William Sohn

Publications (2)6.42 Total impact

• Article: Antibody-mediated Hsp70 protein therapy.

  James E Hansen, William Sohn, Charles Kim, Sophia S Chang, Natalie C Huang, Donaldson G Santos, Grace Chan, Richard H Weisbart, Robert N Nishimura
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  ABSTRACT: Intracellular Hsp70 provides cytoprotection against a variety of stressful stimuli, and an effective means of increasing intracellular Hsp70 levels could prove beneficial in the prevention and treatment of a variety of human diseases. A novel protein transduction domain consisting of the single chain Fv fragment of an anti-DNA antibody known to penetrate into living cells and tissues, mAb 3E10, has recently been used to deliver functional proteins to cells. The ability of the single chain Fv fragment to deliver Hsp70 into living cells was tested by generating an Fv-Hsp70 fusion protein. Fv-Hsp70 was produced as a secreted protein in both COS-7 cells and the methylotropic yeast strain Pichia pastoris and was shown capable of penetrating into COS-7 cells and primary rat cortical neurons. Pre-treatment with Fv-Hsp70 protected both COS-7 cells and primary rat cortical neurons against subsequent exposure to hydrogen peroxide. These results provide the first evidence that the Fv fragment of mAb 3E10 is capable of delivering proteins to neurons and indicate its potential in the development of Hsp70 protein therapy.
  Brain Research 06/2006; 1088(1):187-96. · 2.73 Impact Factor
• Article: Selective IgA immune unresponsiveness to Proteus mirabilis fumarate reductase A-chain in rheumatoid arthritis.

  Richard H Weisbart, Yoon Min, Andrew L Wong, Joanne Kang, Suchada Kwunyeun, Antony Lin, Joon Kim, Grace Chan, Rika Wakelin, William Sohn, Sophia S Chang, Robert N Nishimura
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  ABSTRACT: To determine if selective immune unresponsiveness to microbial antigens is associated with predisposition to rheumatoid arthritis (RA). Proteins from Proteus mirabilis lysate were isolated by SDS-PAGE and examined by Western blotting for antibody responses in sera from patients with RA compared to healthy subjects and patients with psoriatic arthritis (PsA). Although RA patients had marked IgA immune responses to many P. mirabilis proteins compared to healthy subjects, selective unresponsiveness was found in RA to a 66 kDa protein identified as fumarate reductase A-chain (FRD-A) by mass spectroscopy. This was confirmed in Western blots with recombinant FRD-A from P. mirabilis. IgA unresponsiveness to FRD-A was found in 21/59 (35.6%) RA patients compared to 7/63 (11.1%) healthy individuals (p < 0.01) and 6/52 (11.5%) patients with PsA (p < 0.01). IgA unresponsiveness to FRD-A was present in 20/46 (43.5%) RA patients with IgA rheumatoid factors (RF) compared to 1/13 (7.7%) without RF (p < 0.025). Our results identify a selective hole in the IgA immune repertoire for P. mirabilis FRD-A in a subset of IgA RF-positive patients with RA.
  The Journal of Rheumatology 07/2005; 32(7):1208-12. · 3.69 Impact Factor