In vitro effects of monophthalates on cytokine expression in the monocytic cell line THP-1 and in peripheral blood mononuclear cells from allergic and non-allergic donors

TY - JOUR

T1 - In vitro effects of monophthalates on cytokine expression in the monocytic cell line THP-1 and in peripheral blood mononuclear cells from allergic and non-allergic donors

AU - Glue, C

AU - Millner, A

AU - Bodtger, U

AU - Jinquan, T

AU - Poulsen, Lars K.

PY - 2002/12

Y1 - 2002/12

N2 - It has recently been shown that plasticizers are present in indoor air dust, which may lead to human exposure via the inhalation route. Moreover, studies have indicated that plasticizers may possess adjuvant effects increasing the health damaging potential of allergens. The aim of this study was to investigate the in vitro effect of metabolites of phthalate plastisizers, such as whether an adjuvant effect is paralleled by changes of the cytokine expression in the monocytic cell line THP-1 and in peripheral blood mononuclear cells (PBMCs) from allergics and non-allergics. The toxicity monitored by cell viability was determined by incubating THP-1 cells with a 10-fold dilution series of monophthalates for 24 h. At different points in time cytokine expression (IL-1beta, IL-6, IL-12alpha (p35)) in THP-1 cells incubated with non-toxic concentrations of monophthalate (2-20 microg/ml)+/-LPS (1 microg/ml) were determined using Quantitative Competitive RT-PCR. PBMCs from allergics and non-allergics were incubated with monophthalate 220 microg/ml) for up to 48 h and cytokine expression (IL-4, IL-5, IFN-gamma) was measured using real-time PCR. The cytotoxic level of monophthalates is 20-200 microg/ml, depending on the individual monophthalate. There seems to be a correlation between increasing side-chain length and toxicity. Monophthalates did not induce changes in cytokine expression in THP-1 cells, though there is an increase when co-incubating with LPS. Cytokine expression in PBMC seems virtually unchanged when co-incubated with monophthalate, though mono-n-butyl phthalate (MBUP) tends to increase the level of IL-4 in PBMCs from allergic individuals. The two cellular models demonstrated the dynamics of regulated cytokine mRNA and are applicable for in vitro immunotoxicological investigations. The results regarding monophthalates suggest these to have a limited effect on cytokine expression in the monocytic cell line THP-1 and weak effect on cytokine expression in PBMCs from allergic and non-allergic individuals.

AB - It has recently been shown that plasticizers are present in indoor air dust, which may lead to human exposure via the inhalation route. Moreover, studies have indicated that plasticizers may possess adjuvant effects increasing the health damaging potential of allergens. The aim of this study was to investigate the in vitro effect of metabolites of phthalate plastisizers, such as whether an adjuvant effect is paralleled by changes of the cytokine expression in the monocytic cell line THP-1 and in peripheral blood mononuclear cells (PBMCs) from allergics and non-allergics. The toxicity monitored by cell viability was determined by incubating THP-1 cells with a 10-fold dilution series of monophthalates for 24 h. At different points in time cytokine expression (IL-1beta, IL-6, IL-12alpha (p35)) in THP-1 cells incubated with non-toxic concentrations of monophthalate (2-20 microg/ml)+/-LPS (1 microg/ml) were determined using Quantitative Competitive RT-PCR. PBMCs from allergics and non-allergics were incubated with monophthalate 220 microg/ml) for up to 48 h and cytokine expression (IL-4, IL-5, IFN-gamma) was measured using real-time PCR. The cytotoxic level of monophthalates is 20-200 microg/ml, depending on the individual monophthalate. There seems to be a correlation between increasing side-chain length and toxicity. Monophthalates did not induce changes in cytokine expression in THP-1 cells, though there is an increase when co-incubating with LPS. Cytokine expression in PBMC seems virtually unchanged when co-incubated with monophthalate, though mono-n-butyl phthalate (MBUP) tends to increase the level of IL-4 in PBMCs from allergic individuals. The two cellular models demonstrated the dynamics of regulated cytokine mRNA and are applicable for in vitro immunotoxicological investigations. The results regarding monophthalates suggest these to have a limited effect on cytokine expression in the monocytic cell line THP-1 and weak effect on cytokine expression in PBMCs from allergic and non-allergic individuals.

KW - Cell Line

KW - Cytokines

KW - Gene Expression Regulation

KW - Humans

KW - Hypersensitivity

KW - Monocytes

KW - Phthalic Acids

KW - Polymerase Chain Reaction

KW - RNA, Messenger

KW - Reverse Transcriptase Polymerase Chain Reaction

M3 - Journal article

C2 - 12423647

SN - 0887-2333

VL - 16

SP - 657

EP - 662

JO - Toxicology in Vitro

JF - Toxicology in Vitro

IS - 6

ER -