What type of immune response is triggered specifically by the presence of an antigen?

The adaptive immune response is specifically triggered by the presence of an antigen. This type of immune response is characterized by its ability to recognize and remember specific pathogens, leading to a targeted and efficient response. When an antigen enters the body, it is detected by specialized cells called antigen-presenting cells, which process and present the antigen to lymphocytes, including B cells and T cells.

B cells can produce antibodies that bind to the antigen, marking it for destruction or neutralization. T cells can directly attack infected cells or assist other immune cells in mounting a response. This process results in the formation of memory cells, which ensure a faster and more robust response if the same antigen is encountered again in the future.

In contrast, while cell-mediated immunity is a component of the adaptive immune response, it specifically refers to the role of T cells in targeting infected cells. The innate immune response, on the other hand, provides a general, non-specific defense against pathogens immediately upon their entry, without the ability to recognize specific antigens. The inflammatory response is a part of the innate immune response characterized by the accumulation of immune cells and molecules at the site of infection or injury, but it does not involve the specific targeting of antigens like the adaptive response does.