Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033036 (APC)
 10,214 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Progeny from one intra- and two inter-specific backcrosses between divergent strains of mice were typed to map multiple markers in relation to two pigment mutations on mouse chromosome 13, beige (bg) and pearl (pe). Both recessive mutants on a C57BL/6J background were crossed separately with laboratory strain PAC (M. domesticus) and the partially inbred M. musculus stock PWK. The intra- and inter-specific F1 hybrids were backcrossed to the C57BL/6J parental strain and DNA was prepared from progeny. Restriction fragment length polymorphisms were used to follow the segregation of alleles in the backcross offspring at loci identified with molecular probes. The linkage analysis defines the association between the bg and pe loci and the loci for the T-cell receptor gamma-chain gene (Tcrg), the spermatocyte specific histone gene (Hist1), the prolactin gene (Prl), the Friend murine leukaemia virus integration site 1 (Fim-1), the murine Hanukuh Factor gene (Muhf/Ctla-3) and the dihydrofolate reductase gene (Dhfr). This data confirms results of prior chromosomal mapping studies utilizing bg as an anchor locus, and provides previously unreported information defining the localization of the prolactin gene on mouse chromosome 13. The relationship of multiple loci in relation to pe is similarly defined. These results may help facilitate localization of the genes responsible for two human syndromes homologous with bg and pe, Chediak-Higashi syndrome and Hermansky-Pudlak syndrome.
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PMID:Linkage of loci associated with two pigment mutations on mouse chromosome 13. 168 16

APC activity of spleen cells from C57BL/10 (B10) mice infected with LP-BM5 murine leukemia virus (MuLV), which is known as a murine acquired immunodeficiency syndrome (MAIDS) virus, was investigated. The ability of splenic APC from LP-BM5 MuLV-inoculated B10 mice to induce soluble Ag-specific proliferation of cloned Th cells was decreased progressively during the infection. The APC defect was found to be due neither to the decreased expression of Ia Ag nor to the insufficient production of IL-1. It was demonstrated that cloned Th stimulated with virus-infected splenic APC displayed the increased [Ca2+]i with severely decreased inositol phospholipid metabolism, which probably led to the defect of Th proliferative responses. These results suggested that the failure of Th to respond to soluble Ag in MAIDS is at least in part due to a selective defect in signal transduction caused by abnormal APC.
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PMID:A selective signaling defect in helper T cells induced by antigen-presenting cells from mice with murine acquired immunodeficiency syndrome. 215 66

After immunization of B6 mice with the syngeneic retrovirus-induced T cell leukemia/lymphoma FBL-3, two major tumor-specific proliferative T cell clonotypes were derived. T cell clones derived from long-term lines propagated by in vitro culture with irradiated tumor cells and syngeneic spleen cells were exclusively of the Lyt-2+ phenotype. Such clones were cytolytic, retained their proliferative phenotype indefinitely when expanded by repeated cycles of reactivation and rest, and recognized a tumor-specific cell surface antigen in association with class I MHC molecules. This tumor cell antigen was not present on nontransformed virus-infected cells. Class II MHC-restricted MT4+ clones specific for the viral antigen gp70 were derived from lymph node T cells of FBL-3 tumor-immune mice only by in vitro culture with purified Friend virus in the presence of syngeneic splenic APC. Once derived, however, such clones could be stimulated in the presence of FBL-3 tumor cells and syngeneic spleen cells, demonstrating the reprocessing of tumor-derived gp70 antigen by APC in the spleen cell population. In contrast, no reprocessing of the tumor cell surface antigen by splenic APC for presentation to the class I MHC-restricted T cell clones could be demonstrated. Evidence is presented that FBL-3 T leukemia/lymphoma cells function as APC for Lyt-2+ class I MHC-restricted clones, and that no concomitant recognition of Ia molecules is required to activate these clones. Both Lyt-2+ and MT4+ clones were induced to proliferate in the presence of exogenous IL2 alone, but this stimulus failed to result in significant release of immune interferon. In contrast, antigen stimulation of both clones resulted in proliferation as well as significant immune interferon release. Immune interferon production is not required for the generation of MHC-restricted cell-mediated cytolytic function.
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PMID:Distinct proliferative T cell clonotypes are generated in response to a murine retrovirus-induced syngeneic T cell leukemia: viral gp70 antigen-specific MT4+ clones and Lyt-2+ cytolytic clones which recognize a tumor-specific cell surface antigen. 258 53

