Third Line Defences - Antibody Mediated Immunity

Active immunity

Make own antibodies

Passive immunity

Ready made antibodies given

Naturally acquired immunity

Come into contact in natural course of life

Artificially acquired immunity

Needs outside intervention

Naturally acquired passive immunity

Antibodies obtained passively by transfer - mums antibodies pass across placenta

Artificially acquired passively immunity

Injection of antibodies made by someone else, protect temporarily against an infection

Naturally acquired active immunity

Protection obtained by contracting disease

Artificially acquired active immunity

Immunisation

Immunisation

Process whereby person is made immune or resistant to an infectious disease, body makes antibodies against antigen, memory cells remain and destroy antigens if re exposed

Antibody

Secreted by B cells and bind to specific antigen and promote its destruction, apoptosis after clearance of pathogen, comprised of constant and variable regions

Types of antibodies - IgA

On mucosal surfaces and in blood

Types of antibodies - IgD

B cell surface

Types of antibodies - IgE

Active in allergies, protection from parasites

Types of antibodies - IgG

Memory antibody

Types of antibodies - IgM

First one made

Antibody eliminations

Eliminate antigens via activation of complement, attraction of phagocytes, stimulation of inflammation, prevention of viral or bacterial adhesion, precipitation and agglutination, neutralisation, opsonisation

Precipitation

Link large numbers of antigens together

Agglutination

Clumping of cells

B cells

Bone marrow derived, defends against antigens and pathogens, do not directly touch antigen, produce antibodies, provides immunological memory

B cell sensitisation

Each B cell recognises one antigen, display corresponding antibody on membrane, specific antigen binds to antibody on b cell, antigen brought into cell and combines with class ii mhc