Qhov sib txawv tseem ceeb ntawm kev xaiv zoo thiab tsis zoo ntawm T hlwb yog tias nyob rau hauv kev xaiv zoo, ob-zoo T hlwb khi rau cortical epithelial hlwb qhia Class I los yog Class II MHC, thaum nyob rau hauv kev xaiv tsis zoo, ob-zoo. T hlwb khi rau cov pob txha-marrow-derived antigen-presenting cells.
Txoj kev loj hlob ntawm T hlwb yog txheej txheem tseem ceeb hauv kev tiv thaiv kab mob. Cov txheej txheem kev loj hlob tshwm sim hauv thymus thiab muaj ob txoj hauv kev tseem ceeb raws li kev xaiv zoo thiab kev xaiv tsis zoo. Ob leeg yog kho los ntawm cov cim tshwj xeeb uas ua lub luag haujlwm hauv txoj kev loj hlob ntawm T hlwb.
Kev xaiv zoo ntawm T Cells yog dab tsi?
xaiv qhov zoo tshwm sim hauv thymic cortex. Qhov no yog ib txoj kev uas thymocytes tsim ob-zoo T hlwb. Lawv tsiv mus rau hauv lub thymus, ua rau kev nthuav qhia ntawm tus kheej-antigens. Cov tshuaj tiv thaiv tus kheej no yog txuam nrog Major Histocompatibility Complex (MHC). Cov T hlwb uas hnov mob nrog MHC-I thiab MHC-II yuav muaj peev xwm muaj sia nyob. Kev xaiv zoo ntawm T hlwb yog li ua rau pib lub cev tiv thaiv kab mob. Cov txheej txheem no siv sijhawm ntau hnub, thiab qee lub T hlwb raug kev puas tsuaj thaum lub sijhawm nws.
Daim duab 01: Xaiv T Cells
Ntxiv mus, qhov kev xaiv zoo kuj txiav txim siab seb T cell yuav dhau los ua tus pab lossis cytotoxic T cell. Kev xaiv zoo ntawm Class I MHC yuav tsim CD8 cytotoxic T cell, thaum xaiv qhov zoo ntawm Class II MHC yuav ua rau CD4 T pab cell. Cov txheej txheem ntawm kev xaiv zoo ntawm T hlwb yuav tsis tshem cov T hlwb uas yuav ua rau autoimmunity.
Kev xaiv tsis zoo ntawm T Cells yog dab tsi?
Kev xaiv tsis zoo ntawm T hlwb tshwm sim hauv medulla ntawm thymus. Thymocytes uas qhia ob qhov zoo (CD4 + / CD8 +) yuav raug xaiv tsis zoo. Cov hlwb raug nthuav tawm nrog antigens los ntawm medullary thymic epithelial hlwb los yog antigen-presenting hlwb xws li macrophages los yog dendritic hlwb. Yog li, qee lub hlwb epithelial raug phagocytosis, ua rau muaj kev xaiv tsis zoo ntawm kev khi ntawm MHC chav kawm I peptides thiab MHC chav kawm II peptides. Thaum xaiv qhov tsis zoo ntawm T cells, CD4+ hlwb cuam tshuam nrog MHC Class II molecules, thiab CD8+ cells cuam tshuam nrog MHC class II molecules. Tsis tas li ntawd, qhov kev xaiv tsis zoo kuj tseem ua rau muaj kev tuag, muab kev cuam tshuam ntawm thymocytes thiab tus kheej-antigens muaj zog heev.
Daim duab 02: Kev xaiv tsis zoo ntawm T hlwb
Tsis tas li ntawd, qhov kev xaiv tsis zoo kuj tseem tiv thaiv kev tsim ntawm tus kheej-reactive T hlwb uas muaj peev xwm ua rau muaj kab mob autoimmune. Thaum kawg ntawm cov txheej txheem xaiv tsis zoo, T hlwb uas tawm hauv thymus yuav muaj peb yam tseem ceeb uas ua rau muaj kev txwv tus kheej, tiv thaiv tus kheej, thiab ib leeg-zoo T hlwb.
