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Biomedical subjects

E Wecker

Publications and source records attributed to E Wecker.

At least 37 records · Page 2Linked to original sources
PubMed1980

Chemical characterization of macrophage cytotoxicity factor, macrophage migration inhibitory factor, T-helper cell-replacing factor and colony-stimulating factor from culture supernatants of concanavalin A-stimulated murine spleen cells.

Supernatants from Concanavalin A-stimulated murine spleen cells were subjected to hydrophobic interaction chromatography on phenyl-Sepharose. Macrophage cytotoxicity factor (MCF), macrophage migration inhibitory factor (MIF), T-helper cell-replacing factor (TRF) and colony-stimulating factor (CSF) were bound at high ionic strength and were released stepwise at low ionic strength. CSF thus could be separated from MCF, MIF and TRF and the bulk of other proteins. Chromatograhy of pools containing MCF, MIF and TRF on Sephadex did not lead to a separation of the three activities which were all found in a molecular weight range of 25.000-55.000. Isoelectric focusing of these pools in pH range from 4 to 9 gave two peaks for MCF in a single sharp peak at pH 5.3. The results demonstrate that the four biological activities can be distinguished on a chemical basis and are accessible for purification and chemical characterization.

Animals↗
PubMed1979

[Soluble mediators as a means of communication between lymphozytes in immune reactions (author's transl)].

Soluble mediators play an important role in the positive and negative regulation of immune reactions. This has been particularly well documented for T-B-cooperation in the humoral immune response to T-dependent antigens. T-helper cells produce a T-cell replacing Factor (TRF) upon mitogenic or antigenic stimulation. It provides the signal to antigen triggered B-cells to begin with active antibody synthesis and secretion and thus it is a positively regulating mediator. Additional functional and some structural characteristics of TRF are described. Antigen specific and non-specific suppressor factors seem to be involved in the negative regulation of immune responses. Thus, the communication between cells of the immune system is largely conducted via soluble signal substances.

Antibody Formation↗
PubMed1977

Mechanism of T-cell help in the immune response to soluble protein antigens. I. Evidence for in situ generation and action of T-cell-replacing factor during the anamnestic response to dinitrophenyl keyhole limpet hemocyanin in vitro.

The involvement of a nonantigen-specific T-helper factor in the anamnestic immune response to dinitrophenyl keyhole limpet hemocyanin is demonstrated employing cultures of unseparated spleen cell populations. In such cultures of primed and boosted spleen cells, a good IgG anti-DNP response could be obtained if the hapten was presented on a heterologous carrier, provided that the homologous carrier was added simultaneously. T-cell depletion and reconstitution experiments show that such a factor, presumably identical with T-cell-replacing factor is produced by primed helper cells upon rechallenge and helps primed B cells, stimulated by soluble heterologous carrier hapten conjugates, to become IgG-secreting cells.

Animals↗
PubMed1977

Mechanism of T-cell help in the immune response to soluble protein antigens II. Reconstitution of primary and secondary in vitro immune responses to dinitrophenyl-carrier conjugates by T-cell-replacing factor.

Spleen cells of dinitrophenyl keyhole limpet hemocyanin (DNPKLH) primed and boosted mice produced a nonantigen-specific helper factor upon in vitro challenge with DNPKLH. This helper factor displays all of the biological characteristics so far described for TRF produced by allogeneic or Concanavalin A stimulation of mouse spleen cells. It restores the primary anti-SRBC response in nude spleen cultures following the same kinetics of action as T-cell-replacing factor (TRF). Conversely, TRF restores the primary in vitro immune response of nude spleen cultures to DNPKLH. TRF also restores the secondary anti-hapten IgG response of T-cell-deprived spleen cell cultures derived from DNPKLH primed and boosted mice. Here the need for carrier specificity is fully overcome. The data therefore suggest that TRF, as a nonantigen-specific maturation signal, is involved in the primary and secondary immune responses to both particulate and soluble antigens.

Animals↗
PubMed1974

Autoradiographic studies on the proliferation of antibody-producing cells in vitro.

A rapid and reliable autoradiographic technique for plaque-forming cells (PFCs) using (14)C rather than tritiated thymidine is described. Its application to PFCs developing in vitro shows that (a) practically all PFCs derive from precursors dividing steadily during the culture period, (b) PFC precursors divide in the absence of T-cell helper function, and (c) at least some PFCs may continue to divide.

Animals↗
PubMed1973

Stimulation of IgG antibody response in vitro by T cell-replacing factor.

A soluble factor (TRF) produced by mixtures of allogeneic mouse spleen, lymph node, and thymus cells functionally replaces T cells in a primary IgM antibody response to sheep blood cells in vitro. It is now shown that TRF can also reconstitute an IgG antibody response in T cell-deprived spleen cultures derived from preimmunized mice. The optimal time of addition and the amount of TRF required differ between primary and secondary in vitro systems.

Animals↗