Figure 1.

Inflammatory response to harmful stimuli. When tissue or cellular damage occurs, danger-associated molecular patterns (DAMPS), pathogen associated molecular patterns (PAMPs) and myriad inflammatory cytokines (TNFα, IL-1β, IL-6, IL-8) are released. These biomolecules can initiate activation of inflammatory pathways resulting in leukocyte recruitment of innate and adaptive immunity, thus establishing a highly coordinated network of many cell types. Activated macrophages, together with damaged endothelial cells, release factors that attract neutrophils and monocytes to the site of inflammation. This represents the first line of defense characterized mostly by phagocytosis and NETosis. Macrophages, together with mature dendritic cells (DCs), are specialized in exposing antigens to lymphocytes (T and B cells), thereby activating antigen-specific adaptive immunity. Lymphocyte differentiation leads to T cell-mediated cytotoxicity, antibody secretion, and antibody dependent cell cytotoxicity (ADCC). Simultaneously, cytokines trigger synthesis and secretion of acute phase proteins from the liver. CTL, cytotoxic T lymphocytes; FDC, follicular dendritic cells; Mφ, macrophage; Mo, monocyte; NK cell, natural killer cell.