Intro to Immunology

Question 1

Provide an overview of the immune system

Answer 1

Breach of mechanical defences leads to activation of innate immune responses, including cytokines.

Cytokines attract more immune cells to the site of invasion

Innate cells (antigen presenting cells) transport foreign antigen to local lymph nodes

Antigen is presented to lymphocytes which start to proliferate and become activated. The lymphocytes
form the adaptive or acquired immune response and have effector functions

Effector lymphocytes can produce antibody or lyse virus infected cells

These lymphocytes will migrate to the site of invasion and destroy the invading object or pathogen.

The animal returns to health

Question 2

What are the species differences when it comes types of immunity?

Answer 2

Innate immunity is displayed in Invertebrate, Urochordate, lampreys, cartilaginous fish, bony fish and mammals

Adaptive immunity is present in lampreys, cartilaginous fish, bony fish and mammals

Vaccination is possible in cartilaginous fish, bony fish and mammals

Question 3

List the characteristics of innate immunity

Answer 3

First line of immune defence against micro-organisms.

Induced rapidly induced within hours (normally lasts only a short time)

Non-specific (not activated by a specific antigen so antigen independent),

Poorly regulated

No amplification capacity

No memory develops

Can’t discriminate between the body’s own cells (self) and foreign objects (non-self).

Found in invertebrates (e.g insects, crab, starfish (and many others)) and so is an evolutionary ancient and primitive method of defending the body against pathogens.

Question 4

List the characteristics of adaptive immunity

Answer 4

Slower to develop
Immune responses last longer
Very specific involves receptors on cells and remembers foreign antigens through memory cells which are long lived.
Crucial in vaccination which relies on the formation of memory cells which are activated when the animal encounters the pathogen (virus or bacteria etc).

Question 5

What are the links between innate and adaptive immunity ?

Answer 5

-Cytokines
-Complement
-Antigen Presenting Cells

Question 6

Define the term major histocompatibility complex (MHC) and antigen presentation

Answer 6

Glycoproteins expressed on cell surface that present peptide chains to other cells

Two classes:
Class I:
Expressed on the surface of most cells
Class II: