Question

1.1 Explain the principles of serological reactions in gels. (for 5 marks)
1.2 Discuss the processing and presentation of antigens by phagocytes. (for 10 marks)

Answer 1

Answer 1.1: Many diagnostic and research evaluations are based upon the serological reactions in the gels. These reactions are based upon the facts and principles as discussed below:

1. The gels are themselves non-immunological in nature, hence do not interfere with the antigen-antibody reaction
2. The gels pose as an appropriate medium for movement of both antigens and antibodies, hence serves as a suitable medium for their migration and interaction
3. The antigen-antibody reaction is independent of the medium it takes place in
4. The antigen-antibody reaction produces a visible product/digest in the gel which can be distinguished from the other parts of the plate as positive

Answer 1.2: The antigen processing and presentation represents one of the major events of cell-mediated immune response in the body. The antigens which are attacked by the cellular arm of the immune system are first encountered by the phagocytes. The phagocytes ingulf these cells and digest them into smaller monomers by hydrolyzing them in their hydrolyzing chambers. This causes generation of multiple monomers of the antigen. These monomers of the antigens are then transferred to the membrane of the receptor on the same cell duly holded by a suitable receptor. This antigen monomer is then presented to the cytotoxic cell or intermediate immune cell for further necessary action.