Thanks Long. I know my posts are heavy on the science, but that's where I feel like I can contribute the most. Being of scientific mind I like to understand the the fundamentals of a therapeutic approach. In that way when I hear something from the company in a news release, presentation or paper I can hopefully determine what impact the news might have and guess about what it might mean.
As far as your question, that is a tough one to answer. I think if you look at it from a perspective of what is being induced that creates immunity, then probably the most important thing in my mind is T-cell mediated immunity. That is a broad topic that involves T cells that directly kill target cells, cells that promote T cells that kill targets and cells that act to limit immune activation.
Going from that perspective then off the top of my head, IL-12 is extremely important because of the effects I already posted. To just add a little more to the IL-12 story, IL 12 is one of the necessary cytokines to drive a subset of T cells (CD4) to become TH1 cells. TH1 cells are important for the reasons I already posted and many more reasons I've not tried to elaborate on. Activated DCs also make IL-12 that can then stimulate (with IL-18) bystander cells to make IFN gamma. IFN gamma is absolutely critical for so many relevant functions. For some pathogens winning or losing the fight depends on a continuous presence of IL-12. Take it away and the mouse loses. Take it away and then add it back after the mouse declines but before death and the mouse wins. I don't know if winning against tumor cells requires a continuous presence of IL-12, I suspect it might since tumor cells produce so many inhibitory molecules.
Once a T cell finds its matching antigen it undergoes activation and it is critical that the cell proliferate. A properly activated T cell can divide two or three times in a 24 hour period and can go on doing so for several days. Thus, one activated T cell can give rise to 1000's of clones that are all specific to the same antigen. IL-2 (T-cell growth factor)is an important proliferation signal for T cells that the activated T cells themselves make, but so do TH1 cells and other cells. In some circumstances the IL-2 made by the TH1 cell can be very important (for example when a naive T cell finds a tumor cell with a MHC:antigen complex that matches its specificity). Take away IL-2 and the t cell dies.
Those are probably the two most important in my opinion. But other cytokines like IFN gamma and TGF alpha are also very important.
