Sesh 9: Biological Therapies

Question 1

What is innate immunity in simple terms ?

Answer 1

A rapid non specific first response

Question 2

What is adaptive immunity in simple terms.

Answer 2

A slower but more specific response

Question 3

What happens when the innate immune response is exposed to virus of bacteria ?

Answer 3

The body has many diff responses by diff cells

Dendritic cells , polymorphic neutrophils , mast cells , macrophages

The cells recognise virus or bacteria and produce defensins , interferons , lysosomes , complement proteins that stimulate immune system and also attack infectious agent

Question 4

How does the adaptive immune response respond to bacteria or virus ?

Answer 4

B cells under the influence it T cells can recognise specific infectious agents and produce a targeted antibody directed against that agent to either directly kill the cell or to promote the further recruitment such as complement proteins to kill the bacteria

Question 5

What does the innate system comprise off ? In more detail

Answer 5

Comprising of dendritic cells , MAC, PMNs they respond to microbial pathogen PAMPs , these are recognised by specific receptors and those receptors respond and are activated by bacterial proteins and can be activated by antibodies as well.

Microbial proteins can be targeted by complement proteins and acute phase proteins can further activate macrophages and dendritic cells but also if complement can directly kill the bacteria

Question 6

Adaptive immune system

Answer 6

The response is based around B and T cells. That respond to bacterial proteins to proliferate and produce populations of B cells that produce antibodies that can further target infectious agents

Question 7

The immune system and disease ;

Autoimmunity

Answer 7

The immune system can go array and go under or over active and cause a disease state :

Autoimmunity is a disease state where immune system targets healthy tissues eg joints can faith arthritis or pancreas can get diabetes , or lung can get lung disease.

Question 8

Immune system and disease -

Immunodeficiency

Answer 8

Immune system can be under active whereby inherited conditions can affect normal development these can cause increased susceptibility to infections

Question 9

Immune system and disease - hypersensitivity

Answer 9

Immune system can be overactive and cause hypersensitivity e.g peanut allergy or bee sting where there’s an excessive response to antigen or protein

Question 10

Immune system and disease ; cancer

Answer 10

Cancer - immune system fails to clearl premalignant cells and contribute to progression of cancer . HIV have increased risk of certain cancer

Question 11

What is autoimmunity and give examples ?

Answer 11

Where an antibody made by a B cell targets healthy tissues

In brain MUltiple sclerosis is an autoimmune disease. Which an autoantibody targets the lining of the nerve cells,

the immune system can target the thyroid glands, thyroiditis so increased thyroxine

In stomach the immune system can target the gastric parietal cells resulting in a. Condition called pernicious anaemia which is failure to absorb B12 it can target adrenal glands causing impatience by if natural steroids causing Addison’s disease

Question 12

In autoimmune disorders the treatment is to suppress the immune system ; ways of doing this include ?

Answer 12

Remove T cells that are infrequently used

Use drugs that reduce proliferation of T and B cells so prevent them from producing autoantibodies. Examples include 6-amp a chemotherapy drug

Plasma exchange to filter the blood to remove antibodies from the blood

Steroid to help reduce inflammation

Question 13

What are autoantibodies?

Answer 13

Autoantibodies are antibodies that recognise parts of our own body.

Autoantibodies can be found in
healthy people, particularly as we get older, but they are also found in some autoimmune diseases. In a few specific diseases, autoantibodies are actually causing the disease e.g. Grave’s disease, myasthenia gravis.

Question 14

There are a number of immunosuppressants ;

Answer 14

Commonly used steroids

Calcineurin inhibitor’s which inhibit calcium metabolism in cells

Cytotoxics which prevent proliferation of T and B cells such as methotrexate

Rituximab used in autoimmune conditions targets CD20 , this proteins is present on most B cells by targeting this antigen and can deplete these cells and reduce the production of the autoantibodies

Question 15

Difference between autoimmunity and immune deficiency?

Answer 15

Autoimmunity is the over activation of the immune system

Immune deficiency is the under-activation of the immune system

Question 16

Define primary and secondary immunodeficiency?

Answer 16

Primary -
where there is a mutation which can affect the development of B and T cells and then people have recurrent infections from early ages

Secondary -
Where patient has haematological cancer or had treatment with chemotherapy drugs that induced depletion of B and T cells or induce an abnormal T cell population leading to recurrent infections

Question 17

Further explanation of primary immunodeficiency?

Answer 17

Primary immunodeficiency tend to be rare and heterogenous .

Can have antibody deficiencies where mutation affects B and T cells and example of this can be severe combines immunodeficiency

Can have immunodeficiency that affect multiple lymphocytes subsets dependant in the mutations present .

Question 18

Secondary immunodeficiency

Answer 18

As stated chemotherapy or concurrent malignancies such as myeloma or chronic lymphocytic leukaemia is characterised by low immunoglobulin levels and abnormal B and T cell function. There can also be abnormalities in neutrophil counts or function

Question 19

Management of primary immunodeficiency?

Answer 19

Patients can be asymptomatic whilst others present at birth with major recurrent infections.

Prophylactic antibiotics
Vaccination
If immunodeficiency is associated with immunoglobulin deficiency it’s possible to replace immunoglobulin levels therapeutically and given as a drip

Allogenic transplant - receives normal stems from compatible donor usually brother or sister ,

Gene therapy - introduce normal gene into affected individual by packaging the gene into the virus and then seeds into the liver or the bone marrow and then the normal gene is transcribed in the individual and fully corrected