Final answer:
To determine which type of immune response will be stimulated, one must consider the antigen's characteristics and how it is recognized by B cells and T cells. The adaptive immune system, through its vast receptor diversity, initiates specific responses (clonal expansion and clonal selection) against the pathogen introduced.
Step-by-step explanation:
How to Determine Which Type of Immune Response Will Be Stimulated The type of immune response stimulated by an antigen is influenced by factors such as the antigen's molecular class, complexity, and size. There are two main types of specific immune responses, which involve either B cells or T cells, both key white blood cells in the immune system. The adaptive immune response, which includes both B cell (humoral) and T cell (cell-mediated) branches, takes days or weeks to establish. It is more specific than the innate immune system.
T cell-mediated immune responses are triggered when T cells recognize processed foreign antigens associated with self-MHC molecules, leading to clonal expansion and a specific response against the presenting pathogen. B cells, on the other hand, when stimulated by a TH2 pathway, differentiate into antibody-secreting plasma cells in a process known as clonal selection.
The specificity of the adaptive immune system is due to its ability to develop an incredible variety of receptors through a process that allows for up to 10^11 different receptor types. This diversity ensures that the immune system can recognize and respond to a vast array of pathogens.
Cell-mediated immune responses involve TH1 cells and macrophages, targeting intracellular pathogens and associated with inflammation, while humoral immune responses involve B cells and antibodies targeting extracellular pathogens.