CD5 and systemic lupus erythematosus: Furthermore, when the spleen cells from lupus mice (MRL/lpr mice) were cultured with PD-L1 positive MDSCs, only PD-L1 positive MDSCs form control mice remarkably suppressed plasma cell (CD19-CD138+) population and expanded IL-10 producing B 10 cell (CD19+CD5+CD1d+) (Figure 2D).