Increased psoriasin and CXCL8 expression
in keratinocytes
stimulated with CD4-PP contributes to a decrease in infection. (A)
During S. aureus infection, keratinocytes showed
an increase in S100A7 levels when treated with CD4-PP
(*p < 0.05, paired t test). No
differences in S100A7 expression were observed in
(B) MRSA- or (C) GAS-infected keratinocytes nor in (D) uninfected
keratinocytes treated with CD4-PP. (E) Representative images of keratinocytes
infected with MRSA with or without CD4-PP treatment depicting psoriasin
peptide (green) and nucleus (blue). (F) Densitometric analysis of
psoriasin staining in MRSA-infected samples showed a significant increase
of keratinocytes treated with CD4-PP (*p < 0.05,
unpaired t test). CD4-PP increased the expression
of CXCL8 in keratinocytes infected with (G) S. aureus (ATCC 29213), (H) MRSA (CCUG 31966), and (I) GAS
(ATCC 19615) and (J) uninfected keratinocytes (*p < 0.05, paired t test). Survival of skin pathogens
is shown for (K) S. aureus (ATCC 29213), (L) MRSA
(CCUG 31966), and (M) GAS (ATCC 19615) after infecting keratinocytes.
The survival in treatment groups is relative to untreated control.
CD4-PP was initiated at the same time as infection (treatment at 0
h) or after 2 h of infection (treatment after 2 h) (****p < 0.0001, one-way ANOVA). Relative mRNA expression of target
genes was performed in at least three independent sets in duplicate
or triplicate. Microscopy imaging and densitometry analysis were performed
in three independent experiments, with each experiment consisting
of 4–5 random view fields. The average integrated density of
each cell per set used for statistical analyses.