Engineering and use of (32)P-labeled human recombinant interleukin-11 for receptor binding studies.

Human interleukin-11 (hIL-11) is a pleiotropic cytokine that is involved in numerous biological activities such as hematopoiesis, osteoclastogenesis, neurogenesis and female fertility. IL-11 is obviously a key reagent to study the IL-11 receptors. However, conventional radio-iodination techniques lead to a loss of IL-11 bioactivity.

Negative regulation of onconstatin M signaling by suppressor of cytokine signaling (SOCS-3).

Oncostatin M (OSM) is known to inhibit the growth of melanocytes and early-stage melanomas, but this ability is lost with melanoma progression. The biological effects of OSM involve the activation of Janus kinases (Jak) and signal transducer and activator of transcription (STAT) factors. Since SOCS (suppressor of cytokine signaling) a recently described family of regulatory proteins, has been shown to act through down-regulation of Jak-STAT signaling, we investigated their putative role in the inhibition of OSM signaling in the human melanoma cell line A375.

Negative cross-talk between interleukin-3 and interleukin-11 is mediated by suppressor of cytokine signalling-3 (SOCS-3).

Previous studies have shown that addition of interleukin-3 (IL-3) abrogated the B-cell potential of primary colonies supported by IL-11, erythropoietin, IL-7 and steel factor. However, the mechanism by which IL-3 exerts its inhibitory role is not understood. Using a variant of the mouse pro-B cell line Ba/F3 which expresses both IL-3 and IL-11 receptors, we showed that pretreatment of these cells with IL-3 before stimulation by IL-11 suppressed the tyrosine phosphorylation and nuclear translocation of STAT3 (signal transducer and activator of transcription 3).

Monoclonal antibodies against the human interleukin-11 receptor alpha-chain (IL-11Ralpha) and their use in studies of human mononuclear cells.

A panel of 14 hybridoma cell lines secreting monoclonal antibodies against the human interleukin-11 receptor alpha chain (hIL-11Ralpha) was obtained using two different approaches. Two antibodies were raised against peptides of the N- and C-terminal sequences, respectively, of the extracellular part of the hIL-11Ralpha. Another group of 12 antibodies was generated against a hybrid protein consisting of the extracellular part of the hIL-11Ralpha fused to mature full-length human IL-2.

Definition of receptor binding sites on human interleukin-11 by molecular modeling-guided mutagenesis.

Interleukin-11 (IL-11) belongs to the interleukin-6 (IL-6)-type subfamily of long-chain helical cytokines including IL-6, ciliary neurotrophic factor (CNTF), leukemia inhibitory factor (LIF), oncostatin M, and cardiotrophin-1, which all share the glycoprotein gp130 as a signal transducing receptor component. IL-11 acts on cells expressing gp130 and the IL-11 receptor (IL-11R) alpha-subunit (IL-11Ralpha). The structural epitopes of IL-11 required for the recruitment of the individual receptor subunits have not yet been defined.

Natural splicing of exon 2 of human interleukin-15 receptor alpha-chain mRNA results in a shortened form with a distinct pattern of expression.

We report the existence of eight different interleukin-15 receptor alpha-chain (IL-15Ralpha) transcripts resulting from exon-splicing mechanisms within the IL-15Ralpha gene. Two main classes of transcripts can be distinguished that do or do not (Delta2 isoforms) contain the exon 2-coding sequence. Both classes were expressed in numerous cell lines and tissues (including peripheral blood lymphocytes) at comparable levels and could be transcribed in COS-7 cells, and the proteins were expressed at the cell surface.

Antigen-presenting cells that phagocytose apoptotic tumor-derived cells are potent tumor vaccines.

We have reported recently that treatments combining injections of apoptotic bodies from tumor cells and interleukin 2 led to tumor regression and induced specific protection. In the present study, we show that tumor-bearing rats were cured with an 80% success rate by injection of antigen-presenting cells (APCs) that had phagocytosed apoptotic bodies derived from poorly immunogenic tumor cells, whereas phagocytic cells exposed to nonapoptotic tumor cell extracts were essentially without effect. In addition, curative vaccination using APCs that had phagocytosed apoptotic bodies generated a tumor-specific cytotoxic T-cell response and long-term protection from parental tumor challenge.

Cotranscription and intergenic splicing of human galactose-1-phosphate uridylyltransferase and interleukin-11 receptor alpha-chain genes generate a fusion mRNA in normal cells. Implication for the production of multidomain proteins during evolution.

In the past 10 years, much attention has been focused on transcription preinitiation complex formation as a target for regulating gene expression, and other targets such as transcription termination complex assemblage have been less intensively investigated. We established the existence of poly(A) site choice and fusion splicing of two adjacent genes, galactose-1-phosphate uridylyltransferase (GALT) and interleukin-11 receptor alpha-chain (IL-11Ralpha), in normal human cells. This 16-kilobase (kb) transcription unit contains two promoters (the first one is constitutive, and the second one, 8 kb downstream, is highly regulated) and two cleavage/polyadenylation signals separated by 12 kb.

5-Fluorouracil-resistant colonic tumors are highly responsive to sodium butyrate/interleukin-2 bitherapy in rats.

Advanced colorectal cancer is generally refractory to 5-fluorouracil (5-FU) chemotherapy. This is linked to the emergence of resistant cell populations, probably due to a selection process. The identification of molecular markers and the improvement of alternative therapies thus remain important.

Apoptosis induced by sodium butyrate treatment increases immunogenicity of a rat colon tumor cell line.

We have recently demonstrated that a treatment combining the cell differentiating agent sodium butyrate (NaBut) and interleukin-2 (IL2) resulted in a remission of established peritoneal colorectal carcinomatosis in rats. NaBut or IL2 treatment alone, never cured these tumour-bearing rats. In the present investigation, we report that NaBut-treatments induce apoptosis in the colonic cancer cells both in vitro and in vivo.

[Induction of apoptosis, in vitro and in vivo, on colonic tumor cells of the rat after sodium butyrate treatment].

Sodium butyrate (NaB) is known to induce the process of cell differentiation, particularly for epithelial colonic cells. We previously observed that treatment with NaB in association with interleukin 2 (IL2), cures 60% of peritoneal carcinomatosis induced by injection of DHDK12/TRb cells in syngenic rats [15]. In the present work, we evidenced in vitro metabolic alterations of the DHDK12/TRb cell line treated with NaB, followed by an apoptotic process.

Optimisation of CCL64-based bioassay for TGF-beta.

Transforming growth factor beta (TGF-beta) is released by a variety of cells and known to be involved in many different processes including the immune response, wound healing and carcinogenesis. As most experimental investigations have been based on quantitative analysis of TGF-beta production using a bioassay, it seemed important to test the validity and limitations of this method. This paper analyses several parameters that may impair TGF-beta quantification by bioassay.