Which cell type is most effective at presenting antigen to naive T cells in tissues?

Which cell type is most effective at presenting antigen to naive T cells in tissues?

• A. Neutrophil
• B. Dendritic cell
• C. Eosinophil
• D. Basophil

Answer: (B)

Antigen presentation to naive T cells is best carried out by dendritic cells, which are the professional antigen-presenting cells of the immune system. They constantly sample tissues for foreign antigens, process them, and migrate to lymphoid tissues where they express high levels of MHC class II and co-stimulatory molecules like CD80/CD86. This combination provides both the peptide–MHC signal and the necessary second signal to fully activate naive T cells, leading to their proliferation and differentiation. Dendritic cells are especially adept at initiating responses because they can present antigen to naive T cells and also tailor the cytokine environment to influence T cell fate. Neutrophils focus on rapid pathogen killing and lack the robust antigen-presenting machinery; eosinophils and basophils play more specialized roles in parasites and allergic responses and are not efficient at priming naive T cells.

Antigen presentation to naive T cells is best carried out by dendritic cells, which are the professional antigen-presenting cells of the immune system. They constantly sample tissues for foreign antigens, process them, and migrate to lymphoid tissues where they express high levels of MHC class II and co-stimulatory molecules like CD80/CD86. This combination provides both the peptide–MHC signal and the necessary second signal to fully activate naive T cells, leading to their proliferation and differentiation. Dendritic cells are especially adept at initiating responses because they can present antigen to naive T cells and also tailor the cytokine environment to influence T cell fate. Neutrophils focus on rapid pathogen killing and lack the robust antigen-presenting machinery; eosinophils and basophils play more specialized roles in parasites and allergic responses and are not efficient at priming naive T cells.