Which of the following immune disorders is characterized by the immune system attacking and damaging its own body tissues?

Explanation: During cell-mediated immunity, T cells recognize antigens that are presented by antigen-presenting cells (APCs) such as macrophages. Macrophages engulf and process pathogens, and then they display fragments of the pathogens' antigens on their cell surface using major histocompatibility complex (MHC) molecules. T cells, specifically helper T cells, interact with these antigen-presenting macrophages and become activated to initiate immune responses.

Incorrect choices:
b. B cells present antigens to helper T cells during the humoral immune response, not during cell-mediated immunity.
c. Plasma cells are not involved in antigen presentation; they are terminally differentiated B cells that produce antibodies during the humoral immune response.
d. Memory cells are formed after the immune system encounters an antigen and are not directly involved in antigen presentation.

Explanation: Celiac disease is an autoimmune disorder in which the immune system attacks and damages the lining of the small intestine in response to the ingestion of gluten, a protein found in wheat, barley, and rye.

Incorrect choices:
a. Rheumatoid arthritis primarily affects the joints, not the small intestine.
b. Sjögren's syndrome primarily affects the salivary and lacrimal glands, not the small intestine.
d. Type 1 diabetes mellitus is an autoimmune disorder in which the immune system attacks and destroys insulin-producing beta cells in the pancreas, not the small intestine.