(a) Entry of WT or an extracellular protease-null mutant strain of MRSA into organotypic human skin constructs . (b–e) Entry of WT, extracellular protease-null mutant strain and UV-killed WT strain of MRSA into epidermis (b), dermis (c) and adipose tissue (d) of FLGft/ft Balb/c mice sensitized by OVA was tracked as described in Figure 3. NTC was processed as negative control (e). (f–o) To correlate entry of MRSA strains with cutaneous immune response, gene expression of indicated cytokines (f–n) and indicated AMPs (o) was measured in the same whole skin biopsies from panel (b–d). To compare relative expression level of each AMP, data was shown as relative to GAPDH expression. Data represent mean ± SEM of results from 5–6 independent experiments. *P<0.05, **P<0.01, ***P<0.001.