Difference Between Opsonization and Neutralization

The key difference between opsonization and neutralization relies on the way they perform the immunological response. In opsonization, the pathogens are marked prior to being destroyed while in neutralization, the effect of the pathogen is neutralized.

Immunologic responses can be innate or adaptive. Pathogens possess pathogen recognition receptors, which make it easier to be identified by the host. In opsonization, the host produces opsonins. However, in neutralization, the host produces neutralizing antibodies to neutralize the effect of the antibody-antigen reaction.

CONTENTS

1. Overview and Key Difference
2. What is Opsonization 
3. What is Neutralization
4. Similarities Between Opsonization and Neutralization
5. Side by Side Comparison – Opsonization vs Neutralization in Tabular Form
6. Summary

What is Opsonization?

Opsonization is the process which removes pathogens from the system upon being marked by means of opsonins. Opsonins are molecules that can recognize pathogens. Pathogens possess pathogen recognition receptors. Moreover, opsonins are present in phagocytes and participate in recognizing pathogen recognition receptors. Some examples of opsonins are receptors such as Fc receptor and complement receptor 1 (CR1), etc. Opsonins also have the capability to induce the complement pathway and activate phagocytosis.

Figure 01: Opsonization

Opsonins bind to the epitope of a pathogen. When the opsonins bind to the pathogen, the phagocytes attract to the pathogen and facilitate phagocytosis. Opsonization can also activate adaptive immune responses. In this regard, the antibody IgG binds to the opsonized pathogen. Thus, this allows the antibody-dependent cell-mediated cytotoxicity in cells. In the absence of opsonins, inflammation can take place and damage healthy tissues during infection.

What is Neutralization?

In immunology, neutralization means neutralizing the effect of an antigen by an antibody. The antibodies that participate in these reactions are called neutralizing antibodies. The diphtheria antitoxin is a neutralizing antibody that can neutralize the biological effects of the diphtheria toxin. Therefore, these antibodies neutralize the effect and destroy the antigen consequently.

Figure 02: Neutralization

These neutralizing antibodies are placed at the tips of Y shaped antibody molecules. These antibodies are also stickier than normal antibodies. They are also called broadly neutralizing antibodies as they affect multiple strains of particular viruses.

What are the Similarities Between Opsonization and Neutralization?

  • Opsonization and neutralization are immunologic responses.
  • Both have the ability to activate the complement pathways.

What is the Difference Between Opsonization and Neutralization?

Opsonization is the process of removing pathogens by marking with the opsonins while neutralization is the process of removing the effect of an antigen by binding with a neutralizing antibody. So, this is the key difference between opsonization and neutralization.

The below infographic summarizes the difference between opsonization and neutralization.

Summary – Opsonization vs Neutralization

Opsonization and neutralization are two important reactions in immunology. Production of opsonins takes place in opsonization. In contrast, the production of neutralizing antibodies takes place in neutralization to neutralize the effect of the antigen. Opsonization activates the complement system. Moreover, both act on the adaptive immune system of the body. However, opsonization activates phagocytes to destroy the pathogen. In contrast, neutralization reactions neutralize the effect of antibody-antigen reactions. Therefore, this is the summary of the difference between opsonization and neutralization.