Transcript Ch. 8 White blood cells

(White Blood Cells)
Leucocytes
Specific – 3rd
line
Non- specific –
2nd line
Blood films – Romanowsky stain
Neutrophil
Red Blood
Cells
Eosinophil
Macrophage
Lymphocyte
Basophil
Lymphocytes - Types
B cells
Memory
BM
Plasma
BP
T cells
Helper
TH
Cytotoxic
TC
Immunity Words

Antigen – causes an
immune response
(usually a pathogen)

Antibody – protein
produced by B cells to
destroy specific
antigens
B cells

Responsible for Humoral Immunity

Produces antibodies which circulate in the
blood and destroy specific antigens

Usually effective against pathogens that do
not invade cells (eg, bacteria)
B cells

Memory cells
Survive for many years (decades)
 ‘Remember’ how to make antibodies to a
specific disease so that if re-infection occurs,
immune reaction is quicker


Plasma cells
Antibody factories
 Produce a specific type of antibody
 Have a shorter life span than memory cells

T cells

Responsible for Cell-mediated immunity

Destroys cells of the body that have been
invaded by specific pathogens

Destroy cells mainly by phagocytosis or
‘eating’ them and also by activating other
immune cells
T cells

Cytotoxic T cells (TC or TK)
Kill cells that contain an antigen
 Generally kill intracellular pathogens such as
viruses


Helper T Cells (TH)
Activate other T cells and B cells by releasing
chemical messengers called lymphokines
 Triggers white cell replication by releasing
cytokines

I
B
B
B
Pathogens produce
specific antigens
I
Y
There are many different types of B cells in
our blood which have receptors on their
surface that can recognise many different
types of antigens
I
I
The antigen will bind to the appropriate B
cell, triggering an immune response
B
I
I
I
I
Y
I
Y
The Immune Response
B
I
I
I
Antibody
production
B
I
I
I
I
I
B
B
B
I
I
I
I
I
Memory Cells
I
I
I
B
I
I
I
B
Plasma Cells
I
I
I
B
I
B
B
I
I
I
I
Proliferation
I
I
I
Monoclonal Selection
Antibodies
Antibodies bind to antigens and
destroy them by puncturing them and
attracting phagocytes and T cells to
them
Lymphocyte interaction
Antigen
B
Chemical
Activation
TH
BM
BP
Chemical
Activation
TH
TC
TH
Directly
attack
infected cells
TC
TC
Other T cells

Two other types of T cells exist:

T suppressor cells


Natural Killer Cells


De-activate immune response when the antigen is gone
(opposite of helper cells)
Specifically kill tumour cells in a similar way to cytotoxic cells
killing infected cells
Both cell types are not well understood