B cell deficiency induces cytotoxic memory CD8+ T cells during influenza-associated bacterial pneumonia

This study explores the role B cells play in protection against super-infection with previous heterotypic influenza memory. B cell deficiency results in increased inflammatory lung environment and lung tissue injury during super-infection. Loss of B cells increased populations of memory CD8+ T cells in the lung and these CD8+ T cells were transcriptionally and functionally distinct from WT mice. RNA-seq: WT (C57BL6) and uMT mice were challenged with influenza (X31) at D0, challenged with influenza (PR8) at day 54, challenged with MRSA USA300 or PBS vehicle at day 60 followed by lung tissue harvest at day 61. RNA was extracted from CD8 T cells sorted from harvested lungs. WT FF (n=4) WT FFS (n=4) uMT FF (n=3) uMT FFS (n=3) Comparisons were made between mouse genotype and infection type (FF vs. FFS)