Fig 2: The results of leukocyte transendothelial migration (LTEM) assay of S100A6 antibody attenuation. We first treated pooled serum (20% serum) of the AE patients to mimic the disease, followed by S100A6 attenuation. (a) Compared with the serum from HC subjects (20% HC serum treatment), 20% AE serum treatment significantly enhanced the LTEM activity of Toledo cells (N = 3). (b) Compared with IgG control (AE serum + IgG), S100A6 antibodies (AE serum + antibody) attenuated the LTEM activity promoted by AE serum, resulting in an effect similar to human immunoglobulin (AE serum+IVIG; N = 3).

Fig 3: The results of 5-azacytidine treatment and ELISA. (a) We had HL-60 cells treated with 5-azacytidine for 96 h, followed by a qPCR assay to examine S100A6. mRNA level was quantified with 2-??Ct by using 18S as an internal control. 5-azacytidine treatment significantly enhanced the expression of S100A6 gene in a dosage-dependent manner (N = 9, three replications * three rounds of assay). (b) Autoimmune encephalitis (AE) serum contained a significantly higher concentration of S100A6 protein than healthy control (HC) serum did (N = 8).

Fig 4: The results of the adhesion assay. Toledo cells were treated with different concentrations of S100A6 recombinant proteins, 0%, 20%, or 40% of the average concentrations in the AE patients. Toledo cells carrying green fluorescence were seeded on plates that had been coated with hCMECs in advance. After 2 h of co-culture, the plates were washed with buffer to remove the Toledo cells that had not adhered to the hCMEC layer. More Toledo cells adhering to the hCMEC layer denoted higher adhesion ability. (a) The bright field and fluorescence columns illustrate the positions of hCMECs and Toledo cells, respectively. (b, c) An increase in S100A6 concentration caused a significant increase in adhesion ability (N = 3). (d, e) AE serum also caused a significant increase in adhesion ability than the control serum (N = 3).