Which class of macromolecule is most likely to be antigenic/immunogenic?

Which class of macromolecule is most likely to be antigenic/immunogenic?

• A. Nucleic acid
• B. Carbohydrates
• C. Lipids
• D. Proteins

Answer: (D)

Antigens are substances that provoke an immune response. Proteins are the most immunogenic because their amino acid sequences and complex three-dimensional folding create a vast array of distinct epitopes—surface features that antibodies can recognize and bind, as well as peptide fragments that T cells can detect when presented by MHC molecules. This combination of many linear and conformational epitopes and the efficient processing of proteins by antigen-presenting cells leads to strong, specific, and versatile adaptive immune responses. In contrast, nucleic acids and lipids generally present fewer, less diverse epitopes, and carbohydrates often require attachment to a protein to become highly immunogenic.

Antigens are substances that provoke an immune response. Proteins are the most immunogenic because their amino acid sequences and complex three-dimensional folding create a vast array of distinct epitopes—surface features that antibodies can recognize and bind, as well as peptide fragments that T cells can detect when presented by MHC molecules. This combination of many linear and conformational epitopes and the efficient processing of proteins by antigen-presenting cells leads to strong, specific, and versatile adaptive immune responses. In contrast, nucleic acids and lipids generally present fewer, less diverse epitopes, and carbohydrates often require attachment to a protein to become highly immunogenic.