Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The original human NK-like line YT was reported to lyse K562 and several B- and T-cell lines. The YT subline we are investigating, YT-INDY, does not lyse K562 or the T-cell line Molt-4. It does, however, lyse the EBV+ Burkitt lymphoma (BL) B-cell line Raji and EBV-immortalized B-cell lines. Several EBV- BL lines and an EBV- pre-B-cell leukemia line that we tested were not appreciably lysed by YT-INDY. To determine if EBV plays a role in TC susceptibility to lysis by YT-INDY, we compared YT-INDY's ability to lyse the EBV- BL line BL41 to its ability to lyse an EBV-infected derivative of BL41. The EBV-infected cell line was lysed, on average, at twice the level of the uninfected line. CD28/B7 interactions appeared to be involved in TC recognition by YT-INDY. Therefore, we examined the level of expression of B7 molecules on the infected and uninfected BL41 lines. An average of 15% of the uninfected BL41 cells expressed B7-1/B7-3, compared to 79% of the infected. B7-2 expression was similar in the two cell lines. Lysis of EBV-infected BL41 was reduced by anti-B7-1/B7-3 (BB1) or anti-CD28 antibodies (Abs) to the level of lysis of the uninfected line, indicating that upregulation of B7-1/B7-3 by the virus may be responsible for the enhanced susceptibility. We attempted to determine the particular EBV latent protein responsible for B7-1/B7-3 upregulation by analyzing BL41 clones expressing LMP1, EBNA-2/EBNA-LP, or EBNA-1. All of the high-expressing clones showed a higher level of B7-1/B7-3 expression than the vector-transfected control cell line, with LMP1-expressing clones expressing the highest amount. EBNA-1 clones and a high-expressing EBNA-2/EBNA-LP clone had a slightly higher density of B7-2 on their surface than the remaining clones. The increased expression of molecules of the B7 family correlated with increased susceptibility of the clones to lysis by YT-INDY. Anti-CD28 or a combination of anti-B7-1/B7-3 and anti-By-2 did not inhibit lysis of the clones to the level of lysis of the vector-transfected control cell line in all cases. We conclude that intact EBV enhances susceptibility to YT-INDY lysis by upregulating B7-1/B7-3. EBV proteins expressed individually also enhance susceptibility to lysis and upregulate members of the B7 family.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Upregulation of B7 molecules by the Epstein-Barr virus enhances susceptibility to lysis by a human NK-like cell line. 753 Nov 16

Murine AIDS (MAIDS) is induced by infection with the replication-defective virus (BM5def) component in the LP-BM5 murine leukemia virus (MuLV) mixture. The disease is characterized by polyclonally activated CD4+ T cells and B cells. It is known that BM5def is expressed at highest levels in B lymphocytes and that B cells serve as viral antigen-presenting cells. Full and sustained activation of CD4+ T cells against a conventional Ag usually requires both TCR and costimulating signals. Among various molecules known to provide costimulatory function, the expression of CD54 (ICAM-1) and CD11a/CD18 (LFA-1) on MAIDS B cells was increased, whereas that of CD2, heat-stable Ag (CD24), CD80 (B7-1), and CD86 (B7-2) was unchanged from normal. C57BL/6 mice depleted of both CD54 and CD11a expression as a result of chronic administration of mAb had developed no MAIDS at 4 wk and 8 wk after LP-BM5 MuLV infection. In addition, the proliferative response of B cells to mitogen was well conserved, whereas MAIDS-associated increases in serum Ig levels were inhibited. Replication of BM5def was suppressed markedly in infected mice treated with the CD54 and CD11a mAbs. These results suggest that the CD54/CD11a signal transduction pathway is a critical determinant of MAIDS development, and the lack of an immune response against viral Ag is enough to suppress BM5def replication and to prevent MAIDS.
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PMID:Rapid development of murine AIDS is dependent of signals provided by CD54 and CD11a. 760 73

