Not Your Mother’s Molecules: Researchers Mull Clinical Potential of “Unconventional” Immune Cells

Ribbon structure of MHC class I and unconventional APC molecules.

Before the immune system can mount a protective response against a disease-causing pathogen, proteins known as major histocompatibility complex, or MHC, molecules must present immune cells with a pathogen portion. Most studies to date have focused on MHC class I or II molecules that present protein fragments, but immunologists have identified several so-called nonclassical MHC molecules and “unconventional” T cells that employ other methods of presenting foreign material to the immune system. A new report from PLOS Pathogens summarizes a 2017 NIAID-sponsored workshop in which researchers shared the current understanding of such alternative mechanisms and considered how they may be exploited to develop novel vaccines against HIV, tuberculosis and cancer.