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Related Concept Videos

Complement System01:27

Complement System

4.3K
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...
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Combined Effects of Drugs: Synergism01:27

Combined Effects of Drugs: Synergism

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Synergism is a useful mechanism where combining two or more drugs is more effective than each constituent used alone. Such combinations are also called supra-additive interactions. The drugs collectively enhance the final therapeutic effect by acting on different targets. Another advantage is that the low dose of each constituent drug is sufficient to achieve the desired effect. This helps reduce the duration of therapy and lower the adverse effects of these drugs.
Such synergistic combinations...
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Antimicrobial Proteins01:23

Antimicrobial Proteins

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Antimicrobial proteins are important components of the immune system. They aid the body in combating pathogens by either killing them directly or hindering their replication processes. Four main types of antimicrobial substances are interferons, the complement system, iron-binding proteins, and antimicrobial proteins.
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
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Complementation Tests00:49

Complementation Tests

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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...
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Antibody Actions01:26

Antibody Actions

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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...
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Humoral Immune Responses01:36

Humoral Immune Responses

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Overview
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Related Experiment Video

Updated: Oct 22, 2025

In Vitro Methods for Comparing Target Binding and CDC Induction Between Therapeutic Antibodies: Applications in Biosimilarity Analysis
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In Vitro Methods for Comparing Target Binding and CDC Induction Between Therapeutic Antibodies: Applications in Biosimilarity Analysis

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The case of complement inhibitors.

Marina Noris1

  • 1Istituto di Ricerche Farmacologiche Mario Negri IRCSS, Clinical Research Center for Rare Diseases Aldo e Cele Daccò, Bergamo, Italy.

Advances in Biological Regulation
|August 29, 2021
PubMed
Summary
This summary is machine-generated.

The complement system

Keywords:
COVID-19ComplementComplement inhibitory drugsEndothelial cellsInflammationThrombosis

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Methods for Quantitative Detection of Antibody-induced Complement Activation on Red Blood Cells
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Related Experiment Videos

Last Updated: Oct 22, 2025

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Area of Science:

  • Immunology
  • Virology
  • Pathophysiology

Background:

  • Severe COVID-19 involves lung and multiorgan inflammation and coagulation.
  • Overactivation of the complement system plays a dual role in SARS-CoV-2 infection.
  • While it can control milder infections, massive complement activation in severe cases exacerbates inflammation and thrombosis.

Purpose of the Study:

  • To investigate the role of complement system overactivation in severe COVID-19.
  • To evaluate the efficacy and safety of complement inhibitors in managing severe COVID-19.
  • To determine optimal complement targets for therapeutic intervention in SARS-CoV-2 infection.

Main Methods:

  • Review of uncontrolled studies and controlled clinical trials involving complement inhibitors.
  • Analysis of existing data on complement activation in COVID-19 patients.
  • Ongoing clinical trials investigating various complement inhibitors.

Main Results:

  • Results from complement inhibitor studies in COVID-19 are mixed, with some showing promise and others being negative.
  • Massive complement activation in severe COVID-19 intensifies inflammation and promotes a procoagulant state.
  • The precise benefit-to-risk profile of complement inhibitors remains unclear.

Conclusions:

  • Complement system overactivation significantly contributes to the pathophysiology of severe COVID-19.
  • Complement inhibitors represent a potential therapeutic strategy, but further research is essential.
  • Clarifying the best targets within the complement cascade is crucial for effective treatment of COVID-19.