Related Experiment Video
Updated: Jun 19, 2026
06:17
Depletion of Specific Cell Populations by Complement Depletion
Published on: February 5, 2010
Complement: coming full circle.
Gaëlle Le Friec1, Gaëlle Le Friec, Claudia Kemper
1King's College London, MRC Centre for Transplantation, London SE1 9RT, UK.
Archivum Immunologiae Et Therapiae Experimentalis
|October 30, 2009
Summary
The complement system, a key part of innate immunity, also regulates adaptive immunity and immune homeostasis. This review explores its expanded role beyond pathogen defense.
Area of Science:
- Immunology
- Innate Immunity
- Adaptive Immunity
Background:
- The complement system is traditionally viewed as a crucial component of innate immunity, responsible for pathogen elimination through opsonization, phagocytosis, and direct lysis.
- Emerging evidence highlights the complement system's significant involvement in modulating adaptive immune responses, including B- and T-cell activation and lineage commitment.
Purpose of the Study:
- To provide a concise overview of the evolving understanding of the complement system's functions.
- To illustrate the complement system's transition from a basic defense mechanism to a critical regulator of overall immune homeostasis and acquired immunity.
Main Methods:
- Literature review
- Synthesis of current research on complement system functions
- Analysis of the complement system's role in both innate and adaptive immunity
Main Results:
- The complement system is essential for effective adaptive immune responses, including the contraction phase.
- Complement plays a vital role in immune homeostasis, maintaining balance within the immune system.
Conclusions:
- The complement system is a multifunctional regulator of immunity, integral to both innate and adaptive responses.
- Understanding the expanded role of complement is crucial for comprehending general immune homeostasis and acquired immunity.
Related Concept Videos
01:27Complement System
The complement system is a group of approximately 20 plasma proteins that strengthen the body's defenses against infections through opsonization, inflammation, and cell lysis. Opsonization involves coating pathogens with complement proteins, making them more recognizable and facilitating phagocyte engulfment. Certain complement proteins induce inflammation that attracts immune cells to the site of infection. Cell lysis involves the destruction of pathogens through the formation of a membrane...
00:49Complementation Tests
A complementation test is a simple cross to identify whether the two mutations are located on the same gene or different genes. It was first performed by Edward Lewis in the 1940s while working on fruit flies. He developed the test to identify the location and arrangement of different mutations on chromosomes.
Organisms heterozygous for different mutations are crossed pairwise in all combinations. If present on different genes, the mutations can complement each other by providing the missing...
Organisms heterozygous for different mutations are crossed pairwise in all combinations. If present on different genes, the mutations can complement each other by providing the missing...
01:26Antibody Actions
Antibodies, or immunoglobulins, are critical players in the immune system's arsenal against invading pathogens. Produced by B cells and plasma cells, their primary role is to detect and bind to specific antigens, molecules found on the surface of pathogens like bacteria or viruses. Beyond antigen recognition, antibodies perform several vital functions that contribute to immune defense.
Neutralization
Antibodies can bind to pathogens, preventing them from infecting host cells. This process...
Neutralization
Antibodies can bind to pathogens, preventing them from infecting host cells. This process...
01:18Principle of Equivalence
According to Albert Einstein (1897-1955), free-falling and feeling weightless are intrinsically linked. If a person were in free-fall under gravity, for example, diving towards the Earth from an airplane, they would feel completely weightless. Similarly, a person descending in a lift may feel partially weightless. Broadly speaking, it is assumed that an object in a uniform gravitational field and an object undergoing constant acceleration in the absence of gravity are under the same...
01:22Consecutive Reactions
Consecutive reactions involve a sequence where the product of a preceding reaction becomes the reactant for the subsequent one. In a simple scheme, A transforms into B, which further reacts to form C, with rate constants k1 and k2, respectively. This concept is evident in the radioactive decay series. Assuming an initial state with only A present, the conservation of matter leads to three coupled differential equations, determining the concentrations of A, B, and C over time.The rate of change...
01:22Amplifying Signals via Enzymatic Cascade
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...