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Specific Immunity
What is specific immunity?
• Third line of
defense
• Pathogen specific
• Involves antigens
and antibodies
What are B- and T-cells?
• Both start in
marrow
• T cells
– Matures in _____
– Kill
infected/cancerous
cells
– Helper, cytotoxic
• B cells
– Matures in ______
– Become plasma
cells
– Produce
antibodies
What are antibodies and antigens?
• Gamma () globulins
– Also immunoglobins
(Ig)
• Antigens
– Haptens
– Epitopes
• animation
The Two Types of Specific Immunity
What is antibody-mediated immunity?
• AKA humoral
immunity
• Involves B cells
• Manufacture of
antibodies
– Adhere to
antigens
• Marks pathogens
for destruction
What types of antibodies are there?
• IgA
• IgG
• Ig
M
• IgE
• IgD
How does
antibodymediated
immunity work?
• Clonal selection
Activation of B Cells
• T-independent antigen
• T-dependent antigen
Figure 17.6
How does antibodymediated immunity
work?
• Clonal selection
– Helper T cell
must confirm
(with exception—
see later in
lecture)
• Plasma cell
formation
– Also memory cell
formation
• Antibody
manufacture
How do antibodies work to protect me?
• Bind with
antigen
• Possible
outcomes
– Opsonization
– Agglutination
– Complement
activation
– Neutralizatio
n
How does cell-mediated immunity work?
• Types of T cells involved
–
–
–
–
Helper T (CD4)
Cytotoxic T (CD8)
Memory T
Delayed hypersensitivity T
• Allergic reactions, organ rejection
– Suppressor T
– Antigen Presenting Cells (APC)
• MHC-I
• MHC-II
Antigen-Presenting Cells
• Digest antigen
• Ag fragments on
APC surface with
MHC
– B cells
– Dendritic Cells
Activated macrophages: Macrophages
stimulated by ingesting Ag or by cytokines
Figure 17.12
How does cellmediated
immunity
work?
• Three Types of T cells
involved
– Cytotoxic
lymphocyte
– Activated
macrophages
– Natural killer cell
How does
cell-mediated
immunity
work?
• All players
How does I become immune to a pathogen?
• Acquired immunity
– Natural
• Active
• Passive
– Artificial
• Active
• passive
Do antibodies stay around forever?
• Nearly so!
• Primary vs. secondary immune response
What are
monoclonal
antibodies?
• Use
cancerous
plasma cells
– Myeloma
– Hybridoma
: cancerous
+ normal B
cells
together
– animation
How are
vaccines made?
• Killed whole cell
• Inactivated virus
• Live/attenuated
cell/virus
• Antigenic
molecule from
cell/virus
• Genetically
engineered
antigens
Figure 17.18