The membrane-bound proteins CD30 ligand (CD30L), CD40L and 4-1BBL are members of the tumor necrosis factor (TNF) superfamily. They are expressed mainly by activated T cells. Primary and cultured Hodgkin and Reed-Sternberg (H-RS) cells, regarded as the malignant components of Hodgkin's disease (HD), display high levels of the counter-receptors for these ligands, ie CD30, CD40 and 4-1BB. CD30L and CD40L are known to share some biological activities that can be linked to the unbalanced secretion of cytokines seen in HD. In addition, cell contact-dependent molecules such as adhesion or activation antigens are critically involved in T cell/H-RS cell interactions. Primary and cultured H-RS cells frequently overexpress intercellular adhesion molecule-1 (ICAM-1/CD54), BB-1 (B7-1/CD80) and B70/B7-2 (CD86). Here we show that CD30L and CD40L, but not 4-1BBL upregulate CD54 expression by cultured H-RS cells on the mRNA and protein level, as a result of transcriptional gene activation. Furthermore, enhanced CD54 surface expression by these cells is accompanied by increased shedding of surface-bound CD54, as evidenced by high levels of the 82 kDa soluble (s) CD54 form detectable in culture supernatants after specific stimulation. Addition of CD30L in combination with CD40L to cultured H-RS cells additively enhanced CD54 surface expression and its shedding. These results may give a plausible explanation why sCD54 serum levels are increased in patients with HD.
Leukemia 1996 May
PMID:The CD30 ligand and CD40 ligand regulate CD54 surface expression and release of its soluble form by cultured Hodgkin and Reed-Sternberg cells. 865 79

In order to determine the indication of B7 (B7-1 and B7-2) molecules-mediated immuno-gene therapy for human leukemias, we investigated 94 human leukemic samples for the expression of MHC molecules required for tumor antigen-specific signals and of B7-1, B7-2, and ICAM-1 molecules required for non-specific costimulatory signals. All samples were strongly positive for MHC class I and 84% for class II antigen. B7-1, B7-2 and ICAM-1 were expressed in 5%, 22% and 16% of the total cases, respectively. Especially in 54 AML samples, B7-1 was only expressed in one case, while B7-2 was detected in as many as 15 cases (28%). We have also examined 13 human myelo/monocytic cell lines for the expression of class II and costimulatory molecules and found that significant expression of costimulatory molecules was induced in human leukemic cells by some suitable drugs, among which interferon-gamma (IFN-gamma) was the most potent inducer. Our results indicate that when the B7-mediated immuno-gene therapy was applied to human leukemias, especially to AML, B7-1 was rather preferable to B7-2 in that the latter was more widely expressed on human leukemic cells. Furthermore, since gene-transfer systems occasionally accompany serious problems, it should be taken into account that costimulatory molecules on human myelo/monocytic leukemic cells could be induced ex vivo without the introduction of exogenous genes.
Leukemia 1996 Jul
PMID:Expression of costimulatory molecules in human leukemias. 868 98

Freshly collected chronic lymphocytic leukemia B cells (B-CLL cells) are known to be inefficient at stimulating allogeneic T cells, and to lack significant expression of B7 (CD80 and CD86) costimulatory molecules. We investigated the potential of CD40 triggering to up-regulate the expression of adhesion and costimulatory molecules on B-CLL cells, and to enhance their immunogenicity towards allogeneic T cells. B-CLL cells cocultured with human CD40 ligand-expressing mouse fibroblasts rapidly up-regulated CD54 and CD58 adhesion molecules and B7-1 (CD80) and B7-2 (CD86) costimulatory molecules, and acquired a strong stimulatory capacity towards CD4+ as well as isolated CD8+ allogeneic T cells. Costimulation by both CD80 and CD86 proved critical for allogeneic T cell proliferation and CD25 and HLA-DR expression, since these were strongly inhibited by anti-CD80 or anti-CD86 monoclonal antibodies, and completely abrogated by CTLA4-Ig fusion protein, which blocks both CD80 and CD86. B7 costimulation also proved critical for restimulation of primed B-CLL-reactive T cells. Most importantly, priming of purified CD8+ T cells with CD40-triggered allogeneic B-CLL cells resulted in cytotoxic activity against the unstimulated B-CLL cells. These findings raise the possibility that CD40 triggering of B-CLL cells might be exploited in immunotherapeutic protocols.
Leukemia 1997 Apr
PMID:CD40 triggering of chronic lymphocytic leukemia B cells results in efficient alloantigen presentation and cytotoxic T lymphocyte induction by up-regulation of CD80 and CD86 costimulatory molecules. 909 98

