Figure 1.

Responses involved in innate and adaptive immunity. Fast and nonspecific responses, occurring against all factor identified as nonself, are involved in innate immunity; conversely, adaptive immunity is a highly specific, complex and slow response mediated by T and B lymphocytes, which release antigen-specific antibodies and cytokines. Immunomodulators can directly affect innate and adaptive response or the factors involved, thus leading to immunostimulant or immunosuppressive effects.