Pentraxins: Difference between revisions

Latest revision as of 03:43, 13 February 2025

Pentraxins[edit]

Pentraxins are a family of proteins characterized by their cyclic multimeric structure. They play a crucial role in the innate immune system by recognizing pathogens and damaged cells, thereby facilitating their clearance. The most well-known members of this family are C-reactive protein (CRP) and serum amyloid P component (SAP).

Structure[edit]

Pentraxins are defined by their pentameric structure, which is a ring-like arrangement of five identical subunits. This structure is stabilized by non-covalent interactions. The pentraxin domain is highly conserved and is responsible for calcium-dependent ligand binding. The structure of CRP, for example, reveals a discoid shape with a central pore, which is typical of pentraxins.

Function[edit]

Pentraxins are involved in the acute phase response, a rapid inflammatory response to tissue injury or infection. They function as pattern recognition molecules, binding to specific molecular patterns on the surface of pathogens or apoptotic cells. This binding activates the complement system and promotes phagocytosis by macrophages and neutrophils.

C-reactive protein (CRP)[edit]

CRP is a major acute-phase protein in humans. It is synthesized by the liver in response to cytokines such as interleukin-6 (IL-6). CRP levels in the blood increase rapidly during inflammation, making it a useful clinical marker for inflammatory diseases and infection.

Serum amyloid P component (SAP)[edit]

SAP is another pentraxin that is involved in the clearance of cellular debris and the inhibition of amyloid fibril formation. It is found in all vertebrates and is highly conserved across species.

Clinical Significance[edit]

The measurement of CRP levels is commonly used in clinical practice to assess the presence and intensity of inflammation. Elevated CRP levels are associated with a variety of conditions, including bacterial infections, autoimmune diseases, and cardiovascular disease.

Related pages[edit]

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-'''Pentraxins''' are a family of multifunctional, conserved proteins that play key roles in the immune system. They are characterized by a cyclic multimeric structure and are classified based on their primary structure into short and long pentraxins. Pentraxins act as pattern recognition molecules in the innate immune response, binding to pathogens and damaged cells, and initiating their removal through phagocytosis or complement activation.
+== Pentraxins ==
-==Classification==
+[[File:CRP_pretty.png|thumb|right|Structure of C-reactive protein (CRP), a member of the pentraxin family.]]
-Pentraxins are divided into two main classes: short and long pentraxins.
-* '''Short Pentraxins:''' The prototypical members of this class are C-reactive protein (CRP) and serum amyloid P component (SAP). These proteins are produced primarily by the liver in response to inflammatory cytokines.
+Pentraxins are a family of [[proteins]] characterized by their cyclic multimeric structure. They play a crucial role in the [[innate immune system]] by recognizing pathogens and damaged cells, thereby facilitating their clearance. The most well-known members of this family are [[C-reactive protein]] (CRP) and [[serum amyloid P component]] (SAP).
-* '''Long Pentraxins:''' This class includes Pentraxin 3 (PTX3), which is produced by various cell types, including endothelial cells, fibroblasts, and immune cells, in response to pro-inflammatory signals.
-==Structure==
+== Structure ==
-Pentraxins are characterized by a pentameric structure, which is crucial for their ability to bind ligands. Each monomer in the pentamer is composed of a conserved pentraxin domain. Long pentraxins have an extended N-terminal domain in addition to the common pentraxin domain.
-==Function==
+Pentraxins are defined by their pentameric structure, which is a ring-like arrangement of five identical subunits. This structure is stabilized by non-covalent interactions. The pentraxin domain is highly conserved and is responsible for calcium-dependent ligand binding. The structure of CRP, for example, reveals a discoid shape with a central pore, which is typical of pentraxins.
-Pentraxins play a crucial role in the innate immune response. They are involved in:
-* '''Pathogen Recognition:''' Pentraxins can recognize and bind to microbial pathogens, facilitating their opsonization and removal.
+== Function ==
-* '''Complement Activation:''' By binding to pathogens, pentraxins can activate the complement system, leading to the lysis of the pathogen.
-* '''Modulation of Inflammation:''' Pentraxins can influence the inflammatory response by interacting with immune cells and affecting their function.
-* '''Tissue Repair:''' Long pentraxins, in particular, have been implicated in tissue remodeling and repair processes.
-==Clinical Significance==
+Pentraxins are involved in the [[acute phase response]], a rapid inflammatory response to tissue injury or infection. They function as pattern recognition molecules, binding to specific molecular patterns on the surface of pathogens or apoptotic cells. This binding activates the [[complement system]] and promotes [[phagocytosis]] by [[macrophages]] and [[neutrophils]].
-Pentraxins are biomarkers for various diseases due to their role in inflammation and immune response.
-* '''Inflammatory Diseases:''' Elevated levels of CRP and PTX3 are associated with inflammatory conditions, such as rheumatoid arthritis and systemic lupus erythematosus.
+=== C-reactive protein (CRP) ===
-* '''Cardiovascular Diseases:''' CRP levels are used as a marker for cardiovascular risk assessment, as they can indicate underlying inflammation in the vascular system.
-* '''Infection:''' High levels of pentraxins can indicate an ongoing infection, as they are part of the acute phase response.
-==Research Directions==
+CRP is a major acute-phase protein in humans. It is synthesized by the [[liver]] in response to [[cytokines]] such as [[interleukin-6]] (IL-6). CRP levels in the blood increase rapidly during inflammation, making it a useful clinical marker for [[inflammatory diseases]] and [[infection]].
-Research on pentraxins is focused on understanding their role in disease and their potential as therapeutic targets. For example, targeting pentraxins in diseases characterized by excessive inflammation or in cancer to modulate the immune response.
+=== Serum amyloid P component (SAP) ===
+SAP is another pentraxin that is involved in the clearance of cellular debris and the inhibition of [[amyloid fibril]] formation. It is found in all vertebrates and is highly conserved across species.
+== Clinical Significance ==
+The measurement of CRP levels is commonly used in clinical practice to assess the presence and intensity of inflammation. Elevated CRP levels are associated with a variety of conditions, including [[bacterial infections]], [[autoimmune diseases]], and [[cardiovascular disease]].
+== Related pages ==
-==See Also==
 * [[Innate immune system]]
-* [[C-reactive protein]]
+* [[Acute phase response]]
 * [[Complement system]]
-* [[Inflammation]]
+* [[Phagocytosis]]
-==References==
-<references/>
 [[Category:Immunology]]
 [[Category:Proteins]]
-{{Medicine-stub}}