Question

1-Write short account on the importance of antigen presenting cells in the cell mediated immunity?

2-The immune system kills the pathogens by different mechanisms. Depending on your study of the course, explain these mechanisms?

3-Write short notes on the isohemagglutinins and how they can be used to detect B cell function?

Answer 1

Answer for question no-1

Antigen presenting cell (APC) is a type of immune cells whcih excute the function of pathogen detection ,engulfment and also indicate the threat to the cell mediated immunity. APCs phagocytose the antigen and digest them and forms small pieces of the antigens.The fragmented antigens come on the surface of APC and becomes the indicator for other immune cells.In order to process the antigen, dendritic immune cells come into play to process the antigen and some times works like an APCs. Once the phagocytosis is completed, the vesicles of phagocytosis forms the phagolysosome by fusing with lysosomes. Inside the phagolysosomes, the resultant fragments gets loaded on to the MHC class I and II and get transported back to the surface of APCs.Once MHC I and II present on the surface ,it can identifies the invaders. Therfore, the antigen fragment embedded in the MHC II molecule allows the other immune cells to respond in order to fight off the attack of pathogens.