Transcript immnity organ 3

IMMUNE SYSTEM
ORGANS & CELLS
I – STEM OR MOTHER CELLS:
 It’s
the place of the origin (Generation of
lymphocytes)
 *found in the fetal liver during embryonal
life.
 *then after birth → from bone marrow.
II- PRIMARY LYMPHOID ORGANS :
(CENTRAL LYMPHOID ORGAN)
Function …
*maturation
*education
of the cellslymphocyte
*differentiation
 Where the cells enter to grow, proliferate,
mature, differentiate & transformed into the
secondary lymphoid organ.

THESE ORGANS ARE …
 Thymus
→ for T-lymphocytes.
 Bursa equivalent (In mammals), bursa
fabracius (In birds).
 Bursa equivalent (bone marrow) in mammals
& payer patches in cattle.
THYMUS GLAND 1ST
 It
is bi-lobe gland present on both sides in
the esophagus in the entrance of esophagus
cavity.
 In birds →it is 14 lobes
 It found from birth & continue to increase
in size to full size at puberty, then decrease
in size.
 The thymus consist of cortex & medulla.
 There is thymus barrier between the blood
and the T cell unable to react with antigen.
 T- lymphocyte → called T cell because it’s
maturation occurin thymus.
IN THIS THYMUS:
 The
T cell maturation.
 education (Carry receptor called CD4 & CD8)
 Differentiation.
T cytotoxic & T suppressor → carry CD8
T helper → carry CD4
2ND BURSA OF FABRICIUS
 Sac
of lymphoid tissue present on
cloaca present in birds.
 Responsible for maturation, education
& differentiation of B-lymphocytes
3RD BURSA EQUIVALENT
 Group
of tissues differ from mammals to
another.
 In human, rodents → bone marrow.
 In cattle → payers patches
III-SECONDARY LYMPHOID
ORGANS:(PERIPHERAL I.O)..

Spleen, lymph nodes, tonsils, lymphoid organ (MALT).
MALT→ mucosal associated lymphoid tissue.
1.
Spleen:
 Consist of white pulb & red pulb.
 For B cell in perarteriolosheath
 For T-Cell in white follicle.
Lymph node:
2.
It is consist of : cortex → housing of B-cell
 Paracortical area → housing T-Cell.
 Medulla → for another immune cells.
3.
Tonsils
4.
Malt
Aggregates of lymphoid organ. e.g. BALT → baronchial associated
lymphatic tissue.
MALT → mucosal associated lymphatic tissue.
GALT → gut associated lymphatic tissue.



Other
name
Function
Size
Removal
Reaction
to antigen
1ry lymphoid
2ry lymphoid
Central L.T
Peripheral
L.T
Maturation, education,
differentiation
Increase to size ↑ in to
full size puberty
After the immunity
Can’t react with Ag
The small
size on life
Not affect
the puberty
React with
Antigen
CELL OF IMMUNE SYSTEM
1- Lymphocytes
Origin
Maturation
education
Storage
B cells
T cells
B.M, liver of fetus
B.M., liver of fetus
Bursa of fabricius
Thymus
bursa equivalent (B.M.,
players patches)
Spleen, (Periaertiolar
tonsils, cortex) lymph
node, MALT.
Spleen (white
follicle), tonsils
(Paracortical area)
L.node, MALT
CONTINUE….
Types
One
1 type
Th→ T helper, help both
humeral and cell mediated
immunity (Carry CD4)
Tc → T cytotoxic
Ts → T suppress of
immune system after
complete Ag destructiare.
Cells products
(Secretions)
Bcel differentiate to
plasma cell & memory
cells.
Plasma cell: secret
Antibody
Active Tc release certain
enzymes called
lymphokine.
CONTINUE….
Lymphocytes transformation
Life spane
1. For Ag
2. E-rosette formation
(receptor to sheep RBC)
3. C3b for complement
4. Carry MHC
5. Other receptor
Yes to plasma
cell
Short
Receptor
BCR
No
Yes to small
lymphocytes
Long
Yes
MHCI &MHCII
because it is
Apc
CD19, CD21
No
MHCI
TCR
Yes
CD3
Th → CD4
Tc & Ts → CD8
CD2 & CD 58
CELLS THAT LINK IN INNATE &
ADAPTIVE IMMUNITY (APC)..
Antigen Presenting Cells:
A) Dendritic cell:
 It is cell found in epithelial tissue.
 It is APC & act also as phagocytic cell as m.ø.
What is APC doing?
 APC → Carry to Ag on MHCII, this antigen is exogenous
Ag- & present it to Th.
 T helper carry CD4 for MHCII or carry Ag direct to B
cells.
 N B APC → carry the antigen after engulfment,
fragmentation to different epitopes.
 Then epitope exposed on surfaces of APC with MHCII.
B) Macrophage: as (A)
C) B cells:
 Act as APC in the 2ry immune response
 Can be activated directly by exogenous
antigen but fully activated by T-helper
cell which secret factors → help B-cell
to be fully activated.
RECEPTORS OR MARKERS OF T
& B CELL
1) Ag binding receptors → BCR, TCR
BCR (B cell
receptor)
 2 class of
immunoglobulin (IgM
and IgD)
 There are 200,000500,000
 Bivalent
 Specified
TCR (T cell receptor)




2 polypeptide (α, β)
100,000 copy
Is less
Not specified
2) OTHER RECEPTOR ON T CELL
CD2
 CD3
 CD4
 CD8

& CD58 → Bind m.ø.
→ To amplify signals.
on Th → for MHCII.
on Tc & Ts → for MHCI.
3) MAJOR HISTO-COMPATIBILITY
COMPLEX



Group of surface receptor.
MHCI: On an nucleated cells, carry endogenous
antigenous for T cytotoxic & T suppressor.
MHCII: on APC (m.ø. B cells & dendritic cells)
 Carry exogenous Ag.
 To T helper and B cells
4) RECEPTOR FOR REGULATOR THE
FUNCTION OF T & B CELLS
 For
complement
 For cytokine
 For antibody
5) RECEPTOR FOR UNKNOWN FUNCTION.
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