Modulation of experimental autoimmune encephalomyelitis with trichinella spiralis-derived excretory-secretory antigens

Savremena istraživanja na eksperimentalnim modelima autoimunskih bolesti ukazuju da infekcija helmintom Trichinella spiralis (T. spiralis), inhibira nastanak ili ublažava simptome autoimunskih poremećaja kao što su eksperimentalni autoimunski encefalomijelitis (EAE), eksperimentalni kolitis i dijabetes melitus tip 1. Tokom infekcije parazitom T. spiralis ekskretorno-sekretorni metabolički produkti mišićnih larvi (ES L1) su ključni za interakciju sa organizmom domaćina. Stoga je pretpostavka da su upravo ES L1 produkti odgovorni za modulaciju toka autoimunskih oboljenja. Međutim, tačna uloga ES L1 antigena ovog parazita u modulaciji bolesti, kao i mehanizmi te modulacije nisu još uvek u potpunosti razjašnjeni. Predmet ovog istraživanja bilo je ispitivanje uticaja direktne primene ES L1 produkata kao i dendritskih ćelija (DC) stimulisanih ovim antigenima na tok i modulaciju EAE-a kod DA pacova, sa ciljem da se utvrde mehanizmi imunomodulacije kao i uloga dendritskih ćelija u njima. Ovde prikazani rezultati, dobijeni u in vitro studijama na modelu DC izolovanih iz kostne srži DA pacova, potvrdili su da ES antigeni T. spiralis dovode do delimičnog sazrevanja DC koje se mogu označiti kao tolerogene DC koje se odlikuju niskom produkcijom pro-inflamatornog citokina IL-12p70 i povećanom produkcijom anti-inflamatornog citokina IL-10. U ovom radu prvi put je ustanovljeno da primena DC stimulisanih ES L1 antigenima T. spiralis (DC/ES L1) ima inhibitorni efekat na razvoj EAE-a kod DA pacova kao i da je ovaj efekat dozno zavisan. Najveći uticaj na smanjenje težine bolesti ostvaren je primenom doze od 5 x 106 DC/ES L1. Mehanizam koji je u osnovi ovog fenomena zasniva se na polarizaciji imunskog odgovora u pravcu Th2 i regulatornog tipa praćenog povećanom produkcijom Th2 i anti-inflamatornih citokina (IL-4, IL-10 i TGF-β), a smanjenom produkcijom pro-inflamatornih citokina IFN-γ i IL-17. Takođe, dolazi do povećanja procentualne zastupljenosti CD4+CD25+Foxp3+ regulatornih T-limfocita (Treg) na sistemskom nivou u slezini i na nivou ciljnog organa, u CNS-u...Recent studies indicated that Trichinella spiralis infection could successfully ameliorate or even prevent a number of autoimmune diseases established in animal models, such as experimental autoimmune encephalomyelitis (EAE), experimental colitis, type 1 diabetes mellitus. During the course of infection parasite T. spiralis communicates with the host organism and affects cells of the immune system through excretory-secretory products (ES L1) released from the muscle larvae. Mechanisms by which ES L1 influences polarization of immune response and its role in immunomodulation of autoimmune diseases has not been elucidated yet. In the current study, the potential of T. spiralis ES L1 products, injected directly or co-cultivated with dendritic cells (DCs), to promote immune regulation and control EAE development were investigated in order to reveal mechanisms of ongoing immunomodulation and the role of DCs in it. Results presented here confirmed that in vitro stimulation of DCs with T. spiralis ES L1 antigens led to partial maturation of these cells, as indicated by expression of the surface markers. Stimulation of DCs from DA rats with T. spiralis ES L1 antigens (DCs/ES L1) also resulted in significant reduction in IL-12p70 production and increased production of IL-10. In this study it was shown for the first time that application of DCs/ES L1 was able to reduce the clinical signs and duration of the EAE in a dose-dependent way, with the dose of 5 x 106 cells being most efficient in reduction of disease severity. The analysis of underlying mechanisms indicated that amelioration of EAE in DCs/ES L1 pretreated animals was due to decreased production of pro-inflammatory (IFN-γ and IL-17), increased production of Th2 and anti-inflammatory cytokines (IL-4, IL-10 and TGF-β), as well as activation of CD4+CD25+Foxp3+ regulatory T cells (Treg) both on systemic level in spleen and in target organ, i.e. spinal cord. Another approach included assessment of the immunomodulatory capacity of prophylactic administration of T. spiralis ES L1 antigens in DA rats applied in different doses and time points before EAE induction..