THE ADAPTIVE IMMUNE SYSTEM

II. HUMORAL IMMUNITY

B. WAYS THAT ANTIBODIES HELP TO DEFEND THE BODY

9. Immobilization of Bacteria and Protozoans

Fundamental Statements for this Learning Object:

1. Flagella and cilia are organelles of locomotion and enable motile microorganisms to move towards or away from environmental molecules through a process called taxis.
2. Antibodies are made against the flagella of motile bacteria or the flagella or cilia of motile protozoans.
3.  The Fab portions of the antibodies bind to these locomotor organelles and arrest the organism's movement blocking its ability to spread.

 

LEARNING OBJECTIVES FOR THIS SECTION

Humoral Immunity refers to the production of antibody molecules in response to an antigen (def). These antibody molecules circulate in the plasma of the blood and enter tissue and organs via the inflammatory response. Humoral immunity is most effective microbes or their toxins located in the extracellular spaces of the body.

Antibodies or immunoglobulins (def) are specific glycoprotein configurations produced by B-lymphocytes and plasma cells in response to a specific antigen and capable of reacting with that antigen.

The antibodies produced during humoral immunity ultimately defend the body through a variety of different means. These include:

1. Opsonization
2. MAC Cytolysis
3. Antibody-dependent Cellular Cytotoxicity (ADCC) by NK Cells
4. Neutralization of Exotoxins
5. Neutralization of Viruses
6. Preventing Bacterial Adherence to Host Cells
7. Agglutination of Microorganisms
8. Immobilization of Bacteria and Protozoans
9. Promoting an Inflammatory Response

In this section we will look at immobilization of bacteria and protozoans.

9. Immobilization of Bacteria and Protozoans

Flagella and cilia are organelles of locomotion and enable motile microorganisms to move towards or away from environmental molecules through a process called taxis (def). The mucosal surfaces of the bladder and the intestines constantly flush bacteria away in order to prevent colonization. Motile bacteria that can swim chemotactically toward mucosal surfaces may have a better chance to make contact with the mucous membranes, attach, and colonize.

For More Information: Bacteria Using Motility to Contact Host Cells from Unit 3

 

Antibodies are made against the flagella of motile bacteria or the flagella or cilia of motile protozoans. The Fab portions of the antibodies bind to these locomotor organelles and arrest the organism's movement blocking its ability to spread.

Concept Map for Ways in which Antibodies Protect the Body

 

• QUIZ YOURSELF ON THIS SECTION

Gary E. Kaiser, Ph.D.
Professor of Microbiology
The Community College of Baltimore County, Catonsville Campus
This work is licensed under a Creative Commons Attribution 4.0 International License.
Based on a work The Grapes of Staph at https://cwoer.ccbcmd.edu/science/microbiology/index_gos.html.