C57BL/6 (B6, H-2b) mice are CTL responders to both Sendai virus and Moloney leukemia virus. In the former response the H-2Kb class I MHC molecule is used as CTL restriction element, in the latter response the H-2Db molecule. B6 dendritic cells (DC) are superior in the presentation of Sendai virus Ag to CTL in comparison with B6 normal spleen cells. Con A blasts have even less capacity to present viral Ag than NSC, and LPS blasts show an intermediate capacity to present viral Ag. H-2Kb mutant bm1 mice do not generate a CTL response to Sendai virus, but respond to Moloney leukemia virus, as demonstrated by undetectable CTL precursors to Sendai virus and a normal CTL precursor frequency to Moloney virus. Compared to B6 mice, other H-2Kb mutant mice show decreased Sendai virus-specific CTL precursor frequencies in a hierarchy reflecting the response in bulk culture. The Sendai virus-specific CTL response defect of bm1 mice was not restored by highly potent Sendai virus-infected DC as APC for in vivo priming and/or in vitro restimulation. In mirror image to H-2Kb mutant bm1 mice, H-2Db mutant bm14 mice do not generate a CTL response to Moloney virus, but respond normally to Sendai virus. This specific CTL response defect was restored by syngeneic Moloney virus-infected DC for in vitro restimulation. This response was Kb restricted indicating that the Dbm14 molecule remained largely defective and that a dormant Kb repertoire was aroused after optimal Ag presentation by DC. In conclusion, DC very effectively present viral Ag to CTL. However, their capacity to restore MHC class I determined specific CTL response defects probably requires at least some ability of a particular MHC class I/virus combination to associate and thus form an immunogenic complex.
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PMID:Failure or success in the restoration of virus-specific cytotoxic T lymphocyte response defects by dendritic cells. 283 54

Activation of the Fas cell surface molecule, either by specific antibody or by its as yet unidentified ligand, has been shown to induce apoptosis. Because apoptosis is also evoked in target cells by cytolytic T cells, we investigated whether the Fas pathway is involved in CD4+ T cell-mediated cytotoxicity. Analysis of Fas expression in APC, such as the B lymphoma A20.2J and MHC class II-transfected fibroblasts RT2.3, revealed a correlation between the degree of expression and sensitivity to cytotoxic attack, high level of Fas expression in A20.2J being associated with efficient lysis. To examine whether increased Fas expression in RT2.3 would render these cells more susceptible to CD4+ CTL lysis, they were transfected with a Fas gene expression vector. Indeed, Fas- but not mock-transfected RT2.3 proved to be more sensitive to lysis by either Ag specifically or nonspecifically activated CD4+ CTL. Similarly, MHC class II-negative, Fas-transfected L1210 leukemia cells were lysed with nonspecifically activated CD4+ CTL. The importance of the Fas engagement in CD4+ CTL-mediated cytotoxicity is further substantiated by the failure of both cloned and normal CD4+ CTL to lyse B cell blasts from Ipr mice. These mice are known to have a defect in functional Fas expression. Although the bulk of CD4+ T cell-mediated lysis appears to be Fas induced, the fact that the effector phase of A20.2J lysis is only partially Ca2+ independent indicates that other pathways also contribute to target cell death.
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PMID:Fas antigen is the major target molecule for CD4+ T cell-mediated cytotoxicity. 750 60

After BMT, donor T cells are activated which can display GvHD as well as GvL activities. In order to study this GvL-specific T-cell response in vitro, proliferative T-cell clones from post-BMT PBMCs were generated by stimulation with a patient's leukemic cells. One CD4+ T-cell clone (designated M-33) displayed strong proliferative activity against the patient's leukemic cells but not against the patient's EBV-LCLs. The induction of proliferation, however, appeared not to be leukemia specific. Detailed analysis of the reactivity patterns revealed that T-cell clone M-33 recognizes an as yet unknown nonpolymorphic determinant in the context of self HLA-DRw52, presented by all but one type of APC. T-cell clone M-33 proliferated upon stimulation by PB-MCs, freshly isolated B cells, monocytes, dendritic cells, leukemic B cells, and nonleukemic B-cell blasts; solely in vitro EBV-transformed B cells and in vivo EBV-infected B cells failed to induce proliferation of T-cell clone M-33. Neither surface expression of MHC or accessory molecules on the EBV cells nor suppression caused by the EBV-infected cells could explain their failure to stimulate T-cell clone M-33. We therefore hypothesize that the absence of the stimulatory capacity once the B cells are virally infected could be the result of competition for MHC class II binding of the Epstein-Barr viral peptides, thus affecting the postulated DRw52-restricted peptide for recognition by T-cell clone M-33.
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PMID:Epstein-Barr virus infection abrogates the stimulatory capacity of B cells to a major histocompatibility complex class-II-restricted proliferative T-cell clone. 774 17

The aim of our study was to examine the potential usefulness of transducing the protein kinase C-gamma (PKC-gamma) cDNA gene into tumor-specific T cells as a technique for facilitating the generation of large numbers of functional Ag-specific T for tumor therapy. Murine CD8+, F-MuLV gag-specific CTL clones, and CD4+, F-MuLV env-specific Th clones, as well as bulk-cultured T cell lines with defined Ag specificity to FBL-3, a Friend murine leukemia virus (F-MuLV)-induced tumor, were transduced with a retroviral vector pZipNeoPKC-gamma and selected in G418. The results demonstrated that PKC-gamma-transduced clones remained activated in culture, as evidenced by continued expression of up-regulated levels of IL-2R, which were as high after 6 mo in culture without Ag restimulation as 24 h after Ag stimulation. In vitro functional studies demonstrated that PKC-gamma-transduced CD8+ T cell clones maintained specific cytolytic activity to FBL-3, and PKC-gamma-transduced CD4+ T cell clones maintained specific proliferative activity to FBL-3 or F-MuLV Ag presented by irradiated syngeneic APC. Short-term bulk-cultured T cells specific to FBL-3 were also transduced and could be grown long term in vitro with maintenance of functional specificity. In vivo study showed that PKC-gamma-transduced CD4+ T cells were able to proliferate in response to Ag plus IL-2 stimulation in vivo in a similar pattern as the parental T cells. Therapy with adoptively transferred PKC-gamma-transduced T cell clones and lines into syngeneic mice, with or without FBL-3 tumor, showed that the PKC-gamma-transduced T cells were not tumorigenic and were effective in curing mice with disseminated FBL-3.
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PMID:Retroviral transduction of protein kinase C-gamma into tumor-specific T cells allows antigen-independent long-term growth in IL-2 with retention of functional specificity in vitro and ability to mediate tumor therapy in vivo. 793 May 83

