Dr. Miguel Tam and Plasmacytoid Dendritic Cells

Dr. Miguel Tam came to our class last Monday to talk about his research on CD2X regulation of INIF I production by plasmacytoid dendritic cells.

The innate immune system contain dentritic cells that can recognize harms from the environment.
Pathogenic Bacteria signals conventional dendritic cells that - stimulate effector functions.

There are two types of dendritic cells, plasmacytoid dendritic cells (pDC) and and conventional dendritic cells (cDC).  When a virus is recognized by a pDC, the cell produces type I interferons (IFN-I) which stimulates an antiviral response.

Dr. Tam's experiments were to determine the role of CD2X in the production of INF-I.

First, Dr. Tam was able to prove that pDC cells were able to express CD2X.

Second, Dr. Tam wanted to determine the role CD2X played in IFN-I production.  He was able to prove CD2X deficiency stimulates IFN-I production with the use of knockout mice.

Third, Dr. Tam wanted to determine the role of CD2X in an antiviral response so he infected knockout mice and WT mice with MCMV.  Both CD2X and IFN-I were expressed higher in CD2XKO mice.  50:50 chimera mice (CD2XKO and WT) were also exposed to MCMV and the KO cells produced more INF-I than WT.  The experiment was repeated with a different mouse virus and again the CD2XKO cells produced more IFN-I and Dr. Tam was able to conclude that CD2X had an effect on the production of IFN-I. 

Finally, Dr. Tam wanted to determine the mechanism for CD2X production of IFN-I.  A Src molecule is phosphorlated as one the the steps in a chain reaction for CD2X to produce IFN-I.

After all of the experiments were finished Dr. Tam was able to conclude that CD2X controls production in pDC cells and CD2X regulation of IFN-I has an effect on the viral load.  If CD2X is low, IFN-I is high.

IFN-I is involved in psoriasis and systemic Lupis.  Understanding the the mechanisms behind IFN-I could lead to better control and treatment of certain types of autoimmune diseases.