Mouse IgE clone SPE‐7 can contain functional mouse IgG.

The article discusses the presence of mouse IgG antibodies in the widely used mouse IgE clone SPE-7, which is used to study IgE biology and function. The study found that SPE-7 contains IgG2a/b-IgE complexes, which can alter the functional profile of IgE. The presence of IgG in SPE-7 was confirmed through various assays, including enzyme-linked immunosorbent assays (ELISA) and liquid chromatography-mass spectrometry (LC-MS). These findings challenge the concept that IgE exerts antigen-independent effects on mast cell degranulation and survival. The study suggests that the presence of contaminating IgGs in therapeutic IgE antibodies should be considered, as they may alter the functional and pharmacological profile of these antibodies. [Extracted from the article]