Question

1. In terms of response time and antibody production, how is a primary immune response different from a secondary immune response?
2. What is a difference between a pathogen and an allergen?
3. How is an autoimmune disorder different from an allergy?

Answer 1

1.

Primary Immune response

Primary Immune response is the reaction which occurs when an antigen comes in contact with the immune system for the first time. Naive B cells and T cells are respondind cells. This primary response is mainly seen in Lymph nodes and spleen.

* Response Time

- The primary response is weaker than seconary response

- Lag phase is long, almost 4-7 days.

- Takes long time to give immunity.

*Antibody production

- The main antibody produced is IgM and small amount of IgG is produced.

- Antibody level reaches peak in 7- 10 days.

- Less amount of antibodies are produced in primary response.

- Antibody levels decreases rapidly.

Secondary Immune Response

Secondary Immune Response is the reaction which occurs when the same antigen comes to contact with the immune system multiple times.It appears in bone marrow, spleen, lymph nodes. Memory B cells are associated with it.

* Response Time

- Secondary response is stronger than primary response.

- Lag phase is very short, 1-3 days.

- Rapid action.

* Antibody Production

- Large amount of antibodies are produced as a result of this .

- Large quantity of IgG and small amount of IgM, IgA ,IgE are also produced.

- Antibody levels remain high for longer period.

- Antibody level reaches peak in 3-4 days.

2.

Pathogen

Pathogen can be defined as a infectious agent which causes diseases or illness. It can be a bacteria, virus, protozoa, ..Pathogen can be an agent which disrupt the normal physiology of a multicellular organism. It can affect a wide range of organisms.

Examples

Bcateria

Prions

Fungi

Viruses

Allergen

Allergen can be defined as any substance which is eaten or inhaled and causes allergic reaction. It is a type of antigen that affects the immune response. Allergens are specific to organisms. One allergen which cause allergy to an individual may not cause allergy to other one. It stimulates Type 1 hypersensitivity reaction through IgE responses. Pollen, dust, dander can cause allergy.

Example

Dust

Soy

Pollen

* Allergens are not Pathogens.

* Allergens are antigens .

* Allergens and pathogens differ in range of infection.

3.

Auto Immune Disorders

Auto immune Disorders are defined as a condition when the immune system of our body mistakenly attacks ourown body parts. Here Immune system considers ourown body parts as antigens and produce autoantibodies. There are about 100s of autoimmune disorders.

Examples

Graves disease

Celiac disase

Rheumatoid arthritis

Allergy

Allergy is caused by allergens. Allergy is caused by external agent, allergen and our immune system is affected. These allergens are antigens . Airborne materials, pollen, dander, mold, dust can cause alergy. Allergies are not very harmful to the body. Allergy is caused by hypersensitivity of the immune system to substances in the environment.

Examples

allergic eyes

asthma

* Autoimmune disorders are caused when own body parts are treated as antigens by immune system. Allergies are caused by external antigens.

* Autoimmune disorders are harmful but allergies are not at all very harmful.

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