An excellent study by Japanese researchers published in @ sciencemagazine demonstrates how the surface of the same DC is sequestered by the co-stimulatory molecule # CD80 and promotes # Tcell # activation. Immunology, tolerance, and immunotherapyhttps: // t. co / RcArRXV9XTDavid Usharauli(@ 3DiMMUNE ) on April 23, 2019.
1. The authors first noticed that, in contrast to # macrophages # dendritic cells did not stain with the soluble # PD1 molecule, despite the fact that DCs expressed high levels of @ PDL1 ( PD1 ) ligands. However, it was noted that DCs also expressed# CD80 at a higher level. pic. twitter.com / hH1CbYxt7LDavid Usharauli(@ 3DiMMUNE ) on April 23, 2019.
3. 3. On the same cell surface, the co-expression of # PDL1 with # CD80, but not with CD86, PDL2, or any other CO -# stimulatory molecule, had a# functional consequence for OVA-specific T cell activation. It made it possible to produce IL-2 and # activation with greater vigor. pic. X0miudAspA twitter.comDavid Usharauli(@ 3DiMMUNE ) on April 23, 2019.
5. 5. The combination of # PDL1 and # CD80 molecules, which cannot interact with one another, also made it possible for T cells to more effectively inhibit the production of IL-2 in this instance. It demonstrated mechanically that” liberated” PDL1 on DCs cross-interacts with PD1 in T cells and # inhibits it. pic. YxM6oskg3q on twitter.comDavid Usharauli(@ 3DiMMUNE ) on April 23, 2019.
7. 7. Similar to this, mice expressing mutant PDL1 or CD80 molecules underwent brain priming with brain-specific antigens, though the effect appears to be minimal. pic. P2fyIusL1M on twitter.comDavid Usharauli(@ 3DiMMUNE ) on April 23, 2019.
It suggests that the PDL1 # sequestration by CD80 on DCs is not a significant immune system control path. The authors did not demonstrate whether it undermines tolerance for gut bacteria or defense against pathogens.David Usharauli(@ 3DiMMUNE ) on April 23, 2019.