All good, pugs!
Hi guys.
Are dendritic cells considered to be a part of the innate (non-specific) and adaptive(specific) immune response?
Antigen presenting cells play roles in both the adaptive and innate immune response, hence why they are considered to be a 'branch' between the two responses. While their action in engulfing antigen is innate (non-specific), they activate the adaptive immune response and thus can be considered to be apart of both responses. I would say their action is mostly innate though.
Also, how are complement proteins activated?
Is this correct? Complement proteins punch holes in the cell membrane of bacteria, rupturing their cell membrane, causing their contents to spill out thus killing the bacteria?
The specifics regarding complement activation is not necessary at a VCE level. You just need to know that in the presence of a pathogen, compliment can be activated. In actuality there are 3 different activation pathways of the compliment system. One of them is the "classical" pathways which involves the binding to antibodies mentioned by Chocolatemilkshake. I found reading into extra depth about the compliment system quite fascinating (especially its involvement in alzheimer's).
As for the functions of compliment, I usually talk about:
- opsonization (a certain compliment protein will bind to pathogen surface and aid in its engulfment by phagocytes)
- chemotaxis (compliment proteins activated in presence of pathogen will attract immune cells)
- MAC (as has been mentioned - disrupting the cell membrane and causing the lysis of the cell).
Also, when the antigen presenting cells present the antigen to the T helper cells, do the T helper cells' T cell receptors bind to the antigen and if so is the antigen attached to the MHC class II?
the antigen presenting cell (i.e. dendritic cell) presents antigen to the t helper cell via its mhc class 2. The t helper cell's t cell receptors will bind to the antigen. this clonal selection will cause the clonal expansion of this t helper cell. this is all you need to know.
Also, the release of interferon to disable virus-infected cells would be a specific response right? Because since the infected cells are being targeted it would be a part of the cell-mediated response which is a part of the specific/adaptive immune response?
This would not be considered a specific response. While it is certainly directed at virus infected cells, it is still a very general immune mechanism. Specific responses target specific antigens, and since the release of these interferon are simply in response to viruses generally, they are an innate immune response.
Platelets adhering to a virus would be considered a non-specific response right? Because don't platelets congregate on a pathogen regardless of what type of pathogen it is, it can happen to any pathogens?
correct.
But know that a specific responses refer to responses targeting a specific antigen, not a specific pathogen.