Effect of polyadenylic.polyuridylic acid on the proliferative responsiveness of mouse thymus and spleen cells

The effects of polyadenylic.polyuridylic acid [poly(A).poly(U)] on in vitro proliferations of thymus and spleen cells from C57BL/6 mice were investigated. Mice were injected intravenously with 30 micrograms of poly(A).poly(U) or placebo. Two days later, thymus, spleen and peritoneal cells from these mice were prepared and cultured in pooled or non-pooled conditions. Cell proliferations were assessed by the technique of incorporation of tritiated thymidine. It has been revealed that the in vitro proliferations of thymus and spleen cells as well as the productions of interleukin-1 by peritoneal adhering cells and interleukin-2 by spleen cells were significantly enhanced in the cultures of cells from poly(A).poly(U)-treated mice. These enhancing effects were observed only in the cultures of pooled cells from mice whose genetic homogeneity is suspected. Furthermore, thymus cells from poly(A).poly(U)-treated mice acted as strong responder cells but not as stimulators in one way mixed cultures. Thus, the enhanced cellular responsiveness may be mediated by the increased production of cytokines and antigen recognitions of thymus-derived cells following activations via the adjuvant effect of poly(A).poly(U).

Adjuvant Treatment with Chemotherapeutic Agents and Polyadenylic-Polyuridylic Acid in Operable Stomach Cancers: I. Enhancement of Natural Killer Cell Activity

Natural Killer (NK) cell activity of 47 operable stomach cancer patients was sequentially studied before and after chemotherapy in association with polyadenylic. polyuridylic acid [poly(A).poly(U)]. NK activity was determined by an in vitro 4 h chromium release assay using nonadherent mononuclear cells isolated from peripheral bloods as effectors and human myeloblastic cells (K562) as targets. The following results were obtained: 1) The mean NK activity of the 47 patients tested before chemotherapy was significantly lower than that of 14 healthy controls. 2) The patents who received chemotherapy consisting of 5 FU (12 mg/kg) and adriamycin (40 mg/M2) showed an increase in NK activity 5 days after injection as compared to that of the same patients tested before chemotherapy. 3) In these patients, an additional administration of poly(A) poly(U) (100mg) resulted in a further significant increase of NK activity 2 days later, whereas the control patients who received placebo showed no change of NK activity.