Correlation of infectious RSV virus production with impaired mitochondrial respiration in cell lines knocked out for specific mitochondrial genes and/or retrovirus-rescued. KO derivatives thereof lacking Complex I α subcomplex subunit 10 (FA10−/−), FB10−/−, or transmembrane protein 261 (TMEM261−/−), as well as retrovirus-rescued controls (FA10*, FB10*, and TMEM261*) were (A and B) infected with RSV (MOI indicated) for 24 h prior to analysis for the cell-associated virus by (A) qPCR and (B) plaque assays to determine the viral RNA copy number and infectious virus (plaque forming units pfu/mL), respectively, or (C) assessment for their mitochondrial bioenergetic activities as per Figure 1B. Results represent the mean ± SEM (n = 3 independent experiments, each performed in triplicate). *** p < 0.001, * p < 0.05 compared to the rescued or wild-type cells.