Pembukaan Undang-undang Dasar 1945

40 p.; 29 cm

Effects of polar glycopeptidolipids of Mycobacterium chelonae (pGPL-Mc) on granulomacrophage progenitors

International audienc

Quantitative and qualitative changes in CD44 and MEL-14 expression by T cells in C57BL/6 mice during aging

International audienc

Improved expression of human interleukin-2 in high-cell-density fermentor cultures of Escherichia coli K-12 by a phosphotransacetylase mutant.

A fluoroacetate-resistant mutant of Escherichia coli K-12 (MM-294) accumulated less acetate in the medium during growth to high cell density in fermentor cultures and was shown to be defective in its phosphotransacetylase activity. The mutant had an improved ability to continue growing during induction of interleukin-2 (IL-2) synthesis, and in fermentor cultures it gave a higher level of specific IL-2 accumulation than its parent during expression under control of the temperature-sensitive pL promoter. In flask cultures at lower cell density, the mutant again produced less acetate than the parent, although both showed a much lower level of acetate accumulation than that seen in fermentors at high cell density. Both showed a higher specific expression level of IL-2 in flask cultures, and there was a greater difference between the mutant and its parent in the final extent of specific IL-2 accumulation in fermentor cultures compared with flask cultures. Thus, the concentration of acetate in the medium, which was much higher in fermentor cultures (greater than or equal to 300 mM after 5 h of induction) than in flask cultures (less than or equal to mM) of the parent organism, was a significant factor in limiting expression of the heterologous protein product, IL-2. The acetate kinase-phosphotransacetylase pathway was therefore a major source of acetate formation in these cultures. Blocking this pathway improved accumulation of IL-2 and did not slow growth

Surface antigen expression in spleen cells of C57B1/6 mice during ageing : influence of sex and parity

International audienc

Quantitative and qualitative changes in CD44 and MEL-14 expression by T cells in C57BL/6 mice during aging

International audienc

Effects of polar glycopeptidolipids of Mycobacterium chelonae (pGPL-Mc) on haematopoietic regeneration and resistance to infection of sublethally irradiated mice

International audienc

Sex and parity modulate cytokine production during murine ageing

We have previously shown that physiological hormone differences related to pregnancy or sex affect the age-related distribution of mononuclear cell populations during murine ageing. To determine whether such changes are involved in the age-related changes in functions of T cells, we examined the secretion of major T cell immunoregulatory cytokines (IL-2, IL-4, interferon-gamma (IFN-γ), IL-3, IL-6 and granulocyte-macrophage colony-stimulating factor (GM-CSF)) of in vitro concanavalin A-activated spleen cells of C57Bl/6 mice. The study included multiparous and virgin females and males at 2, 8, 15 and 23 months of age. Short-term effects of parity (8 months) were evidenced by the decrease of IFN-γ and the preserved IL-2 production in multiparous females (8 months), while IFN-γ was unchanged and IL-2 decreased in virgin mice. The increase in IL-4 production appeared earlier in multiparous females (15 months) than in virgin mice (23 months). The increase in IL-4/IFN-γ and IL-4/IL-2 ratios at 8 and 15 months, respectively, in multiparous females, suggests that pregnancy modifies the Th1/Th2 equilibrium. In late adulthood (15 months), IL-6 and GM-CSF production was higher in multiparous females than in virgin males or females. Sex differences were also noticed: IFN-γ secretion capacity was lower in males than in females during ageing. This study underlines that the onset, magnitude and kinetics of the age-related changes in cytokine production are parity- and sex-dependent. These changes probably influence the incidence of age-related diseases and may explain the greater longevity of females

Surface antigen expression in spleen cells of C57B1/6 mice during ageing : influence of sex and parity

International audienc

Surface antigen expression in spleen cells of C57Bl/6 mice during ageing: influence of sex and parity

So far all studies on the murine ageing process have been conducted on virgin mice. Immune ageing may be influenced by sex hormone differences related to sex or pregnancies. The aim of this study was to investigate whether pregnancies and gender influence the cell changes observed during ageing in a peripheral lymphoid compartment of C57Bl/6 mice. Using flow cytometry, changes in (Thy1.2+) T cell, (B220+) B cell and (CD11b/Mac-1) macrophage spleen populations were monitored in 2, 8 (3 months after last pregnancy) 15 and 23-month-old mice including males, virgin and multiparous females. The development of naive (CDCD44low), memory (CD44high), activated/memory (MEL-14, CD62L) cells were investigated in CD4+ and CE8+ T cell subsets. Both short term (at 8 months) and long term (at 15 and 23 months) effects of multiparity were obvious in the lymphocyte/macrophage population changes associated with the ageing process. Short-term effects included delayed appearance of CD4+CD44high memory lymphocytes and increased numbers of both CD4+MEL-14low activated/memory cells and Mac-1+ macrophages when compared with virgin control mice. Later effects of multiparity were increased CD8αdull populations and increased T/B cell ratios and the ratio of memory to naive CD4+ cells (CD44+high/CD44+low). A sex effect was noticed: males exhibited lower Mac-1+ levels and memory/naive ratio in CD4+ subset than virgin females throughout life. These results suggest that gender and/or pregnancies affect the age-related distribution of lymphoid and macrophage cell populations in the spleen of C57Bl/6 mice