Moreover, infection with the ΔsepA strain resulted in reduced bacterial invasion both in the absence (WT = 100 ± 6.58% versus ΔsepA mutant = 55.56 ± 13.53%, P = 0.0286, MWUT) and in the presence (WT = 268.6 ± 49.93% versus ΔsepA mutant = 68.52 ± 10.2%, P = 0.0286, MWUT) of AAT. Here, SERPINA1 is linked to infection.