IgD is primarily expressed as a receptor on which cells?

IgD is primarily expressed as a receptor on which cells?

• A. IgD
• B. IgG
• C. IgA
• D. IgM

Answer: (A)

B cells carry their antigen receptor on the cell surface in the form of membrane-bound immunoglobulins. Naive mature B cells co-express membrane-bound IgM and IgD, which function together as the B cell receptor to recognize antigen and trigger activation. Among the immunoglobulin classes listed, IgD is the one primarily expressed as a receptor on the B cell surface, while the others are typically secreted antibodies found in blood or mucosal areas. So IgD serves as the receptor on B cells in this context.

B cells carry their antigen receptor on the cell surface in the form of membrane-bound immunoglobulins. Naive mature B cells co-express membrane-bound IgM and IgD, which function together as the B cell receptor to recognize antigen and trigger activation. Among the immunoglobulin classes listed, IgD is the one primarily expressed as a receptor on the B cell surface, while the others are typically secreted antibodies found in blood or mucosal areas. So IgD serves as the receptor on B cells in this context.