Biology subjects

Akcan, U.

Publications and source records attributed to Akcan, U..

3 recordsLinked to original sources

bioRxiv2026

High prevalence of CNS-directed autoantibodies in patients with schizophrenia

Schizophrenia is a severe neuropsychiatric disorder whose etiology and biological heterogeneity remain poorly understood. Immune dysregulation has long been implicated, but the breadth and clinical significance of autoantibody responses remain unclear beyond rare individual examples. Here we use Rapid Extracellular Antigen Profiling-a proteome-scale assay for autoantibodies against extracellular and secreted proteins-to profile 352 individuals with schizophrenia and 971 community controls. We find that schizophrenia is marked by a striking elevation in extracellular autoantibody burden, present near disease onset, and approaching nearly twice control levels in the most severely ill patients. This burden increases with age in a pattern that diverges from controls and targets central nervous system antigens, including neuroactive receptors, neuronal ion channels, proteins involved in synaptic function, and blood-brain barrier integrity. Autoantibodies against blood-brain barrier antigens impair barrier function ex vivo and are associated with broader central nervous system autoreactivity, supporting a model in which barrier disruption promotes loss of tolerance to brain antigens. At the clinical level, higher baseline autoantibody burden predicts reduced responsiveness to the antipsychotic risperidone, suggesting that autoantibodies contribute to treatment resistance. Together, these findings identify humoral autoimmunity as a pervasive component of schizophrenia and imply that therapies that reset humoral immunity or reduce autoantibody burden may benefit patients beyond those with currently recognized antibody-mediated syndromes. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=115 SRC="FIGDIR/small/722731v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@e51fb5org.highwire.dtl.DTLVardef@84c86forg.highwire.dtl.DTLVardef@1832712org.highwire.dtl.DTLVardef@17a0f84_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2026

Th17 effector cytokines induce shared and distinct microglial and endothelial cell responses in post-streptococcal encephalitis

Group A Streptococcus (GAS) infections can lead to neuropsychiatric sequelae in children, yet the mechanisms driving post-infectious brain pathology remain poorly defined. In a mouse disease model, Th17 lymphocytes induce microglial activation, blood-brain barrier (BBB) dysfunction, and neural circuit impairment; however, the transcriptional programs underlying these effects, and the specific Th17-derived cytokines involved are unclear. Using mouse genetics, single-cell RNA sequencing, and spatial transcriptomics, we show that GAS infections induce inflammatory gene programs in microglia and brain endothelial cells (BECs), accompanied by downregulation of BBB-associated transcripts in BECs. Spatial transcriptomic analyses reveal that GAS-responsive microglia are enriched near infiltrating T cells. Several chemokines upregulated in microglia following GAS infection in mice are elevated in sera from affected patients. Conditional ablation of GM-CSF in CD4+ T cells partially attenuates microglial chemokine gene expression, but does not restore BBB integrity. Neutralization of IL-17A partially rescues BBB transcriptional changes in BECs and reduces microglial chemokine expression; however, compensatory peripheral immune responses associated with persistent infection exacerbate BBB disruption. In contrast, microglia/macrophage-specific deletion of IL-17 receptor A partially rescues BBB deficits following GAS infection. Together, these findings identify IL-17A-IL-17RA signaling in microglia as a critical driver of BBB dysfunction after GAS infections.

neuroscience↗

bioRxiv2021

Protein scaffold-based multimerization of soluble ACE2 efficiently blocks SARS-CoV-2 infection in vitro

Soluble ACE2 (sACE2) decoy receptors are promising agents to inhibit SARS-CoV-2, as their efficiency is less likely to be affected by common escape mutations in viral proteins. However, their success may be limited by their relatively poor potency. To address this challenge, we developed a large decoy library of sACE2 fusion proteins, generated with several protease inhibitors or multimerization tags. Among these decoys, multimeric sACE2 consisting of SunTag or MoonTag systems, which were originally utilized for signal amplification or gene activation systems, were extremely effective in neutralizing SARS-CoV-2 in pseudoviral systems and in clinical isolates. These novel sACE2 fusion proteins exhibited greater than 100-fold SARS-CoV-2 neutralization efficiency, compared to monomeric sACE2. SunTag or MoonTag in combination with a more potent version of sACE2, which has multiple point mutations for greater binding (v1), achieved near complete neutralization at a sub-nanomolar range, comparable with clinical monoclonal antibodies. Pseudoviruses bearing mutant versions of Spike, alpha, beta, gamma or delta variants, were also neutralized efficiently with SunTag or MoonTag fused sACE2(v1). Finally, therapeutic treatment of sACE2(v1)-MoonTag provided protection against SARS-CoV-2 infection in an in vivo mouse model. Overall, we suggest that the superior activity of the sACE2-SunTag or sACE2-MoonTag fusions is due to the greater occupancy of the multimeric sACE2 receptors on Spike protein as compared to monomeric sACE2. Therefore, these highly potent multimeric sACE2 decoy receptors may offer a promising treatment approach against SARS-CoV-2 infections. One Sentence SummaryMultimerization of sACE2 markedly enhanced the neutralization of SARS-CoV-2 by blocking multiple viral spike proteins simultaneously.

molecular biology↗