Final answer:
CD4+ T cells are mainly responsible for the pathogenesis of asthma and can be suppressed by corticosteroids, thus reducing inflammation.
Step-by-step explanation:
The type of cells in asthma that play a major role in the pathogenesis of the disease and can be effectively suppressed by corticosteroids are CD4+ T cells. In asthma, these cells are involved in what is known as a type II hypersensitivity reaction, where they contribute to the recruitment and activation of eosinophils that release cytokines and inflammatory mediators. Corticosteroids work by suppressing the activity of these CD4+ T cells, along with other immune cells, and reducing inflammation.
Mast cells are also involved in hypersensitivity reactions and asthma, but they are primarily associated with type I hypersensitivity responses (allergic reactions) where they release histamine and other inflammatory molecules. These cells can phagocytize pathogens and are a source of chemicals promoting inflammation, however, the primary role in asthma involves CD4+ T cells, which are the target of corticosteroid suppression.