Which statement about T cell independent responses is accurate?

Which statement about T cell independent responses is accurate?

• A. They require helper T cells to produce any antibodies.
• B. They generate high-affinity IgG antibodies via somatic hypermutation.
• C. They occur without T cell help and often produce mainly IgM with limited class switching.
• D. They only respond to protein antigens.

Answer: (C)

T cell independent antibody responses happen without helper T cell signals. They’re typically triggered by antigens that strongly engage B cell receptors or provide innate cues, such as certain polysaccharides or lipopolysaccharides. Because there’s no T cell help, B cells can become antibody-secreting cells quickly, but the response largely stays as IgM with only limited class switching to other antibody classes and minimal somatic hypermutation. This means you get a faster but weaker and less refined response, with poorer affinity maturation and memory compared with T cell–dependent responses. That’s why the accurate statement is that these responses occur without T cell help and often produce mainly IgM with limited class switching.

T cell independent antibody responses happen without helper T cell signals. They’re typically triggered by antigens that strongly engage B cell receptors or provide innate cues, such as certain polysaccharides or lipopolysaccharides. Because there’s no T cell help, B cells can become antibody-secreting cells quickly, but the response largely stays as IgM with only limited class switching to other antibody classes and minimal somatic hypermutation. This means you get a faster but weaker and less refined response, with poorer affinity maturation and memory compared with T cell–dependent responses.

That’s why the accurate statement is that these responses occur without T cell help and often produce mainly IgM with limited class switching.