Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0153470 (Spleen)
 4,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human embryonal carcinoma cells sometimes display the developmental potential of early embryonic stem cells. While available data do not clearly identify a counterpart of these tumor cells in normal development, previous comparisons of human embryonal carcinoma and yolk sac carcinomas indicated that these cell types are closely related, and suggested that embryonal carcinoma cells might resemble the progenitors of extraembryonic endoderm. To analyse further cell-differentiation lineage in these tumors, we produced monoclonal antibodies to cytostructurally associated antigens of human embryonal carcinoma cells. Spleen cells from mice immunized with a detergent-insoluble extract of cultured human embryonal carcinoma cells were fused to NS-1 myeloma cells, and hybridoma supernatants were screened by indirect immunofluorescence on the immunizing cell line, then on a panel of cell lines derived from human embryonal carcinomas, yolk sac carcinomas, and a range of neoplastic and normal tissues. Monoclonal antibody GCTM-1 stained the nuclei of all human cells tested and served as a positive control; this antibody immunoprecipitated proteins of 85 and 66 k Da from human embryonal carcinoma cells. GCTM-2 recognized an epitope on a 200-k Da extracellular protein present on the surface of embryonal carcinoma cells, and stained the surface of visceral yolk sac-type carcinoma and colorectal carcinoma cells as well. Enzymatic analysis of carbohydrate residues on the GCTM-2 antigen revealed that it was a keratan sulphate proteoglycan, and suggested that the epitope recognized by the antibody lies on the core protein. In immunoblots, antibody GCTM-3 bound to a 57-k Da cytoskeletal protein expressed in human embryonal carcinoma. This antibody decorated filamentous arrays in cell lines from human embryonal carcinoma, visceral yolk sac carcinoma, parietal yolk sac carcinoma (endodermal sinus tumour), and adenocarcinoma and large cell carcinoma of the lung. Antibody GCTM-4 recognized a determinant present on a 69-k Da polypeptide, associated with a component of the lysosomal compartment, which was expressed in embryonal carcinoma cells, but no other cell type tested. The results with this antibody panel thus allow distinction between human embryonal carcinoma and yolk sac carcinoma, but provide further evidence of a close relationship between these cell types.
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PMID:Analysis of cell-differentiation lineage in human teratomas using new monoclonal antibodies to cytostructural antigens of embryonal carcinoma cells. 324 84

Several cytotoxic T-lymphocyte (CTL) epitopes have been defined in hepatitis C virus (HCV) proteins. CTL may play an important role in the control of infection by HCV. Here, we identify a highly conserved antigenic site in the HCV core recognized by both murine and human CTL. Spleen cells from mice immunized with a recombinant vaccinia virus expressing the HCV core gene were restimulated in vitro with 11 peptides from the core protein. CTL from H-2d mice responded to a single 16-residue synthetic peptide (HCV 129-144). This conserved epitope was presented by a murine class I major histocompatibility molecule (H-2Dd) to conventional CD4- CD8+ CTL mapped by using transfectants expressing Dd, Ld, or Kd, but was not seen by CTL restricted by H-2b. The murine epitope was mapped to the decapeptide LMGYIPLVGA. The same 16-residue peptide was recognized by CTL from two HCV-seropositive patients but not by CTL from any seronegative donors. CTL from two HLA-A2-positive patients with acute and chronic hepatitides C recognized a 9-residue fragment (DLMGYIPLV) of the peptide presented by HLA-A2 and containing an HLA-A2-binding motif, extending only 1 residue beyond the murine epitope. Therefore, this conserved peptide, seen with murine CTL and human CTL with a very prevalent HLA class I molecule, may be a valuable component of an HCV vaccine against a broad range of HCV isolates. This study demonstrates that the screening for CTL epitopes in mice prior to human study may be useful.
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PMID:An epitope in hepatitis C virus core region recognized by cytotoxic T cells in mice and humans. 751 63

Hepatitis C Virus (HCV) causes most cases of posttransfusion hepatitis. Chronic HCV infection is highly related to chronic hepatitis, cirrhosis and hepatocellular carcinoma. Current therapies are only minimally effective and no vaccine has been developed. DNA-based immunization could be of prophylactic and therapeutic value for HCV infection. By intramuscular inoculation in BALB/c mice with an HCV recombinant plasmid pCI-HCV-C, we found significant levels of IgM antibody, but no significant IgG rise. After boost the immunized mice with recombinant HCV-core protein (cp1-10; 1-164aa), the anticore IgG, verified by Western-blotting, rose rapidly, which was two weeks earlier than that with control plasmid. Spleen cells from pCI-HCV-C immunized mice gave higher proliferation index (PI) than control (P < 0.05). The PI of cp1-10 boosted mice was even higher. Proliferation blocking assay with mAb proved the responding cell to be of CD4+ CD8- phenotype, supporting specific priming of T helper cells. A 51Cr-releasing CTL assay specific for HCV-core was developed, and a specific CTL response against HCV-core was demonstrated in both pCI-HCV-C immunized mice and mice boosted with cp1-10. Strong cytotoxic activity against peptide-pulsed p815 cells (H-2d), but not EL-4 cells (H-2b), suggested MHC class I restriction of the CTL activity. Blocking of CTL with mAb proved the effector cells to be of CD4- CD8+. Three CTL epitopes in HCV-core protein were demonstrated. We failed to detect CTL when immunized only with core protein. The results suggested that vaccination with HCV-core derived DNA sequences could be an effective method to induce humoral and cellular immune responses to HCV.
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PMID:Characterization of the humoral and cellular immune responses against hepatitis C virus core induced by DNA-based immunization. 1046 52

The immunogenicity of a truncated HCV core protein (Co.120) was studied in BALB/c and C57BL/6 mice, given three intramuscular injections of antigen, adjuvanted with either aluminum hydroxide or Freund's adjuvant. A rapid antibody response was noted after the first dose, with both strains of mice eventually exhibiting comparable levels of anti-core IgG (titers >1:100000), with a mixed IgG1/IgG2a subclass response. Spleen cells from Co.120-immunized mice gave a significant specific proliferative response. IFN-gamma gene expression was also detected after an ex-vivo specific stimulation of spleen cells in all immunized mice. This response was independent of dose, H-2 genetic background or type of adjuvant. The results indicated that immunization with the Co.120 protein elicits a potent anti-HCV humoral and cellular immune response.
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PMID:A truncated HCV core protein elicits a potent immune response with a strong participation of cellular immunity components in mice. 1142 69