Clonal selection (proliferation and
differentiation)
1. Which cells secrete interleukin and
other proteins that stimulate cytotox-
ic T cells to undergo clonal activation?
a. Active helper T cells
b. Memory helper T cells
c. Infected body cells
2. The major histocompatibility com-
plex (MHC) on the surface of a cell:
a. prevents antigens from entering
the cell.
b. binds to fragments of processed
antigens and presents them to lym-
phocytes.
c. destroys infected cells by releasing
toxic chemicals.
3. If microbes are released after an
infected cell is killed,
a. phagocytes kill the released mi-
crobes.
b. memory helper T cells attack the
released microbes.
c. toxic chemicals kill the released
chemicals.
S
The active cytotoxic T cells
recognize infected body cells with
the presented antigen and kill them.
[
3b
Cytotoxic T cells release chemicals
(such as
granzymes
,
perforins
, and
granulysins
) that kill the foreign cells.
Granzymes
Activated
cytotoxic
T cell
Recognition
and attachment
Microbe----
t? r
j
^
_
Infected
Recognition
and attachment
A
0
— Granulysin
Perforin
Phagocyte
( ^ b o d y cell
i
.
- J
A
Infected body cell
undergoing apoptosis
»
J
— Microbe
A
d
.
Infected
. t^body cell
Channel
A :
]
\
Infe‘cted bodycell
undergoing cytolysis
Key.
PJTCR IC D 8 protein
Antigen-MHC-I
complex
PROCESS DIAGRAM
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