Transcript Tissue effector memory T cells Lymphoid central memory T cells

T-CELL MEMORY
Central
Effector
Immunological memory
Inhabitants: 46 000
Area: 1400 km2
1781:
Measles epidemic in the Faroe Islands
No measles for 65 years
1846:
Measles epidemic
Those individuals, who were older than 65 years and were infected
in 1781 did not became sick, but some elderly people got the
infection
1. Life-long protection can be induced against some viruses
2. Presence of the virus is not needed for the maintenance of
immunological memeory
DEVELOPMENT OF CELLULAR MEMORY
Negative regulation of the immune system
AICD
DIFFERENTIATION
Naive
lymphocytes
Az antigen-specific cell
number
Activation Induced Cell Death
Memory
Secunder
effector cells
Primary effector
cells
EXPANSION
AICD
MEMORY
5
10
15
20
25
30
Days
Days
Presence of specific antibodies during primary and secondary immune
responses protects against repeated infections
• A successful primary immune response eliminates the pathogen and results in
long-lasting immunological memory
• Antibodies produced during the primary immune response protect against reinfection by neutralization and opsonization.
Both effector B and T cells and memory B and T cells
are produced during a primary immune response
Both antibodies and T memory cells specific to vaccinia virus are
Detectable Decades after vaccination
Specific antibody titer drops to 0.1-1% of the
maximunm within a year.
Number of memory B-cells is 10%-of the Max.
and stays constant over many years
The number of memory T-cells also stays
constant over decades
Comparison of the B-cell populations that participate
in the primary and secondary adaptive immune responses
The amount and affinity of
antibody increase after
successive immunizations
with the same antigen
IgG antibody suppresses the activation of naive B cells
by cross-linking the B-cell receptor and FcγRIIB1
on the B-cell surface
Passive immunization with anti-Rhesus antigen IgG prevents
hemolytic anemia of the newborn
Highly mutable viruses such as influenza gradually
escape from immunological memory without stimulating
a compensatory immune response
Memory CD4 T cells express an altered CD45 isoform
that works more effectively with the T-cell receptor
and co-receptors
Naive T
Effector T
AICD
Cytokines/cytotoxicity
Central memory T
Effector memory T
PERIPHERAL TISSUES
Skin dermis, gut lamina propria,
alveolar space
PERIPHERAL
LYMPHOID ORGANS
Tissue-specific migration
Effector T
Effector T
Cytokines/cytotoxicity
ANTIGEN/ SITE OF INFLAMMATION
Cytokines/cytotoxicity
T-cells differentiate into central and effector memory cells
Tissue resident memory
cells
CYTOTOXIC MEMORY T LYMPHOCYTES
PRODUCTION OF
EFFECTOR
MOLECULES
Tissue effector memory T cells
Resting
Activated
Lymphoid central memory T cells
Resting
Activated
Proliferation
Cytotoxicity
AGE
THYMUS
PERIPHERY
M
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N
M
A
O
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R
V
Y
E
IMMUNOLOGICAL EXPERIENCE
Memory T cell frequency in
the blood is a marked
underestimate of the total
frequency and numbers of
memory T cells in the whole
body. Estimates of the number
of T cells in human tissues are
2 × 1010 in the skin,17, 1 ×
1010 in the lungs18, 3 × 1010 in
the intestines and 20 × 1010 in
lymphoid tissues (that is, the
spleen, the lymph nodes and
the bone marrow). Therefore,
peripheral blood T cells (5–10
× 109 in human blood)
represent only 2–2.5% of the
total T cell complement in the
body, and memory T cells
represent the predominant T
cell subset in mucosal sites,
skin, spleen and bone marrow
Donna L. Farber1,2, Naomi A.
Yudanin1 and Nicholas P.
Restifo NRI 2014 p24