Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04626 (erbB-2)
 5,251 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human epithelial mucin, MUC-1, is commonly expressed in adenocarcinoma including 80% of breast cancers. erbB-2 is overexpressed in approximately 30% of breast cancers. Expression of MUC-1 and erbB-2 may be partially overlapping but discoordinate. Therefore, combined use of antibodies directed against these two antigens might increase the number of patients who benefit from immunotherapy. Monoclonal antibody (MAb) DF3 recognizes the MUC-1 tandem repeat. We investigated phagocytosis and cytolysis of cultured human breast cancer cells by monocyte-derived macrophages mediated by MAb DF3 and its bispecific antibody (BsAb) DF3xH22 with the second epitope directed against the Fc component of phagocytic cells. Purified monocytes from healthy donors were cultured with granulocyte macrophage colony-stimulating factor with or without IFN-gamma. antibody-dependent cellular phagocytosis (ADCP) and antibody-dependent cellular cytotoxicity (ADCC) assays were performed with these macrophages and MUC-1-expressing target cells (ZR75-1) in the presence of MAb DF3 and BsAb DF3xH22. ADCP was measured by two-color fluorescence flow cytometry using PKH2 (green fluorescent dye) and R-phytoerythrin (RPE) (red)-conjugated MAb against human CD14 and CD11b and was confirmed by confocal microscopy. ADCC was measured by (51)Cr release assay. Immunohistochemical staining studies of MUC-1 and erbB-2 were performed on 67 primary breast cancer tissues. Expression of MUC-1 and erbB-2 was partially overlapping but discoordinate in 67 consecutive breast cancers. Both MAb DF3 and BsAb DF3xH22 mediated ADCP. However, ADCP mediated by MAb DF3 was greater than that mediated by BsAb DF3xH22. ADCC as detected by (51)Cr release was not seen with either antibody. The addition of IFN-gamma to monocyte-derived macrophage cultures inhibited ADCP compared to granulocyte macrophage colony-stimulating factor alone. Given the partially overlapping but discoordinate expression of MUC-1 and erbB-2 in breast cancer, therapy directed toward both antigens should be considered. MAb DF3 and the BsAb DF3xH22, can effectively mediate phagocytosis of MUC-1-expressing target cells. Further investigations are needed to determine whether this antibody-induced phagocytosis results in long-term specific T-cell activation against MUC-1.
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PMID:Phagocytosis of breast cancer cells mediated by anti-MUC-1 monoclonal antibody, DF3, and its bispecific antibody. 1135 26

Freshly isolated human polymorphonuclear cells (PMNCs) constitutively express Fcgamma receptor (Fc-gammaR) II and FcgammaRIII on the cell surface but not FcgammaRI. Cytokines such as interferon-gamma (IFNgamma), granulocyte-macrophage colony-stimulating factor (CSF), and granulocyte-CSF trigger FcgammaRI expression on (PMNCs). Because PMNCs express interleukin (IL)-2 receptor, we investigated whether IL-2 can induce FcgammaRI expression on PMNCs isolated from IL-2-treated metastatic renal cell carcinoma (MRCC) and low-grade non-Hodgkin lymphoma (LGNHL) patients. Pretherapy flow cytometry analysis of Fcgamma receptors on PMNCs did not show FcgammaRI expression. Interestingly, 3 days after therapy, PMNCs displayed a detectable amount of FcgammaRI on the cell surface. Kinetic studies on the in vivo effects of IL-2 on MRCC patients showed that FcgammaRI was transiently expressed, starting within 3-6 days of therapy, remaining expressed for 10-15 days, and rapidly declining, whereas such expression remained stable for months in LGNHL patients. In contrast, Fc-gammaRII was not affected. In addition, FcgammaRI+ PMNCs coated in vitro with a bispecific antibody Fab anti-FcgammaRI x anti-HER-2/neu formed intercellular conjugates with a human HER-2/neu-transfected 3T3 cell line (HER-2/neu-3T3). Interleukin-2 treatment increased the number of FcgammaRIII low eosinophils, leading to a change in FcgammaRIII distribution among granulocyte cell subsets. In vitro IL-2 treatment of purified PMNCs failed to generate Fc-gammaRI expression, suggesting that IL-2 indirectly causes FcgammaRI expression. During the IL-2 administration, we did not observe significant changes in IFNgamma serum level. In conclusion, our observation may be used to potentiate the antitumor effects of IL-2 in novel immunotherapy regimens, perhaps by redirecting FcgammaRI+ PMNCs against cancer cells by heteroconjugate antibodies and monitoring the biologic activity of subcutaneous IL-2 in cancer patients.
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PMID:Subcutaneous administration of interleukin-2 triggers Fcgamma receptor I expression on human peripheral blood neutrophils in solid and hematologic malignancies. 1156 39

