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J Kettman

Publications and source records attributed to J Kettman.

At least 19 recordsLinked to original sources
PubMed1990

Polyoma-induced thymic epithelial tumors: analysis by 2D gel electrophoresis of tumors upon labeling the entire tumor bearing host.

Injection of neonatal C3H/Bi mice with polyoma virus (PTA-5) results after 4 to 20 weeks in the development of thymic epithelial tumors in 2/3 of the mice. These tumors appear to be the result of a neoplastic proliferation or transformation of thymic epithelial cells. The tumors contain immature lymphoid infiltrates characteristic of normal tissue and express the same function as normal tissue by providing the microenvironment for T cell maturation. To establish more comprehensively the relation of neoplastic to normal thymic epithelial cells, tumor-bearing mice and their normal counterparts were labeled in vivo by injection of S35-L-methionine. The stroma and lymphoid cells were separated and analyzed by two dimensional gel electrophoresis followed by radiofluorography. It was found that the epithelial portion of the tumor differed in several structural polypeptide components from normal tissue while the polypeptide composition of the thymocyte population remained unaltered. It was concluded that the neoplasia is confined to the epithelium compartment and the function of the neoplastic organ is maintained.

Animals↗
PubMed1989

Consecutive radiofluorography and silver staining of two-dimensional gel electrophoretograms: application in determining the biosynthesis of serum and tissue proteins.

The methodology for conventional radiofluorography of two-dimensional gels, followed by rehydration of the gel and subsequent silver staining, is described. The image obtained by radiofluorography is referred to as biosynthetic image, and the image obtained by silver staining as constitutive image. Since the two images are already in close register (the same gel), reliable identification of polypeptides by the two different assays is possible, and the comparison provides valuable information on the catabolism of each entity. The utility of this procedure is illustrated in experiments involving a labeling with L-[35S]methionine of an entire mouse. Both serum and tissue samples were analyzed by two-dimensional gel electrophoresis with the aim of determining several categories of polypeptides in terms of their biosynthetic rates and their composition.

Animals↗
PubMed1988

Prospective partition analysis of independently assorted sets. Accessory elements supporting clonal lymphoid activation by mitogens.

Accessory cells for mitogen-induced clonal proliferation of lymphocytes can be found after in vitro culture of murine spleen cells. Mitogenic activation of T cells (concanavalin A) depends on such accessory cells. When the cultures in which the accessory cells developed are partitioned, assortment of the accessory cells in cultures is found. When small numbers (1-10) of responder cells, T cells, are dispensed into the above cultures, clonal growth of the T cells is achieved. Neither the dose-response profile of accessory cells nor that of responding cells shows single hit kinetics. Re-categorizing the data set reveals that only cultures with over 20 adherent cells were likely to promote T cell growth and single hit kinetics for the responding cell clone and the accessory cell clone were obtained.

Animals↗
PubMed1988

Toward an objective classification of cells in the immune system.

The relative abundance of individual proteins shared among clones of lymphocytes provides a meaningful basis for cellular classification. Twelve clones of T cells (obtained by limiting dilution) were analyzed by two-dimensional gel electrophoresis for polypeptide content and then evaluated by the computational technique known as principal component analysis. As a result, relatedness of the clones was established and expressed in terms of taxonomic distances. The data show that a comprehensive and objective classification of the cells involved in the immune system can be approached.

Animals↗
PubMed1986

Analysis of the activation of lymphoid cells by mitogens in vitro with limiting dilution methods: adherent peritoneal cells suppress B-cell activation and synergize with WEHI-3 in the activation of T cells by Con A.

Adherent peritoneal cells (APC) have often been used as a pure and effective macrophage population. Using partition analysis and small numbers of lymphoid cells activated by mitogens (concanavalin A for T cells (in the presence of TCGF) and LPS + DxS for B cells) we found that APC were accessory cells for T cell activation and growth but were not effective for B cells. Although APC were effective in assisting T-cell mitogenesis, they were not especially efficient. However, when APC were mixed with irradiated WEHI-3 cells (a tissue culture line previously shown to exhibit accessory cell activity in vitro for mitogenic activation T and B cells), the APC and WEHI-3 showed apparent synergy. One reason for failure of APC to assist B-cell mitogenesis was traced to the presence of a suppressor cell population which overcame the accessory cell help given by irradiated WEHI-3 cells to LPS-DxS stimulated murine B cells. It is thus possible to find "helper" effects (synergy of APC and WEHI-3 assisting the mitogenesis of T cells), as well as suppressor effects within the range of cells found in adherent accessory cells.

Animals↗
PubMed1984

Activation/suppression of the immune response in vitro by antigen and dextran sulfate. 2. The role of T-cell subsets determined by cell separation and partition analysis.

