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Biomedical subjects

H Jakob

Publications and source records attributed to H Jakob.

At least 109 records · Page 6Linked to original sources
PubMed1978

Association of the H-Y male antigen with beta2-microglobulin on human lymphoid and differentiated mouse teratocarcinoma cell lines.

The expression of the H-Y antigen has been tested on several human lymphoid lines and mouse teratocarcinoma cell lines during differentiation. The human male lymphoid cell line Raji is a very useful target for studies of the H-Y antigen by lymphocytotoxicity test with rat anti-H-Y sera. With a few exceptions, all cells carrying the Y chromosome were H-Y positive. One of the exceptions is the human Daudi cell line which, besides lacking H-Y antigen, also lacks beta2-microglobulin. We have studied a possible association between the H-Y antigen, beta2-microglobulin, and HLA antigen with redistribution experiments. The results strongly suggest that H-Y antigen is not associated with HLA antigens but with beta2-microglobulin.

Animals↗
PubMed1978

Complexity of nuclear and polysomal polyadenylated RNA in a pluripotent embryonal carcinoma cell line.

The base-sequence complexities and relative abundance of polysomal and nuclear polyadenylated [poly(A+)] RNA sequences have been analyzed in a pluripotent embryonal carcinoma cell line. Polysomal RNA and nuclear poly(A+) RNA have a complexity representing respectively 0.5% and 2.5% of the single copy component of haploid mouse DNA (1.8 X 10(6) K base pairs). By hybridization with specific cDNAs, three abundance classes were found in polysomal poly(A+) RNA, representing respectively 31%, 33%, and 36% of the RNA, with base sequence complexities of 0.1 X 10(3), 0.9 X 10(3), and 14.5 X 10(3) kilobases. This corresponds to 7000-8000 different mRNA species of an average length of 2000 nucleotides, present on an average of 5 to 600 copies per cell. In nuclear RNA, a major class of abundance was found with a complexity of 100 X 10(3) kilobases, each sequence being present in 1 copy per nucleus. The majority of the polysomal poly(A+) RNA sequences are represented in the nuclear poly(A+) RNA but are present in a more restricted range of relative abundance implying posttranscriptional mechanisms of quantitative modulation: polysomal RNA sequences appear to be preferentially transcribed into nuclear cDNA suggesting a preferential location of these sequences close to poly(A) sequences. The presence of a specialized gene product, globin specific RNA, could not be detected either in the nuclear or polysomal compartments of embryonal carcinoma cells, even at levels that would have detected one sequence per 50 cells.

Base Sequence↗
PubMed1978

T-cell-mediated cytotoxic immune responses to F9 teratocarcinoma cells: cytolytic effector T cells lyse H-2-negative F9 cells and syngeneic spermatogonia.

Murine thymus derived (T) lymphocytes primed in vivo to mouse 129 (H-2bc) derived H-2-negative F9 embryonal carcinoma cells and rechallenged in vitro with X-irradiated F9 stimulator cells differentiated into anti-F9 cell immune cytotoxic T lymphocytes (CTL). Using CBA mouse derived splenic responder T cells, F9 stimulator cells triggered a primary cytotoxic anti-F9 response. The CTL generated lysed the F9 antigen-positive target cells F9. PCC3 and PCC4, but not the F9 antigen-negative mouse 129 derived PYS tumor cells, nor LPS induced H-2bc blast cells. Mouse 129 anti-F9 cell antisera but not H-2k anti-H-2bc antisera blocked the lytic interaction with F9 target cells. Similarily unlabeled F9 cells but not H-2bc blast cells inhibited the anti-F9 cell cytotoxicity H-2k anti-F9 cell immune CTL were found to be cytotoxic for syngeneic spermatogonia, known to express the F9 antigen. The results suggest not only that CTL can recognize and lyse H-2-negative target cells, but also that CTL precursors can be sensitized against H-2-negative stimulator cells. From the data available it may be inferred that anti-F9 Cell immune CTL recognize the F9 antigen, known to be linked with the T/t locus. Since anti-F9 cell immune CTL lyse syngeneic spermatogonia, the system may be useful to analyze in vitro the induction and effector phase of a T-cell-mediated cytotoxic autoimmune orchitis.

Animals↗
PubMed1978

Carbohydrate structure and cell differentitation: unique properties of fucosyl-glycopeptides isolated from embryonal carcinoma cells.

From embryonal carcinoma cells labeled with fucose, two main classes of glycopeptide products of Pronase digestion can be distinguished by Sephadex G-50 column chromatography: one eluted near the excluded volume and a smaller one. The large fucosyl-glycopeptides are scarcely present in differentiated cells derived from embryonal carcinoma cells (i.e., fibroblastlike cells, myoblasts, and parietal yolk-sac carcinoma). During in vitro differentiation of embryonal carcinoma cells, these large glycopeptides disappear almost completely. The small glycopeptides were analyzed by paper electrophoresis, concanavalin A-Sepharose affinity chromatography, and digestion with an endoglycosidase. The major components of these glycopeptides from embryonal carcinoma cells appear to be different from complex glycopeptides known to occur in adult cells. The glycopeptide pattern of mouse preimplantation embryos resembles that of embryonal carcinoma cells. These results suggest that the carbohydrate profile changes fundamentally during early stages of mammalian development.

Cell Differentiation↗
PubMed1978

Metabolic cooperation between mouse embryonal carcinoma cells and their differentiated derivatives.

Metabolic cooperation has been used as an index of intercellular communication between mouse embryonal carcinoma (EC) and other cell types. EC cells do not cooperate with differentiated cells of various properties or origins. In contrast they cooperate with cells of all other EC lines tested, including a human teratocarcinoma line, but with different efficiencies. This might reflect differences either in cell-cell interactions or in the formation of gap junctions. During in vitro differentiation, EC cells appear to remain isolated from differentiated cell types.

Cell Adhesion↗
PubMed1976

Cell lines derived from teratocarcinomas.

A variety of cell lines have been isolated in vitro from transplantable teratocarcinomas. Some of them correspond to embryonal carcinoma (EC) cells. They are malignant and represent the stem cells from which all differentiated tissues derive in the tumor or in vitro. EC cells share some biochemical and antigenic properties with multipotential embryonic cells. From one of these EC cell lines, variants have been isolated in vivo and in vitro. Some are of EC type but restricted in their pattern of differentiation; others are altered in their tumorigenicity or in their antigenic characteristics. Another class of such variants corresponds to non-EC types. The most interesting ones correspond to tumoral lines of extra-embryonic tissues. All these cell lines constitute a valuable material for the study of mouse development and differentiation.

Acid Phosphatase↗
PubMed1975

[Mouse teratocarcinoma: differentiation in cultures of a multipotential primitive cell line (author's transl)].

A line of primitive cells of teratocarcinoma is able of differentiating during in vitro cultures. The differentiated cell types correspond to derivatives of the three germ layers. They appear according to a reproducible schedule. The differentiated cell types exhibit a normal karyotype. They have lost their tumorigenicity and have a limited life span. Agregates containing various numbers of primitive cells have been prepared and plated in culture dishes. Their study shows that the first differentiated cell types appear only when the agregates are greater than a certain critical mass. Primitive cells carry on their surface the F9 but not the H-2 antigen. During differentiation in culture, the H-2 antigen appears rapidly on certain cells. The fraction of H-2-carrying cells increases as a function of time while that of F9-carrying cells decreases.

Animals↗