1 . While some allergies (过敏症) disappear over time or with treatment, others last a lifetime. For decades, scientists have been searching for the source of these lifetime allergies.
Recently, researchers found that memory B cells may be involved. These cells produce a different class of antibodies known as IgG, which ward off viral infections. But no one had identified exactly which of those cells were recalling allergens or how they switched to making the IgE antibodies responsible for allergies. To uncover the mysterious cells, two research teams took a deep dive into the immune (免疫的) cells of people with allergies and some without.
Immunologist Joshua Koenig and colleagues examined more than 90, 000 memory B cells from six people with birch allergies, four people allergic to dust mites and five people with no allergies. Using a technique called RNA sequencing, the team identified specific memory B cells, which they named MBC2s that make antibodies and proteins associated with the immune response that causes allergies.
In another experiment, Koenig and colleagues used a peanut protein to go fishing for memory B cells from people with peanut allergies. The team pulled out the same type of cells found in people with birch and dust mite allergies. In people with peanut allergies, those cells increased in number and produced IgE antibodies as the people started treatment to desensitize them to peanut allergens.
Another group led by Maria Curotto de Lafaille, an immunologist at the Icahn School of Medicine at Mount Sinai in New York City, also found that similar cells were more plentiful in 58 children allergic to peanuts than in 13 kids without allergies. The team found that the cells are ready to switch from making protective IgG antibodies to allergy-causing IgE antibodies. Even before the switch, the cells were making RNA for IgE but didn’t produce the protein. Making that RNA enables the cells to switch the type of antibodies they make when they encounter allergens. The signal to switch partially depends on a protein called JAK, the group discovered. “Stopping JAK from sending the signal could help prevent the memory cells from switching to IgE production,” Lafaille says. She also predicts that allergists may be able to examine aspects of these memory cells to forecast whether a patient's allergy is likely to last or disappear with time or treatment.
“Knowing which population of cells store allergies in long-term memory may eventually help scientists identify other ways to kill the allergy cells,” says Cecilia Berin, an immunologist at Northwestern University Feinberg School of Medicine. “You could potentially get rid of not only your peanut allergy but also all of your allergies.”
1. Why did scientists investigate the immune cells of individuals with and without allergies?| A．To explore the distinctions between IgG and IgE. |
| B．To uncover new antibodies known as IgG and IgE. |
| C．To identify cells responsible for defending against allergies. |
| D．To reveal cells associated with the development of allergies. |
| A．Make. . . less destructive. | B．Make. . . less responsive. |
| C．Make. . . less protective. | D．Make. . . less effective. |
| A．MBC2s make antibodies and proteins that prevent allergies. |
| B．Memory B cells generate both RNA for IgE and the corresponding protein. |
| C．JAK plays a role in controlling antibody production when exposed to allergens. |
| D．Allergists are capable of predicting whether an allergy will last or disappear. |
| A．RNA Sequencing Is Applied in Immunology Research |
| B．Specific Cells Related to Peanut Allergies Are Identified |
| C．Unmasking Cells’ Identities Helps Diagnose and Treat Allergies |
| D．Newfound Immune Cells Are Responsible for Long-lasting Allergies |
