Vpliv zaviralcev tumor nekroznega faktorja alfa na interepitelijske celice v črevesni sluznici bolnikov s kronično vnetno črevesno boleznijo

Jakopič, Maja (author), Kopitar, Andreja Nataša (mentor)

Kronična vnetna črevesna bolezen (KVČB) je avtoimunska bolezen pri kateri gre za napačno odzivanje na antigene. Bolnike s KVČB uvrščajo v grobem v dve kategoriji: ulcerozni kolitis in Crohnovo bolezen. Povečanje količine TNF-α je mogoče zaslediti v vnetem tkivu, torej tudi v vneti sluznici bolnikov s KVČB. Biološka zdravila, ki se lahko uporabljajo za zdravljenje KVČB so zaviralci TNF-α. Zaviralci TNF-α vplivajo na znotrajcelično signalizacijo. Delujejo tako, da zavirajo celičen cikel, pospešujejo apoptozo aktiviranih celic, zavirajo produkcijo citokinov, ali izboljšajo delovanja regulatornih celic T. Ključnega pomena pri homeostazi v črevesni sluznici je komunikacija med imunskimi celicami in odziv na antigene. Limfociti T in njihov odziv imajo pomembno funkcijo pri patogenezi KVČB. V naši raziskavi smo se osredotočili na določene podvrsti limfocitov T v vneti črevesni sluznici bolnikov s KVČB. Limfociti so bili izolirani iz biopsije črevesne sluznice bolnikov s KVČB, ki so zaradi neučinkovitosti odziva na standardno terapijo, prejeli zaviralce TNF-α. Vsem so bili odvzeti vzorci črevesne sluznice pred in po treh mesecih zdravljenja. Sodelovalo je 26 bolnikov, od tega 15 bolnikov s CB, 11 pa je bilo diagnosticiranih kot bolniki z UK. Za primerjavo smo vključili še 10 zdravih kontrol. Z metodo pretočne citometrije smo izmerili deleže limfocitnih podvrst. Razlike med bolniki in kontrolno skupino so se pokazale v razmerju med citotoksičnimi limfociti T, ki izražajo/ne izražajo kostimulatorne molekule CD28, pri populaciji aktiviranih citotoksičnih limfocitov T, aktiviranih celicah T pomagalkah in regulatornih limfocitih T. Sklepamo, da so citotoksični limfociti T (CD8+CD28+ in CD8+CD28-) ter njuno razmerje vpleteni v razvoj bolezni. Pri ulceroznem kolitisu so se po terapiji zmanjšali deleži citotoksičnih limfocitov T, ki izražajo molekulo CD28 in rezidualnih limfocitov T, pri odzivnih bolnikih z UK pa smo zaznali tudi manjši delež aktiviranih citotoksičnih limfocitov T po terapiji. Aktiviranih celic T pomagalk, ki izražajo receptor IL2R, je pri neodzivnih bolnikih s CB pred terapijo več kot pa pri odzivnih. Značilnost KVČB je tudi moteno delovanje regulatornih celic T, kar smo potrdili tudi v naši študiji, saj je bil njihov delež pri kontrolni skupini večji, kot pri bolnikih s KVČB pred terapijo.

• Language: Slovenian
• Keywords: kronična vnetna črevesna bolezen, KVČB, ulcerozni kolitis, Crohnova bolezen, TNF-α, limfociti T
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Year: 2018
• PID: 20.500.12556/RUL-101963
• COBISS.SI-ID: 4774735
• Publication date in RUL: 15.07.2018

Secondary language

• Language: English
• Title: Effect of tumor necrosis factor alpha inhibitors on interepithelial cells in colonic mucosa of patients with inflammatory bowel disease

Abstract

Inflammatory bowel disease (IBD) is an autoimmune disease triggered by inappropriate response to antigens. Patients with IBD can be ranked roughly into two categories: ulcerative colitis (UC) and Crohn's disease (CD). An increase level of TNF-α can be observed in inflamed tissue, and also in the inflamed mucosa of patients with IBD. Biological agents that can be used for the treatment of IBD are TNF-α inhibitors, impacting intracellular signaling. They inhibit the cell cycle, accelerate apoptosis of activated cells, inhibit cytokine production, or improve the activity of regulatory T cells. Communication between immune cells and response to antigens is crucial for homeostasis in the intestinal mucosa. Lymphocytes T and their response have an important function in the pathogenesis of IBD. In our study, we focused on certain subtypes of T lymphocytes in the inflamed bowel mucosa of patients with IBD. The lymphocytes were isolated from biopsy of the intestinal mucosa of patients with IBD who received TNF-α inhibitors due to the ineffectiveness of the response to standard therapy. All samples were taken from the intestinal mucosa before and after three months of treatment. 26 patients participated, 15 of which were CD patients, and 11 were diagnosed as patients with UC. For comparison, we included 10 healthy control patiens. We used flow cytometry method to measure the ratios of lymphocytic subtypes in the research subjects. The differences between patients and control group showed in i) cytotoxic T lymphocytes expressing costimulatory molecules CD28, ii) ratio of cytotoxic T lymphocytes expressing/not expressing costimulatory molecules CD28, iii) the population of activated cytotoxic T cells, iv) activated helper T cells and v) regulatory T cells. We conclude that the cytotoxic T cells (CD8 + CD28 + and CD8 + CD28-) and their ratios are involved in the development of the disease. Patients with UC had lower frequency of cytotoxic T lymphocytes expressing CD28 molecule and residual lymphocytes T after treatment, moreover UC patients who responded to therapy had lower frequency of activated cytotoxic T cells after treatment. Activated T cells expressing IL2R receptor are more represented in non-responsive CB patients before treatment than in responsive. The feature of the IBD is also the disrupted activity of T regulatory cells, which was also confirmed in our study, as the proportion of Treg in the control group was higher than in patients with IBD before therapy.

• Keywords: inflammatory bowel disease, IBD, ulcerative colitis, Crohn's disease, TNF-α, lymphocytes T