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B Flesch

Publications and source records attributed to B Flesch.

6 recordsLinked to original sources
PubMed1995

Biotinylation: a nonradioactive method for the identification of cell surface antigens in immunoprecipitates.

A nonradioactive method was employed to detect different cell membrane antigens on human polymorphonuclear granulocytes, monocytes and platelets. We compared the reactivity of one monoclonal antibody, N1III10, assumed to be Fc gamma RII-specific by functional assays, with other well-characterized monoclonal antibodies and human sera. Intact cells were incubated with biotin N-hydroxysulfosuccinimide ester which preferentially reacts with lysine residues in polypeptides. Biotin-labeled cells were lysed and the antigen was isolated from the cell lysate by immunoprecipitation with the antibody bound to Protein A-Sepharose. The precipitates were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transferred onto nitrocellulose membrane, and visualized by a streptavidin-alkaline phosphatase system with a suitable substrate. Using this biotin-labeling system we could show that N1III10 detects a 40 kDa antigen on monocytes and platelets, comparable to that expected of Fc gamma RII monoclonal antibodies.

Alkaline Phosphatase↗
PubMed1991

Alloantiserum recognizing a DQw2 split which is associated with DR3.

A typing serum MUE 38539 II, was found to recognize a DR3-associated split of DQw2. In cytotoxicity tests, MUE 38539 II yielded positive test results with B lymphocytes but not with monocytes of DR3-positive cell donors. This was in contrast to other typing reagents for DR3 that react with B lymphocytes as well as monocytes. Lymphocytotoxicity tests using MUE 38539 II were negative with DR7- and DQw2-positive cells. The assumption that the serum recognizes a DR3-associated split of DQw2, and not DR3 itself, was confirmed by the lack of reactivity with a DQw4- and DR3-positive lymphoblastoid cell line (RSH). The assumption was also corroborated using reagents from a family in which DR3 and DQw2 were not found in the usually described linkage. In two lines, DR3 was associated with DQw- (2707 and 2710), and in the cell line 2704, DQw2 was associated with DRw-. The serum MUE 38539 II was exclusively cytotoxic with lymphoblastoid cell lines from those family members who were positive for DQw2, independently of the DR3 antigens of the cells.

Cytotoxicity Tests, Immunologic↗
PubMed1988

[Streptozocin-sensitized lymphocytes suppress the glucose-stimulated insulin secretion of the islands of Langerhans].

Isolated islets of Langerhans (from C57Bl/6J mice) were either incubated with culture medium only or medium substituted by 1 mM streptozocin (SZ) and cultivated with lymphocytes (Ly) for seven days. Ly were isolated from the same mouse strain sensitized against SZ by 5 x 40 mg SZ per kg and day intraperitoneally or 1 mg SZ subcutaneously in vivo. Glucose-stimulated insulin secretion rate was used as an indicator for the metabolic condition of islets. SZ-pretreated islets showed significantly decreased insulin secretion in the presence of Ly. The secretion capacity of untreated islets was not impaired.

Animals↗