Principals of innate and adaptive immunity. Immunity to microbes & fundamental concepts in immunology

Microorganisms such as bacteria that penetrate the epithelial surfaces of body for first time are met immediately by cells and molecules can mount an innate immune response. Phagocytic macrophages conduct defense against means surface receptors able to recognize bind common constituents many bacterial surfaces. Bacterial binding these trigger macrophage engulf bacterium also induce secretion biologically active molecules. Activated secrete cytokines, which defined proteins released affect behavior other bear them. They release known chemokines attract with chemokine neutrophils monocytes from bloodstream. Macrophages in response initiate process inflammation. Antigen-presenting (APCs) a heterogeneous group mediate cellular processing presenting antigens recognition certain lymphocytes T cells. Classical APCs include dendritic cells, macrophages, Langerhans B Innate lymphoid (ILCs) belong lineage but do not express antigen-specific receptors. These have important functions responses infectious microorganisms regulation homeostasis