A couple of people have asked me about adjuvants, which was the subject of #24 on the midterm. I was looking for the choice with "innate response" in it. All the others include the word "antigen". or the idea of an antigen The overall big picture is that stimulation of the innate system and release of cytokines is quite important in shaping the immune response to an antigen.
Here are some further comments on adjuvants: In the context of vaccines, an adjuvant is something that is not the antigen and that is added to the vaccine in order to increase the response. They are used with injected vaccines, because the soluble protein antigen may not produce much response. Afterall, this is not how microbes are normally encountered by the immune system. In order to get a good response, some phagocytosis is particularly important, as is subsequent release of cytokines, and perhaps also general release of inflammatory paracrines. Because there is no antibody produced yet, the phagocytosis necessarily is working through innate mechanisms . A common hypothesis involves the toll-like receptors, but this is still a matter of dispute and research. Classical adjuvants usually include certain bacterial products. Also used are viral molecules in particles called virosomes.
A source of confusion here is that a common adjuvant is inorganic aluminum hydroxide. In fact, at present, in the United States, this is the only adjuvant used (I think). It is usually claimed to work by binding the antigen molecules, creating a particle that is something like a bacteria, which is then phagocytized, working of course via innate receptors.
There is a clear "best answer" to this question, since four of the choices clearly include the idea of an antigen. But I can see how the sole reference to bacterial products in the correct answer might have been confusing to some. So I am giving one extra point to anyone who missed this question. This will be done automatically. You don't need to get in touch.