Identification of pathogenic autoantibodies in anti-laminin gamma-1 pemphigoid

• Project/Area Number: 26860906
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Dermatology
• Research Institution: Kurume University
• Principal Investigator: 李 小光 久留米大学, 皮膚細胞生物学研究所, 研究員 (80724971)
• Project Period (FY): 2014-04-01 – 2015-03-31
• Project Status: Discontinued (Fiscal Year 2014)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2014: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: autoantibody / epitope / laminin γ1 / N-linked glycosylation / anti-laminin γ1 / pemphigoid

Outline of Annual Research Achievements

Anti-laminin (LM) γ1 pemphigoid is an autoimmune blistering disease with IgG antibodies to LMγ1. To characterize anti-LMγ1 autoantibodies, sera from 24 anti-LMγ1 pemphigoid patients and 6 normal controls were harvested. Normal human dermal extract (NHDE), five different cell lines, and recombinant proteins (RPs) of LMγ1 were employed as LMγ1 antigen sources for immunoblotting (IB) and immunofluorescence (IF). Unexpectedly, the molecular weights (MWs) of LMγ1 in lysates of five cell lines are different. After deglycosylation with PNGase F, the MWs of LMγ1 become smaller and identical. Patient sera failed to react with LMγ1 in five cell lysates or culture supernatants by IB and showed negative results in IF of cell lines, although all patient sera can react with LMγ1 in NHDE. In contrast, 20 (83%) and 18 (75%) of 24 patient sera reacted with LMγ1 in LM521 and LM411 RPs, respectively. In addition, patient sera failed to react with LMγ1 in deglycosylated cell lysates or supernatants. Compared to those without deglycosylation, patient sera reacted more weakly with deglycosylated LMγ1 in NHDE and more strongly with deglycosylated LMγ1 in LM521, LM411 and C-terminal domain of LM511 RPs. In summary, anti-LMγ1 antibodies in patient sera are heterogeneous. N-linked glycosylation influences at least partly the reactivity of anti- LMγ1 antibodies. This work has been published recently (Li et al. J Dermatol Sci. 2015 77(2):125-9.)

Research Products

• [Journal Article] N-linked glycosylation on laminin γ1 influences recognition of anti-laminin γ1 pemphigoid autoantibodies. (2015)
  • Author(s): Li X, Qian H, Takizawa M, Koga H, Tsuchisaka A, Ishii N, Hayakawa T, Ohara K, Sitaru C, Zillikens D, Sekiguchi K, Hirako Y, Hashimoto T.
  • Journal Title: J Dermatol Sci Volume: 77 Issue: 2 Pages: 125-129
  • DOI: 10.1016/j.jdermsci.2014.12.003
  • Peer Reviewed
• [Presentation] Recognition of laminin gamma 1 by anti-laminin gamma 1 pemphigoid sera. (2014)
  • Author(s): Hua Qian, Xiaoguang Li, Hiroshi Koga, Atsunari Tsuchisaka, Norito Ishii, Yoshiaki Hirako, Takashi Hashimoto.
  • Organizer: 第113回日本皮膚科学会総会
  • Place of Presentation: 京都
  • Year and Date: 2014-05-31 – 2014-06-01