Absence of specific autoantibodies in patients with narcolepsy type 1 as indicated by an unbiased random peptide-displayed phage screening.

Narcolepsy type 1 (NT1) is an enigmatic sleep disorder characterized by the selective loss of neurons producing orexin (also named hypocretin) in the lateral hypothalamus. Although NT1 is believed to be an autoimmune disease, the orexinergic neuron-specific antigens targeted by the pathogenic immune response remain elusive. In this study, we evaluated the differential binding capacity of various peptides to serum immunoglobin G from patients with NT1 and other hypersomnolence complaints (OHCs). These peptides were selected using an unbiased phage display technology or based on their significant presence in the serum of NT1 patients as identified from previous studies. Although the subtractive biopanning strategy successfully enriched phage clones with high reactivity against NT1 serum IgG, the 101 randomly selected individual phage clones could not differentiate the sera from NT1 and OHC. Compared to the OHC control group, serum from several NT1 patients exhibited increased reactivity to the 12-mer peptides derived from TRBV7, BCL-6, NRXN1, RXRG, HCRT, and RTN4 proteins, although not statistically significant. Collectively, employing both unbiased and targeted methodologies, we were unable to detect the presence of specific autoantibodies in our NT1 patient cohort. This further supports the hypothesis that the autoimmune response in NT1 patients likely stems primarily from T cell-mediated immunity rather than humoral immunity.

Establishment of a Vietnamese ethnicity induced pluripotent stem cell line (VRISGi001-A) from umbilical cord blood hematopoietic stem cells under a feeder-free system.

We have established the original footprint-free Vietnamese human induced pluripotent stem cell line, VRISGi001-A, from cord-blood derived CD34 + hematopoietic stem cells (HSCs) of a 35 year old healthy woman under cGMP-compliant process. For the hiPSC induction, three Sendai virus vectors carrying four reprogramming factors including c-MYC, SOX2, KLF4, and OCT3/4 were delivered into CD34+ HSCs. The VRISGi001-A cell line expresses the majority of the pluripotent markers and differentiate in vitro into derivatives of three germ layers. The availability of Vietnamese hiPSC line could contribute to the improvement of inadequate genetic diversity in the currently available hiPSC lines.