Search results for "Cytotoxicity"

Cytotoxicity of the indole alkaloid reserpine from Rauwolfia serpentina against drug-resistant tumor cells.

2015

Abstract Background: The antihypertensive reserpine is an indole alkaloid from Rauwolfia serpentina and exerts also profound activity against cancer cells in vitro and in vivo. The present investigation was undertaken to investigate possible modes of action to explain its activity toward drug-resistant tumor cells. Material and methods: Sensitive and drug-resistant tumor cell lines overexpressing P-glycoprotein (ABCB1/MDR1), breast cancer resistance protein (ABCG2/BCRP), mutation-activated epidermal growth factor receptor (EGFR), wild-type and p53-knockout cells as well as the NCI panel of cell lines from different tumor origin were analyzed. Reserpine's cytotoxicity was investigated by res…

Potential involvement of IL-22 and IL-22-producing cells in the inflamed salivary glands of patients with Sjogren's syndrome.

2012

OBJECTIVES: In chronic inflammatory disorders, interleukin (IL)-22 may act either as a protective or as a pro-inflammatory cytokine. At mucosal sites, IL-22 is mainly produced by CD4(+) T cells and by a subset of mucosal natural killer (NK) cells expressing the receptor NKp44 (NKp44(+) NK cells). The aim of this study was to investigate the IL-22 expression in the salivary glands of patients with primary Sjögren's syndrome (pSS). METHODS: Minor salivary gland biopsies were obtained from 19 patients with pSS and 16 with non-specific chronic sialoadenitis. Quantitative gene expression analysis by TaqMan real-time PCR and immunohistochemistry for IL-17, IL-22, IL-23 and STAT3 (signal transduce…

Antibodies to vascular endothelial cells in chronic rejection of renal allografts.

2000

Clonal analysis of liver-infiltrating T cells in patients with LKM-1 antibody-positive autoimmune chronic active hepatitis

1991

SUMMARY Autoantibodies against microsomal antigen of liver and kidney (LKM-1) are diagnostic markers for a subgroup of autoimmune chronic active hepatitis (AI-CAH). Cytochrome P4S0dbl, now classified as cytochrome P450 IID6, is the major antigen of LKM-1 antibodies. Immunohistological studies suggest that hepatic injury in AI-CAH is mediated by liver-infiltrating T cells. In the present study the specificity and function of liver-infiltrating T cells was analysed at the clonal level. Phenotypical characterization of 189 T cell clones isolated from four liver biopsies of LKM-1 antibody-positive patients showed an enrichment of CD4+CD8- T cells. Five CD4+CD8- T cell clones proliferated specif…

Phase I study in melanoma patients of a vaccine with peptide-pulsed dendritic cells generated in vitro from CD34(+) hematopoietic progenitor cells.

2000

Dendritic cells (DCs) are professional antigen-presenting cells (APCs) that can be used for vaccination purposes, to induce a specific T-cell response in vivo against melanoma-associated antigens. We have shown that the sequential use of early-acting hematopoietic growth factors, stem cell factor, IL-3 and IL-6, followed by differentiation with IL-4 and granulocyte-macrophage colony-stimulating factor allows the in vitro generation of large numbers of immature DCs from CD34(+) peripheral blood progenitor cells. Maturation to interdigitating DCs could specifically be induced within 24 hr by addition of TNF-alpha. Here, we report on a phase I clinical vaccination trial in melanoma patients us…

Rapid High Efficiency Sensitization of CD8+ T Cells to Tumor Antigens by Dendritic Cells Leads to Enhanced Functional Avidity and Direct Tumor Recogn…

2003

Abstract Myeloid-origin dendritic cells (DCs) can develop into IL-12-secreting DC1 or non-IL-12-secreting DC2 depending on signals received during maturation. Through rapid culture techniques that prepared either mature, CD83+ DC1 or DC2 from CD14+ monocytes in only 2 days followed by a single 6–7 day DC-T cell coculture, we sensitized normal donor CD8+ T cells to tumor Ags (HER-2/neu, MART-1, and gp100) such that peptide Ag-specific lymphocytes constituted up to 16% of the total CD8+ population. Both DC1 and DC2 could sensitize CD8+ T cells that recognized peptide-pulsed target cells. However, with DC2, a general decoupling was observed between recognition of peptide-pulsed T2 target cells…

MHC-unrestricted recognition of bacteria-infected target cells by human CD8+ cytotoxic T lymphocytes.

1992

Abstract A CD8 + αβTCR + T cell clone (A35) was isolated from the synovial fluid of a patient with postenteric reactive arthritis caused by Yersinia enterocolitica . This clone efficiently killed autologous and allogeneic target cells that had been preincubated with live but not with heat-killed bacteria. There was no restriction by polymorphic parts of HLA-A, -B. or -C molecules and a HLA class II-deficient mutant cell line was lysed as efficiently as its normal counterpart, whereas infected HLA class I-deficient cells (Daudi cells) were not. The clone showed crossreaction between Yersinia enterocolitica , Escherichia coli , Pseudomonas aeruginosa , and Streptococcus pyogenes , but did not…

Lysis of human melanoma cells by autologous cytolytic T cell clones. Identification of human histocompatibility leukocyte antigen A2 as a restriction…

1989

From the peripheral blood of the melanoma patient (AV), we derived cytolytic T lymphocyte (CTL) clones that lysed the autologous tumor line SK-MEL-29, but not autologous EBV-B cells, K562, and other tumor targets. By immunoselection experiments it was shown that the CTL clones recognized at least three different antigens on the autologous tumor cells. We demonstrate here that these melanoma antigens are presented to the CTL in association with HLA-A2. First, HLA-A2-reactive pregnancy sera as well as an mAb against HLA-A2 inhibited the CTL lysis. Second, immunoselected melanoma subclones that were resistant to lysis by CTL clones against the three antigens described were found to lack expres…

Cytolytic T-cell clones against an autologous human melanoma: specificity study and definition of three antigens by immunoselection.

1989

Cytolytic T-lymphocyte (CTL) clones against an autologous melanoma (SK-MEL-29) were generated by mixed lymphocyte tumor culture and subsequent cloning of responder lymphocytes at limiting dilutions. These CTL clones lysed autologous melanoma but not autologous Epstein-Barr virus-transformed B cells and none of the allogeneic tumor targets included in the specificity analysis. The lysis of autologous melanoma targets could be inhibited by monoclonal antibodies against monomorphic HLA class I determinants. For proliferation of CTLs, the stimulation with the relevant target antigen on autologous tumor cells was essential. Immunoselection experiments carried out with two CTL clones revealed the…

Activity of the antiestrogenic cajanin stilbene acid towards breast cancer

2014

Antiestrogenic therapy is a mainstay for estrogen receptor (ERα)-positive breast cancer. Due to the development of resistance to established antihormones such as tamoxifen, novel compounds are required. The low abundant cajanin stilbene acid (CSA) recently isolated by us from Pigeon Pea (Cajanus cajan) has structural similarities with estrogen. We analyzed the cytotoxic and anticancer activity of CSA in ERα-positive and -negative human breast cancer cells in vitro, in vivo and in silico. CSA exerts anticancer and antiestrogenic activities towards ERα-positive breast cancer, and it showed cytotoxicity towards tamoxifen-resistant MCF-7 cells, implying that CSA may be active against tamoxifen-…