and with for at the cells were times with at RT and by The and of Sf9 cells were in The number of Sf9 cells was to Sf9 cells Stossel T.P. J. Full Text Full Text PDF PubMed Scopus Google were used cells in of αM in Sf9 to residues of the αM lectin domain was the and and the αM a and into the described The fragment was and between the and of the a that mediates of the recombinant into the Sf9 cell was by The was with and recombinant was after into Sf9 The αM soluble lectin domain at the of in the human αM I domain a was used to and domain described Cell. Full Text PDF PubMed Scopus Google Scholar). the was in and the domain was domain were 50 and the domain was 50 the domain bound to was with Cell. Full Text PDF PubMed Scopus Google to the The was by the of for at The of the was by after and by the The was the or of the a to Sf9 αM cells were by at for 5 and with Sf9 cells platelets. the number of cells cells, of cells were with of cells were between cells expressing Stossel T.P. J. Full Text Full Text PDF PubMed Scopus Google and cells with recombinant to αM was after 3, was after and after at or 5 were used for The and of Sf9 cells were in of and lectin domain were in Ab. platelets were with 5 Sf9 cells in in the or of for with at Sf9 cells were times with and by THP-1 cells, cells, or Sf9 cells, the of for or when with platelets was to to the of the increase for the chilled platelet are or were the were were the αM THP-1 cells have provided evidence that the αMβ2 receptor mediates chilled platelet phagocytosis (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google Scholar). shown in cells expressing αMβ2 J. J. PubMed Scopus Google chilled platelets with times than RT platelets. for THP-1 cells, platelet ingestion was inhibited by that the terminus of by (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google Scholar, K.M. Josefsson E.C. Isaac N.A. Clausen H. Hartwig J.H. Stossel T.P. Science. 2003; 301: 1531-1534Crossref PubMed Scopus (213) Google cells expressing not chilled platelets cells expressing and of αM and αX (p150) the αM I domain or αM lectin domain was by the corresponding αX were used to which of αM is to mediate chilled platelet The of cells expressing integrin the αM I domain or the αM lectin domain the I were and cells expressing an αM chain the lectin domain chilled human platelets to a to that of the ingestion mediated by the αM cells expressing an αM chain the I domain not chilled platelets. uptake of chilled platelets mediated by the lectin domain of αM is shown by in cells expressing αMβ2 or the αM lectin domain in with in a of chilled platelets shown are platelets that with exposed on the of cells expressing or αM I not chilled platelets and platelets bound to for the αMβ2 receptors in cells, or of the GPIbα terminus with the inhibited chilled human platelet phagocytosis mediated by the αM lectin domain that were on the of cells and that the of the and were The of the was used to the of the recombinant αMβ2 and and αM I domain and αM lectin domain Platelets to Sf9 the αM recombinant αM on cells for that is to that of the of neutrophil αMβ2 J. Google Scholar). We used a to and recombinant αM on the of recombinant αM recombinant αM were in Sf9 cells the αM I lectin and C terminus or αM the I domain a of the region, the lectin and the C lectin domain. that the Sf9 cells the receptor at the of and lectin with an the of the recombinant or that the recombinant were on the of Sf9 recombinant αM with the and of Sf9 cells the or the lectin domain The of the αM recombinant were Sf9 cells with an I domain and the lectin cells not The lectin domain of and the lectin domain to be bound to Sf9 cells expressing by We chilled or RT platelets with Sf9 cells expressing the or the lectin domain. chilled human platelets bound to or lectin Sf9 cells than platelets at room temperature and with or cells expressing lectin domain showed binding to RT platelets with cells; binding of the lectin domain to chilled platelets was higher than to platelets. of chilled platelets to was inhibited by the of that binding is mediated by β-GlcNAc Sf9 cells with chilled or RT platelets not platelet αM αM I by THP-1 αM lectin and I were soluble in Sf9 cells and αM I a and from Cell. Full Text PDF PubMed Scopus Google bound to GPIbα in platelet shown in The soluble αM I domain also bound to fibrinogen, a to the I by H. H. T. J. H. and of the soluble I domain to and of neutrophil binding to platelet by αM I domain was shown (5Simon D.I. Chen Z. Xu H. Li C.Q. Dong J.F. McIntire L.V. Ballantyne C.M. Zhang L. Furman M.I. Berndt M.C. Lopez J.A. J. Exp. Med. 2000; 192: 193-204Crossref PubMed Scopus (509) Google Scholar, R. Chen Z. Zhang R. Lopez J. D.I. J. Exp. Med. 2003; PubMed Scopus Google Scholar). The soluble αM I not the phagocytosis of chilled human platelets in at of or H. H. T. J. H. and The soluble αM lectin domain an of than the and also GPIbα from platelet to its to the soluble I of of soluble αM lectin domain in a the ingestion of chilled platelets by THP-1 cells and was Other were to I domain in chilled platelet of the αM I not its binds to and neutrophil adhesion to or to platelets R. Chen Z. Zhang R. Lopez J. D.I. J. Exp. Med. 2003; PubMed Scopus Google Scholar). chilled platelet phagocytosis by THP-1 cells at shown to neutrophil binding of platelets platelet phagocytosis was also of the or of and was not by a αM I domain or by on we that the αM I domain does not a in the phagocytosis of chilled human platelets in in GPIbα is to to the αM I which to the von Willebrand factor