studies

HEPATOLOGY, VOLUME 62, NUMBER 1 (SUPPL) AASLD ABSTRACTS 247A
Disclosures:
Palak J. Trivedi - Grant/Research Support: Wellcome Trust
Cyriel Y. Ponsioen - Advisory Committees or Review Panels: Takeda; Consulting:
AbbVIE; Grant/Research Support: AbbVIE, Schering Plough, Dr. Falk Pharma,
Tramedico Netherlands, Takeda
Ulrich Beuers - Consulting: Intercept via University of Amsterdam, Novartis via
University of Amsterdam; Grant/Research Support: Falk, Zambon; Speaking and
Teaching: Falk Foundation, Gilead, Roche, Shire
Hanns-Ulrich Marschall - Consulting: Albireo
Olivier Chazouillères - Consulting: APTALIS, MAYOLY-SPINDLER
Andrew Mason - Advisory Committees or Review Panels: AbbVie, Novartis,
Intercept; Grant/Research Support: Abbvie, Gilead, Astellas
Christopher L. Bowlus - Advisory Committees or Review Panels: Gilead Sciences,
Inc; Grant/Research Support: Gilead Sciences, Inc, Intercept Pharmaceuticals,
Bristol Meyers Squibb, Takeda, Lumena, Merck; Speaking and Teaching: Gilead
Sciences, Inc
Michael Trauner - Advisory Committees or Review Panels: MSD, Janssen, Gilead,
Abbvie; Consulting: Phenex; Grant/Research Support: Intercept, Falk Pharma,
Albireo; Patent Held/Filed: Med Uni Graz (norUDCA); Speaking and Teaching:
Falk Foundation, Roche, Gilead
Christoph Sarrazin - Advisory Committees or Review Panels: Bristol-Myers
Squibb, Janssen, Merck/MSD, Gilead, Roche, Abbvie, Janssen, Merck/MSD;
Consulting: Merck/MSD, Merck/MSD; Grant/Research Support: Abbott, Roche,
Merck/MSD, Gilead, Janssen, Abbott, Roche, Merck/MSD, Qiagen; Speaking
and Teaching: Gilead, Novartis, Abbott, Roche, Merck/MSD, Janssen, Siemens,
Falk, Abbvie, Bristol-Myers Squibb, Achillion, Abbott, Roche, Merck/MSD, Janssen
Gideon Hirschfield - Advisory Committees or Review Panels: Intercept Pharma;
Consulting: Dignity Sciences, GSK, NGM Bio, Lumena, J & J; Grant/Research
Support: BioTie; Speaking and Teaching: Falk Pharma
Christian P. Strassburg - Advisory Committees or Review Panels: Novartis, Roche;
Speaking and Teaching: Novartis, Merz, MSD, Falk Pharma, BMS, Abbvie
Michael P. Manns - Consulting: Roche, BMS, Gilead, Boehringer Ingelheim,
Novartis, Idenix, Achillion, GSK, Merck/MSD, Janssen, Medgenics; Grant/
Research Support: Merck/MSD, Roche, Gilead, Novartis, Boehringer Ingelheim,
BMS; Speaking and Teaching: Merck/MSD, Roche, BMS, Gilead, Janssen, GSK,
Novartis
The following authors have nothing to disclose: Tobias J. Weismuller, Bettina
E. Hansen, Mohamad Imam, Henrike Lenzen, Kristian Holm, Annika Bergquist,
Daniel Gotthardt, Douglas Thorburn, Rinse K. Weersma, Johan Fevery,
Tobias Mueller, Christoph Schramm, Konstantinos Lazaridis, Brian D. Juran,
Martti A. Färkkilä, Stephen P. Pereira, Sven Almer, Cynthia Levy, Annarosa
Floreani, Emina Halilbasic, Kidist K. Yimam, Piotr Milkiewicz, Dep K. Huynh,
Albert Pares, Christine N. Manser, George N. Dalekos, Bertus Eksteen, Gabi
I. Kirchner, Vincent Zimmer, Luca Fabris, Pietro Invernizzi, Felix Braun, Marco
Marzioni, Christoph P. Berg, Ansgar W. Lohse, Keith D. Lindor, Tom H. Karlsen,
Kirsten M. Boberg
77
Ig Repertoire of Autoantigen-Specific B cells in Primary
Biliary Cirrhosis
Weici Zhang 1 , Patrick S. Leung 1 , Ying Sun 1,2 , Thomas P. Kenny 1 ,
Guo-Xiang Yang 1 , Xiao-Song He 1 , Christopher L. Bowlus 3 , Ross
L. Coppel 4 , Ignacio Sanz 6 , Aftab A. Ansari 5 , M. Eric Gershwin 1 ;
1 Internal Medicine, University of California, Davis, CA; 2 Hepatology,
Center for Non-Infectious Liver Diseases, Beijing 302 Hospital,
Beijing, China; 3 Division of Gastroenterology and Hepatology,
University of California at Davis, Sacramento, CA; 4 Department
of Microbiology, Monash University, Melbourne, VIC, Australia;
5 Department of Pathology, Emory University School of Medicine,
Atlanta, GA; 6 Department of Medicine, Division of Rheumatology
and Lowance Center for Human Immunology, Emory University,
Atlanta, GA
Background: Autoantibodies to the E2 subunit of pyruvate
dehydrogenase (PDC-E2) are the serological hallmark of PBC.
