1 / 14

Function - maturation - differentiation

LYMPHOID ORGNS. Function - maturation - differentiation - proliferation Primary ( central ) L.O. T and B startto express Ag - s pecific receptors Secondary (peripheral) L.O. L y proliferation and differentiation after

damisi
Download Presentation

Function - maturation - differentiation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. LYMPHOID ORGNS Function-maturation - differentiation - proliferation Primary(central) L.O. T and B startto express Ag - specificreceptors Secondary (peripheral) L.O. Lyproliferation and differentiation after interaction with Ag

  2. Primary(central) L.O. 1) Thymus 2)Bone marrow

  3. Thymus 1 Morphology: lobular organ  cortex medulla Function: maturation of T cells (only 1 x 106 of 5 x 107 tymocytov mature) Maturation:  3 STEPS: 1) Migration and proliferation 2)Differentiation 3)Selection

  4. 1) Migration and proliferation Thymocytes react with epithelial cells (cortex), dendritic cells and Mph (medulla) 2)Differentiation 1) step - 3 negat. thymocytes (CD3-,CD4-,CD8-) markers CD44+,CD25+,CD117+ TCR genes not rearranged 2) step- differentiation - TCR  TCR γ markers CD44-, CD25+, CD117+ 3) thymocytes TCR γ   T Ly (CD3+, CD4-, CD8-) 5% of matured T cells thymocytes TCR   Th (CD3+, CD4+, CD8-) Tc (CD3+, CD4-, CD8+)

  5. THYMUS 2 POSITIVE SELECTION Only thymocyteswith affinity to „self“-MHC + Ag survive AIM: Elimination of nonfunctional T cells MHC + epitop-AgTCR/CD3

  6. THYMUS 3 NEGATIVE SELECTION Thymocytes with high affinity to MHC + selfAg are eliminated - clonal deletion or inactivated – clonalanergy AIM:Elimination of AUTOREACTIVE T cells

  7. Secondary lymphoid organs Functions 1.Trapping and concntration of Ag 2.Production of Ab and Ag specific T cells Secondary lymphoid organs: 1.Spleen - blood born microbs and Ag 2.Lymph nodes - lymphatic pathway > skin, mucosa 3. Mucosa associated lymphatic tissue (MALT) – lining of mucosa surface Ag invading mucosa

  8. SPLEEN Function- Ab synthesis and releasing to circulation - hemokaterhesis / Tra Er ( Structure: red pulp white pulp

  9. SLEZINA Red pulp plazma cells, Ma, Er, Tr,PMNL andLy. White pulp - (PeriArteriolarLymphoidSheath- PALS). T cells round central arteria B cells in primary folicules( non stimulated) secondary folicules(Ag stimulated) germinal centre / memory cells B Ly represent 50%spleen cells, 30-40%- T Ly.

  10. Lymph node (LN) Structure - cortx - medulla Cortex Primary folicules–non activated B cells Secondary folicules- response to Ag - Activated B cels– differentiation to plasma cells - Th support B cell differentiation - dendritic cells – Ag presentation - FDC - activation of memory cells - Mph Interfolicular space and in paracortex– T cells (mainly Th) Medulla Ly, high number of Mph anddendritic cells

  11. Lymph node (LN) Ag enters LN and trapped by Mph anddendriticcells Degradation of Ag . Fragments (epitopes) are expressed on the surface of APC cells together with MHC molecules Activation of T cells The first mitotic wave in T zones is recorded 1-2 days after contact with Ag  prolif. of B Ly, germinal centrers

  12. Immune system of mucosa- MALT >50% of lymphoid tissue • - (GALT) gut-associatedlymphoidtissues • - (BALT) bronchus-associatedlymphoidtissue • (GUALT) genitourinary-associatedlymphoidtissue • Exmples of MALT: tonsiles, appendix, Peyer`s patches, etc. …

  13. Mucosa associated lymphatic tissue - MALT Structure of MALT 1.Organized MALT (o-MALT) – immune cells in epithelial layer of mucosa and under epithelium Induction of immune reaction 2. DiffuseMALT (d-MALT) – various types of lymphoid cells (B andT Ly, Ma, Ne, Eo, Ma)in laminapropria Effector phase of immune reactions

  14. OrganizedMALT (o- MALT) Peyer`s patches : 1. Lymphoid folicules(>100) central part - B Ly, FDC, DC, Ma peripheral part - T Ly 2. Epithelium - „M“ cells – transport of Ag - intra epithelia T Ly – 80% belong to CD8+ (regulatory function)

More Related