B cells upregulate CD86 in the presence of CD4 T cells. B cells and CD4 T cells were purified from PBMCs of CL patients (n = 10), incubated for 5 days separately or together, with or without promastigote L. panamensis antigen (pLAg), and stained for CD20, CD86, CD80, and HLA-DR. A. Expression of CD86 within the CD20+ gate. B. Expression of CD80 within the CD20+ gate. C. Expression of HLA-DR within the CD20+ gate. *p < 0.05, **p < 0.01.