The document summarizes the process of humoral immunity, which involves B cells and antibodies. It divides the process into two parts: 1) Antigens are engulfed by macrophages and dendritic cells, which then activate helper T cells. The activated helper T cells then stimulate B cell activation. 2) B cells encounter the same antigen and present fragments on their surface. Helper T cells interact with these fragments and release cytokines to activate the B cells. The activated B cells undergo clonal selection and differentiate into memory B cells and plasma cells, which release antibodies into extracellular fluids.

1. NIK_IKMAL/ASASI/2013 BIOLOVE (15-01-2013) 1:21 a.m
Humoral Immunity (antibody mediated immunity)
Involve B cells (activated by Helper T cells)
I divide this process into 2 parts for us to understand better
In this picture, Part 1 is numbered as 1
Where Part 2 is numbered as 2 and 3
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2. NIK_IKMAL/ASASI/2013 BIOLOVE (15-01-2013) 1:21 a.m
Part 1
engulf by phagocytosis
antigen macrophage/dentritic antigen becomes
cells fragment (small pieces)
Helper T cell will bind to the binding of fragments
the antigen-MHC to type II MHC molecules fragment binds to type II
complex of the APC at produce APC (antigen MHC molecules
the TCR presenting cell)
then cytokines released cytokines will activate
TCR is (T-cell receptor)
by APC helper T cell
become memory helper
T cells and Helper T cells helper T cells undergo
(mitosis and clonal selection
differentiate)
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3. NIK_IKMAL/ASASI/2013 BIOLOVE (15-01-2013) 1:21 a.m
Part 2
phagocytosis
B cells encounter the
same antigen (break into small
fragment)
fragment will bind to
B cell now become APC Type II MHC molecule on
the surface of B cell
helper T cells bind to
helper T cells release
antigen-MHC complex of
cytokines
APC
become memory B cells cytokines activated B cell
and effector B cells and B cells undergo
(plasma cells) clonal selection
effector B cells released
antibody which the goes
into the extracellular
fluid (blood)
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