Hi, I have a few Qs :
1. is legionella encapsulated?
2. germinal centres contain small but critical no. of dendritic cells as well as B cells?
3. does germinal centre remain active and clearly visible for years after initial antigen challenge?
4. are the only critical mechanisms of T cellls in destruction of pathogens: killing of virus-infected cells and helping B cells make Ab?
please explain/site some web
thanks in advance
2006-11-22 10:29:09 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Medicine
1. No strains of Legionella have no capsules. But according to my research the main goal is to get inside a macrophage vacuole, which seems to make them immune to the immune system, and happily pro-create there. This is not a classic capsule, but a very sneaking one indeed.
2. http://en.wikipedia.org/wiki/Germinal_center has some general information. Sounds like the answer to this question is "yes".
3. No. The GC sort of dies out after about 3 weeks post-antigenic stimulation. However, the memory B cells (which I recall are released into the blood stream) can last for 20 years. I could be wrong about the "release" part of my answer.
4. I guess the answer here depends on how far in depth you consider the mechanisms. There are probably mechanisms that I don't know about, and probably mechanisms no one knows about. But for simplicities sake, I think the answer to your question is simply "yes".
2006-11-22 11:20:43 · answer #1 · answered by dumbdumb 4 · 1⤊ 0⤋
Germinal centers contain a specific type of dendritic cell, different from the rest of the innate system. They are called FOLLICULAR DENDRITIC CELLS, and are involved in positive clonal selection in B-Cell activiation.
Germinal centers are always active, we are constantly being exposed to new antigens, and thus we need to continue to generate B memory cells to maintain immnunity.
T-Cells go way above and beyond cytotxicity and B-Cell activation. Cytokines are the regulators of the immune system. T-Cells release plenty of cytokines.
2006-11-23 01:08:08 · answer #2 · answered by Brian B 4 · 0⤊ 0⤋
Looking for here...
http://www.nature.com/nri/index.html
http://pathmicro.med.sc.edu/book/welcome.htm
2006-11-22 18:46:56 · answer #3 · answered by Fantasmagorico arrechera 4 · 0⤊ 0⤋
By ding, there's some stuff out there!
I mean - none of your "How big's yr k**b?" or "Is Britney Spears a woman?"
Fair takes yr breath away.
2006-11-22 18:34:40 · answer #4 · answered by migdalski 7 · 0⤊ 3⤋