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microbe
antigen
epitope
phagocyte
Ag-binding site
Fab region
Fc region
Fc receptor
Antibody (Ab)
(Male, Brostoff, Roth, Roitt, 2006)
(Yoes Prijatna Dachlan, 2011)
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acterial Pathogen
S. pneumoniae
!1"
collagen
region
!1r !1s
(Yoes Prijatna Dachlan, 201#)
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Ag can bind in pockets orgrooves or on extended
surfaces in the binding sites ofAbs
(Yoes Prijatna Dachlan, 2010)(Janeway, CA., 2001)(Janeway, CA., 2001)
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S. pneumoniae
$psoni%ation$psoni%ation!&b
!'$ !D
!1" !'P AP
PhagocytosisPhagocytosis
'eceptor *or
!'P AP
!&b'Fcϒ '
S. pneumoniae
(Yoes Prijatna a!hlan, 201")
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Ag 1
Ag 2
Ag &
Ab 1
Ab 2
Ab &
re+ognisi
epitope
A$D. '.!$/. .P$P.
(Yoes Prijatna Dachlan, 2011)(Male, Brostoff, Roth, Roitt, 2006)
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Ag
cell
Plasma cellAgAb
Actiation
Ag
(Yoes Prijatna Dachlan 2011)
mmnogenicity, peci*icity
3
!lonal selection theory
cell cell
$. !.44 5 $. P.!F!Y
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#he Clonal $ele!tion
#heory
%n &enerati'e
lyhoi* or&ans
4ymphocyte clones matres
in the absence o* Ags
!lones o* matre
lymphocytes
speci*ic *or dierse Ags
A&s enter
lyhoi* tiss+es
Ag-speci*ic clones are
actiated (selected)
by Ags
Ag-speci*ic immne
responses occr
(Abbas, 2015)(Yoes Prijatna Dachlan,2015)
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Ag cell
Ag
'eceptor
AP!
Antigen
67!
molecle!'
cell
A/.
- Mole!+les that are
se!ifi!ally re!o&nie* /y
anti&en re!etors either B
!ells or # !ells
- Mole!+les that initiate
a*ati'e i+ne
resonses
(Yoes Prijatna Dachlan, 2011) (Male, Brostoff, Roth, Roitt, 2006)
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(Yoes Prijatna Dachlan 2010)
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(Abbas, 2010)(Yoes Prijatna Dachlan
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Peptide inding to !"# $olecules
Involved in inding to !"# $olecules
P1(Asp52)
P4(Ile55)
P6(Gln57)
P7(Ile5)P!("er60)
In recognition
% T cells
P2(#$r5%)
P5(&e56)
P(Asn5!)
(Abbas, 2010)(Yoes Prijatna Dachlan
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IMMUNOGEN
More recently, the term
immunogen has been
designated to refer to molecules that induce the
activation of T or B cellsin
the presence ofappropriate costimulatory
molecules
EPITOPE
• The B and T-cellantigen
receptors recognize a unique region of the
antigen
• = Antigenic
determinant
• Comple Ags contain
several epitopes(or!ynsi,R., 13 Clin %)
(Yoes Prijatna Dachlan 2011)
ANTIGEN are any substances that are capable, under appropriateconditions, of inducing the formation of antibodies and reactingspeci!cally "ith the antibodies so produced# They react "ith both T-cell recognition receptors and antibodies $%abris&ie,'B#, ())*+ ss Clinmm.
