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Z Steplewski

Publications and source records attributed to Z Steplewski.

208 records · Page 12Linked to original sources
PubMedDate not supplied

A gastrointestinal-specific monoclonal antibody that may be of clinical value in cytologic material.

A new monoclonal antibody (MAb), 29-10, produced by immunization of mice with cells from the SW 1116 colorectal carcinoma cell line, detected an antigen present in cytologic touch imprints of surgically resected normal and neoplastic gastrointestinal (GI) tissue, including specimens from the stomach and the colon. These imprints were fixed in 95% ethanol and stained with the avidin-biotin immunoperoxidase technique. In tested cases, 22 (100%) of 22 imprints from GI adenocarcinomas and from normal GI tissue, as well as 13 (56.6%) of 23 imprints from colonic polyps, stained positively while no staining was demonstrable in imprints from other tissues. In histologic sections, only 4 (23%) of 17 colonic adenocarcinomas and 3 (11.5%) of 26 polyps stained positively. The staining ability of MAb 29-10 was compared to that of MAb 19-9, another colorectal antibody, and was found to be markedly superior for binding of the antigen in cytologic preparations. This tissue-specific antibody may be useful in identifying malignant cells of metastatic carcinoma as to their GI tract origin.

Adenocarcinoma↗
PubMedDate not supplied

Cytokine combinations for induction of antigen-specific cytolytic T lymphocytes from peripheral blood lymphocytes.

We studied effects of varied cytokine combinations on allogeneic cytotoxic T lymphocyte (CTL) generation in a mixed lymphocyte-tumor cell culture. Sensitized with allogeneic melanoma cell line (MM-8.1 or MM-28), peripheral blood mononuclear cells (PBMC) were cultured in medium containing various combinations of cytokines that included human recombinant interleukin-2 (rIL-2) alone (MB-2), rIL-2 and rIL-4 (MB-2,4) and rIL-1, rIL-2, rIL-4 and rIL-6 (MB-1,2,4,6). Lymphocytes proliferated for more than 50 days and manifested stimulating cell-specific cytotoxicities in 1 of 5 cultures with MB-2, in 4 of 5 with MB-2,4 and in 5 of 5 with MB-1,2,4,6. Lymphocytes grew up to 10(6) fold in culture with MB-2,4 or MB-1,2,4,6 at day 90-100. Stimulating cell MM-8.1 (HLAABC+,DR-) induced CD3+, CD8+, CD56- CTLs and MM-28 (HLA-ABC+, DR+) mainly generated CD3+, CD4+, CD56- CTLs. Monoclonal antibodies against HLA-ABC and HLA-DR molecules suppressed the stimulating cell-specific cytolytic activity of CD8+ and CD4+ CTLs, respectively. These data indicate that combination of rIL-1, rIL-2, rIL-4 and rIL-6 offer an efficient system to generate allogeneic, tumor-specific CTLs from PBMCs and that HLA molecules expressed on stimulating cells play an important role in CTL generation.

Antigens, CD↗
PubMedDate not supplied

External beam radiation enhances antibody mediated radiocytotoxicity in human glioma cells in vitro.

Enhanced accumulation of monoclonal antibodies in tumor tissue has been observed as a result of external beam irradiation (EBR). This effect was mainly attributed to increased vascular leakage due to unspecific radiation damage of vascular endothelial cells. The aim of this study was to investigate the effects of EBR on expression and antibody-binding of epidermal growth-factor receptor (EGF-R) in human glioma cells in-vitro. High-grade glioma cells were irradiated with conventional x-rays (0-3600 Rad) and surface binding, internalization and radiocytotoxicity of 125I-labeled monoclonal antibody (MAb) 425, specific for human EGF-R, was tested. EBR showed a short-term dose and time dependent increase of specific MAb 425 binding and internalization in receptor positive cell lines U87-MG and A1207. This effect was probably due to a mitotic block and an increase in cellular volume. Combination of EBR and 125I-425 showed additive effects on cell vitality/survival and was more pronounced in contact inhibited cells as compared to cells growing in a log-phase. We assume that cells exposed to 125I-labeled MAb 425 are only able to accumulate a critical number of DNA double-strand breaks when the doubling-time is prolonged e.g. under contact-inhibition or radiation induced mitotic blockade. We conclude that EBR has no negative effects on EGF-R expression, MAb-binding and internalization. The combination of EBR and 125I-MAb 425 enhances cytotoxic efficacy and thus supports adjuvant use in the clinical management of high-grade glioma.

Animals↗