INTERLEUKIN 10 PROTECTS ACTIVATED HUMAN T LYMPHOCYTES AGAINST GROWTH FACTOR WITHDRAWAL-INDUCED CELL DEATH BUT ONLY ANTI-FAS ANTIBODY CAN PREVENT ACTIVATION-INDUCED CELL DEATH

Interleukin 10 (IL-10) is a pleiotropic T cell-derived cytokine best known for its negative regulatory effects on T cell immunity. It inhibits responses indirectly by downregulating expression of major histocompatibility complex (MHC) molecules and co-stimulatory molecules such as CD80 on antigen presenting cells as well as directly via its effects on responding cells. On the other hand, IL-10 has been shown to protect activated T cells against apoptosis caused by withdrawal of the major growth factor, IL-2, and allow proliferation of T cells in the absence of IL-2. However, we show here that this IL-10-dependent, IL-2 independent proliferative response is short-lived, and that IL-10-responsive T cells cannot multiply in its presence. Moreover, inclusion of exogenous IL-10 in clonal cultures propagated with IL-2 results in suppression of their growth. These findings, together with the observation that IL-10 fails to protect T cells against activation-induced cell death (a fas/fas-ligand-dependent phenomenon blocked only by certain antagonistic anti-fas reagents), suggest that the negative regulatory effects of IL-10 outweigh the upregulated proliferation observed on some T cell clones (TCC) in the absence of IL-2.     

Correction to: Ecological modeling and distribution analysis of digger scorpions: Odontobuthus doriae,Odontobuthus bidentatus (Scorpiones: Buthidae) and Scorpio maurus (Scorpiones: Scorpionidae) in Iran using the maximum entropy method

Applied Entomology and Zoology - The word “Odonthubutus” should be replaced with “Odontobuthus” throughout the article.     

Activity of liposomal interleukin-2 in vitro.

Preclinical in vitro assessment of highly purified natural human interleukin-2 (IL-2) packed in egg lecithin liposomes was performed in short- and long-term T-cell cloning and propagation systems, and in experiments testing induction of lymphokine-activated killer (LAK) cells. Liposomal IL-2 (lip-IL-2) was essentially as active as free natural or recombinant IL-2 for cloning and culture of both helper and cytotoxic alloreactive T cells. However, lip-IL-2 was found to be markedly inferior to free natural or recombinant IL-2 for the induction of LAK cells from normal donors. Nevertheless, lip-IL-2 was able to maintain LAK cytotoxicity of populations preactivated with free IL-2. These results suggest that lip-IL-2 can interact with activated T cells and LAK cells in the same way as free IL-2, but that it is much less efficient at activating LAK-cell precursors.     

Prerequisites for the Immunotherapy of Cancer

Tumours express proteins not commonly found in normal cells, or over-express certain proteins. These may in some cases serve as target antigens for immunological attack. It is therefore essential to improve our understanding of the nature of these target epitopes and the cells which recognize them, in order to develop immunotherapy as a realistic treatment for cancer. A small group of around 40 investigators recently came together at the Heinrich Fabri Institute of the University of Tübingen to discuss the identification of human tumour antigens and the exploitation of this knowledge for effective immunotherapy. Accepted: 4 March 1999     

Variation of Neisseria gonorrhoeae Lipooligosaccharide Directs Dendritic Cell–Induced T Helper Responses

Gonorrhea is one of the most prevalent sexually transmitted diseases in the world. A naturally occurring variation of the terminal carbohydrates on the lipooligosaccharide (LOS) molecule correlates with altered disease states. Here, we investigated the interaction of different stable gonoccocal LOS phenotypes with human dendritic cells and demonstrate that each variant targets a different set of receptors on the dendritic cell, including the C-type lectins MGL and DC-SIGN. Neisseria gonorrhoeae LOS phenotype C constitutes the first bacterial ligand to be described for the human C-type lectin receptor MGL. Both MGL and DC-SIGN are locally expressed at the male and female genital area, the primary site of N. gonorrhoeae infection. We show that targeting of different C-type lectins with the N. gonorrhoeae LOS variants results in alterations in dendritic cell cytokine secretion profiles and the induction of distinct adaptive CD4⁺ T helper responses. Whereas N. gonorrhoeae variant A with a terminal N-acetylglucosamine on its LOS was recognized by DC-SIGN and induced significantly more IL-10 production, phenotype C, carrying a terminal N-acetylgalactosamine, primarily interacted with MGL and skewed immunity towards the T helper 2 lineage. Together, our results indicate that N. gonorrhoeae LOS variation allows for selective manipulation of dendritic cell function, thereby shifting subsequent immune responses in favor of bacterial survival.     