and to mediate platelet adhesion to neutrophils (5Simon D.I. Chen Z. Xu H. Li C.Q. Dong J.F. McIntire L.V. Ballantyne C.M. Zhang L. Furman M.I. Berndt M.C. Lopez J.A. J. Exp. Med. 2000; 192: 193-204Crossref PubMed Scopus (509) Google Scholar, R. Chen Z. Zhang R. Lopez J. D.I. J. Exp. Med. 2003; PubMed Scopus Google Scholar). GPIbα on platelets that in by the αMβ2 receptor leading to chilled platelet phagocytosis and clearance from the by (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google Scholar). We that chilled platelet phagocytosis be reconstituted by expressing αMβ2 and evidence that chilled platelet phagocytosis is mediated by the αM lectin not the αM I domain. We have shown that GPIbα exposed β-GlcNAc residues on N-linked on the 1) GPIbα is the binding of succinyl wheat germ a lectin that binds to exposed β-GlcNAc 2) of platelets of β-GlcNAc residues with the increase in binding to cooled human platelets and phagocytosis (4Hoffmeister K.M. Josefsson E.C. Isaac N.A. Clausen H. Hartwig J.H. Stossel T.P. Science. 2003; 301: 1531-1534Crossref PubMed Scopus (213) Google Scholar). We that the αM lectin domain and binds to exposed and clustered β-GlcNAc residues to mediate chilled platelet αMβ2 is the receptor chilled platelet ingestion and to the αM in cooled platelet we used cells expressing a αM I domain or an αM lectin domain and have used to the iC3b, intercellular adhesion molecule-1, or binding to the αM I domain J. J. PubMed Scopus Google to the and of the αM lectin domain J. Google Scholar). Furthermore cells expressing the αMβ2 receptor are of and the and opsonic I of αMβ2 when on myeloid cells S. J. PubMed Scopus Google Scholar). cells expressing type αMβ2 or αX chain the αM lectin domain chilled platelets that were not by whereas cells expressing the αM I domain platelet phagocytosis by the αMβ2 and the αM lectin domain was inhibited the of the GPIbα the of N-linked or by the of soluble methylated that chilled platelets with the αM lectin domain through exposed β-GlcNAc β-GlcNAc on cells is an and is that a macrophage lectin and the ingestion of chilled platelets, whereas in not phagocytosis of platelets. We have that of the exposed β-GlcNAc residues the to to the αMβ2 and an that does not require by serum (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google Scholar). The αM lectin of and I J. PubMed Scopus Google Scholar, J. Google a in the phagocytosis of J. J. PubMed Scopus Google Scholar). is that chilled platelets to the αM lectin domain and of the αMβ2 and is that the mechanism described for chilled platelet clearance also to platelet platelets in the lose and β-GlcNAc leading to by expressing αMβ2 the chilled platelet clearance mechanism not have solely to platelets by and to platelets. is to that von Willebrand factor receptors GPIbα clustered a mechanism described for the receptor in S. PubMed Scopus Google Scholar). platelets with of exposed β-GlcNAc be to GPIbα and therefore from the The of Sf9 cells expressing or the lectin domain to chilled or RT platelets was also Sf9 cells expressing the bound to chilled platelets than to room temperature platelets, an interaction inhibited by the with soluble methylated Sf9 cells expressing lectin domain bound chilled platelets than RT platelets. also binding to Sf9 cells expressing the lectin domain that the a higher for its ligands. of the αM in the with the and therefore to the αM lectin domain that its binding to β-GlcNAc residues on the of RT platelets. of the lectin domain on cells the also to of the αM lectin binding to exposed ligands on RT platelets or Furthermore of the domain the αM lectin domain and binding of the lectin domain ligands by Sf9 cells, are with The of Sf9 cells also the of the lectin domain this domain is in The of exposed or β-GlcNAc residues on platelets or is We and a soluble of the αM lectin that this domain recognize the in GPIbα and its N-linked by a to for on platelets by an to be in a transfusion the for chilled platelets to be in we that the αM lectin domain bound to GPIbα and that of the soluble domain in a chilled platelet ingestion by THP-1 cells (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google Scholar). soluble αM I the I domain or not the phagocytosis of chilled human platelets in by THP-1 platelet phagocytosis was also of the of to a of the αM I domain to chilled platelet phagocytosis and to the and of the αM lectin domain. for αM I domain binding to the lectin domain J. Google the αM I a not inhibitory on chilled platelet phagocytosis by THP-1 to the of the αM lectin domain and of the or of the I mediate chilled platelet of the αM lectin domain to platelets therefore be used in the to for the by and by we have that chilled platelets in the of (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google GPIbα clusters on cooled platelets hemostatic and does not von Willebrand (3Hoffmeister K.M. Felbinger T.W. Falet H. Denis C.V. Bergmeier W. Mayadas T.N. von Andrian U.H. Wagner D.D. Stossel T.P. Hartwig J.H. Cell. 2003; 10: 87-97Abstract Full Text Full Text PDF Scopus (341) Google and clearance mediated by GPIbα be we that chilled platelet phagocytosis solely on the αM lectin domain and was of the αM domain and αM I domain. to the of mediates platelet adhesion to the αM I domain of neutrophils in blood and chilled platelet ingestion through the αM lectin domain by the clearance mechanism for chilled platelets be to platelets its in the clearance mechanism for platelets in We for the with the and cells, Falet for with the Isaac for for and for the