Download 14.3 Vaccination

14. Immunodiagnosis,
Immunotherapy & Vaccination
王 家 鑫，MD
College of Veterinary Medicine
14.1 Immunodiagnosis
• ELISA for animal disease diagnosis
Enzyme-linked immunosorbent assay(ELISA)
— detection of antigen
— detection of antibody
• Immunological colloidal gold signature
(Immunochromatography),
(Colloidal gold immunoassay，GIA)
• Immunofluorescence diagnosis
Immunochromatography
Detection of CSFV antibody in swine serum, plasma or whole blood
Detection of microbal antigens by immunofluorescence staining
Rabies virus in salivary gland
herpes simplex virus
14.2 Immunotherapy
Cytokine therapy
• IFN-α/IFN-βare used for virus infection.
• IFN-γis better than IFN-α/IFN-β.
• GM-CSF and IL-2 for the treatment of
bovine mastitis.
• Anti-TNF-αtherapy
Immunomodulating agents
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Biological response modifiers
Immunosuppressors
Traditional Chinese veterinary medicine
Antibody therapy
14.3 Vaccination
1. Active Immunization
vaccines
2. Passive Immunization
Antibody
Passive Immunization
• Vaccines
♥ The generation of a controlled adaptive
immune response that will protect an
individual from pathogenic infection/
disease.
♥ Induction of immunological memory.
Types of vaccine approaches to
common pathogens
• Attenuated organism: live, but non-pathogenic
Give good CD8 T cell responses because they lead
to intracellular protein synthesis. Some risk of
reversion or pathogenesis in immunodeficient
animals.
• Killed whole organism: heat, chemical fixation.
Does not elicit as good CD8 response. Inactivated
whole bacteria can cause unwanted inflammation.
• Subunit vaccine: specific protein of microorganism
Safe, can be effective. Problems of poor CD8
responses and low natural adjuvancy.
• Conjugate vaccine: Specific portion of
microorganism (Often carbohydrate) linked to
carrier protein.
This is the basis of recent vaccines for infants for
Haemophilus influenzae (bacterial menigitis) and
pneumococci.
• DNA vaccines: introduce plasmid DNA directly
into host cells.
Relatively cheap, specific, and targets CD8 cells.
Technical problem of getting DNA into host cells
(Gene gun). Some safety concerns.
• Recombinant vectored vaccines: putting
new genes in attenuated organism (such as
vaccinia)
Still experimental, but works well in animals.
Safety concerns.
• Modern adjuvants (TLR agonists), cytokines
CpG DNA (TLR9 agonist). Cytokines that boost
growth or numbers of dendritic cells (GM-CSF),
T cell responses (IL-2). Target best APCs.
14.3.1 Live, Attenuated Vaccines
14.3.2 Inactivated or “Killed” Vaccines
• Pathogens are inactivated by heat or chemical
means.
• Killed vaccines often require repeated boosters
to maintain the immune status of host.
• Killed vaccines induce a predominantly humoral
immune response; they are less effective than
attenuated vaccines in inducing cell-mediated
immunity and in eliciting IgA response.
14.3.3 Subunit Vaccines
• Inactivated exotoxins(Toxoids)
• Capsular polysaccharides
• Recombinant protein antigens
14.3.4 Conjugate vaccines
Conjugate vaccines
provide a peptide
that stimulates CD4
T cells to antigens
that lack good
determinants, such
as bacterial capsular
polysaccharides.
Stimulates a good IgG
antibody response to
the carbohydrate
Immune stimulatory complexes(ISCOMs) delivery system
Lipid + Peptides
ISCOMs are lipid carriers that act as adjuvants but
have minimal toxicity. They seem to load peptides
and proteins into the cell cytoplasm, allowing MHC
class I-restricted T-cell response to peptides to
develop.
Epitopes on VP1 protein of foot-andmouth disease virus (FMDV)
14.3.5 DNA vaccine
• The DNA vaccine is a plasmid that
contains one or more genes of the
pathogen that is being immunized against
behind a strong eukaryotic promoter.
Transcription and translation occur from
the vaccine plasmids that find their way
into the nucleus of the muscle cells, to
make the pathogen-derived protein.
Gene gun
14.3.6 Recombinant Vector Vaccines
Mammalian cells
独特型疫苗
Swine flu goes global
The genetics of the virus are so novel that humans are
unlikely to have much immunity to it, scientists say. The
current seasonal flu vaccine, which targets a different
H1N1 strain, also isn't likely to offer any protection.
Discussions are under way as to whether a new vaccine
for the swine flu strain should be produced. The WHO
has recommended that vaccine makers continue to
manufacture the seasonal flu strain but begin thinking
about how to manufacture large doses of a vaccine that
incorporates a weakened version of the current swine flu
strain. For now, the virus is treatable with the influenza
drugs oseltamivir (Tamiflu) and zanamivir (Relenza).
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