Question

Inflammatory molecules are released by mast cells in type I hypersensitivities; type II hypersensitivities, however, are characterized by which of the following?

a) Formation of immune complexes
b) Activation of T cells
c) Antibody-dependent cell-mediated cytotoxicity
d) Opsonization of pathogens

Answer 1

Type II hypersensitivity reactions are characterized by antibody-dependent cell-mediated cytotoxicity (ADCC).

Step-by-step explanation:

Type II hypersensitivity reactions involve the binding of IgG and IgM antibodies to cell-surface antigens or matrix-associated antigens on basement membranes. These antibodies can activate the complement system, leading to an inflammatory response and lysis of targeted cells, or they can be involved in antibody-dependent cell-mediated cytotoxicity (ADCC) with cytotoxic T cells. Therefore, the correct answer is c) Antibody-dependent cell-mediated cytotoxicity.