Vaginal
microbicides hold great promise for the prevention of
viral diseases like HIV, but the failure of several
microbicide candidates in clinical trials has raised important questions regarding the parameters to be evaluated to determine in vivo efficacy in humans. Clinical trials of the candidate
microbicides nonoxynol-9 (N9) and
cellulose sulfate revealed an increase in
HIV infection, vaginal
inflammation, and recruitment of HIV susceptible lymphocytes, highlighting the need to identify
biomarkers that can accurately predict
microbicide toxicity early in preclinical development and in human trials. We used quantitative proteomics and RT-PCR approaches in mice and rabbits to identify
protein changes in vaginal fluid and tissue in response to treatment with N9 or
benzalkonium chloride (BZK). We compared changes generated with N9 and BZK treatment to the changes generated in response to
tenofovir gel, a candidate
microbicide that holds promise as a safe and effective
microbicide. Both compounds down regulated
mucin 5 subtype B, and
peptidoglycan recognition protein 1 in vaginal tissue; however, mucosal brush samples also showed upregulation of
plasma proteins fibrinogen,
plasminogen,
apolipoprotein A-1, and
apolipoprotein C-1, which may be a response to the erosive nature of N9 and BZK. Additional
proteins down-regulated in vaginal tissue by N9 or BZK treatment include CD166
antigen, olfactomedin-4, and anterior gradient
protein 2 homolog. We also observed increases in the expression of
C-C chemokines CCL3, CCL5, and CCL7 in response to treatment. There was concordance in expression level changes for several of these
proteins using both the mouse and rabbit models. Using a human vaginal epithelial cell line, the expression of
mucin 5 subtype B and olfactomedin-4 were down-regulated in response to N9, suggesting these markers could apply to humans. These data identifies new
proteins that after further validation could become part of a panel of
biomarkers to effectively evaluate
microbicide toxicity.