Mammarenaviral Infection Is Dependent on Directional Exposure to and Release from Polarized Intestinal Epithelia

Warner, Nikole L.; Jokinen, Jenny D.; Beier, Juliane I.; Sokoloski, Kevin J.; Lukashevich, Igor S.

To determine if cellular polarization unexpectedly perturbed the replication of OW arenaviruses, polarized and non-polarized Caco-2 cells were infected with both strains of LCMV, MOPV, as well as reassortant virus ML-29. The replication kinetics were monitored in both polarized and non-polarized cells by plaque assay. LCMV-Arm ( Figure 2A ) and LCMV-WE ( Figure 2B ) exhibited similar replication kinetics regardless of the polarization state of the Caco-2 cells. It should be noted that at 24 h post infection LCMV-WE did show a slight difference in titer between the polarized and non-polarized Caco-2 cells, but these differences were not observed in further time points. As such, neither LCMV-Arm, nor LCMV-WE, infections were significantly impacted by the polarization of Caco-2 cells during apical infection ( Figure 2 ). In addition, similar to LCMV, ML-29 was not significantly impacted by polarization of these cells ( Figure 2C ); however, peak viral titers were approximately 2-log lower than those for LCMV or MOPV ( Figure 2D ). Taken together these results indicate that polarization of Caco-2 has minimal, if any, inadvertent effect on replication kinetics of the OW arenaviruses. To determine if cellular polarization unexpectedly perturbed the replication of OW arenaviruses, polarized and non-polarized Caco-2 cells were infected with both strains of LCMV, MOPV, as well as reassortant virus ML-29. The replication kinetics were monitored in both polarized and non-polarized cells by plaque assay. LCMV-Arm ( Figure 2A ) and LCMV-WE ( Figure 2B ) exhibited similar replication kinetics regardless of the polarization state of the Caco-2 cells. It should be noted that at 24 h post infection LCMV-WE did show a slight difference in titer between the polarized and non-polarized Caco-2 cells, but these differences were not observed in further time points. As such, neither LCMV-Arm, nor LCMV-WE, infections were significantly impacted by the polarization of Caco-2 cells during apical infection ( Figure 2 ). In addition, similar to LCMV, ML-29 was not significantly impacted by polarization of these cells ( Figure 2C ); however, peak viral titers were approximately 2-log lower than those for LCMV or MOPV ( Figure 2D ). Taken together these results indicate that polarization of Caco-2 has minimal, if any, inadvertent effect on replication kinetics of the OW arenaviruses.