Re: prostate cancer and cell vaccines

Myeloid dendritic cell (mDC) Most similar to monocytes. mDC are made up of at least two subsets:

(1) the more common mDC-1, which is a major communicator of T cells

(2) the extremely rare mDC-2, which may have a function in fighting wound infection

IL-12 TLR 2, TLR 4 Plasmacytoid dendritic cell (pDC) Look like plasma cells, but have certain characteristics similar to myeloid dendritic cells. By virtue of interferon production alone they can activate or transfer.

So, splitting hairs as to whether dendrites transfer or activate is a discussion of a good chess game. Using the word "Killer" is lay-person, metaphorical speak, not textbook, Immunology.

[Every helper T-cell is specific to one particular antigen. Only professional antigen-presenting cells (macrophages, B lymphocytes, and dendritic cells) are able to activate a resting helper T-cell when the matching antigen is presented. However, macrophages and B cells can only activate memory T cells whereas dendritic cells can activate both memory and naive T cells, and are the most potent of all the antigen-presenting cells.

Life span varies but activated t-cells and dendrites live only a few days, although research is indicating there are ways to extend that lifespan to weeks.

Some of the latest and greatest, not to mention expensive immune therapies boast loudly about "trained dendrites."

Well, tagging is pretty well established as primary dendrite function mow!

I will find that presentation but you can use tagging as a key word in your browser. Google: "Myeloid dendrites and tagging"

So, immune therapies bragging about dendrite based vaccines,(for lack of better term) can only be partially effective, especially if used as primary therapy.

The reasons why dendritic injections are only partially effective against cancer are:

1) The proceedure by-passes the very first and most important part of the immune response. Tagging.

2) Dendritic cells,(active,) only live a short time.

3) Activated T-lymphocytes also have short life span and are specific to one antigen.

4) Histocompatability complexes are what prevent tagging in the first place and therefore even when a lymphocyte is activated it has to find the antigen by efficient process as life span is an issue, if we rely on these activated lymphocytes to just come accross the antigen by happenstance, (how many activate cells die before finding their targets?)

5) The immune assualt must initially come from lymphatic system before the bone marrow kicks in to over drive.
The entire immune cascade rarely happens with tumor vaccines.

So, lets remember what the overall theme of the posting is.

Most tumor vaccines are helpful, therapeutic, but the mountains of empiracle data indicates they are not curative.

There are always exceptions to anything however.

That is why I advocate tumor vaccines as part of an overall war but downplay the hype so other therapies do not get excluded.

Tumor vaccines are just one weapon in that war.
A war where losing can't be an option!

Bret Peirce Tweet