Ama-T Lymphocyte kanye nezimpendulo ezithile ze-Cellular Immune Responses
Uhlelo lokuzivikela komzimba lomuntu luyinethiwekhi eyinkimbinkimbi yamaseli nama-molecule asebenzisana ukuvikela umzimba ekuthelelekeni nasezifweni. Ingxenye eyodwa ebalulekile yalolu hlelo yi-T lymphocytes, edlala indima ebalulekile empendulweni ethile yokuzivikela komzimba yamaseli. Lesi sihloko sizohlola ngokujulile ukuthi ayini ama-T lymphocytes, ukuthi asebenza kanjani, kanye nokubaluleka kwawo empendulweni yokuzivikela komzimba.
Isingeniso kuma-T Lymphocytes
Ama-T lymphocyte awuhlobo lwamaseli amhlophe egazi ayingxenye ebalulekile yesistimu yokuzivikela eguquguqukayo. Ngokungafani nesistimu yokuzivikela engokwemvelo, ehlinzeka ngokuzivikela kokuqala ngokumelene namagciwane, isistimu yokuzivikela eguquguqukayo inikeza ukuzivikela okuqondile nokuqinile ngemva kokuba umzimba uvezwe ku-pathogen. Ama-T lymphocyte akhula emnkantsheni wethambo, kodwa avuthwa endlaleni ye-thymus, etholakala ngemuva kwethambo lesifuba, yingakho igama elithi "T" ku-"thymus."
Kunezinhlobo ezimbili eziyinhloko zama-T lymphocyte ngokusekelwe emsebenzini wazo: amaseli e-T awusizo (Th) kanye namaseli e-T ayingozi (Tc). Lezi zinhlobo ezimbili zamaseli zinendima ehambisanayo ekugcineni ubuqotho besimiso somzimba sokuzivikela.
Ukusebenza kwe-T Lymphocyte
Inqubo yokusebenza kwe-T lymphocyte iqala lapho i-T-cell receptor (TCR) ibona izingcezu ezithile ze-antigen ezivezwa ama-molecule amakhulu e-histocompatibility complex (MHC) ebusweni bamaseli aveza i-antigen (ama-APC) njenge-macrophages noma amaseli e-dendritic. Ukusebenzisana phakathi kwe-TCR kanye ne-MHC-antigen complex kubalulekile ekunqumeni ukucaciswa kwempendulo yomzimba.
Ngemva kokuqashelwa kwe-antigen, amaseli e-T adinga isignali yesibili yokuvuselela amandla e-costimulatory enikezwa ukusebenzisana kwama-molecule ebusweni be-APC kanye neseli le-T. Kuphela ngemva kokuba izimpawu zombili sezitholiwe lapho iseli le-T lizosebenza ngokugcwele futhi liqale ukwanda nokwenza imisebenzi yalo yomphumela.
Ukusebenza Kwamaseli E-T Asizayo Nama-Cytotoxic
Amaseli e-Helper T (Th): Amaseli e-Helper T adlala indima ebalulekile ekusizeni ezinye izimpendulo zomzimba. Lokhu akwenza ngokukhulula ama-cytokine, angama-molecule esithunywa abonisa amanye amaseli omzimba. Amaseli e-Helper T ahlukaniswa futhi abe yizingxenye eziningana ngokusekelwe ohlotsheni lwe-cytokine ayikhiqizayo kanye nempendulo ethile ayidluliselayo, njenge-Th1, Th2, Th17, kanye ne-Tregs (amaseli e-T alawulayo).
– I-Th1: Ikhiqiza ama-cytokine afana ne-interferon-gamma (IFN-γ) avuselela ama-macrophage futhi abalulekile ekuphenduleni ngokumelene namagciwane angaphakathi kweseli, njengama-virus athile namabhaktheriya.
– I-Th2: Ikhiqiza ama-cytokine afana ne-interleukin-4 (IL-4) edlala indima ekuphenduleni izifo ezibangelwa yizinambuzane kanye nasezinqubweni zokungezwani komzimba ngokukhuthaza ukukhiqizwa kwama-antibody ngamaseli e-B.
– I-Th17: Idlala indima ekuvikeleni amabhaktheriya angaphandle kanye nesikhunta, futhi inegalelo ekukhuleni kwezifo zokuzivikela komzimba.
– Ama-Tregs: Ahilelekile ekulondolozeni ukubekezelelana kwamasosha omzimba nokuvimbela ukuzivikela komzimba ngokunikeza izimpawu zokuvimbela ukuvimbela ukusebenza ngokweqile kwamanye amaseli omzimba.
