Question

5. Explain why direct antigen activation of CTLs and B cells is more important than APC-initiated activa- tion in subsequent encounters with a microbe. Why is the APC-initiated pathway needed at all?

6. There are many interactions between the innate and adaptive defense systems. List as many of them as you can and explain how they work. Why are these interactions important? Are all of them beneficial?

7. What are the two ways that polysaccharides, DNA, and lipid antigens can elicit an immune response? How are these responses different than that elicited by a peptide antigen?

8. Why is the level of specific IgM antibodies of di- agnostic significance?

Answer 1

5 )Activation of CTL and B cells lead to release of chemoattractant cytokinesis which in turn amplify the the inflammatoy signal by attracting additional immune cells.

APC cells are vital for effective adaptive immune response, as functioning of both cytotoxic and helper T cell is dependent on APCs.

6) Innate defense system is old and is passed on to us since birth. Adaptive system is more new and can mold itself new immune antigens. The adaptive system is dependent on the innate system to act and form memory. If the interaction between the two goes wrong many immunological defects and diseases arise, eg. rejection of grafts during transplantation.

7) ploysaccharides, DNA and lipids can elicit immune response if they are attached with a peptide.

In this case mo memory shall be formed as it happens during peptide antigen.

8) Each IgM signifies the type of antigen in body fluids.