Monoclonal Autoantibodies from Patients with Autoimmune Diseases: Specificity, Affinity and Crossreactivity of MAbs Binding to Cytoskeletal and Nucleolar Epitopes, Cartilage Antigens and Mycobacterial Heat-Shock Protein 60
摘要:
Serum autoantibodies produce typical immunofluorescence staining patterns on HEp-2 cells, which are frequently used for diagnostic purposes. These include antibodies recognizing cytoskeletal and nuclear epitopes. The detailed analysis of human monoclonal antibodies (MAbs) should help to understand which antigens or autoantigens were involved in the generation of these immune responses. Here, three MAbs are described staining HEp-2 cells in a characteristic pattern. They were derived from peripheral blood B cells of two patients with rheumatic diseases (rheumatoid arthritis and relapsing polychondritis). Their binding reactivities were characterized in detail in several assay systems and their affinities measured. Although the antibodies differed in their fine specificity and crossreactivity, all three MAbs (2 IgM, 1 IgA) bound to purified cytoskeletal antigens (desmin) and, in addition, to cartilage antigens (human collagen type 11, proteoglycans). The binding to HEp-2 cells could be inhibited specifically with soluble antigens as shown by intracellular flow cytometry. The affinities for both groups of antigens were relatively high (examples: K-D (desmin) = 0.1 X 10(-7) M; K-D (collagen) = 3.5 X 10(-7) M). Two of the MAbs also bound to heat-shock protein 60 (HSP60) derived from Mycobacterium tuberculosis. The results prove that antibodies and B cells with reactivity to both intracellular cytoskeletal and nuclear antigens and exogenous antigens (e. g. HSP60) exist in patients with rheumatic diseases. Similar to an animal model such human B cells may be induced by the exogenous antigen (IiSP60) and crossreact with local auto-antigens related to the disease (cartilage). In this way they might contribute to pathogenic processes. Due to their additional crossreactivity with intracellular cytoskeletal and nuclear antigens, these antibodies simultaneously can be detected in the HEp-2 immunofluorescence assay.
Regioselectivity and Stereospecificity in a Contrastereoelectronically Controlled Pinacol Rearrangement of Alkoxycyclobutane Derivatives. A Novel Route to Vicinally Substituted Cyclopentanones
作者:Debasis Patra、Subrata Ghosh
DOI:10.1021/jo00113a036
日期:1995.4
A four-step sequence for the synthesis of vicinally substituted cyclopentanones 5 and 9 has been developed starting from the acyclic ketones 1. The key step involves a stereospecific pinacol-type rearrangement of the cyclobutane ring embodied in oxabicyclo[3.2.0]-heptanes 4 and 8 involving exclusive migration of the stereoelectronically disfavored cyclobutane bond. The oxabicyclo[3.2.0]heptanes have been obtained by copper(I) triflate (CuOTf) catalyzed intramolecular photocycloaddition of the dienes 3 prepared from the ketones 1 on reaction with (ethoxyvinyl)lithium followed by allylation of the carbinols 2. The regioselectivity observed in bond migration has been attributed to be the result of the stabilization of the cation 15 by the neighboring hydroxyl group that is generated during the rearrangement.
A convenient route to vicinally substituted cyclopentanones via pinacol type rearrangement of cyclobutanes
作者:Subrata Ghosh、Debasis Patra
DOI:10.1016/0040-4039(93)88087-y
日期:1993.7
A convenient route to the vicinallysubstituted cyclopentanones 4,8 have been developed via rearrangement of oxabicyclo[3.2.0]heptanes obtained through intramolecular [2+2] photocycloaddition in dienes derived from ketones 1, 7.
Monoclonal Autoantibodies from Patients with Autoimmune Diseases: Specificity, Affinity and Crossreactivity of MAbs Binding to Cytoskeletal and Nucleolar Epitopes, Cartilage Antigens and Mycobacterial Heat-Shock Protein 60
作者:T MENGE
DOI:10.1078/0171-2985-00107
日期:——
Serum autoantibodies produce typical immunofluorescence staining patterns on HEp-2 cells, which are frequently used for diagnostic purposes. These include antibodies recognizing cytoskeletal and nuclear epitopes. The detailed analysis of human monoclonal antibodies (MAbs) should help to understand which antigens or autoantigens were involved in the generation of these immune responses. Here, three MAbs are described staining HEp-2 cells in a characteristic pattern. They were derived from peripheral blood B cells of two patients with rheumatic diseases (rheumatoid arthritis and relapsing polychondritis). Their binding reactivities were characterized in detail in several assay systems and their affinities measured. Although the antibodies differed in their fine specificity and crossreactivity, all three MAbs (2 IgM, 1 IgA) bound to purified cytoskeletal antigens (desmin) and, in addition, to cartilage antigens (human collagen type 11, proteoglycans). The binding to HEp-2 cells could be inhibited specifically with soluble antigens as shown by intracellular flow cytometry. The affinities for both groups of antigens were relatively high (examples: K-D (desmin) = 0.1 X 10(-7) M; K-D (collagen) = 3.5 X 10(-7) M). Two of the MAbs also bound to heat-shock protein 60 (HSP60) derived from Mycobacterium tuberculosis. The results prove that antibodies and B cells with reactivity to both intracellular cytoskeletal and nuclear antigens and exogenous antigens (e. g. HSP60) exist in patients with rheumatic diseases. Similar to an animal model such human B cells may be induced by the exogenous antigen (IiSP60) and crossreact with local auto-antigens related to the disease (cartilage). In this way they might contribute to pathogenic processes. Due to their additional crossreactivity with intracellular cytoskeletal and nuclear antigens, these antibodies simultaneously can be detected in the HEp-2 immunofluorescence assay.