In Patients with Hyper IgM Syndrome, There Is a Genetically

question 14

Multiple Choice

In patients with hyper IgM syndrome, there is a genetically based deficiency in expression of CD40 ligand. In addition to defects in antibody isotype switching, these patients have defects in T cell-mediated immune responses and become infected with intracellular parasites. Which one of the following normal functions of CD40 ligand is important in T cell-mediated immunity?

• A)CD40-dependent isotype switching is required to produce antibody isotypes that activate T cells.
• B)CD40 ligand is required for CTL killing of CD40-expressing infected cells.
• C)CD40 ligand is required for maturation of CD4⁺ T cells in the thymus.
• D)CD40 ligand on activated T cells binds to CD40 on antigen-presenting cells (APCs), and this enhances the expression of B7-1, B7-2, and cytokines by the APCs.
• E)CD40 ligand on T cells binds to B7-1 and B7-2 on APCs, and this enhances the function of the APCs.

---

Definitions:

Explicit Mission Statement

A clear, concise statement that defines an organization's purpose and primary objectives.

Coercive Leader

A leadership style characterized by the use of threats and punishment to influence the behavior of others.

Instantaneous Obedience

Immediate compliance with orders or commands without any delay.

Motivation

The psychological forces that influence an individual's direction, intensity, and persistence of voluntary behavior.