Amaseli e-T ane-cytotoxic (Tc): Lawa maseli anekhono eliqondile lokubulala amangqamuzana omzimba atheleleke ngamagciwane, ikakhulukazi amagciwane. Uma esesebenze, aqaphela amangqamuzana athelelekile ngokusebenzisa ukuboniswa kwe-MHC class I kwama-peptide angaphandle futhi awabhubhise ngokukhulula amaprotheni anobuthi njenge-perforin nama-granulemes.
Impendulo Yokuzivikela Ethile Yamaseli
Impendulo yokuzivikela komzimba eqondene namaseli ibhekisela ekhonweni lohlelo lokuzivikela komzimba lokukhomba nokubhubhisa amagciwane noma amaseli athelelekile ngokunemba okuphezulu. Ama-T lymphocyte adlala indima ebalulekile kulokhu kusabela, ngezici ezimbili eziyinhloko: ukuqashelwa okuqondile kwama-antigen kanye nokuqaliswa kokubhujiswa noma ukususwa komgomo.
Uma esesebenze, amaseli e-T awagcini nje ngokukhula kodwa futhi ahluka ngamaseli e-effector angathuthela endaweni yokutheleleka. Lawa maseli e-effector enza imisebenzi ehlukahlukene kuye ngohlobo kanye ne-microbe abayibonayo. Isibonelo, amaseli e-T asebenzayo abulala ngqo amaseli aphethwe yigciwane, kuyilapho amaseli e-T asizayo evuselela amanye amaseli omzimba ukuze andise impendulo yomzimba.
Ngaphezu kwalokho, amaseli e-T nawo adlala indima ekwakheni inkumbulo yokuzivikela komzimba. Amanye ama-T lymphocyte asebenzayo ahlukaniswa ngokwengeziwe abe amaseli enkumbulo angahlala isikhathi eside kakhulu emzimbeni. Lawa maseli enkumbulo avumela impendulo yokuzivikela komzimba esheshayo nephumelelayo kakhulu ekuthelelekeni kwesibili ngegciwane elifanayo, indlela esetshenziswa ekuthuthukisweni kwemithi yokugoma.
Imiphumela Empilweni Nasezifweni
Indima ebalulekile yama-T lymphocyte ekuphenduleni komzimba isho nokuthi ahlobene kakhulu nezimo ezahlukahlukene zezifo. Ukungasebenzi kahle kwamaseli e-T, njengokusebenza okungalawulwa noma ukwehluleka ukuqaphela amaseli omzimba 'njengawo uqobo,' kungaholela ezifweni zokuzivikela komzimba, lapho isimiso somzimba sokuzivikela sihlasela khona izicubu zomzimba.
Ngakolunye uhlangothi, ezinye izifo ezibangelwa amagciwane, njengegciwane lesandulela ngculaza, zihlasela amaseli e-T asizayo, okwenza kube buthaka wonke amasosha omzimba. Ukuntuleka kwezinombolo zamangqamuzana e-T ezanele kanye nomsebenzi wawo kushiya umzimba usengozini enkulu yokutheleleka okuhlukahlukene okungena ngengozi abantu abanezinhlelo zomzimba ezinempilo abavame ukuzilawula.
Ukwelashwa nge-immunotherapy kusetshenziswa ama-T lymphocyte, njengokuthuthukiswa kokwelashwa ngamaseli e-CAR (Chimeric Antigen Receptor), kubonise amandla ekwelapheni izinhlobo ezahlukene zomdlavuza, ngokushintsha amaseli e-T ukuze ahlasele ngqo amaseli esimila.
Isiphetho
Ama-T lymphocyte ayisici esibalulekile sesimiso sokuzivikela esiguquguqukayo, esinomthwalo wokuqashelwa nokususwa kwezifo ezithile. Ngenxa yobunzima bezinhlobo ezahlukene ezisebenzayo kanye nekhono lazo lokukhumbula izifo, ama-T lymphocyte ahlinzeka ngokuvikelwa okulungiselelwe nokuhlala isikhathi eside. Ukuqonda izindlela zokusebenza kwama-T lymphocyte akugcini nje ngokuhlinzeka ngokuqonda ngemisebenzi eyisisekelo yesimiso sokuzivikela kodwa futhi kuvula indlela yokuthuthukiswa kwezindlela zokwelapha ezintsha zokulwa nezifo ezithathelwanayo, izifo zokuzivikela komzimba, kanye nomdlavuza. Ucwaningo oluqhubekayo kule ndawo luthembisa inkathi entsha ekunakekelweni kweziguli okuphumelelayo nokwenziwe ngokwezifiso.