Dendritic cells (DCs) are potent antigen-presenting cells and have shown promise to function as "natural" vaccine adjuvants. Currently, most cancer vaccine trials using DCs generate autologous DCs ex vivo for each patient. Systemic treatment with Flt3 ligand (FL) results in a marked increase of DCs in tissues such as spleen and lymph nodes in mice and in the peripheral blood and skin of humans. In light of these observations, we questioned whether FL could be used systemically as a vaccine adjuvant to stimulate DC mobilization in vivo, circumventing the need to generate DCs ex vivo. Ten patients with HER-2/neu-overexpressing cancer were enrolled in a phase 1 study to receive a HER-2/neu peptide-based vaccine targeting the intracellular domain of the HER-2/neu protein. All patients received 20 microg/kg FL per day subcutaneously for 14 days. Five patients received the HER-2/neu peptide-based vaccine alone on day 7 of the 14-day cycle, and 5 patients received the vaccine admixed with 150 microg granulocyte macrophage-colony-stimulating factor (GM-CSF) on day 7 of the FL cycle. T-cell proliferative responses to HER-2/neu peptides and intracellular domain protein suggest that vaccine regimens including FL as an adjuvant were not effective in eliciting a significant HER-2/neu protein-specific T-cell proliferative response. However, including FL as a vaccine adjuvant was effective in boosting the precursor frequency of interferon-gamma-secreting HER-2/neu-specific T cells. The small sample size of each group, however, did not allow a statistically significant comparison of immune responses between the FL alone and FL with GM-CSF arms. Finally, vaccine regimens including FL as a vaccine adjuvant were associated with the development of apparent autoimmune phenomena in some patients.
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PMID:Flt3 ligand as a vaccine adjuvant in association with HER-2/neu peptide-based vaccines in patients with HER-2/neu-overexpressing cancers. 1192 74

To determine the toxicity and immunogenicity of the HER-2/neu, HLA-A2-restricted peptide E75 in patients with metastatic breast and ovarian cancer, 14 patients were vaccinated with escalating amounts of E75 (100, 500, and 1000 microg) mixed with 250 microg granulocyte macrophage colony-stimulating factor as adjuvant. Each vaccine dose was administered in a total volume of 1.5 ml divided into four intradermal injections and administered weekly for 4 weeks, followed by monthly boosts for a total of 10 injections. Vaccinations were well tolerated without significant toxicity. Blood was drawn before, at 8 weeks, and up to 13-16 months after vaccination for measurement of cellular immunity. Seven of 8 patients tested had significant delayed type hypersensitivity to E75 defined as >5 mm induration. Peripheral blood mononuclear cells from 5 of 9 patients tested proliferated to E75 with a stimulation index of > or = 2.0. Of 8 vaccinated patients tested for induction of a CTL response, 4 responded to stimulation by autologous dendritic cells plus cytokines by eliciting E75-specific lytic activity consistent with the presence of activated/memory cells, 2 others after in vitro stimulation with E75 + interleukin-12 +/- anti-CD152(33KD), whereas 2 others did not respond. Four patients with E75-specific CTLs present specifically recognized E75 on indicator tumors as demonstrated by cold-target inhibition of tumor lysis. These 4 patients showed E75-specific IFN-gamma production. peripheral blood mononuclear cell from 3 of these patients proliferated to E75, but stimulation indices were higher in the prevaccine samples. All 4 of the patients showed DTH responses to E75. These results demonstrate that vaccination with E75+ granulocyte macrophage colony-stimulating factor can induce both peptide-specific IFN-gamma and epitope specific CTLs, which lyse HER-2/neu+ tumors in stage IV patients.
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PMID:Toxicity, immunogenicity, and induction of E75-specific tumor-lytic CTLs by HER-2 peptide E75 (369-377) combined with granulocyte macrophage colony-stimulating factor in HLA-A2+ patients with metastatic breast and ovarian cancer. 1242 28

