Anti-HCRTR2 (aa 2-14) polyclonal antibody

Background A recent publication suggested molecular mimicry of a nucleoprotein (NP) sequence from A/Puerto Rico/8/1934 (PR8) strain, the backbone used in the construction of the reassortant strain X-179A that was used in Pandemrix (R) vaccine, and reported on anti-hypocretin (HCRT) receptor 2 (anti-HCRTR2) autoantibodies in narcolepsy, mostly in post Pandemrix (R) narcolepsy cases (17 of 20 sera). In this study, we re-examined this hypothesis through mass spectrometry (MS) characterization of Pandemrix (R), and two other pandemic H1N1 (pH1N1)-2009 vaccines, Arepanrix (R) and Focetria (R), and analyzed anti-HCRTR2 autoantibodies in narcolepsy patients and controls using three independent strategies. Methods MS characterization of Pandemrix (R) (2 batches), Arepanrix (R) (4 batches) and Focetriar (1 batch) was conducted with mapping of NP 116I or 116M spectrogram. Two sets of narcolepsy cases and controls were used: 40 post Pandemrix (R) narcolepsy(PP-N) cases and 18 age-matched post Pandemrix (R) controls (PP-C), and 48 recent(<= 6 months) early onset narcolepsy (EO-N) cases and 70 age-matched other controls (O-C). Anti-HCRTR2 autoantibodies were detected using three strategies: (1) Human embryonic kidney (HEK) 293T cells with transient expression of HCRTR2 were stained with human sera and then analyzed by flow cytometer; (2) In vitro translation of [(35) S]-radiolabelled HCRTR2 was incubated with human sera and immune complexes of autoantibody and [(35) S]-radiolabelled HCRTR2 were quantified using a radioligand-binding assay; (3) Optical density (OD) at 450 nm (OD450) of human serum immunoglobulin G (IgG) binding to HCRTR2 stably expressed in Chinese hamster ovary (CHO)-K1 cell line was measured using an in-cell enzyme-linked immunosorbent assay (ELISA). Results NP 116M mutations were predominantly present in all batches of Pandemrix (R), Arepanrix (R) and Focetria (R). The wild- type NP109-123 (ILYDKEEIRRIWRQA), a mimic to HCRTR234-45 (YDDEEFLRYLWR), was not found to bind to DQ0602. Three or four subjects were found positive for anti-HCRTR2 autoantibodies using two strategies or the third one, respectively. None of the post Pandemrix (R) narcolepsy cases (0 of 40 sera) was found positive with all three strategies. Conclusion Anti-HCRTR2 autoantibody is not a significant biological feature of narcolepsy or of post Pandemrix (R) autoimmune responses.

Methamphetamine (METH) and modafinil are psychostimulants with different long-term cognitive profiles: METH is addictive and leads to cognitive decline, whereas modafinil has little abuse liability and is a cognitive enhancer. Increasing evidence implicates epigenetic mechanisms of gene regulation behind the lasting changes that drugs of abuse and other psychotropic compounds induce in the brain, like the control of gene expression by histones 3 and 4 tails acetylation (H3ac and H4ac) and DNA cytosine methylation (5-mC). Mice were treated with a seven-day repeated METH, modafinil or vehicle protocol and evaluated in the novel object recognition (NOR) test or sacrificed 4 days after last injection for molecular assays. We evaluated total H3ac, H4ac and 5-mC levels in the medial prefrontal cortex (mPFC), H3ac and H4ac promotor enrichment (ChIP) and mRNA expression (RT-PCR) of neurotransmitter systems involved in arousal, wakefulness and cognitive control, like dopaminergic (Drd1 and Drd2), alpha-adrenergic (Adra1a and Adra1b), orexinergic (Hcrtr1 and Hcrtr2), histaminergic (Hrh1 and Hrh3) and glutamatergic (AMPA Gria1 and NMDA Grin1) receptors. Repeated METH and modafinil treatment elicited different cognitive outcomes in the NOR test, where modafinil-treated mice performed as controls and METH-treated mice showed impaired recognition memory. METH-treated mice also showed i) decreased levels of total H3ac and H4ac, and increased levels of 5-mC, ii) decreased H3ac enrichment at promoters of Drd2, Hcrtr1/2, Hrh1 and Grin1, and increased H4ac enrichment at Drd1, Hrh1 and Grin1, iii) increased mRNA of Drd1a, Grin1 and Gria1. Modafinil-treated mice shared none of these effects and showed increased H3ac enrichment and mRNA expression at Adra1b. Modafinil and METH showed similar effects linked to decreased H3ac in Hrh3, increased H4ac in Hcrtr1, and decreased mRNA expression of Hcrtr2. The specific METH-induced epigenetic and transcriptional changes described here may be related to the long-term cognitive decline effects of the drug and its detrimental effects on mPFC function. The lack of similar epigenetic effects of chronic modafinil administration supports this notion.