Hydroquinone inhibits bone marrow pre-B cell maturation in vitro

Area of Science:

• Immunology
• Toxicology
• Hematology

Background:

• Benzene exposure causes myelotoxicity and immunotoxicity.
• Benzene-induced immunotoxicity mechanisms are not fully understood.
• The role of altered marrow lymphoid cell differentiation in benzene toxicity is unexplored.

Purpose of the Study:

• To investigate the effect of hydroquinone, a benzene metabolite, on B-lymphopoiesis in murine bone marrow.
• To determine if hydroquinone exposure impacts B cell differentiation stages.

Main Methods:

• Murine bone marrow cells were depleted of mature B cells and cultured.
• Cells were exposed to hydroquinone for 1 hour prior to culture.
• B cell production was assessed by surface IgM expression and colony formation.
• Adherent cell populations were also quantified.

Main Results:

• Hydroquinone exposure reduced the generation of surface IgM+ B cells.
• A numerical increase in pre-B cells (cytoplasmic mu heavy chain+, sIgM-) was observed.
• Hydroquinone treatment decreased the number of adherent cells in bone marrow cultures.

Conclusions:

• Hydroquinone appears to block late-stage B cell differentiation in bone marrow.
• This differentiation block results in reduced B cell output and pre-B cell accumulation.
• Hydroquinone's toxicity to regulatory cells may contribute to its myelotoxic effects on B-lymphopoiesis.