[PMC free article] [PubMed] [Google Scholar] 15. protecting T15 idiotype among Personal computer reactive antibodies in old age. 055:B5; 10g/ml) for 4C5 days. Collected cells were then assayed via ELISpot on phosphorylcholine (Personal computer2)-BSA (Biosearch, Petaluma, CA) coated plastic plates as explained in Ratliff et al.20. Total IgM secreting cells were also assessed on anti-IgM coated plates by ELISpot as with Ratliff et al.20. Serial dilutions of cells were plated and antibody secreting cells (ASC) recognized to determine the rate of recurrence of ASC by linear regression analysis20. In LPS stimulated cultures, 90% of ASC reactive to Personal computer secreted IgM. LPS activation showed experimental variance as measured by IgM ASC per 103 isolated B cells. The average and standard deviation (SD) of IgM ASC/103 cells for B cell subsets in young mice were: FO splenic B cells, 57 51; CD23? immature bone marrow B cells 35 34; and CD23+ immature bone marrow B cells O6BTG-octylglucoside 25 19. From older mice, IgM ASC/103 were: FO splenic B cells 109 73; CD23? immature bone marrow B cells 58 62; and CD23+ immature bone marrow B cells 36 39. There were no statistically significant variations in the IgM ASC reactions obtained for any B cell subset between young adult and aged mice. In the absence of LPS, IgM reactions were only O6BTG-octylglucoside ~10% of that seen upon LPS activation. Given the variability in IgM ASC derived per 103 cells after tradition with LPS, PC-reactive ASC were normalized to the number of total IgM antibody secreting cells. Identification of the T15 idiotype T15 idiotype manifestation was recognized on Personal computer reactive antibodies from LPS stimulated B cells in ELISpot assays. LPS stimulated B cells were cultured on Personal computer2-BSA coated plates. After washing, plates were developed with the anti-T15 IgG1 mAb HB33/Abdominal1-2 (BioXCell, W. Lebanon, NH) followed by HRP-anti-IgG1 specific antibody (Jackson Immunoresearch, Western Grove, PA) and colorimetric ELISpot analysis to identify PC-reactive, T15 idiotype positive ASC. Abdominal1-2 recognizes a conformational epitope generated by both the Ig weighty chain and light chain of T1531. Anti-PC antibodies identified by Abdominal1-2 carry close similarity, albeit not necessarily total variable region identity, to the prototypic germ-line T15 antibody32. The incidence of Personal computer reactive antibody secreting cells expressing the T15 idiotype as recognized via Abdominal1-2 binding was compared to the total incidence of Personal computer reactive antibody secreting cells (observe above) and percentages of T15+ Personal computer reactive ASC were estimated. In some experiments, ELISA assays were used to assess T15 idiotype manifestation on anti-PC antibodies in supernatants from LPS stimulated B cells after 4C5 days in tradition. T15 expressing antibodies were captured plates coated with the anti-T15 idiotype antibody Abdominal1-2. Development O6BTG-octylglucoside of these plates was with anti-IgM-alkaline phosphatase (AP) and used an ELISA Amplification System (Life Systems, Grand Island, NY) according to the manufacturers instructions. Binding of supernatant IgM to Abdominal1-2 (anti-T15) coated plates was compared to the binding of supernatant IgM to Personal computer2-BSA plates to estimate proportions of T15+ anti-PC IgM antibodies. The results of this ELISA assay for T15 were compared, O6BTG-octylglucoside in several experiments, to a competitive assay based on T15 idiotype assays explained previously9,10. In the competitive ELISA, Abdominal1-2 (10g/ml) was coated onto MaxiSorb plates (Thermo Scientific, Waltham, MA). Supernatants from LPS stimulated B cells (25l neat or appropriately diluted) were added to the Abdominal1-2 coated plates followed by addition of 2ng of AP labeled-T15 antibody (TEPC 15; Sigma Aldrich). The degree of competition for labeled T15 was compared to that for graded concentrations of T15 protein. The amounts of T15 antibody estimated from the solid phase ELISA methods were comparable to those acquired by competitive ELISA. Labeling of immature bone marrow and splenic transitional B cells with BrdU Mice were given 5-bromo-2-deoxyuridine (BrdU) in drinking water (1mg/ml) O6BTG-octylglucoside supplemented with 5% glucose for a period of 3 days. Cells were stained for surface antigens for immature B cells as explained above Rabbit polyclonal to PDCL and for BrdU incorporation having a BD BrdU Flow Kit as previously reported33. Statistical Analysis Groups were compared by unpaired two-tailed.