Abstract: Novel polypeptides derived from human fibronectin, and fusion proteins containing those peptide sequences are described which define a receptor binding site on fibronectin that binds to the platelet receptor glycoprotein GPIIb-IIIa expressed by cells. The receptor binding site of human fibronectin includes at least fibronectin amino acid residues 1410-1436. The polypeptides facilitate attachment of cells to substrates either alone or in conjunction with RGD-containing peptides. Vectors preparing the fusion proteins and antibodies are also described. Methods for promoting cell attachment and for inhibiting cell adhesion are also described.

Abstract: An antibody that immunoreacts with a ligand-induced binding site (LIBS) on GPIIIa, and particularly, a LIBS induced in a platelet-associated GPIIb-IIIa/fibrinogen complex is disclosed. Further disclosed are diagnostic systems and methods for assaying LIBS-containing platelets in a vascular fluid sample using the antibodies of the invention.

Abstract: The present invention discloses polypeptides consisting essentially of an amino acid residue sequence corresponding to a formula selected from the group consisting of: Tyr-His-Asp-Arg-Lys-Glu-Phe-Ala-Lys-Phe-Glu-Glu-Glu-Arg-Ala-Arg-Ala-Lys-Tr p-Asp-Thr-Ala-Asn-Asn (SEQ ID NO 1); Ala-Asn-Asn-Pro-Leu-Tyr-Lys-Glu-Ala-Thr-Ser-Thr-Phe-Thr-Asn-Ile-Thr-Tyr-Ar g-Gly-Thr (SEQ ID NO 2); Ile-His-Asp-Arg-Lys-Glu-Phe-Ala-Lys-Phe-Glu-Glu-Glu-Arg-Ala-Arg-Ala-Lys-Tr p-Asp-Thr-Ala-Asn-Asn-Pro-Leu-Tyr-Lys-Glu-Ala-Thr-Ser-Thr-Phe-Thr-Asn-Ile-T hr-Tyr-Arg-Gly-Thr (SEQ ID NO 4); and Gly-Pro-Asp-Ile-Leu-Val-Val-Leu-Leu-Ser-Val-Met-Gly-Ala-Ile-Leu-Leu-Thr-Gl y-Leu-Ala-Ala-Leu-Leu-Ile-Trp-Lys-Leu-Leu-Ile-Thr-Ile-His-Asp-Arg-Lys-Glu-P he-Ala-Lys-Phe-Glu-Glu-Glu-Arg-Ala-Arg-Ala-Lys-Trp-Asp-Thr-Ala-Asn-Asn-Pro- Leu-Tyr-Lys-Glu-Ala-Thr-Ser-Thr-Phe-Thr-Asn-Ile-Thr-Tyr-Arg-Gly-Thr (SEQ ID NO 5), as well as diagnostic kits including same.

Abstract: A polypeptide consisting essentially of an amino acid residue sequence corresponding to a formula selected from the group consisting of:Tyr-His-Asp-Arg-Lys-Glu-Phe-Ala-Lys-Phe-Glu-Glu-Glu-Arg-Ala-Arg-Ala-Lys-Trp -Asp-Thr-Ala-Asn-Asn; andAla-Asn-Asn-Pro-Leu-Tyr-Lys-Glu-Ala-Thr-Ser-Thr-Phe-Thr-Asn-Ile-Thr-Tyr-Arg -Gly-Thr.

Abstract: Receptor-induced binding sites (RIBS) expressed in a ligand when that ligand is bound in a complex with a receptor are disclosed, as are polypeptides that correspond in amino acid residue sequence with a RIBS expressed by a receptor-ligand complex. Particularly-preferred polypeptides correspond to a RIBS amino acid sequence of the gamma chain of human fibrinogen. Monoclonal antibodies that immunoreact with a RIBS but do not substantially immunoreact with either the ligand or the receptor when free in solution are also disclosed, as are hybridomas secreting those antibodies, and methods of making and using such antibodies.

Abstract: An integrin-activating antibody is disclosed that immunoreacts with an integrin and when immunoreacted increases the binding affinity of the integrin for binding to ligands specific for the integrin. The antibody also immunoreacts with a ligand-induced binding site (LIBS) on the integrin when the integrin is specifically bound to its ligand. Further disclosed are therapeutic compositions and methods for promoting cell adhesion using the disclosed integrin-activating antibodies.

