Hematopoetik sitokin interlökin-7 ve mutant interlökin-7`nin (W143) hücre içi sinyal düzenlenmesindeki rolü

Abstract

47 VI.ÖZET IL-7, B- ve T-hücre gelişiminde önemli rol oynayan bir lenfopoetin olarak tanımlanmıştır. Antijen spesifik reaktivite sergileyen T lenfositlerin artışım sağlamaktadır. EL-7 reseptörü IL-7Rcc ve ye zincirlerinden meydana gelmektedir. Reseptör ligand etkileşimini takiben birkaç kinaz sınıfi aktifleşmektedir. Bunlar, Janus kinaz ailesi, Src kinaz ailesi ve PI-3 kinaz üyelerini kapsamaktadır. Sinyal iletimi sonucunda STAT, c-myc, NFAT ve AP-1 gibi bazı transkripsiyon faktörleri aktive olmakta ve tümör hücrelerine, mikrobik ve viral enfeksiyonlara karşı immün cevabı yönlendirmektedir. Bu tez çalışmasında; IL-7 ve mutant IL-7' nin trofik etkisi, proliferasyon deneyleri ile incelenmiştir. Ayrıca, IL-7 bağımlı hücre içi sinyal akış yolunda ilk protein olan Jak3 aktivitesi, insan anti Jak3 poliklonal antikoru kullamlarak immunpresipitasyon ve Western blot yöntemleri ile hematolojik hastalıklarda araştırılmıştır. Elde edilen sonuçlarda, mutant IL-7 tiplerinden alanin ve histidin (W143A ve W143H) tiplerinin hücre proliferasyonu ve Jak3 aktivitesini azalttığı saptanmıştır. Bu bulgular ışığında bu mutant IL-7 tiplerinin doğal IL-7 antagonistleri olduğu düşünülmektedir. Buna dayanarak, bu mutant IL-7'lerin otoimmün yetmezlik, Hodgkin lenfoma, Sezary lösemi, kronik lenfositik lösemi ve akut lenfoblastik lösemi gibi hematolojik hastalıklarda tedavi amaçlı kullanılabilecekleri düşünülmektedir.48 VII. SUMMARY IL-7 is an important lymphopoietin and plays a critical role in both B- and T-cell development. It promotes expansion of T lymphocytes exhibiting antigen- specific reactivity.The IL-7 receptor is comprised of two chains, JJL-7Ra and IL- 2Ryc. Following receptor interaction, rapid activation of several classes of kinases occurs, including members of the Janus and Src families and PI-3 kinase. A number of transcription factors are subsequently activated including STATs, c- myc, NFAT and AP-1. IL-7 maybe implemented to promote strong and effective immune responses directed against tumor cells, or against microbial or viral infection. In this thesis study, IL-7 and mutant IL-7 (W143 A, F, H, P and Y) trophic effects are tested by proliferation assay. The first protein of IL-7 dependent cell signaling pathway known Jak3 activity is detected by immunoprecipitation and western blot using anti human Jak-3 polyclonal antibody in malignant lymphoid cell lines. According to the results the mutant IL-7s, W143 A and W143 H have decreased B and especially T-cells proliferation in comparison to native IL-7. Mutant IL-7A and IL-7H also have downregulated Jak3 activation by decreasing Jak3 tyrosine phosphorylation. Results suggested that these mutant IL- 7s may be useful to cure autoimmune diseases and some hematologic malignancies including Hodgkin lymphoma, Sezary leukemia, chronic lymphocytic leukemia and acute lymphoblastic leukemia diseases.

48 VII. SUMMARY IL-7 is an important lymphopoietin and plays a critical role in both B- and T-cell development. It promotes expansion of T lymphocytes exhibiting antigen- specific reactivity.The IL-7 receptor is comprised of two chains, JJL-7Ra and IL- 2Ryc. Following receptor interaction, rapid activation of several classes of kinases occurs, including members of the Janus and Src families and PI-3 kinase. A number of transcription factors are subsequently activated including STATs, c- myc, NFAT and AP-1. IL-7 maybe implemented to promote strong and effective immune responses directed against tumor cells, or against microbial or viral infection. In this thesis study, IL-7 and mutant IL-7 (W143 A, F, H, P and Y) trophic effects are tested by proliferation assay. The first protein of IL-7 dependent cell signaling pathway known Jak3 activity is detected by immunoprecipitation and western blot using anti human Jak-3 polyclonal antibody in malignant lymphoid cell lines. According to the results the mutant IL-7s, W143 A and W143 H have decreased B and especially T-cells proliferation in comparison to native IL-7. Mutant IL-7A and IL-7H also have downregulated Jak3 activation by decreasing Jak3 tyrosine phosphorylation. Results suggested that these mutant IL- 7s may be useful to cure autoimmune diseases and some hematologic malignancies including Hodgkin lymphoma, Sezary leukemia, chronic lymphocytic leukemia and acute lymphoblastic leukemia diseases.