cellular response to molecule of bacterial origin

Definition

Target type: biologicalprocess

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a stimulus by molecules of bacterial origin such as peptides derived from bacterial flagellin. [GOC:mah]

Cellular response to molecules of bacterial origin is a complex and multifaceted process that involves a coordinated effort by the host's innate and adaptive immune systems to detect, neutralize, and eliminate invading bacteria. The process begins with the recognition of bacterial components by pattern recognition receptors (PRRs) expressed on the surface of various immune cells, such as macrophages, neutrophils, and dendritic cells. These PRRs recognize conserved molecular patterns, known as pathogen-associated molecular patterns (PAMPs), which are unique to bacteria and absent in host cells. Examples of PAMPs include lipopolysaccharide (LPS) found in the outer membrane of Gram-negative bacteria, peptidoglycan (PGN) present in the cell wall of both Gram-positive and Gram-negative bacteria, flagellin from bacterial flagella, and bacterial DNA. Upon recognition of PAMPs, PRRs trigger downstream signaling pathways that activate transcription factors, leading to the production of inflammatory cytokines and chemokines. These signaling pathways involve various signaling molecules, including Toll-like receptors (TLRs), NOD-like receptors (NLRs), and RIG-I-like receptors (RLRs). The production of inflammatory cytokines, such as TNF-α, IL-1β, and IL-6, initiates the recruitment of immune cells to the site of infection and promotes inflammation. Chemokines, such as CXCL8, attract neutrophils and other immune cells to the site of infection. Once at the site of infection, neutrophils and macrophages phagocytose and destroy bacteria. Neutrophils release antimicrobial peptides and reactive oxygen species (ROS) that kill bacteria. Macrophages also present bacterial antigens to T cells, initiating the adaptive immune response. The adaptive immune response involves the activation of T cells and B cells, which specifically recognize and target bacterial antigens. T cells differentiate into helper T cells (Th1 and Th17) and cytotoxic T cells (CTLs). Th1 cells produce cytokines that activate macrophages and CTLs. Th17 cells produce cytokines that recruit neutrophils. CTLs directly kill infected cells. B cells differentiate into plasma cells, which produce antibodies that bind to bacteria and neutralize their ability to infect cells. These antibodies also opsonize bacteria, making them more susceptible to phagocytosis. The cellular response to molecules of bacterial origin is a crucial mechanism for protecting the host from bacterial infections. However, excessive or inappropriate immune responses can lead to tissue damage and disease.'
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Proteins (1)

Compounds (36)