Question

Immunopathic reactions can occur when antibody combines with antigen on the surface of a tissue cell. This event either activates the complement sequence whose membrane attack complex kills the cell, or triggers cytotoxicity by natural killer (NK) cells. What is this cytolysis called?

CXCR4
TLR
CEA
AFP
ADCC

Answer 1

The cytolysis you asked about in immunopathic reactions is called antibody-dependent cell-mediated cytotoxicity (ADCC), and it's a key mechanism of Type II hypersensitivity reactions.

Step-by-step explanation:

The cytolysis you are referring to is known as antibody-dependent cell-mediated cytotoxicity (ADCC). ADCC is a cytotoxic mechanism by which cells, typically NK cells or cytotoxic T cells, kill a target cell that has antibodies bound to its surface. These cells recognize the bound antibodies through their Fc receptors, and upon binding, they can secrete cytotoxic molecules such as perforin and granzymes that lead to the lysis of the target cell.

This process is important for eliminating pathogen-infected cells or cells that have become abnormal. In the context of hypersensitivity, such reactions form part of Type II hypersensitivity reactions, where IgG or IgM antibodies bind to antigens on cell surfaces, leading to destruction of these cells.