ToB S11 - Innate & Adaptive Immunity Flashcards Preview

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Flashcards in ToB S11 - Innate & Adaptive Immunity Deck (8)
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Define innate immunity

The non-specific immunity you are born with that comes into play immediately or within hours of an antigens appearance in the body


Define adaptive immunity

The antigen-specific response


Outline the differences between the innate and adaptive immunity


- Present from birth

- Non-specific

- Not enhanced by second exposure

- No memory

- Poorly effective without adaptive response



- Arises from exposure to microorganisms

- Specific pathogen immunity

- Enhanced by second exposure

- Acquires memory (memory cells)

- Poorly effective without the innate immune system


Outline complement

A cascade of blood soluble proteins that lead to the opsonisation of bacteria or the direct lysis of it by formation of the MAC complex


What are the humoral components of the innate immune system?

- Transferrin and lactoferrin - deprive microorganisms of iron

- Interferons - inhabit viral replication

- Lysozyme - Breaks down peptidoglycan in the bacterial cell wall

- Fibronectin - opsonises bacteria and promotes their phagocytosis

- Complement - Causes destruction of microorganisms directly or with the help of phagocytic cells

- TNF-α - Supresses viral replication and activates phagocytes


What are the cellular components of the innate immune system?

- Macrophages and monocytes - Phagocytosis and antigen presentation to lymphocytes

- Neutrophils - phagocytic and anti-bacterial

- Eosinophils - anti-parasite and allergic response

- Basophils and mast cells - allergic response

Natural killer cells - recognise and kill abnormal cells Eg tumour cells


What are the humoral components of the adaptive immune system?

- Cytokine - promote the differentiation and proliferation of lymphocytes

- Perforin - Released by T killer cells that destroy cell walls

- Antibodies - Protect host by neutralisation (prevents binding to epithelia), opsonisation and complement activation


What are the cellular components of the adaptive immune response?

T Cell - T helper and T killer cells

T helper - Becomes activated when the CD4 binds to a specific antigen on the MHC/antigen complex of an APC (Antigen presenting cell). Once activated, it clones itself to form active T-helper cells and T-memory cells

T-Killer cells - release perforin when the cell is already infected

B-cell - divide to form plasma cells and memory cells when activated by T-helper cells and release cytokines. Plasma cells produce specific immunoglobulin for non-self antigen