Dab tsi yog qhov zoo sib xws ntawm kev xaiv qhov zoo thiab qhov tsis zoo ntawm T Cells?
- Ob leeg ua lub luag haujlwm tseem ceeb hauv kev sib kho kom haum rau lub cev tiv thaiv kab mob.
- Lawv koom nrog hauv txoj kev loj hlob thiab kev loj hlob ntawm T cells.
- Ntxiv mus, ob qho tib si xaiv cov txheej txheem muaj nyob rau hauv thymus.
- Kev nthuav qhia ntawm tus kheej-antigens yog ib qho tshwm sim hauv ob qho tib si.
- Ob leeg yog qhov tseem ceeb los tswj lub cev tiv thaiv kab mob hauv kev ua haujlwm raug.
Qhov txawv ntawm qhov zoo thiab qhov tsis zoo xaiv ntawm T Cells yog dab tsi?
Qhov sib txawv tseem ceeb ntawm kev xaiv zoo thiab tsis zoo ntawm T hlwb yog raws li qhov kev nthuav qhia antigen tshwm sim. Hauv kev xaiv zoo ntawm T hlwb, qhov kev nthuav qhia antigen tshwm sim ncaj qha los ntawm kev sib koom ua ke ntawm MHC chav kawm I thiab chav kawm II, uas ua rau muaj ob-zoo T hlwb. Nyob rau hauv sib piv, thaum lub sij hawm tsis zoo xaiv ntawm T hlwb, antigen-tam sim no hlwb zoo li macrophages sib txuas cov antigens rau T hlwb. Hauv cov ntsiab lus ntuj, kev xaiv tsis zoo yuav tshwm sim tom qab xaiv qhov zoo. Txawm hais tias ob qho tib si coj qhov chaw hauv thymus, thaj tsam ntawm thymus qhov twg txhua tus txheej txheem tshwm sim txawv. Tsis tas li ntawd, kev xaiv zoo yuav tshwm sim hauv cortex, thaum xaiv qhov tsis zoo tshwm sim hauv medulla.
Tsis tas li ntawd, qhov kev xaiv tsis zoo kuj tseem ua rau muaj kev tuag thiab ua rau apoptosis. Qhov no feature tsis muaj nyob rau hauv kev xaiv zoo. Tsis tas li ntawd, kev xaiv tsis zoo kuj tuaj yeem tiv thaiv kev tsim cov hlwb uas muaj peev xwm ua rau nws tus kheej tsis zoo. Qhov no txo qis qhov kev pheej hmoo ntawm cov lus teb autoimmune.
Cov hauv qab no qhia txog qhov sib txawv ntawm qhov zoo thiab qhov tsis zoo ntawm cov T cells hauv daim ntawv teev npe rau kev sib piv ntawm ib sab.
Summary – Zoo vs Negative Xaiv T Cells
kev xaiv zoo thiab tsis zoo ntawm T hlwb yog ob yam tseem ceeb hauv txoj kev loj hlob T cell uas tshwm sim hauv thymus. Thaum xaiv qhov zoo tshwm sim hauv thymic cortex, kev xaiv tsis zoo tshwm sim hauv thymic medulla. Qhov sib txawv tseem ceeb ntawm kev xaiv zoo thiab tsis zoo ntawm T hlwb yog nyob ntawm kev sib koom tes ntawm T cell nrog kev nthuav qhia antigen. Hauv kev xaiv zoo, ob lub hlwb zoo txuam nrog MHC chav kawm I thiab II raug tsim. Hauv qhov sib piv, thaum xaiv qhov tsis zoo, cov tshuaj tiv thaiv kab mob xws li dendrites muab cov tshuaj tiv thaiv rau T cell. Yog li, qhov no qhia txog qhov sib txawv ntawm qhov zoo thiab qhov tsis zoo ntawm T cells.
