Lecture 13: How To React To Danger

What is immunological danger

Damage

Type of cold virus

Rhinovirus

Type of bacteria

S. Typhimurium

Type of plasmodium

P. Falciparum

SARS - COV 2

Coronavirus

External epithelia causes of infection

• Wound

• Insect bite

• Skin surface

Mucosal surfaces which are at risk of infection

• Airway

• Gastrointestinal tract

• Reproductive tract

What condition does campylobacter jejuni cause

Diarrhoea

What is schistosoma mansoni

A water Bourne parasite

Type of defences in the airway to prevent sickness

• Mucus

• Cilia

• Defensins

What is a type of response

Inflammation

What are pattern recognition receptors

Receptors which recognise patterns of danger in the body and respond to them. They contribute to the cardinal signs.

How do we recognise danger

• Molecules which recognise danger such as proteins derived from bacteria, fungi, Protozoa

• Large variety of receptors that recognise the presence of foreign DNA such as from viruses or bacteria.

How do viruses survive in a host

Try to use the hosts DNA to synthesise their own proteins

What causes inflammation

Receptors being triggered due to the recognition of DNA

What molecules underly the cardinal signs of inflammation

• Histamine

• Peptides

• Cytokines

• chemokines

What are the cardinal signs of inflammation

Pain, heat, redness, swelling

3 main components of the lymphatic system

• Lymphatic vessels

• Lymph nodes

• Lymph

What are lymphatic vessels

The lines which connect the whole system

What are lymph nodes

A point in a network at which the lines or pathways intersect/ branch

What is lymph

A colourless fluid consisting of while blood cells which drain through the lymphatic system and into the bloodstream

Specialised lymph organs

Thymus & spleen

Role of the spleen

Drains & filters blood

What substances exit and enter lymph nodes

Lymph & blood

What are lymph nodes

The points where cells meet

What type of blood cells are immune cells

White

How many red blood cells do we have

5-6 million per ul of blood

How many red blood cells are made a second

2 million

Life span of red blood cells

110 days

What substances do red blood cells transport

Oxygen & carbon dioxide

Types of white blood cells

Neutrophils, basophils, macrophages, eosinophils, monocytes, mast cells, dendritic cells T cells & B cells

Adaptive white blood cells

T cells & B cells

Innate white blood cells

Neutrophils, macrophages, dendritic cells

How quick are the innate & adaptive responses after infection

Innate = first 12 hours

Adaptive = day 1-5

What is complement

• A cascade of proteins in a serum which sense danger & amplify the immune response

How is complement activated

By antibodies or molecules from pathogens

How does complement amplify the inflammatory response

By directly killing pathogens or attracting more immune cells to the sight of infection.

What is the main role of neutrophils

They are active phagocytic cells which engulf the bacteria / pathogen and therefore eliminate it

How are neutrophils recruited

By inflammation into tissues

Are neutrophils long or short lived

Short lived

What are nets used for

Capturing bacteria

What are the most abundant type of WBC's

Neutrophils

What is CRAMP

An important protein in phagocytosis

What are macrophages

Active phagocytic cells which consume & kill pathogens

Where do macrophages develop

In tissues from precursors

How are macrophages activated

By inflammation : they must be activated to work

Are macrophages long or short lived

Long

Role of dendritic cells

Migrate out of peripheral tissues through lymphatic vessels to meet T cells and carry proteins to lymph nodes

Where do dendritic cells develop

In tissues from precursors

What do dendritic cells activate

The adaptive immune responses