Interestingly, a subpopulation of anti-PDC-E2 autoantibodies
are cross-reactive to chemical xenobiotics including 2-octynoic
acid (2OA) and 6, 8-bis (acetylthio) octanoic acid (SAc), both
putative etiological agents of PBC. Recent studies suggest that
anti-PDC-E2 is derived from de novo activated autoantigen-specific
B cells, or from B cells previously primed by xenobiotics
when self-tolerance was originally compromised. Examination
of antigen specific plasmablasts from PBC demonstrate an
extraordinary frequency of circulating plasmablasts specific
for PDC-E2 without significant detection of reactivity to xenobiotic
antigens; this is in striking contrast to comparable sera
analysis. We propose that circulating PDC-E2 plasmablasts
result from positive selection to xenobiotics, i.e. the “original
sin” was the creation of a neoantigen between a chemical
xenobiotic and a self peptide. Our aim herein was to identify
Ig sequences from plasmablasts directed to PDC-E2. Methods:
1,680 single plasmablast cells (CD3 – CD19 + CD20 lo/– CD27 hi C-
D38 hi ) were obtained from PBC with high PDC-E2-specific
plasmablasts (>30%). Thereafter, Ig heavy chain (IgH) and Igk
or Igl light chain (IgL) gene transcripts were amplified using a
IgG, IgA and IgM H and L chain gene specific primer cocktail
and sequenced. A total of 420 functional paired IgH and
Igk or Igl gene sequences were analyzed. CDR3 length and
frequency of positively and negatively charged residues in
various V gene libraries were analyzed. Differential analysis
was performed comparing IgM versus IgG or IgA gene libraries.
Results: Our data revealed a decreased diversity of IgH
and IgL usage with preferential usage of IGHV3-23, IGHV3-
30, IGHV3-7, IGHV4-39, IGHV3-15, IGHV1-18, IGHV3-74
and IGKV3-20, IGKV2-28. Moreover, the usage of IGHV3-
23 and IGHV3-30 increased by two-fold in PBC compared to
controls. Thirty-two clonal V region sequences in the repertoire
were identified and shared among PBC patients. Interestingly,
the unique rearrangements accounted for 0.84% of the total
sequenced IgH rearrangements and the majority of sequences
are highly mutated with an average of 17 replacement mutations
per sequence. Conclusion: We suggest that the original
breach of tolerance was secondary to molecular mimicry in
a genetically susceptible host to a neoantigen that includes a
chemical xenobiotic of PDC-E2; subsequently, through determinant
spreading and autoantibody maturation, the predominant
hallmark of PBC arises, autoantibodies directed at the inner
lipoyl domain of PDC-E2.
Disclosures:
Christopher L. Bowlus - Advisory Committees or Review Panels: Gilead Sciences,
Inc; Grant/Research Support: Gilead Sciences, Inc, Intercept Pharmaceuticals,
Bristol Meyers Squibb, Takeda, Lumena, Merck; Speaking and Teaching: Gilead
Sciences, Inc
Ignacio Sanz - Advisory Committees or Review Panels: Pfizer; Consulting: Genentech,
Sanofi; Grant/Research Support: MedImmune
The following authors have nothing to disclose: Weici Zhang, Patrick S. Leung,
Ying Sun, Thomas P. Kenny, Guo-Xiang Yang, Xiao-Song He, Ross L. Coppel,
Aftab A. Ansari, M. Eric Gershwin