11.1 Antibody Production and Vaccination

UNDERSTANDINGS• Every organism has unique molecules on the surface of its cells.• Pathogens can be species specific although others can cross species barriers.• B lymphocytes are activated by T lymphocytes in mammals.• Activated B cells multiply to form clones of plasma cells and memory cells.• Plasma cells secrete antibodies.• Antibodies aids the destruction of pathogens.• White cells release histamine in response to antigens.• Immunity depends upon the persistence of memory cells.• Vaccines contain antigens that trigger immunity but do not cause the disease.• Fusion of a tumor call with an antibody-producing plasma cell creates a hybridoma cell.• Monoclonal antibodies are produced by hybridoma cells.

APPLICATIONS/SKILLS• A: Smallpox was the first infectious disease of humans to have been eradicated by vaccination.• A: Monoclonal antibodies to HCG are used in pregnancy tests.• A: Antigens on the surface of red blood cells stimulate antibody production in a person with a different blood group.• S: Analysis of epidemiological data related to vaccination programs.GuidanceLimit the immune response to mammals.

Immune Response Macrophage encounters a pathogen and engulfs it

Pieces of the pathogen are displayed on the cell membrane of the macrophage (antigen presentation)

Helper T cells become activated, changing the immune response from non-specific to specific.

http://www.nobelprize.org/educational/medicine/immunity/immune-detail.html

Immune Response Helper T cells activate the specific B cell type that is able to produce the specific antibody needed. Activated B cell begins cell cloning.

◦ Plasma cells: secrete antibodies to help fight of primary infection◦ Memory cells: long lived cells circulating in the blood waiting for secondary infection

http://www.nobelprize.org/educational/medicine/immunity/immune-detail.html

Primary Immune Response and True Immunity

Primary immune response occurs during the first encounter with a pathogen

Takes time; associated with symptoms (depends on the pathogen)

If a second infection of the same pathogen occurs, memory cells are capable of responding quickly

Little to no symptoms

Antibodies Antibodies are proteins produced by leucocytes in response to a specific pathogen

Y shaped

At the ends of the Y are two sequences of amino acids that are unique to the type of antibody

These are the binding sites

http://www.di.uq.edu.au/sparq/images/antibody.jpg

Antibodies Antibodies bind to pathogens and mark them for destruction

Can use the two binding sites to bind to two antigens causing antigens to bind together

Leads to clumps of pathogens (agglutination)

This helps phagocytic cells find the pathogens more easily

http://4.bp.blogspot.com/-jBbIGtBmxGQ/Ta3UesLcLnI/AAAAAAAABMo/Xwvi5Tfn6OA/s1600/monoclonal+antibodies.jpg

Blood Types ABO blood type is based on the presence/absence of the A protein or B protein.

◦ A protein= Type A◦ B protein= Type B◦ Both= Type AB ◦ Neither= Type O

Rh factor is based on the presence/absence of Rh protein.

◦ Has Rh protein= Rh+◦ No Rh protein= Rh-

Blood Types If a person receives blood from someone that is a different blood type, their immune system treats it like a pathogen

Antibodies will bind to the proteins (antigens) on the blood cells.

This tags the blood cells for destruction.

Antibodies binding to more than one blood cell can lead to blood clots.

Can lead to allergic reaction symptoms, possible anaphylactic shock.

http://blogs.hightechhigh.org/oliviaaguilar/files/2013/03/antibody.jpeg

Allergies Allergic reaction occurs when leucocytes encounter a non-pathogenic substance and initiate an immune response.

When first exposed, IgE antibodies are produced.

These antibodies bind to WBC’s called mast cells.

When the allergen is encountered again, IgE antibodies bind to the allergen and cause the mast cells to release histamines.

Some symptoms caused by histamines include congestion, sneezing, itchy skin, hives, etc.

Vaccines Vaccines contain some components of the pathogen without causing the actual illness.

The immune system recognizes the antigens.

This leads to primary immune response.

Upon exposure to the real pathogen, secondary immune response is initiated, preventing symptoms of the disease.

http://www.saburchill.com/IBbiology/chapters04/images/130307001.jpg

Smallpox Vaccine developed by Edward Jenner

Took pus from a cowpox wound and inserted it into a child.

Went on to vaccinate others in the same way.

Eradication achieved by a worldwide vaccination program. 1977 saw the last ever naturally occurring case of the disease in Somalia and in 1980 the World Health Organization (WHO) declared the disease ‘dead’.

Monoclonal Antibodies Primary immune response is considered to be polyclonal because the pathogen is being recognized as many antigens.

Each of the proteins on the exterior can cause an immune response.

Polyclonal antibodies are difficult to work with diagnostically or therapeutically for this reason.

Researchers have developed a way to produce “pure” strains of antibodies that react only with specific antigens (monoclonal antibodies)

The production of monoclonal antibodies

1. An animal (often a mouse) is injected with an antigen and in response produces specific plasma cells

2. The plasma cells are harvested from the spleen of the animal

3. Harvested plasma cells fused with tumor cells (which are capable of endless divisions) forming a hybridoma cells

4. The hybridoma cells are screened to determine which ones are producing useful antibodies (ELISA test)

5. The selected hybridoma is allowed to divide to produce clones

6. Hybridomas are then used to synthesize large quantities of a single (monoclonal) antibodies for use in diagnostic tests and treatment

Pregnancy tests use monoclonal antibodies

http://www.sumanasinc.com/webcontent/animations/content/pregtest.html

http://www.hhmi.org/biointeractive/immunology-virtual-lab

HomeworkVOCAB

Leucocytes, plasma cell, macrophage, antigen presentation, cell cloning, primary infection, secondary infection, antibodies, binding site, agglutination, vaccine, polyclonal response, capsid, monoclonal antibodies, hybridoma, ELISA, hCG

OTHER

Pg 454- Challenge yourself 1, a-c

Pg 458- Exercises 1-4