Final answer:
The majority of dendritic cells are conventional dendritic cells, which present antigens in MHC class II molecules. These cells, alongside macrophages and B cells, play a crucial role as professional antigen-presenting cells in triggering the adaptive immune response.
Step-by-step explanation:
The majority of dendritic cells belong to the subtype known as conventional dendritic cells, which are also referred to as classical dendritic cells. Dendritic cells are critical immune cells that process antigen material and present it on the surface of other cells to induce an immune response.
In context to the antigen-presenting molecules, dendritic cells present antigens in MHC class II molecules. These molecules are specifically found on the cells of the immune system, which includes macrophages, dendritic cells, and B cells. These cells are termed "professional" antigen-presenting cells because they have the role of presenting antigens to T cells to activate them, an essential function in orchestrating the adaptive immune response.