DR. DAVID PHILLIPS/VISUALS UNLIMITED INCThe paper
C. Ohnmacht et al., “Basophils orchestrate chronic allergic dermatitis and protective immunity against helminths,” Immunity, 33:364-74, 2010.Free F1000 Evaluation
Basophils were deemed critical in allergic response and parasite removal, but their precise role has been controversial. David Vöhringer, now at Universitätsklinikum Erlangen, found that basophils are not involved in the primary response against infection with parasitic worms (helminths), as researchers assumed, but rather play a role in immunological memory.
The lucky break
Type 2 helper T cells (Th2) cells secrete IL-4, which promotes B-cell production of antibodies essential for the removal of helminths. Basophils also release IL-4, so Vöhringer wondered if basophils might act coordinately with Th2 cells. He started by trying to conditionally remove a protease that was specific to basophils. Luckily, the engineered mice were unable to make basophils at all, thus providing the researchers with a model for studying basophil immunology.
Vöhringer’s mice could mount a perfectly adequate Th2 response to parasites, indicating that basophils weren’t needed for instigating the antibody response. It suggested that basophils, “are not as sweepingly essential as first claimed,” says Faculty Member Rick Maizels. Surprisingly, though, the mice failed to clear re-infections with parasites, suggesting that basophils are required for Th2–mediated immunological memory.
The next step
Now, Vöhringer is looking for the mechanism by which basophils contribute to long-term immunological memory and trying to identify which type of B cell interacts with basophils.
F1000 evaluators: J. Hewitson and R. Maizels (Univ of Edinburgh) • R. L. Stevens (Brigham and Women’s Hosp, Harvard Med School) • D. Mucida (The Rockefeller University) and H. Cheroutre (La Jolla Inst for Allergy & Immunology)