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Toxicological information

Exposure related observations in humans: other data

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Administrative data

Endpoint:
exposure-related observations in humans: other data
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: Non-validated assay, can be used in weight of evidence approach only.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2005
Report Date:
2005

Materials and methods

Type of study / information:
Human peripheral blood-derived dendritic cells (DC) respond to a variety of chemical allergens by up-regulating expression of the costimulatory molecule CD86. It has been postulated that this measure might provide the basis for an in vitro alternative approach for the identification of skin sensitizing chemicals. DC, exposed in culture to the highest non-cytotoxic concentrations of various chemical allergens, displayed marginal up-regulation of membrane CD86 expression; the interpretation being that such changes were insufficiently sensitive for the purposes of hazard identification.
Endpoint addressed:
other: Contact sensitization
Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Immature DC were derived from human monocytes and treated with the test substance at both non-cytotoxic concentrations and concentrations which induced a 10–18% decrease in viability for 48 hours. TNFα was used as a positive control and media alone was as vehicle control.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Batch No.: not specifiedPurity: 99%

Method

Ethical approval:
confirmed and informed consent free of coercion received
Details on study design:
Immature DC were derived from human monocytes. Treatment of cultured DC: Prior to the start of an experiment, a concentration of 1.1E+06 cells/mL DC cell suspensions (2.7 mL) were plated in each well of a 6-well culture dish. Control cells received medium alone, and the test substance was conducted in triplicate wells for 48 h in the presence of GM-CSF and IL-4 at final in-well concentrations of 10 ng/mL each. Cytotoxicity was assessed flow cytometrically using propidium iodide dye exclusion. TNFa (40 ng/mL) was included in experiment as a positive control for CD86 upregulation. Flow cytometric measurement of surface antigenCD86 expression: Forty-eight hours after treatment with the chemicals, CD86 surface marker expression was measured using flow cytometry. An appropriately conjugated isotype-matched Ab was used to control for nonspecific staining. CD86 expression was considered to be up-regulated when the MFI of the chemical-treated DC was 120% of control.
Exposure assessment:
measured
Details on exposure:
TYPE OF EXPOSURE MEASUREMENT: Area air sampling / Personal sampling / Exposure pads / Biomonitoring (urine) / Biomonitoring blood / other:EXPOSURE LEVELS: concentrations of the test substance: 0.1, 0.2, 0.4, 0.8 mMEXPOSURE PERIOD: 48 hNo additional data

Results and discussion

Results:
CD86 expression in DC-treated cells with the test substance was less than 120% of control even when cell viability dropped to 90% or below.

Applicant's summary and conclusion

Conclusions:
No changes were observed in CD86 expression with the teat substance even when the concentration used reduced cell viability to 90% or less.
Executive summary:

Immature DC were derived from human monocytes and treated with the test substance at both non-cytotoxic concentrations and concentrations which induced a 10–18% decrease in viability for 48 hours. TNFα was used as a positive control and media alone was as vehicle control.

No changes were observed in CD86 expression with the teat substance even when the concentration used reduced cell viability to 90% or less.

The test substance is considered negative in this assay for sensitization.