Figure 1.

SOSTDC1 expression is abundant in T_FH cells but not in T_H1 cells or naïve CD4⁺ T cells. Naïve SMARTA (CD45.1⁺) cells were transferred into C57BL/6J (CD45.2⁺) mice followed by LCMV Armstrong infection the next day. On day 8 after infection, CD45.1⁺ T_FH (CD4⁺CD44⁺SLAM^-CXCR5⁺) and T_H1 (CD4⁺CD44⁺SLAM⁺CXCR5^-) cells were sorted and analysed with naïve SMARTA cells (CD4⁺CD62L⁺CD44^-). A. Heat map of the top 20 genes with higher expression in T_FH cells than in T_H1 cells and naïve cells (left). The fluorescence intensity of the Sostdc1 probe in T_FH, T_H1 and naïve cells (right) from previous microarray data from our laboratory (GEO accession code GSE65693). B. Quantitative RT-PCR analysis of Sostdc1 gene expression in T_FH cells and T_H1 cells in the spleen of wild-type (CD45.2⁺) mice adoptively transferred with SMARTA cells (CD45.1⁺) on day 8 post infection with LCMV Armstrong and in naïve CD4⁺ T cells (CD62L⁺CD44^-). C. Immunoblot analysis of SOSTDC1 and β-actin (loading control) expression in naïve, T_FH and T_H1 cells. N. D., not detected. ****P < 0.0001 (unpaired two-tailed t-test; the error bars in A and B indicate the standard errors).