Relapse is more frequent after autologous than allogeneic bone marrow transplantation (BMT), due in part to lack of T-lymphocyte mediated allogeneic graft-versus-leukemia (GVL) effects. Infusions of leukemia-reactive T cells to patients after autologous BMT may be a means for providing a GVL effect. Costimulation of T cells by binding of the CD28 receptor on T cells with B7-counter receptors on antigen presenting cells amplifies antigen-specific T-cell responses. To enhance generation of leukemia reactive cytotoxic T lymphocytes (CTL), the murine B7-1- and B7-2-costimulatory molecule cDNAs were introduced into the MHC class I+, class II-, murine meyloid leukemia cell line C1498. B7-1 expression greatly enhanced the ability of the leukemia cells to generate and expand leukemia reactive CTL in vitro. A highly cytolytic and C1498 specific CD8+ CTL line was generated by B7-1 costimulation. This CTL line proliferated autonomously and produced interleukin-2 when provided B7-1 or B7-2 costimulation by C1498 leukemia cells. To test the in vivo antileukemia properties of this CTL line, irradiated syngeneic BMT recipients were given graded doses of leukemia cells on day 0, followed by CTL infusions beginning on day 1 post-BMT. Recipients of 10(7) CTL had a 3 log reduction in leukemia burden such that 100% of mice were protected from a supralethal leukemic cell dose. Sustained immune responses were detectable up to 3 months postinfusion of the CTL line. B7-1 or B7-2 costimulation in vivo did not augment antileukemia effects of infused CTL post BMT. These results suggest that B7 costimulation of leukemia reactive CTL may be important for their ex vivo generation and expansion for use in human adoptive immunotherapy of leukemia.
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PMID:The role of B7 costimulation by murine acute myeloid leukemia in the generation and function of a CD8+ T-cell line with potent in vivo graft-versus-leukemia properties. 912 56

Ligation of CD28 on T cells with its natural ligands B7-1 (CD80) or B7-2 (CD86) provides a major costimulatory signal for T cells and is of potential importance for tumor rejection. We previously reported a strong expression of B7-1 on Reed-Sternberg cells and anaplastic large cell lymphoma cells. We report here our findings on B7-2 expression by malignant lymphomas (n = 70). B7-2 was present on the neoplastic cells of anaplastic large cell lymphoma in two of three cases studied, and on a subpopulation of the malignant cells in one out of four cases of follicular lymphoma. B7-2 was not expressed by the neoplastic cells of the other non-Hodgkin's lymphomas (n = 32), including T cell-rich B cell lymphoma. In contrast, Reed-Sternberg cells in lymph nodes affected by Hodgkin's disease are strongly positive for B7-2 (n = 31). Evidence for a functional correlate of this expression was obtained by our findings that the combination of anti-B7-1 and anti-B7-2 monoclonal antibodies was more effective than each separately in blocking allogeneic T cell activation (proliferation and cytokine secretion) by Hodgkin's disease-derived cell lines as stimulators. The possible role of B7-1 and B7-2 expression for the course and symptomatology of Hodgkin's disease is discussed.
Leukemia 1997 Jun
PMID:Expression of B7-2 (CD86) molecules by Reed-Sternberg cells of Hodgkin's disease. 917 39

