I want to thank you for sharing your thoughts on immunotherapy in the article in “High Points and Hurdles: Immunotherapy Moves Forward” online at OncLive.
As a patient/survivor/researcher of stage IV melanoma I know first hand of the importance of integrating immunotherapy into a patient’s treatment. Timing of the therapy is everything, along with the patient’s tumor burden and stage.
In the early phase of cancer, the tumor cells are trying to establish a foothold in a foreign land. They do this by recruiting Tregs with cytokines (Il-10, TFG-b etc.) along with chemoattractants and suppressive cells.
Two of the first arrivals are Tregs along with IL-10. In the early phase of cancer, it has been discovered that the patient’s Tregs are elevated along with IL-10 concentration.
So when the macrophages and immune cells arrive at the tumor’s microenvironment, they encounter suppressive conditions allowing the tumor to continue with growth and progress. The elevated IL-10, IL-4 concentration polarizes the monocyte to the M2, and the T-cells to the Th2 phenotypes and shutting down the immune response.
Treg cell migration to Melanoma tumors is mediated by CCL22 released by cancer cells and tumor-associated macrophages. This cytokine plays a role in the trafficking of activated/effector T-lymphocytes to inflammatory sites and other aspects of activated T-lymphocyte physiology. Chemotactic for monocytes, dendritic cells and natural killer cells. Mild chemoattractant for primary activated T-lymphocytes and a potent chemoattractant for chronically activated T-lymphocytes but has no chemoattractant activity for neutrophils, eosinophils, and resting T-lymphocytes This attraction is the beginning of the suprresiveness of the the tumor’s microenviroment.
IL-10 promotes the development of a type 2 cytokine pattern by inhibiting the IFN-γ production of T lymphocytes particularly via the suppression of IL-12 synthesis in accessory cells.
So how can we integrate immunotherapies into treatment timelines to generate the wanted immune response toward the cancer?
- First, you need to evaluate the cancer patient and establish their stage.
- Second, check the tumor’s genetic code for mutations.
- Third, evaluate the patient’s overall health and the ability to go through the therapy
Here is a generic graphic on how to activate an innate and adaptive response.
1) You need to generate tumor-associated Antigens
2) You need to generate “The Danger Signal” (proinflammatory cytokines secreted, IL-1, IL-6, IL-12, TNF-alpha, Nitric Oxide, PGE2)
3) Block the Suppressive factors that inhibit T-cell activation (Anti-CTLA-4, Anti-PD-1, Anti IL-10r) IL-10 suppresses many functions of (NK) cells and T cells, primarily by preventing APCs from producing proinflammatory cytokines, “The Danger Signal”)
4) Tilt the T-cell Differentiation toward the TH1 phenotype and the Macrophage (TAM), Tumor Associated Macrophage polarization toward the M1 phenotype
5) Alter the tumor’s Microenvironment (addition of Multikine)
6) Produce activated CTLs and Memory T-cells(addition of IL-2)
The Bottom line is we need Sequential Combinatorial Therapy with timing and dosage as the major limiting factors in creating the innate and adaptive immune response.
“It is not the strongest of the species that survives, nor the most intelligent, but the one most responsive to change.”