Humoral Immune Response
First encounter between an immunocompetent lymphocyte and antigen (the antigen challenge) usually takes place in spleen or lymph nodes. If the lymphocyte is a B cell humoral immune response.
B cells are stimulated to complete its differentiation when antigens bind to its surface quickly followed by endocytosis of receptor-antigen complex this triggers clonal selection (the process of stimulating B cell to grow and multiply rapidly to be exactly like itself with the same antigen specific receptors).
This process of proliferation and differentiation is the primary immune response that occurs on the first exposure to a particular antigen – there is a lag period of 3-6 days after the antigen challenge (time for differentiation and proliferation) plasma levels of antibodies levels increase, peak at about 10 days, then gradually decline.
On re-exposure to the same antigen secondary immune response (does not matter how many subsequent exposures) – this is faster than primary response due to immunological memory.
Characteristic of the immune response:
• Specificity – triggered by specific antigens
• Diversity – can respond to wide range of antigens
• Memory – re-exposure can produce a more intense response
• Selectivity – normally only targets foreign antigens and not self