Fragment crystallizable region: Difference between revisions

Latest revision as of 17:32, 18 February 2025

Section of an antibody that interacts with cell surface receptors and some proteins of the complement system

The Fragment crystallizable region (Fc region) is a crucial part of an antibody that interacts with cell surface receptors and some proteins of the complement system. This region plays a significant role in the immune response by mediating various effector functions.

Structure[edit]

The Fc region is located at the tail end of the antibody molecule, opposite the antigen-binding fragment (Fab region). It is composed of two heavy chains that form a dimer, creating a Y-shaped structure. The Fc region is responsible for the antibody's ability to communicate with the immune system.

Diagram of an antibody showing the Fc region.

Function[edit]

The primary function of the Fc region is to bind to Fc receptors on the surface of various immune cells, such as macrophages, neutrophils, and natural killer cells. This binding triggers a range of immune responses, including:

Phagocytosis: The process by which cells engulf and digest pathogens and debris.
Antibody-dependent cellular cytotoxicity (ADCC): A mechanism through which immune cells can kill target cells that are coated with antibodies.
Complement activation: The Fc region can initiate the complement cascade, leading to the lysis of pathogens.

Types of Fc Receptors[edit]

Fc receptors are classified based on the type of antibody they bind to. The main classes include:

Fc_ receptors: Bind to IgG antibodies and are involved in phagocytosis and ADCC.
Fc_ receptors: Bind to IgE antibodies and are involved in allergic responses.
Fc_ receptors: Bind to IgA antibodies and play a role in mucosal immunity.

Clinical Significance[edit]

The interaction between the Fc region and Fc receptors is a target for therapeutic interventions. Monoclonal antibodies designed to treat various diseases often have modified Fc regions to enhance their efficacy or reduce adverse effects. For example, altering the glycosylation pattern of the Fc region can improve the antibody's ability to engage with Fc receptors.

Related pages[edit]

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-'''Fragment crystallizable region''' ('''Fc region''') is a crucial part of an [[antibody]] molecule, playing a significant role in the immune response. The Fc region is located at the tail region of an antibody and is composed of the constant regions of heavy chains. Unlike the variable region of the antibody that determines antigen specificity, the Fc region is involved in various effector functions, such as recruitment of immune cells, complement activation, and mediation of antibody-dependent cellular cytotoxicity (ADCC).
+{{Short description|Section of an antibody that interacts with cell surface receptors and some proteins of the complement system}}
-==Structure and Function==
+The '''Fragment crystallizable region''' ('''Fc region''') is a crucial part of an [[antibody]] that interacts with cell surface receptors and some proteins of the [[complement system]]. This region plays a significant role in the immune response by mediating various effector functions.
-The Fc region is composed of two heavy chains that contribute to the Y-shaped structure of an antibody. This region is highly conserved across different antibodies, allowing it to interact with various [[Fc receptors]] (FcRs) present on the surface of immune cells. The interaction between the Fc region and FcRs plays a pivotal role in the immune response, facilitating processes such as phagocytosis, immune complex clearance, and modulation of antibody production.
-===Effector Functions===
+==Structure==
-* '''Phagocytosis:''' The Fc region can bind to Fc receptors on phagocytes, leading to the engulfment and destruction of the antigen-antibody complex.
+The Fc region is located at the tail end of the [[antibody]] molecule, opposite the [[antigen-binding fragment]] (Fab region). It is composed of two heavy chains that form a dimer, creating a Y-shaped structure. The Fc region is responsible for the antibody's ability to communicate with the immune system.
-* '''Complement Activation:''' Certain classes of antibodies can activate the [[complement system]] via their Fc regions, resulting in the lysis of target cells or pathogens.
-* '''Antibody-dependent Cellular Cytotoxicity (ADCC):''' The Fc region can also interact with natural killer (NK) cells, triggering the release of cytotoxic molecules that lead to the destruction of target cells.
-==Clinical Applications==
+[[File:Antibody.svg|thumb|right|Diagram of an antibody showing the Fc region.]]
-The Fc region's ability to mediate various immune responses has been exploited in the development of therapeutic antibodies. Modifications to the Fc region can enhance or diminish antibody effector functions, making it possible to tailor antibody therapies for specific diseases. For example, in cancer therapy, antibodies with enhanced ADCC activity can be designed to more effectively target and destroy tumor cells.
-==Engineering and Modifications==
+==Function==
-Advances in biotechnology have enabled the engineering of antibodies with modified Fc regions to improve their therapeutic efficacy and reduce immunogenicity. Such modifications include changes in glycosylation patterns or amino acid substitutions, which can alter the affinity of antibodies for Fc receptors and complement proteins.
+The primary function of the Fc region is to bind to [[Fc receptors]] on the surface of various immune cells, such as [[macrophages]], [[neutrophils]], and [[natural killer cells]]. This binding triggers a range of immune responses, including:
-==Conclusion==
+* '''Phagocytosis''': The process by which cells engulf and digest pathogens and debris.
-The Fc region of an antibody plays a vital role in the immune response by mediating various effector functions. Its interaction with Fc receptors on immune cells facilitates a wide range of immune responses, from phagocytosis to the activation of the complement system. The ability to engineer the Fc region has significant implications for the development of antibody-based therapies, offering the potential for more effective treatments for a variety of diseases.
+* '''Antibody-dependent cellular cytotoxicity (ADCC)''': A mechanism through which immune cells can kill target cells that are coated with antibodies.
+* '''Complement activation''': The Fc region can initiate the [[complement cascade]], leading to the lysis of pathogens.
+==Types of Fc Receptors==
+Fc receptors are classified based on the type of antibody they bind to. The main classes include:
+* '''Fc_ receptors''': Bind to [[IgG]] antibodies and are involved in phagocytosis and ADCC.
+* '''Fc_ receptors''': Bind to [[IgE]] antibodies and are involved in allergic responses.
+* '''Fc_ receptors''': Bind to [[IgA]] antibodies and play a role in mucosal immunity.
+==Clinical Significance==
+The interaction between the Fc region and Fc receptors is a target for therapeutic interventions. Monoclonal antibodies designed to treat various diseases often have modified Fc regions to enhance their efficacy or reduce adverse effects. For example, altering the glycosylation pattern of the Fc region can improve the antibody's ability to engage with Fc receptors.
+==Related pages==
+* [[Antibody]]
+* [[Antigen-binding fragment]]
+* [[Fc receptor]]
+* [[Complement system]]
 [[Category:Immunology]]
-[[Category:Proteins]]
-{{Immunology-stub}}
-<gallery>
-File:Fragment_crystallizable_region_2fab_fc.svg|Fragment crystallizable region 2fab fc
-File:F_ab2_pFc.png|F ab2 pFc
-</gallery>