Abstract: An antibody that immunoreacts with a ligand-induced binding site (LIBS) on GPIIIa, and particularly, a LIBS induced in a platelet-associated GPIIb-IIIa/fibrinogen complex is disclosed. Further disclosed are diagnostic systems and methods for assaying LIBS-containing platelets in a vascular fluid sample using the antibodies of the invention.

Abstract: Polypeptides derived from the ligand-binding portion of an Integrin alpha subunit are disclosed as are their use for modulation of Integrin ligand binding. Anti-peptide antibodies, hybridomas secreting the antibodies, as well as methods of making and using such antibodies and recombinant DNA molecules coding for the polypeptides are also described. The polypeptides and antibodies to the polypeptides are effective inhibitors of fibrinogen binding to platelets.

Abstract: Polypeptides which are derived from the Arg-Gly-Asp (RGD) binding portion of an Integrin beta subunit are disclosed as are their use for modulation of Integrin ligand binding. Anti-peptide antibodies, hybridomas secreting these antibodies, as well as methods of making and using such antibodies, and recombinant DNA molecules that define the structural gene coding for the polypeptides are also contemplated as within the scope of the present invention.

Abstract: Polypeptides which are derived from the ligand-binding portion of an Integrin alpha subunit are disclosed as are their use for modulation of Integrin ligand binding. Anti-peptide antibodies, hybridomas secreting these antibodies, as well as methods of making and using such antibodies, and recombinant DNA molecules that define the structural gene coding for the polypeptides are also contemplated as within the scope of the present invention.

Abstract: Methods are described for characterizing platelet aggregation defects. The defects are characterized as activation, ligand binding, or post-occupancy defects. In one embodiment of the invention a Cam variant of Glanzmann's thrombasthenia is characterized as having a ligand binding defect. In another embodiment, a patient with myelofibrosis is identified as having an activation defect. Rapid analysis are afforded using fluorescence-activated flow cytometry. Also, diagnostic kits are described which comprise antibodies suitable for characterizing the above defects.

Abstract: A polypeptide consisting essentially of an amino acid residue sequence selected from the group consisting of:Tyr-His-Asp-Arg-Lys-Glu-Phe-Ala-Lys-Phe-Glu-Glu-Glu-Arg-Ala- Arg-Ala-Lys-Trp-Asp-Thr-Ala-Asn-Asn; SEQ ID No 1 andAla-Asn-Asn-Pro-Leu-Tyr-Lys-Glu-Ala-Thr- Ser-Thr-Phe-Thr-Asn-Ile-Thr-Tyr-Arg-Gly-Thr, SEQ ID No 2.

Abstract: Polypeptides which are derived from the Arg-Gly-Asp (RGD) binding portion of an Integrin beta subunit are disclosed as are their use for modulation of Integrin ligand binding. Anti-antibody peptides, hybridomas secreting these antibodies, as well as methods of making any using such antibodies, and recombinant DNA molecules that define the structural gene coding for the polypeptides are also contemplated within the scope of the present invention.

Abstract: A polypeptide analog capable of immunologically mimicking a linear hGPIIb antigenic determinant expressed when platelet-associated GPIIb-IIIa binds fibrinogen is disclosed. An antibody that immunoreacts with the polypeptide and hGPIIb when hGPIIb is present as a platelet-associated GPPIb-IIIa/fibrinogen complex is also disclosed. Further disclosed are diagnostic systems and methods for assaying fibrinogen-bound platelets in a vascular fluid sample using the polypeptides and/or antibodies of the invention.

Abstract: A synthetic polypeptide is disclosed that substantially corresponds in sequence to a portion of the amino acid residue sequence of the 90 amino acid residue extra type III domain of human cellular fibronectin from about position 36 to about position 60 from the amino-terminus. The polypeptide contains about 10 to about 25 amino acid residues. Also disclosed are antibodies and methods of using both the polypeptide and antibodies.

Abstract: A diagnostic site-specific imaging reagent in the form of a receptor and an indicating means selectively binds to a specific cell membrane-associated antigen of a blood platelet that is in a stimulated active state but does not substantially bind to a platelet that is in a non-stimulated resting state. In particular, prelabelled monoclonal antibodies and polyclonal antibodies are prepared that bind and image thrombospondin when it is cell membrane-associated on a thrombin-stimulated platelet, thereby providing means for detecting and discriminating between a stimulated active blood platelet and a non-stimulated resting blood platelet.