Question Material 3 Figure 1c Comparing mockinfected to Salm

Question:

Material:

3. Figure 1c: Comparing mock-infected to Salmonella typhimurium infected lanes a. What does salmonella do to NADPH oxidase expression? (.5 pt) b. Why is tubulin included in this figure (.5 pt) c. What is the main conclusion of this figure (in context of the intro and paper\'s theme (1 pt)

Solution

a. The study shows that the \'respiratory burst\' of phagocytes, that are recruited during inflammation, is actually benefiacial to Salmonella typhimurium, as it provides salmonella with a terminal electron acceptor. Especially, it is important to note that oxygen radicals produced by NADPH oxidase are more important than nitric oxide radicals produced during tetrathionate respiration. This, coupled with the results obtained shows that Salmonella upregulates NADPH oxidase expression. This helps conclude that Salmonella makes use of the radicals produced by NADPH oxidase to gain a terminal electron acceptor.

b. tubulin is included in this figure because it is used to make certain that the salmonella cells under study came from inside mucosal macrophages. Absence of tubulin would have indicated otherwise. The presence of tubulin in a eukaryotic cell extact indicates that the extract contains cytoplasmic content.

c. In context of the intro and the paper theme, the figure indicates increased expression of NADPH oxidase in mucosal macrophages infected with S. typhimurium. NADPH oxidase expression in mock infected ones is verly low or undetectable.