Activated protein C resistance (APCR), usually due to the Arg506-->Gln point mutation of the factor V gene, has emerged as the most important hereditary cause of venous thromboembolism. Using an aPTT based method in the presence of APC, together with a DNA technique based on the polymerase chain reaction, we investigated 65 leukaemic children and 65 age-matched healthy controls for the presence of this mutation. In both groups three children showed APCR. All six children showed the common factor V gene mutation, Arg506-->Gln. Although no child in the control group presented with thrombosis, all three children with acute lymphoblastic leukaemia had thromboembolic events. Whether the poor anticoagulant response to activated protein C in leukaemic children treated with prednisone, vincristine, daunorubicin and asparaginase affects the risk of thrombotic events requires a more extensive multicentre study.
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PMID:Resistance to activated protein C (APCR) in children with acute lymphoblastic leukaemia--the need for a prospective multicentre study. 882 28

Loss of a whole chromosome 5 or a deletion of the long arm, del(5q), is a recurring abnormality in malignant myeloid diseases. In previous studies, we delineated a commonly deleted segment of approximately 4 Mb within band 5q31 that was flanked by IL9 on the proximal side and D5S166 on the distal side. We have generated a physical map of P1 (PAC), bacterial (BAC), and yeast artificial chromosome (YAC) clones of this interval. The contig consists of 108 clones (78 PACs, 2 BACs, and 28 YACs) to which 125 markers (5 genes, 11 expressed sequence tags, 12 polymorphisms, and 97 sequence-tagged sites) have been mapped. Using PAC clones for fluorescence in situ hybridization analysis of leukemia cells with a del(5q), we have narrowed the commonly deleted segment to 1-1.5 Mb between D5S479 and D5S500. To search for allele loss, we used 7 microsatellite markers within and flanking the commonly deleted segment to examine leukemia cells from 28 patients with loss of 5q, and 14 patients without cytogenetically detectable loss of 5q. In the first group of patients, we detected hemizygous deletions, consistent with the cytogenetically visible loss; no homozygous deletions were detected. No allele loss was detected in patients without abnormalities of chromosome 5, suggesting that allele loss on 5q is the result of visible chromosomal abnormalities. The development of a stable PAC contig and the identification of the smallest commonly deleted segment will facilitate the molecular cloning of a myeloid leukemia suppressor gene on 5q.
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PMID:Molecular delineation of the smallest commonly deleted region of chromosome 5 in malignant myeloid diseases to 1-1.5 Mb and preparation of a PAC-based physical map. 919 72

By selective depletion of CD4 and CD8 T cells in vivo using the respective mAbs, we demonstrate that CD4 T cells are necessary for skin graft rejection against thymus leukemia (TL) Ag. The skin expressing T3b-TL Ag from transgenic C3H Tg.Con.3-1 mice given chimeric H-2Kb/T3b-TL gene was rejected when grafted onto C3H/He recipient mice. Depletion of CD4, but not of CD8, T cells blocked rejection. CD8 CTL were generated in MEM (control)-treated C3H/He recipient mice, while Thy-1+ CD4- CD8- CTL were generated in CD8-depleted recipient mice after rejection. However, no CTL were generated in CD4-depleted or both CD4- and CD8-depleted recipient mice. Thus, the generation of both CD8 and Thy-1+ CD4- CD8- CTL was dependent on CD4 T cells. Ab blocking indicated that both CD8 and Thy-1+ CD4- CD8- CTL were TCR alphabeta and recognized TL Ag. We furthermore demonstrated that CD4 T cells in spleen cells from C3H/He mice that had rejected C3H Tg.Con.3-1 skin showed a weak, but significant, proliferative response to in vitro stimulation with mitomycin C-treated C3H Tg.Con.3-1 spleen cells. Analysis of the reactivity of bulk CD4 T cell lines to 73 synthetic overlapping peptides encompassing the entire T3b-TL molecule showed that CD4 T cells recognized multiple epitopes on the T3b-TL molecule in an APC-dependent manner.
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PMID:Requirement of CD4 T cells for skin graft rejection against thymus leukemia (TL) antigen and multiple epitopes on the TL molecule recognized by CD4 T cells. 920 Apr 51


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