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Antigens/ mmunogenicity 0 Antigenicity
Immunogenicit! is theability to induce a humoraland1or CM immune
responses" 2 Ag 3 4-B 2 Memory B
5
6lasma cells 3 A#
T 2 Ag 3 4-T 2 Memory T
5
$T%& T'
Antigenicit! isthe ability to
combinespeci!cally "iththe !nal productof the immune
responses
(Yoes Prijatna Dachlan 2011)
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mmunogen 0immunogenicity
7# 6articular macromolecules of an infectious
agent / proteins or polysaccharides(# mmunogenicity rather depends on a
number of properties of the particularbiological system that the Ag encounters
8# 9ature / foreignness, chemicalcompleity, accessibility, susceptibility tothe Ag processing and presentation
:# The biological system / genotype, dosage
0 route administration, ad;uvants
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A Bo'ine ser+ al/+in
!o8
'abbit
ot immnogenic
trongly immnogenic
trongly immnogenic7man
4orei&nness
(Yoes Prijatna Dachlan 2010)
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Molecular size
7#The most potent immunogens aremacromolecular proteins "ithmolecular "eights ? 7)),))) @a
(# enerally, substances "ith a M
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Mode of contact
- An insuEcient $lo". dose of Ag 3Fo"-zone tolerance $immunologicunresponsiveness.
- cessive doses of Ag 3 Gigh-zone
tolerance- Boosters 3HH the clonal proliferation
of Ag-speci!c T and B cells
- Ioute of contact can inJuence thequalitative nature of a response$iv,id,sc,im,ip.
(Yoes Prijatna Dachlan 2010)
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Chemical compleity
- Gomopolymer / repeating units of a single amino acids KLKLKL 3 6oor immunogen
- Copolymers of ( or D even better D 8 AAs are moreimmunogenic
KL L N LK
- Aromatic AAs $e#g# tyrosine. contribute more toimmunogenicity than nonaromatic residues
- The protein organizational structure $conformational andlinear epitopes.
(Yoes Prijatna Dachlan 2010)
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Accessibility
OOOAAAAA AAAAAOOO
OOOAAAAA AAAAAOOO
OOOAAAAA AAAAAOOO
A-speci!c ( and E-speci!c antibodies antibodies
(Yoes Prijatna Dachlan 2011)
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The protein organizationalstructure $7.
(Yoes Prijatna Dachlan 2010)
(5+/y, 2006)
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The protein organizationalstructure $(.
(Yoes Prijatna Dachlan 2010)(5+/y, 2006)
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2010
(Yoes Prijatna Dachlan 2010)
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2010
Yoes Prijatna a!hlan 2010
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enetic constitution of the host
- T"o di4erent inbred strains of miceresponded very di4erently to
synthetic polypeptide immunogen- MGC gene products play a central
role in determining the degree to
"hich an animal responds to animmunogen
(Yoes Prijatna Dachlan 2010)
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A@'PQA9TR
- Ag persistence is prolonged
- Co-stimulatory signals are enhanced
- Focal inJammation is increased
- The non-speci!c proliferation oflymphocytes is stimulated
(Yoes Prijatna Dachlan 2010)
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The capacity of the drugs toinduce allergic reactions
n the body, formation of hapten ' carriercon;ugates is the basis of allergic responsesto drugs such as penicillin
6enicilloyl-protein derivative S G-C-Con;ugates
(Yoes Prijatna Dachlan 2010)
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5+/y, 2006
(Yoes Prijatna Dachlan 2010)
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Ags / 6rotein, 6olysaccharide, Fipids
T)dependent antigens
6articularly proteinantigens,
B cell activation occursonly
in the presence of T-cell
cyto&ines, and cognate
interaction "ithactivated T
cells
T)independent antigens
• 6olysaccharide molecules
can activate B cells in the
absence of T cell help• Type / 6neumococcal
polysacharide, non
mitogenic
• Type / F6R, a cell "all component ofn ram Dve
bacteria, mitogenic
(or!ynsi,R., 13 Clin %)(Yoes Prijatna Dachlan 2011)
Abs
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poro%oite!P
'AP
A'P
7epatic stage4A
A4A
'ing tropho%oite
'.A
chi%ontsP*.6P-1
'i*ins
.9$'
7'P-2
/ametocyte P*g2:
P*g2&0
P*g#;
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