A patient develops autoimmunity due to impaired immune suppression. Which T-cell subset is most directly affected?

Which hypersensitivity reaction is primarily mediated by immune-complex deposition?

A B cell encounters antigen smaller than 70 kDa in a lymph node. How can this antigen reach follicular B cells?

A patient develops poor antibody responses to protein antigens but normal early IgM responses to polysaccharides. Which pathway is selectively impaired?

Which immunodeficiency is characterized by failure of leukocytes to leave the bloodstream?

The most important function of high endothelial venules is to:

A thymocyte binds self-antigen strongly in the thymic medulla. What is the most likely consequence?

A patient undergoes kidney transplantation. Three months later, biopsy demonstrates mononuclear infiltration and progressive vascular fibrosis. Which type of rejection is occurring?

A developing B cell has completed heavy-chain rearrangement and expresses a pre-BCR with surrogate light chain. Which checkpoint is being assessed?

Which immunoglobulin class is responsible for sensitizing mast cells before allergen exposure?