Apical MeV production after apical and basolateral infection of rmTEC and rmNEC cultures with LAMV and WT MeV. Cultures were infected apically and basolaterally for 4 h with LAMV (MOI 4.5) and washed with PBS, and media was replaced. Apical and basal supernatant fluids were collected every 24 h, and TCID50 was determined by culturing serially diluted culture fluids for 5 d on Vero (LAMV) or Vero/hSLAM (WT MeV) cells. Virus was present only in apical fluids. (A) Production of infectious virus by fully differentiated rmTEC from three individual donors (macaques 69, 292, 296). (B) Averaged amounts of infectious virus produced by fully differentiated rmNEC cultures from one donor in four experiments. (C) Comparison of the averaged amounts of virus produced by rmTEC and rmNEC after apical infection with WT MeV (Bil) and LAMV (Ed). Two-way ANOVAs were used for analysis. Statistical significance was indicated as *P < 0.05, *P < 0.05, **P < 0.01, and ***P < 0.001. Averaged amounts of virus produced by rmTEC and rmNEC after basolateral infection with WT MeV and LAMV are shown in SI Appendix, Fig. S1.