Final answer:
The CD1 antigen is the molecule on APCs that presents lipid antigens, crucial for recognizing tuberculosis infections.
Step-by-step explanation:
The molecule found on the surface of antigen-presenting cells (APCs) that present lipid antigens and plays an important role in recognizing tuberculosis infections is the CD1 antigen. Unlike MHC II molecules, which are also found on APCs and present peptide antigens to T cells, CD1 molecules specialize in presenting lipid-based antigens to T cells. This is particularly relevant in the context of tuberculosis since the bacterium that causes TB, Mycobacterium tuberculosis, contains many unique lipids in its cell wall that are recognized by the immune system. CD1 antigen-presenting molecules therefore play a crucial role in the immune response against tuberculosis.