分子寄生虫病旋毛虫课件.ppt

旋毛虫病 旋毛虫病（trichinosis）是由旋毛线虫（Trichinella spiralis）引起的人畜共患的寄生虫病，流行于哺乳类动物间，人因生吃或半熟食含旋毛虫包囊的猪肉等而感染。 二、 生活史 How Does Trichinella spiralis Make Itselfat Home? secreted tyvelosylated proteins of the larva play a central role. These proteins are always present in the intracellular niche of the larva from Day 7 after infection and may be responsible for redirecting host genomic expression, leading to nurse cell formation. (a) Loss of muscle proteins (eg. actin, myosin and creatine kinase). No muscle contractile proteins can be detected beyond Day 8 after the parasite invades the muscle cell. (b) Enlargement and division of nurse cell nuclei during nurse cell formation. Enlargement of nuclei occurs maximally on Day 8 after the larva invades the muscle cell and nuclei remain enlarged thereafter. Nuclear division and DNA replication occurs during the first 4–5 days after the larva invades the muscle cell, resulting in 4N DNA in each nucleus and approximately 40–60 nuclei per nurse cell. (c) Mitochondrial damage (ie.vacuolization of inner mitochondrial matrix). Mitochondrial damage can be detected throughout the infection period beginning on Day 5 after invasion of the muscle cell by the larva. (d) Collagen type IV synthesis. Synthesis of mRNA begins on Day 7, while collagen protein is detected first on Day 11 after the larva invades the muscle cell. Synthesis of collagen protein ceases on Day 26. (e) Collagen type VI synthesis. Synthesis of mRNA begins on Day 7 after the larva infects the muscle cell and continues at a low level throughout the infection period. (f) Vascular endothelial growth factor (VEGF) mRNA synthesis. Synthesis begins on Day 7–8 after the larva invades the muscle cell and continues throughout the infection period. (g) VEGF peptide synthesis. Synthesis begins on Day 8 after the larva invades the muscle cell and continues throughout the infection period. (h) Secret