Pro-Tumor and Anti-Tumor Functions of IL-17 and of TH17 Cells in Tumor Microenvironment

The current review reveals the seven subclasses of CD4+ T helper cells, i.e. Th1, Th2, Th9, Th17, Th22, regulatory T cells and Tfh, the cytokines produced by them and their role in tumor microenvironment. Main attention was paid to IL-17 and Th17 cells. IL-17-producing cells were described, among which were Treg17 cells and Tc17 cells. The transcription factors, engaged in the activation of Th17 cell differentiation were reviewed. It was shown that Th17 cells might possess regulatory functions in tumor microenvironments that directs toward immunosuppression. The reciprocity between Treg and Th17 cells is realized when the production of a large amount of TGF-β in tumors causes Treg cell differentiation, and the addition of IL-6 shifts the differentiation of naïve T cells to Th17 cells. The main pro-tumor role of IL-17 is the promotion of tumor angiogenesis through stimulation of fibroblasts and endothelial cells. The antitumor functions of IL-17 are associated with enhancement of cytotoxic activity of tumor specific CTL cells and with angiogenesis that provide channels through which immune cells might invade tumor and promote antitumor immunity.

Predominance of IgG1 and IgG3 subclasses of autoantibodies to neutrophil cytoplasmic antigens in patients with systemic lupus erythematosus

The IgG subclasses displayed by antibodies to four neutrophil cytoplasmic antigens were studied in 20 patients with systemic lupus erythematosus (SLE) by solid-phase enzyme immunoassays and monoclonal antibodies to human IgG subclasses. The IgG subclass reactivity of antineutrophil cytoplasmic antibodies (ANCA) was measured in six sera containing antiproteinase3 (PR3) antibodies, in five sera containing antimyeloperoxidase (MPO) antibodies, in sera containing antibactericidal/permeability-increasing protein (BPI) antibodies, and in ten sera containing antilactoferrin (LF) antibodies. The IgG subclass distribution of anti-dsDNA antibodies in eight sera was examined as well. IgGI was the predominant subclass for MPO-ANCA and LF-ANCA, whereas IgG1/IgG3 contributed mainly to anti-PR3, anti-BPI antibodies, and anti-dsDNA antibodies. In addition, we found elevated levels of the total IgG1 and IgG3 isotypes in the sera of our patients. Our results demonstrated a predominance of IgG1/IgG3 ANCA in SLE, suggesting that the isotype distribution of ANCA is a feature of antibody production in this disease.

Antineutrophil cytoplasmic antibodies in patients with systemic lupus erythematosus: prevalence, antigen specificity, and clinical associations

Fifty-five patients with systemic lupus erythematosus (SLE) were examined for antineutrophil cytoplasmic antibodies (ANCA) by indirect immunofluorescence (IIF). Enzyme-linked immunosorbent assay (ELISA) for ANCA against myeloperoxidase (MPO), lactoferrin (LF), proteinase 3 (PR3), elastase (HLE), and bactericidal/permeability-increasing protein (BPI) was performed. The prevalence of ANCA by IIF was 29.1% (16/55 patients). MPO-ANCA were found in 10.9% (6/55), LF-ANCA in 18.2% (10/55), PR3-ANCA in 12.7% (7/55), BPI-ANCA in 23.6% (13/55), and HLE-ANCA in 1.8% (1/55). The levels of BPI-, LF-, and PR3-ANCA correlated with disease activity. A significant association between serositis and the presence of BPI-, LF-, and PR3-ANCA was observed, and PR3-ANCA were found to be associated with arthritis as well. Our results demonstrate that ANCA of various specificities occur in SLE, and BPI appears to be an important target antigen.

Cytotoxicity on L1210 leukemic cells of beta-amanitin-concanavalin A and phallacidin-concanavalin A conjugates

The conjugates beta-amanitin-concanavalin A and phallacidin concanavalin A were tested for direct cytotoxicity on L1210 lymphocytic leukemia cells by a combined in vitro-in vivo bioassay. Both conjugates exerted strong direct cytotoxicity on the tumour cells.

Lysine-orotate potentiates the toxicity of an extract of the mushroom Amanita phalloides

Upon simultaneous administration lysine-orotate increases (about 40-fold) the toxicity in mice of a crude Amanita phalloides extract. This effect, though less prominent, is also observed if these two compounds are injected 1 hr apart. The potentiating effect of lysine-orotate is dose dependent and neither L-lysine nor orotic acid exert any effect on the toxicity of the crude A. phalloides extract. Lysine-orotate increases the toxicity of amatoxins (alpha-amanitin) only, not affecting the toxicity of phalloidins. Thin layer chromatography on silica gel plates and column chromatography on Sephadex LH-20 has proven the formation of a relatively stable complex of amanitin and lysine-orotate. The results demonstrate that lysine-orotate should not be used as a hepatoprotective agent in cases of Amanita intoxication.

Preparation of a beta-amanitin-concanavalin A conjugate of low toxicity

Pure beta-amanitin was isolated by combined adsorption chromatography of a crude methanol extract from Amanita phalloides on Sephasorb HP Ultrafine and Sephadex LH-20. The beta-amanitin was coupled to concanavalin A by the carbodiimide method. The conjugate was purified by fractionation on a column of Sephadex G-75. The molar ratio beta-amanitin to concanavalin A in this conjugate was 4.14. The purified conjugate was tested by thin-layer chromatography and showed characteristic (for amatoxins) bright purple staining but different mobility. The ultraviolet spectrum of the conjugate was different from the spectra of the native beta-amanitin and the native concanavalin A. The toxicity of the conjugate was determined by in vivo toxicological studies and was four-fold lower than that of the native beta-amanitin. These results suggest that this conjugate may be used for immunization procedures and for the production of amatoxin-specific antibodies.