GIDEON blog

Try it Free Latest Updates Video Tutorials
Subscribe , j

Archive for the ‘Therapy’ Category

Antigen vs antibody – what is the difference?

Antigen vs antibody - 3D illustration
3D illustration of antigen in the human body

 

What is the difference between antigen vs antibody, and what role do they play in creating an effective vaccine? With the recent focus on the development of a COVID-19 vaccine there has been much talk of antigens and antibodies, often interchangeably, and little clarity on what they are – or the role they play in creating an effective vaccine. In this blog, we’ll cut through the jargon and discover the facts together.

Antigen

An antigen is any substance or organism that is unrecognized by our immune system. It could be anything from bacteria to chemicals, to viruses … or even foods [1]. Antigens typically trigger an immune response, which may consist of an antibody (more on that later), and are classified by their origins [2]:

  • Exogenous: entering from outside the body
  • Endogenous: generated from within
  • Autoantigens: proteins targeted in autoimmune diseases
  • Neoantigens (or tumor antigens): resulting from tumor cells.
  • Native antigens: An antigen which will later be processed by an antigen-presenting cell

In some cases, these main types have subtypes – but we won’t get into an immunology lecture today. An antigen-presenting cell is a cell that processes and then presents the antigen to T-cells (a form of white blood cells), which can then ‘handle’ the antigen, often by killing the offending cell [3].

Your immune system has “memory” which allows the system to deal with the offending antigen much more quickly and efficiently the next time it is encountered.  Vaccines are designed to simulate that first encounter with an antigen and create a robust memory in case the offending agent reappears in the future. [4].

The importance of vaccines is covered in more detail here, but in short, antigens themselves are crucial in the development of vaccines. Generally, the vaccine consists of a potentially hostile antigen, in a very weak or inactive form.

Antibody

Antibodies are proteins that bind with the antigen in order to neutralize the latter – or make other elements of the immune system “aware” of their presence.  Antibody-producing cells are specifically designed to tackle one type of antigen; and your blood, bone marrow, lymph glands, and spleen will contain millions of them to ensure that every known antigen will be confronted by a corresponding antibody  [5].

Antibodies are secreted by B leukocytes (a form of white blood cell) and circulate in blood plasma either freely or attached to the surface of a B cell.  The B and T cells work in unison to identify and locate antigens, create the correct antibodies, and capture (kill/neutralize) the antigen [6].

A vaccine, by exposing the immune system to a new antigen, will “teach” antibodies the correct format in which to capture or tag that antigen.  When the actual disease antigen later enters the body, the immune system will rapidly respond with minimal discomfort and inconvenience.

Effective vaccination needs both

To summarize – an antigen is a disease agent (virus, toxin, bacterium parasite, fungus, chemical, etc) that the body needs to remove, and an antibody is a protein that binds to the antigen to allow our immune system to identify and deal with it.

Woman with adhesive bandage on her shoulder
Antigens and antibodies work in tandem when vaccinating

 

Don’t take this all for granted, though. As impressive as our immune system is, it’s far from perfect and needs our assistance to prevent harmful antigens from entering the body – through hand washing, face masks, and social distancing. Look after your body and it will look after you!

Did you like this article? Share it on social media!

Check out our latest content here

Want to learn more about vaccines? We’ve got a great ebook for you – GIDEON Guide to Vaccines and Globulin Preparations

References:

[1] M. Encyclopedia, “Antigen: MedlinePlus Medical Encyclopedia”, Medlineplus.gov, 2020. [Online]. Available: https://medlineplus.gov/ency/article/002224.htm

[2] “Antigens | Boundless Anatomy and Physiology”, Courses.lumenlearning.com. [Online]. Available: https://courses.lumenlearning.com/boundless-ap/chapter/antigens/. 

[3] T. Kambayashi and T. Laufer, “Atypical MHC class II-expressing antigen-presenting cells: can anything replace a dendritic cell?”, Nature Reviews Immunology, vol. 14, no. 11, pp. 719-730, 2014. Available: 10.1038/nri3754 

[4] A. Abbas, A. Lichtman and S. Pillai, Cellular and molecular immunology, 9th ed. Philadelphia: Elsevier, 2018, p. 97.

[5] C. Janeway, Immunobiology 5: the immune system in health and disease, 5th ed. Garland Publishing.

[6] L. Borghesi and C. Milcarek, “From B Cell to Plasma Cell: Regulation of V(D)J Recombination and Antibody Secretion”, Immunologic Research, vol. 36, no. 1-3, pp. 27-32, 2006. Available: 10.1385/ir:36:1:27

Reference links in Drugs and Vaccines

Reference links have arrived to the GIDEON Therapy related modules: Drugs and Vaccines.

Every drug and vaccine includes relevant clickable reference numbers that link to relevant source abstracts in peer-reviewed journals.

 

For example:

2014 series of GIDEON eBooks

The 2014 GIDEON ebook series has been released.

This edition incorporates all content added since publication of the last series. Country-series eBooks now include the vaccination schedules for every reporting country as an extra chapter.
Additionally, four new volumes have been added to the series.

Titles now include:

Country series (231 volumes)
Disease series (188 volumes)
GIDEON Guide to Antimicrobial Agents
GIDEON Guide to Vaccines
GIDEON Guide to Medically Important Bacteria
GIDEON Guide to Medically Important Yeasts

The four newer titles incorporate content from GIDEON’s Drugs, Vaccines, Bacteria, Mycobacteria and Yeasts modules. These and all other eBooks in the series are updated annually

These ebooks are available on the GIDEON eBooks website as well as through distributors such as EBSCO and Ingram.

Compare diseases, drugs or pathogens

One of the most important functions of GIDEON is to help users prepare scientific articles, teaching material and other publications (see the Fingerprint case of the month). A new feature now allows users to create custom-designed charts which compare the features of two or more diseases, drugs or pathogens.

For comparison of key clinical and epidemiological features of infectious diseases, in the Diseases tab, click on a disease (step 1 in the image below), and – while holding down the control button – click on other diseases of your choice. Now click on the Compare button (step 2).

Choosing diseases to compare
Choosing diseases to compare

(more…)

Linking between modules

We’re continuing our progress in making it easier to find the information you’re looking for in GIDEON with minimal effort. We have added a new feature in the Microbiology module that link relevant organisms to their drug susceptibility and appropriate vaccines as demonstrated by the highlighted links in this screen shot of the Vibrio Cholerae general tab:
Microbiology Vibrio Cholerae information
These new links are in addition to links added in the past connecting between disease organisms to microbiology and typical therapy to drugs, vaccines and pathogens.
For example see the links from the Anthrax disease general information tab screen shot below, to the Microbiology organism (Bacillus anthracis), Therapy (eg: Ciprofloxacin) and Anthrax vaccine:
Anthrax general disease information

Text search enhanced with case and video

You can search for keywords in GIDEON using the text search feature. Searches case of the month provides some examples, available as a video as well.
Search box

Text search launches

GIDEON has always emphasized ease of use by allowing complete usage without any need for a keyboard by only using a mouse. Today we broke our rule to enable text search through GIDEON. As search has become more popular, it has become the user experience many people feel comfortable with when using the web.

Search will initially display results from our Epidemiology and Therapy modules and will extend to all content in GIDEON, including Diagnosis. See how easy it is to search with GIDEON.

GIDEON Sign In