Telratolimod

3M-052 induces both TNFα and IFNα in human PBMCs in a manner indicative of a dual TLR7/TLR8 agonist. 3M-052 stimulates the production of IL8 in HEK293 cells stably expressing either human TLR7 or TLR8. In contrast, no IL8 is stimulated in empty vector control cells. The TLR8 agonist activity of 3M-052 may be of particular value in the immunization of neonates and infants whose monocytes and antigen presenting cells have a diminished capacity to generate TH1 polarizing signals to TNFα and IFNα.^[2]

PBMC are cultured at 2 × 10⁶/ml in 0.25 ml in 96-well plates. For evaluation of R848 and 3M-052, these compounds are first dissolved in DMSO and then diluted into culture medium to the final desired concentrations. DMSO concentration is maintained at 0.1% in all wells. The cultures are then incubated for 16 hr at 37 ◦C in a humidified atmosphere of 5.0% CO2 in air. The culture plates are then centrifuged to settle cells to the well surface and medium is removed for cytokine analysis by ELISA assay.

The co-administering CpG ODN with Telratolimod (3M-052) is remarkably effective at eliminating large established tumors and establishes long-term protective immunity. This anti-tumor activity is associated with a significant diminution in the frequency of tumor resident MDSC and accumulation of tumor-lytic NK and CD8 T cells, resulting in persistent anti-tumor immunity.^[1]