Brief Communication: The Dependence of Successful Immunotherapy on Adequate Tumor Burden as Shown by the Treatment of AKR Leukemia With Poly A·poly U

Abstract

The therapeutic efficacy of polyadenlyic-polyuridylic acid (poly A-poly U) on the transplantable AKR leukemia varied with the dose of tumor cells implanted. The greater the number of AKR tumor cells injected into 8-week-old AKR mice free of clinical evidence of cancer, the greater the effect of poly A-poly U in mediating host immunologic control of the tumor. Poly A-poly U was either ineffective or could enhance tumor growth when smaller doses of tumor cells were transferred. The efficacy of an immune adjuvant depended on a tumor burden affording optimum host responsiveness. This does not necessarily arise in the host bearing minimal tumor burden.

Leukocyte migration inhibition test in breast cancer patients treated with conventional therapy or with conventional therapy plus poly A � poly U

“…Since the initiation of our trial in humans (November i972), it has also been demonstrated that poly A. poly U retards tumor growth in mice bearing transplantable leukemia (Pendergrast et al, 1975). A prophylactic spontaneous effect on leukemia and on spontaneous mammary tumors in mice was also described (Drake et al, 1974;Lacour, F. et al, 1975a).…”

T and B lymphocyte populations of tumor-bearing mice treated with 1,3-bis(chloroethyl)-1-nitrosourea (BCNU) or pyran

“…The depression of the T cell percentages detected by indirect immunofluorescence (Table 3) observed for tumored controls as against the nontumored controls from day 4 to day 13 is reminiscent of the immunosuppressive effect of tumor burden (Carter et al, 1972;Pendergrast et al, 1975). It was also noted that BCNU treatment did not markedly alter the percentage T cell population of tumor-bearing animals from that observed for the experimental controls, but these animals had significantiy higher percentages of T cells than the tumor controis for days 6, 8, and 11.…”

Therapeutic application of various immunostimulators on the L2C guinea-pig leukemia

“…The antitumor adjuvant activity of several immunomodulators, both chemical and biological in nature, has been extensively examined by numerous investigators in various animal model systems over the past 10 years (Woodruff and Boak, 1966;Matht, 1976;Math6 et al, 1969a,b;Zbar et al, 1971;Bansal and Sjogren, 1973;Currie and Bagshawe, 1970;Mohr et al, 1976;Pearson et al, 1974;Ebbesen, 1974;Pendergrast et al, 1975;Scott, 1975;DiLuzio et al, 1976;Morahan et al, 1974; * This work was supported by contract N01-CP-53566 within the Virus Cancer Program of the National Cancer Institute Reprint requests should be addressed to: D. L. Klein Sampson et al, 1977). The dose, route, and frequency of administration of these stimulators has been determined both prophylactically and therapeutically in order to establish what regimen of treatment is needed to produce maximal suppression of tumor growth (Woodruff et al, 1976;Scott and Bomford, 1976;Smith and Scott, 1972;Halpern et al, 1973;Mohr et al, 1975;Pearson et al, 1973;DiLuzio, 1975;Chirigos et al, 1973;Milas, 1973).…”

“…However, relatively little work has appeared in the literature concerning the therapeutic application of immunopotentiators in animal systems expressing tumors of hematopoietic origin (i.e., leukemias) (Math~ et al, 1973a(Math~ et al, , b, 1974Likhite and Halpern, 1973;Pearson et al, 1972). Since few leukemia models exist, heavy emphasis has been placed on the use of the L1210 (Mathe et al, 1969a(Mathe et al, ,b, 1973a(Mathe et al, , 1974Mohr et al, 1976), LSTRA (Smith and Scott, 1972;Pearson et al, 1972Pearson et al, , 1973, MCAs-10 (Pearson et al, 1974;Chirigos et al, 1975), and AKR (Ebbesen, 1974;Pendergrast et al, 1975;Math6 et al, 1973b) leukemia systems in mouse, and the Shay chloroleukemia model in rat (DiLuzio et al, 1976;DiLuzio, 1975;Likhite and Halpern, 1973). Additional experimental model systems to study the application of active immunotherapy in leukemic animals are therefore highly desirable.…”