GVAX immunotherapy for prostate cancer is comprised of two genetically modified prostate cancer cell lines, CG1940 and CG8711, engineered to secrete granulocyte macrophage-colony-stimulating factor. As part of the matrix of potency assays, CG1940 and CG8711 are tested for the expression level of cell surface HER-2/neu using a quantitative flow cytometer assay. This assay reports the antibody binding capacity value of the cells as a measure of HER-2/neu expression using cells immediately after thawing from cryogenic storage. With optimized cell handling and staining procedure and appropriate system suitability controls, the assay was validated as a quantitative assay. The validation results showed that assay accuracy, specificity, precision, linearity, and range were suitable for the intended use of ensuring lot-to-lot consistency of HER-2/neu expression. Assay robustness was demonstrated using design of experiments that evaluated critical assay parameters. Finally, the assay was successfully transferred to a current good manufacturing practice Quality Control laboratory in a separate facility. Since the overall precision of this assay is better than that of ELISA methods and it can be performed with ease and high throughput, quantitative flow cytometer-based assays may be an appropriate immunological assay platform for Quality Control laboratories for characterization and release of cell-based therapies.
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PMID:Validation of a quantitative flow cytometer assay for monitoring HER-2/neu expression level in cell-based cancer immunotherapy products. 2008 49

BALB/c mice transgenic (Tg) for the transforming rat neu oncogene (BALB-neuT) are genetically predestined to develop mammary carcinogenesis in a process similar to that in humans. We crossed HLA-A2.1/HLA-DR1 (A2.1/DR1) Tg mice with BALB-neuT mice to generate A2.1/DR1 x BALB-neuT triple Tg (A2.1/DR1 x neuT(+)) mice, which represent an improvement over BALB-neuT mice for evaluating vaccination regimens to overcome tolerance against HER-2/neu. A vaccine formulation strategy, consisting of synthetic peptides from the rat HER-2/neu oncogene combined with granulocyte macrophage colony-stimulating factor, was highly effective in preventing the growth of established transplantable tumors in male A2.1/DR1 x neuT(+) mice. Vaccination with HER-2(435-443) (p435) CTL peptide alone induced weak antitumor responses, which were characterized by increased numbers of regulatory T cells (Treg) and low numbers of vaccine-specific CD8(+) CTL and helper T cells (Th). The administration of p435 plus HER-2(776-790) (p776; helper peptide) reversed this situation, inducing functionally active, peptide-specific CTL and Th. There was a striking change in the intratumoral balance of Tregs (decrease) and vaccine-specific Th (increase) that directly correlated with tumor rejection. Intratumoral administration of anti-FasL antibody promoted tumor growth. The decrease in Tregs (Fas(+)) was due to apoptosis induced by cell contact with Fas ligand(+) (L)(+) Th. Mice vaccinated with p435 plus p776 exhibited long-lasting antitumor immunity. Our vaccine regimen also significantly delayed the outgrowth of mammary carcinomas in female A2.1/DR1 x neuT(+) animals. We provide a mechanism to overcome tolerance against HER-2/neu, which proposes a combined vaccination with two (Th and CTL) HER-2 peptides against HER-2/neu-expressing tumors.
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PMID:Peptide vaccination breaks tolerance to HER-2/neu by generating vaccine-specific FasL(+) CD4(+) T cells: first evidence for intratumor apoptotic regulatory T cells. 2023 67


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