Secondary exposure to heavy metal in genetically susceptible mice leads to acceleration of autoimmune response

Abstract

Exposure to mercury (Hg) and silver (Ag) has been shown to induce autoimmune diseases in genetically susceptible rodents. Here, A.SW mice were initially exposed to HgCl₂, AgNO₃ or tap water (control) for 3 weeks. After 13 weeks of stoppage, all mice had secondary exposure to ²⁰³HgCl₂. After secondary exposure, higher and earlier ANoA titers were observed in mice initially exposed to Hg or Ag compared to control. Further, mice initially exposed to Ag showed higher total IgG₁ and IgG_2a, Whole Body Retention and lymph nodes and spleen accumulation of Hg compared to mice initially exposed to Hg and controls. These findings showed an earlier and stronger immunological response in A.SW mice compared with control, following re-exposure to heavy metals indicating an immunological memory. Additionally, secondary exposure to a different heavy metal may aggravate the effects of exposure of at least one of the metals indicating cross-reactivity.

Keywords: A.SW mice; ANoA; Immunological memory; Mercury; Re-exposure; Silver.