Tumour-specific MHC-class-II-restricted responses after in vitro sensitization to synthetic peptides corresponding to gp100 and Annexin II eluted from melanoma cells

In a search for potentially tumour-specific MHC-class-II-restricted antigens, the immunogenicity of endogenous peptides that had been eluted from HLA-DR molecules of the human melanoma cell line FM3 (HLA-DRB1*02x, DRB1*0401) was tested in vitro. Two 16-mers representing gp100 positions 44–59, and annexin II positions 208–223 bound well to isolated DRB1*0401 molecules and are discussed here. HLA-DR-matched normal donors' T cells were cultured with peptide-pulsed artificial antigen-presenting cells (CHO cells cotransfected with genes for HLA-DRB1*0401 and CD80 and coexpressing high levels of both human molecules). Specific sensitization was achieved against both peptides, as measured in assays of autocrine proliferation and interleukin-2 secretion. Moreover, responses to native autologous melanoma cells but not to autologous B cells were also observed. In view of the expression of fas by the activated T cells and of fas ligand by the melanoma cells, blockade of potential fas/fas-ligand interactions was undertaken using monoclonal antibodies (mAb). The antagonistic fas-specific mAb M3, but not the fas agonist M33, caused a markedly enhanced T cell response to FM3 cells. These results demonstrate that synthetic peptide antigens are able to sensitize T cells in vitro for effective MHC-class-II-restricted recognition of melanoma cells. Received: 12 April 1998 / Accepted: 23 April 1998     

New D-modified androstane derivatives as aromatase inhibitors.

Starting from a 16-oximino derivative of 5-androstene the newly-synthesized 16-oximino-17-hydroxy-17-substituted derivatives 2-4 gave by the Beckmann fragmentation reaction the corresponding D-seco derivatives 6-9. Besides, in the case of the 17-hydroxy-17-methyl-16-oximino derivative 2, as a result of the rearrangement, the hydrolysis product 5 of the 16-oximino group with the opposite configuration at the C-17 was obtained. By the Oppenauer oxidation and/or by dehydration of 7 with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ), the corresponding derivatives 12, 13, and 14 were obtained. The structures of 6 and 12 were unambiguously proved by the appropriate X-ray structural analysis. Kinetic analysis for anti-aromatase activity showed that compound 12 expressed the highest inhibition in the denucleated rat ovarian fraction in comparison to other androstene derivatives (IC(50) was 0.42 microM). In comparison to aminoglutethimide (AG) activity, it was 3.5 times lower. The inhibition was competitive, with K(i) of 0.27 microM. Introduction of additional units of unsaturation (compounds 13 and 14) in D-seco derivatives did not increase anti-aromatase activity.     

Surgery for hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetically determined cardiac disease characterised by otherwise unexplained myocardial hypertrophy of the left ventricle, and may result in left ventricular outflow tract obstruction. It is the most common cause of sudden cardiac death in young adults due to arrhythmias. Septal myectomy is a surgical treatment for HCM with moderate to severe outflow tract obstruction, and is indicated for patients with severe symptoms refractory to medical therapy. The surgical approach involves obtaining access to the interventricular septum via transaortic, transapical or transmitral approaches, and excising a portion of the hypertrophied myocardium to relieve the outflow tract obstruction. Large, contemporary series from centres experienced in septal myectomy patients have demonstrated a low early mortality of <2 %, excellent long-term survival that matches the general population, and durable relief of symptoms.     

Optimisation of an extraction procedure and chemical characterisation of Croatian propolis tinctures

Three spectrophotometric methods for the quantitative determination of different flavonoid groups and total phenolics in Croatian propolis samples were optimised and validated. The assay based on the formation of aluminium chloride complex (with galangin as a standard) was applied to the quantification of flavones and flavonols, while the 2,4-dinitrophenylhydrazine method (with pinocembrine as a reference) was used for the quantification of flavanones. Total phenolic content was measured by the Folin-Ciocalteau method using reference solution of caffeic acid:galangin:pinocembrine (1:1:1). Through analytical validation, the most suitable extraction conditions (with respect to time, temperature and concentration of extraction solvent) were determined, and final conditions for the extraction were established (80% ethanol, 1 h at the room temperature). The appropriate ratio between the mass of raw propolis and the extraction solvent volume was also established. By the application of the optimised method of extraction, 10 propolis tinctures were prepared and subjected to the analysis of general pharmacopoeial parameters, which are fundamental for the creation of quality specification (relative density, dry residue of extract, content of ethanol, methanol and 2-propanol). Additionally, the content of waxes as the main inactive constituents was determined in order to observe the level of their migration from crude propolis to the prepared tinctures.     

Synthesis,X-ray crystal structures and biological activity of 16-amino-17-substituted-D-homo steroid derivatives

D-Homo derivatives in the androstane and estrane series, 12-19, were synthesized by a fragmentation-cyclization reaction of 16-oximino-17-hydroxy-17-substituted derivatives 3-9, or by cyclization of the corresponding D-seco derivatives 20-26. The structures were confirmed by X-ray analysis of compounds 12 and 16. Preliminary assessment of inhibitory effects of D-homo derivatives from androstane series towards aromatase, 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), 17 alpha-hydroxylase/C17-20 lyase (P450c17) and 17 beta-HSD indicated much lower inhibitory potential compared to previously tested activity of another type of D-modified steroids, namely D-seco derivatives. Also, assessment of potential antiestrogenic activity of derivatives from estrane series showed absence of such an activity.