Title N-glikozilacija imunogloulina G u likvoru i serumu u multiploj sklerozi Title (english) N-glycosylation G of immunoglobulin G in cererospinal fluid and serum in multiple sclerosis Author Ana Turčić Mentor Ivan Gudelj (mentor)Mentor Dunja Rogić (komentor)Committee member Olga Gornik Kljaić (predsjednik povjerenstva)Committee member Mario Habek (član povjerenstva)Committee member Željka Vogrinc (član povjerenstva)Granter University of Zagreb Defense date and country 2024-05-21, Croatia Scientific / art field, BIOMEDICINE AND HEALTHCARE Universal decimal classificationUDC ) 615 - Pharmacology. Therapeutics. Toxicology Abstract Intratekalna oligoklonska ekspanzija plazma-stanica u multiploj sklerozi (MS) podržava ozljedu središnjega
živčanog sustava (SŽS) i povezana je s aktivnom demijelinizacijom. Struktura N-glikana na konzerviranom
asparaginu 297 u svakoj od CH2 domena Fc regije imunoglobulina G (IgG) izravno utječe na njegove efektorske
funkcije. U upali se obrasci N-glikozilacije IgG-a mijenjaju i moduliraju proupalne ili protuupalne efektorske
funkcije što se potencijalno odražava na status i aktivnost MS-a. Cilj istraživanja bio je analizirati N-glikozilaciju
serumskoga i likvorskog IgG-a te ukupnih serumskih proteina u osoba s MS-om.
Presječna studija uključila je konsekutivne pacijente sa sumnjom na demijelinizacijsku bolest SŽS-a. Dijagnoza
MS-a temeljena je na McDonaldovim kriterijima iz 2017. godine, a kontrolna skupina sastojala se od osoba kod
kojih je dijagnoza MS-a isključena. Analiza fluorescentno obilježenih N-glikana izoliranih iz ukupnih proteina
seruma, serumskoga i likvorskog IgG-a, provedena je tekućinskom kromatografijom ultravisoke učinkovitosti
temeljenom na hidrofilnim interakcijama (HILIC-UPLC). N-glikani su uspoređeni s Expanded Disability Status
Score (EDSS), znakovima aktivnosti bolesti na magnetskoj rezonanciji (MR), brojem relapsa i biljezima
intratekalne upale (broj stanica, koncentracija IgG-a u likvoru i postotak intratekalne sinteze, oligoklonske trake,
pozitivan indeks specifičnih antitijela na neki od virusa morbili, rubela, varicella zoster ili herpes simpleks virusa
tipa 1 i 2 (MRZH reakcija)).
Razlike među skupinama pronađene su samo u N-glikomu IgG-a likvora. Osobe s MS-om imaju veći udio Nglikana s račvajućim N-acetilglukozaminom (P = 2,63 x 10-5) i monogalaktoziliranih N-glikana (P = 1,49 x 10-6)
koji su povezani s prisutnosti oligoklonskih traka. Svojstva N-glikozilacije, specifično strukture
monogalaktozilirane na α6 anteni: FA2[6]G1 (r = 0,56, P < 0,001) i FA2[6]BG1 (r = 0,45, P = 0,001), koreliraju
samo s postotkom intratekalne sinteze IgG-a, ali ne i ukupnom koncentracijom IgG-a u likvoru. Navedena svojstva
također su više zastupljena u MRZH pozitivnih osoba s MS-om. FA2[6]BG1 struktura je povišena u osoba s MSom s većim opterećenjem lezijama na MR-u (P = 0,0186), ali N-glikozilacija IgG-a iz likvora nije promijenjena
ovisno o prisutnosti aktivnih lezija, EDSS-u niti broju relapsa.
Promjene u N-glikozilaciji koje rezultiraju većom monogalaktozilacijom intratekalno sintetiziranih IgG-a
najistaknutija su svojstva u MS-u te su povezana s radiološkom aktivnosti bolesti.
Abstract (english) The intrathecal oligoclonal expansion of plasma cells in multiple sclerosis (MS) supports central nervous system
(CNS) injury and is associated with active demyelination. The structure of the N-glycan at the conserved
asparagine 297 in each of the CH2 domains of the Fc region of immunoglobulin G (IgG) directly affects its effector
functions. In inflammation, IgG N-glycosylation patterns change and modulate pro-inflammatory or antiinflammatory effector functions, potentially reflecting MS status and activity. The aim of the research was to
analyse N-glycosylation of serum and cerebrospinal fluid (CSF) IgG and total serum proteins in people with MS.
A cross-sectional study included consecutive patients with suspected demyelinating disease of the CNS. The
diagnosis of MS was based on the 2017 McDonald criteria, and the control group consisted of people in whom the
diagnosis of MS was excluded. The analysis of fluorescently labelled N-glycans isolated from total serum proteins,
serum and CSF IgG was performed by ultrahigh performance liquid chromatography based on hydrophilic
interactions (HILIC-UPLC). N-glycans were compared with Expanded Disability Status Score (EDSS), signs of
disease activity on magnetic resonance imaging (MRI), number of relapses and markers of intrathecal
inflammation (cell count, IgG concentration in the CSF and percentage of intrathecal synthesis, oligoclonal bands,
positive index specific antibodies to either measles, rubella, varicella zoster or herpes simplex viruses type 1 and
2 (MRZH reaction)).
The differences between groups were found only in the N-glycome of CSF IgG. People with MS had a higher
proportion of N-glycans with bisecting N-acetylglucosamine (P = 2.63 x 10-5) and monogalactosylated N-glycans
(P = 1.49 x 10-6) which were associated with the presence of oligoclonal bands. The N-glycosylation properties,
specifically structures monogalactosylated at the α6 antenna: FA2[6]G1 (r = 0.56, P < 0.001) and FA2[6]BG1 (r =
0.45, P = 0.001), correlated only with the percentage intrathecal synthesis of IgG, but not with the total
concentration of IgG in the CSF. These structures were also more prevalent in MRZH positive people with MS.
The FA2[6]BG1 structure was elevated in MS subjects with higher MRI lesion load (P = 0.0186), but CSF IgG Nglycosylation was not altered depending on the presence of active lesions, EDSS nor the number of relapses.
Changes in N-glycosylation resulting in higher monogalactosylation of intrathecally synthesized IgGs are the most
prominent features in MS and are associated with the radiological activity of the disease.
Keywords
N-glikozilacija
multipla skleroza
autoimune bolesti
demijelinizacijske bolesti
imunoglobulin G
cerebrospinalna tekućina
Keywords (english)
N-glycosylation
multiple sclerosis
autoimmune diseases
demyelinating diseases
immunoglobulin G
cerebrospinal fluid
Language croatian URN:NBN urn:nbn:hr:163:125519 Promotion 2024 Study programme Title: Pharmceutical-biochemical sciences - doctoral study - university study Type of resource Text File origin Born digital Access conditions Open access Terms of use Created on 2024-09-20 11:15:40
