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S Amigorena

Publications and source records attributed to S Amigorena.

63 records · Page 4Linked to original sources
PubMed1988

Regulation of hybridoma B-cell proliferation by immunoglobulin-binding factor.

Immunoglobulin-binding factors (IBF), which are cytokines able to suppress the immunoglobulin production by normal and transformed B cells, have been tested for their ability to interfere with hybridoma B-cell growth. Coculture experiments performed in soft agar between hybridoma B cells and hybridoma T cells secreting IgG-BF indicated that IgG-BF act as a growth regulatory molecule able to inhibit strongly the development of hybridoma B-cell colonies; this cytostatic effect, which appeared not to be a direct cytotoxic effect, was confirmed when using semi-purified IgG-BF in both soft agar and liquid medium cultures of hybridoma B cells. Thus, IBF appear to act as both immunoregulatory and growth regulatory factors. Some of the molecular consequences of this dual effect and its possible role in certain B-cell lymphoproliferative diseases such as multiple myeloma are discussed.

Animals↗
PubMed1987

Software for the quantitative evaluation of in vitro monoclonal antibody production from ELISA data.

Software has been developed which permits the quantitation of monoclonal antibodies secreted by B cell hybridomas. This program does not require the user to enter a large number of complex parameters and can be easily used without any previous computer experience. It fits all the experimental and standard curves by determining overlapping linear domains using the linear least-squares method. The program is based on logarithmic interpolations for determining Ig concentrations comparing experimental samples to Ig concentrations in standards. It provides a complete print-out of the data with editing options and is written in BASIC EDEX 4.0 Commodore computer language. It permits the accurate quantification of minute amounts of monoclonal antibodies and can be used to detect the inhibitory or enhancing effects of lymphokines or cytokines on Ig secretion by hybridoma B cells.

Antibodies, Monoclonal↗
PubMed1987

A sensitive method for testing the effect of immunoglobulin binding factor on Ig secretion by hybridoma B cells.

A microtiter plate assay to detect the effect of immunoglobulin binding factor (IBF) on Ig secretion by hybridoma B cells is described. This technique permits the analysis of Ig secretion by only 200-400 hybridoma B cells using a PFC assay and an ELISA, and therefore increases the IBF/cell number ratio. This increase allows the detection of a strong IBF-mediated inhibitory effect on Ig secretion by hybridoma B cells, which is otherwise difficult to obtain reproducibly. The technique is simple, does not require any transferring step and is convenient, since it permits large numbers of samples to be tested. It can be extended to test IBF for all isotypes or other lymphokines that affect Ig secretion.

Animals↗
PubMed1987

Immunoglobulin G-binding factors (IgG-BF) inhibit IgG secretion by, as well as proliferation of, hybridoma B cells.

Mouse immunoglobulin G-binding factors (IgG-BF) produced either by activated T cells (ATC) or by hybridoma T cells (T2D4) directly inhibit the in vitro IgG secretion by hybridoma B cells. This inhibition affects IgG1, IgG2a and IgG2b and can be detected as early as after 2 h incubation of the cells with IgG-BF eluted from non-equilibrium pH gradient electrophoresis gels. Moreover, IgG-BF also exert a strong growth-inhibitory effect on hybridoma B cells without any detectable immediate cytotoxicity. These results provide an experimental basis to analyze the molecular and biological effects induced by IgG-BF on B cells.

Animals↗
PubMedDate not supplied

21.1.1, a novel activation marker of T and B cells.

A new rat mAb designated mAb 21.1.1 was raised against a T cell hybridoma of mouse origin, T2D4. This antibody, an IgG2b, immunoprecipitates from the membrane extracts of iodinated T2D4 cells a 56-kDa glycoprotein of apparent pI 4.6 which gives a 34-kDa polypeptide after treatment with endoglycosidase F. MAb 21.1.1 reacts with an antigen expressed on murine mitogen-activated thymocytes and T cells, and on B cells stimulated by anti-IgM antibodies. Cells isolated from the spleen, lymph nodes and bone marrow are negative, as are purified resting B cells or T cells. This antigen is strongly expressed on most day-16 fetal thymocytes whereas adult thymocytes are almost negative. mAb 21.1.1 may be useful for the study of activation and differentiation of T and B cells.

Animals↗