Culture of spleen cells with dextran sulfate (DxS) and antigen at various different cell densities revealed a T-cell-dependent regulatory pathway not observed in conventional culture. This finding can be explained by the frequent presence in the cultures of a helper cell and the less frequent presence of a suppressor cell, both activated by antigen and DxS. The classic, radioresistant, antigen-specific, helper T cell was not regulated by this newly revealed pathway. The highly frequent, DxS-dependent helper T cell is Lyt-1+2-. The suppressive effect is mediated by a Lyt-1+2+ population consisting of helpers and latent suppressors that can be made active by DxS or Lyt-1+ cells. The specificity of the Lyt-1+ helper cells was not established, but the high frequency observed implies a nonspecific mechanism. The specificity of the suppressor effect was not determined by these experiments. This regulatory mechanism is similar to the phenomena exhibited by polyclonally activated T-cell populations.

Animals↗
PubMed1984

An attempt to assess the overall diversity of murine T cells using two-dimensional gel electrophoresis.

The technique of two-dimensional gel electrophoresis has been applied to study the changes in protein patterns occurring in murine T lymphocytes after activation by a T cell mitogen. The protein maps of individual T cell clones obtained by limiting dilution were also compared. Whole cell lysates from [35S]methionine-labeled cell clones or cell populations were analyzed and radiofluorographs of gels compared. We found that, during the events of differentiation and clonal proliferation, a T cell population undergoes dramatic changes resulting in pronounced changes in the protein pattern. In a typical gel with about 1000 detectable spots, there were about 50 changes from one day to the next. Certain regions of gels were compared using highly exposed films; in these, a much higher proportion of spots was found to vary (47/255 spots). Furthermore, we found that T cell clones obtained by limiting dilution yield a protein pattern that contains both "stable" and "diverse" regions. In the molecular weight region from about 35 000-43 000, there are 0 to 5 differences when one clone is compared with another. Due to a relatively small number of clones analyzed [16], it is probable that the revealed changes are only a fraction of the diversity which remains to be uncovered.

Animals↗
PubMed1984

Changes in the protein pattern of murine B cells after mitogenic stimulation.

The technique of two-dimensional gel electrophoresis has been applied to study the changes in protein patterns occurring in murine B lymphocytes after activation with the synergistic B cell mitogens lipopolysaccharide and dextran sulfate. Whole cell lysates from [35S]methionine-labeled mitogen-activated B cells were analyzed and radiofluorographs of the gels compared. We found that a large number of proteins appear and disappear during the 5-day activation period (74/206 spots of a nonimmunoglobulin region of the gel). The B cell pattern (in the nonimmunoglobulin region) was also compared with that of mitogen-activated T cells. We identified 19 T cell-specific and 29 B cell-specific proteins, the remaining 1000 or so proteins being common.

Animals↗
PubMed1984

An approach to molecular analysis of T-cell clones by two-dimensional gel electrophoresis: is there interclonal and intraclonal heterogeneity?

To understand the regulation of immunity one must understand the processes and the consequences of the activation of the lymphoid cell, its clonal proliferation, and the ultimate differentiation of the progeny into the effector elements that constitute the immune system. By use of polyclonal mitogens, individual T-cell precursors can be activated for study of their clonal growth and generation of T effector cells. We used two-dimensional gel electrophoresis to study the gene products expressed by such T-cell clones. On comparing the radiofluorograms of such gels for a large set of T-cell clones we find that many gene products are expressed in common, as expected, but that another large set of products varies from one clone to the other and might be designated as markers of T-cell subsets or stages of differentiation. By subdividing the growing clone and analyzing the family of daughter clones, we find considerable variation in gene expression during clonal expansion.

Animals↗
PubMed1983

The structure of the mouse immunoglobulin in gamma 3 membrane gene segment.

The genomic region containing the mouse immunoglobulin gamma 3 heavy chain membrane (M) exons has been located and sequenced. The exon structure is highly similar to that of the other mouse gamma chains, with strong sequence conservation in the coding regions and the intron 5' to the M1 exon. The intron between M1 and M2 shows moderate sequence homology but very strong conservation of size. RNA blots suggest that gamma 3 membrane exon usage is similar to that seen in other immunoglobulin membrane heavy chain mRNAs. The transmembrane region contains the invariant residues which have been noted in all other heavy chain sequences and which were previously proposed to be interactive in a two-chain model for insertion through the lymphocyte membrane. Conserved residues with similar spacing have been seen in class II histocompatibility antigens, which are also two-chain transmembrane molecules, but not in class I antigens, which span cell membranes with a single chain.

Amino Acid Sequence↗
PubMed1978

Primary immune response of guinea pig spleen cells in vitro.

Spleen cells of the primed guinea pig, when cultured alone, failed to make a primary immune response against heterologous erythrocytes. When supplemented with lymphocytes obtained from mineral oil induced peritoneal exudate (PEL), a primary immune response against sheep, horse and chicken RBC was obtained. The kinetics, dose response and requirement of PELs for this response are reported.

Animals↗