Journal: bioRxiv
Article Title: MDA5 multimerization on LINE RNA drives pathogenic extracellular immune complexes in autoimmunity
doi: 10.64898/2026.01.27.702129
Figure Lengend Snippet: a) (Upper) Volcano plot of differentially expressed genes in THP-1-derived macrophages (PMA + IFNγ/LPS) stimulated with MDA5ΔN filament-NP6 ICs over mock. All IC stimulations were performed without the use of intracellular delivery systems. Genes with log 2 -fold change |L2FC| >1 with p <0.05 (red) are shown; all other genes shown have p > 0.05 (gray) or p < 0.05 (blue). (Lower) Reactome pathways of significantly upregulated genes ( p adj < 0.05, L2FC > 0). b) Heatmap of Z -scored expression of interferon, interferon-stimulated genes, and other immune-related genes in THP-1-derived macrophages stimulated with combinations of MDA5ΔN (90nM monomer), 512 bp dsRNA (3 nM), mAb (NP6/NP8, 90 nM). Ctrl indicates isotype control Ab. IFIH1 and IFNB1 are highlighted. c) IFNB1 mRNA levels in THP-1-derived macrophages stimulated with combinations of MDA5ΔN, dsRNA, mAb (F01/F12, either full-length or Fab) as in (b). Data was normalized to mock treatment. P -values were calculated by two-tailed Student’s t test. d) Cellular and extracellular MDA5ΔN protein levels in THP-1-derived macrophages stimulated with MDA5ΔN monomer or filament ICs as in (b). 4 hours post-stimulation, supernatant and washed cell pellet were analyzed for MDA5ΔN, which was added extracellularly. e) IFNB1 mRNA levels in THP-1 macrophages pre-treated with PBS or Fc block for 1.5 hours, then stimulated with dsRNA-bound MDA5ΔN filaments (13.5 nM; 512 bp dsRNA, 0.45 nM) and NP6 Ab (13.5 nM). P -values were calculated by two-tailed Student’s t test. f) (Bottom) IFN-β ELISA using THP-1 macrophages electroporated with siRNAs prior to LPS/IFNγ priming and stimulated with dsRNA-bound MDA5ΔN filaments (90 nM; 512 bp dsRNA, 3 nM) and NP6 Ab (90 nM). (Top) Western blot showing knockdown of TRIF and MAVS proteins prior to IC stimulation. P -values were calculated by two-tailed Student’s t test. g) IFNB1 mRNA levels in THP-1 macrophages stimulated with ICs composed of NP6/NP8 Abs (90 nM), MDA5ΔN (90 nM), and 512 bp dsRNA (3 nM, left; 0.9 nM, middle; 0.3 nM, right). Data was normalized to mock treatment. P -values were calculated by two-way ANOVA to compare NP6 and NP8 IC values across 4 mAb concentrations. Data are presented as mean ± SD of 3 biological replicates. RNA-seq results contain 2 biological repeats. All other data are representative of at least 3 independent experiments. * P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001. n.s , not significant.
Article Snippet: Following adherence, neutrophils were stimulated with either vehicle control, 4 μM ionomycin (Invivogen), or 100nM PMA (Invivogen) for 4 hours at 37°C and 5% CO2.
Techniques: Derivative Assay, Expressing, Control, Two Tailed Test, Blocking Assay, Enzyme-linked Immunosorbent Assay, Western Blot, Knockdown, RNA Sequencing