Our recent studies using various costimulatory molecules have demonstrated that antitumor effect could be induced by B7- or B70-transduced mouse tumors. To augment antitumor effect in vivo, the combination therapy with a costimulatory gene and a cytokine, interkeukin 12 (IL-12), gene to treat metastatic mouse lung tumor was investigated. We transfected with mouse B7 and/or IL-12 into mouse lung carcinoma 3LL, and three transfectants (IL-12/3LL, B7/3LL and IL-12/B7/3LL) were generated. CTL activity induced by the inoculation of IL-12/B7/3LL was increased about 10-fold compared with parental 3LL inoculation. We then examined the therapeutic efficacy of combination with B7 and IL-12-transduced tumors. Four weeks after 3LL inoculation, lung metastasis was significantly reduced by IL-12/B7/3LL post-inoculation, indicating that potent therapeutic antitumor immunity can be induced by combination with costimulators B7 and IL-12. Recently, it was reported that p40 subunit of IL-12 appeared to be a specific inhibitor for IL-12 heterodimer in vitro. To clarify the biological functions of p40 in vivo, we generated the myoblast transfectants which produced IL-12 p40 alone. Local production of IL-12 p40 from transfectant could suppress allogenic CTL induction and Th1-type antibodies (IgG2a/2b/3) production in vivo. Furthermore, IL-12 p40 producing myoblast are less susceptible to rejection compared with parental myoblast, indicating that IL-12 p40 gene transfer may be useful therapeutically in Th1-mediated transplantation and autoimmune disorders.
Leukemia 1997 Apr
PMID:Immunoregulation by B7 and IL-12 gene transfer. 920 58

In contrast to other neoplasms, antigen-specific autologous cytolytic T cells have not been detected in patients with human pre-B-cell leukemias. The absence of efficient B7 family (B7-1/CD80; B7-2/CD86) -mediated costimulation has been shown to be a major defect in tumor cells' capacity to function as antigen-presenting cells. We show here the generation of autologous anti-pre-B-cell leukemia-specific cytolytic T-cell lines from the marrows of 10 of 15 patients with pre-B-cell malignancies. T-cell costimulation via CD28 is an absolute requirement for the generation of these autologous cytolytic T cells (CTL). Although costimulation could be delivered by either bystander B7 transfectants or professional antigen-presenting cells (indirect costimulation), optimal priming and CTL expansion required that the costimulatory signal was expressed by the tumor cell (direct costimulation). These anti-pre-B-cell leukemia-specific CTL lysed both unstimulated and CD40-stimulated tumor cells from each patient studied but did not lyse either K562 or CD40-stimulated allogeneic B cells. Cytolysis was mediated by the induction of tumor cell apoptosis by CD8+ T cells via the perforin-granzyme pathway. Although we were able to generate anti-leukemia-specific CTL from the bone marrow, we were unable to generate such CTL from the peripheral blood of these patients. These studies show that antigen-specific CTL can be generated from the bone marrow of patients with pre-B-cell leukemias and these findings should facilitate the design of adoptive T-cell-mediated immunotherapy trials for the treatment of patients with B-cell precursor malignancies.
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PMID:Ex vivo generation of human anti-pre-B leukemia-specific autologous cytolytic T cells. 922 54

CD80 (B7/BB-1, B7-1) and CD86 (B70, B7-2) take an important role in the interaction between T lymphocytes and antigen presenting cells (APCs) as co-stimulatory molecules. We analyzed the manifestation of adhesion molecules, including CD80 and CD86, on some leukemia and lymphoma cells. Constitutive expression of CD80 and/or CD86 was frequently observed on B cell leukemia/lymphoma cells, while it is rare on myeloid leukemia cells. Interferon-alpha (IFN-alpha) amplified the manifestation of MHC class I and interferon-gamma (IFN-gamma) did both class I and class II. We also showed CD80 could be induced by IFN-alpha on K562 cells, which were originally negative for CD80. Our data implies the immunotherapy via CD80 and CD86 for patients with hematological malignancies and the possibility to enhance it using interferons.
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PMID:The heterogeneous expression of CD80, CD86 and other adhesion molecules on leukemia and lymphoma cells and their induction by interferon. 926 43


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