1. Effector mechanisms of humoral immunity
Effector functions of antibodies

2. Antibodies = Immunoglobulins
Ab = Ig
Proteins that can specifically recognize and bind antigen IMMUNOglobulins – important molecules in immunity ImmunoGLOBULINS – they to the globulin fraction of plasma proteins (gamma globulins)

3. 3

4. k l a (a1 a2) g (g1 g2 g3 g4) d e m IgA(1,2) IgG(1,2,3,4) IgD IgE IgMVH VH VL VL
CDR1
CDR2
CDR3 k l CL CL
Class (isotype)
a (a1 a2)
g (g1 g2 g3 g4) d e m
IgA(1,2)
IgG(1,2,3,4)
V (variable) region
VL i VH
IgD CH CH
C (constant) region
CL i CH
IgE
IgM 4

5. (recognition of Ag and initiation of humoral immune response)
Antibodies
Membrane bound
(recognition of Ag and initiation of humoral immune response)
Secreted
(elimination of Ag)
Four classes
Five classes
IgM i IgD
(naive B cells)
IgM
IgG
IgA
IgE
IgG, IgA i IgE
(memory B cells)
monomers
sIgA – dimer
IgM – pentamer

6. 6

7. Fab
Fab
Ag recognition
Activation of diverse effector mechanisms that eliminate Ag (microbes and microbial toxins) Fc 7

8. Functions of secreted immunoglobulins
Fab fragment related:
Neutralization of antigen
Fc fragment related:
Activation of complement system (IgG, IgM)
Opsonization (IgG)
Antibody dependent cellular cytotoxicity (ADCC)
(IgG)
Eosinophil/Mast cell-mediated reactions (IgE)
at special anatomical sites:
Mucosal immunity (IgA)
Neonatal immunity (IgG) 8

9. Functions of secreted immunoglobulins
Fab fragment related:
Neutralization of antigen
Binding of microbes and microbial toxins and blocking of their effects 9

11. Functions of secreted immunoglobulins
Fc fragment related:
Activation of complement system (IgG, IgM)
Opsonization (IgG)
Antibody dependent cellular cytotoxicity (ADCC) - IgG
Eosinophil/Mast cell-mediated reactions (IgE)

12. Functions of secreted immunoglobulins
Fc fragment related:
Activation of complement system (IgG, IgM)
Opsonization (IgG)
Antibody dependent cellular cytotoxicity (ADCC) - IgG
Eosinophil/Mast cell-mediated reactions (IgE) 12

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14. Functions of secreted immunoglobulins
Fc fragment related:
Activation of complement system (IgG, IgM)
Opsonization (IgG)
Antibody dependent cellular cytotoxicity (ADCC) - IgG
Eosinophil/Mast cell-mediated reactions (IgE) 14

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16. Functions of secreted immunoglobulins
Fc fragment related:
Activation of complement system (IgG, IgM)
Opsonization (IgG)
Antibody dependent cellular cytotoxicity (ADCC) - IgG
Eosinophil/Mast cell-mediated reactions (IgE) 16

17. Defence against helmints and
immediate hypersensitivity reactions (IgE) 17

18. Functions of secreted immunoglobulins
At special anatomic sites:
Mucosal immunity (IgA)
Neonatalna immunity (IgG)

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20. Functions of secreted immunoglobulins
at special anatomical sites:
Mucosal immunity (IgA)
Neonatal immunity (IgG i sIgA)
Maternal antibodies (IgG) are actively transported across the placenta to the fetus and across the gut epithelium of neonates (FcRn)
(passive innate immunity)
Secretory IgA protects neonatus through mother’s milk

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