posted on 2020-07-09, 10:43authored byXinyan Li, Na Li, Kaifeng Rao, Qinghui Huang, Mei Ma
Scarce attention
has been paid to the immunotoxicity of organophosphate
flame retardants (PFRs), which poses a challenge to the systematic
assessment of their health risks. In this study, a battery of in vitro
immunotoxicity screening assays, including adhesion, phagocytosis,
and 48 cytokine/chemokine production, was measured after exposing
THP-1-derived macrophages to six selected common PFRs (TPHP, TDCPP,
TNBP, TOCP, TCEP, and TBOEP) at a noncytotoxic concentration (≤50
μM). Our results showed that TPHP and TBOEP partially attenuated
the adhesion and phagocytosis of the THP-1 mφs and that TDCPP
caused a functional loss of phagocytosis, implying the potential immunosuppression.
In contrast, TNBP and TOCP may cause an immunostimulation by significantly
promoting cell adhesion and enhancing phagocytic efficiency. Additionally,
the results from a cytokine/chemokine secretion analysis revealed
the proinflammatory properties of TDCPP, TPHP, and TBOEP. TOCP was
thought to disrupt the inflammatory balance by inhibiting both proinflammatory
and antiinflammatory cytokines. TCEP showed no effect on adhesion
or phagocytosis and little modulation of cytokine release at this
experimental concentration. Overall, this study supports that PFRs
can be immunotoxic to macrophages in different ways and provides evidence
for developing more sensitive in vitro immunotoxicity bioassay methods.