There are three main types of Professional Antigen-presenting Cells.

http://en.wikipedia.org/wiki/Antigen-presenting_cell

• Dendritic cells (DCs), which have the broadest range of antigen presentation, and are probably the most important APC. Activated DCs are especially potent T_Hcell activators because, as part of their composition, they express co-stimulatory molecules such as B7. This B7 co-stimulator of mature interdigitating dendritic cell (IDC) interacts with surface CD28 of naïve T-cell.
• Macrophages, which are also CD4+ cells and are therefore susceptible to infection by HIV as well, since HIV invades immune cells through CD4+ receptor interactions.
• Certain B-cells, which express (as B cell receptor) and secrete a specific antibody, can internalize the antigen, which bind to its BCR and present it incorporated to MHC II molecule, but are inefficient APC for most other antigens.
• Certain activated epithelial cells.