Immune reactivity in cattle with ocular squamous cell carcinoma after intralesional BCG immunotherapy

Effects of isoniazid (INH) on the BCG-induced local immune response after intravesical BCG therapy for superficial bladder cancer

Because recent investigations showed that the use of isoniazid (INH) severely impaired the local immune reaction to intravesical bacillus Calmette-Guérin (BCG) in the bladder of guinea pigs, in this study the effect of INH in man has been investigated. Patients were treated with BCG with or without oral INH. The concentration of free INH in most urine samples of patients treated with BCG/INH was much higher (mean 38.0 +/- 60.9 micrograms INH/ml) than the minimal inhibitory concentration (MIC; 0.1 microgram INH/ml), suggesting at least a bacteriostatic potential of the INH present. However, in vitro studies showed that these urinary concentrations of INH did not kill BCG organisms effectively, even at a concentration of 150 micrograms/ml for 24 h. After the fifth and sixth BCG instillations a significant increase in the concentration of cytokines (IL2, IL6, IL8 and TNFa), IgG and IgA antibodies to BCG and the number of leukocytes in urine was observed. The leukocytes mainly consisted of granulocytes, besides monocytes/macrophages and, in lower amounts, T- and B-lymphocytes and natural killer (NK) cells. The absolute number of granulocytes and the concentration of IgG antibodies after BCG instillation were significantly suppressed by INH, whereas INH appeared to have no effect on the urinary cytokine and IgA antibody concentrations or the total number and phenotype of the leukocytes present. In conclusion, the results of this study indicate that INH does not impair the local immunological stimulation after BCG instillation in man as severely as was observed in the guinea pig and it may be expected that INH does not impair the antitumor efficacy of BCG.

Immunotherapy of bovine ocular squamous cell carcinoma by repeated intralesional injections of live bacillus Calmette-Guérin (BCG) or BCG cell walls

Thirty cows of the Dutch Friesian and the Maas-Rijn-Ijssel breed with histologically confirmed ocular squamous cell carcinoma were treated by repeated intralesional injection of live bacillus Calmette-Guérin (BCG) (n = 14) or a BCG cell-wall vaccine (n = 16). Complete regression of the primary tumour was observed in 64% and 57% of the animals respectively. In the 2-year follow-up period there was no recurrence of primary tumours. This sharply contrasts with the recurrence frequency (40%-50%) after complete remission induced by a single intralesional injection with BCG, observed in an earlier study. In 1 animal a new primary tumour developed. At necropsy metastases were present in 33% of the treated animals: in 3 of 17 animals that showed complete regression of the primary tumour and in 7 of 13 animals with partial regression or progressive disease. This did not differ significantly from results obtained after a single treatment (27%). Delayed-type hypersensitivity to M. bovis purified protein derivative (PPD) was more persistent in animals showing regression of the primary tumour than in non-responding animals. Of the animals with a positive PPD response 6 months after treatment, 79% showed tumour regression. Regression was observed in only 28% of the animals not responding to PPD after the same period of time.

IN CONCLUSION

(a) recurrence of the primary tumour was not observed after repeated BCG treatment; (b) the frequency of metastases was not decreased compared to results obtained with a single treatment; (c) regression was correlated with a positive delayed-type hypersensitivity reaction to PPD (P less than 0.05) 6 months after treatment; (d) no significant differences were observed when the clinical results of treatment with live BCG and the BCG cell wall vaccine were compared.

Immunological aspects of mammary tumors in dogs and cats: a survey including own studies and pertinent literature

Naturally occurring cancer in companion animals parallels cancer in man more closely than does experimentally induced cancer in inbred laboratory animals. In dogs and cats, as in man, a role for immune responses is indicated in the development of tumors. A survey is presented based on the literature and our own studies concerning the immunological and immunotherapeutic aspects of canine and feline mammary neoplasia. In dogs bearing mammary neoplasms, circulating immune complexes appear to play a negative role in the generation of effective antitumor immune responses. The functional role of peripheral blood lymphocytes and tumor-infiltrating lymphocytes in dogs and cats with mammary tumors is not yet fully established. No tumor antigen responsible for humoral or cellular responses has yet been identified. Extracorporeal perfusion of serum of dogs with mammary tumors and subcutaneous administration of mitomycin- and neuraminidase-treated autologous tumor cells are associated with improved prognosis. The opposite was true for i.v. treatment with BCG or Corynebacterium parvum vaccine in our study, in contrast to a previous report. A number of other treatment modalities in cats and dogs with mammary carcinomas failed to induce tumor regression. Canine and feline mammary carcinomas are good candidates for modern immunotherapeutic approaches.

Local interleukin-2 therapy in bovine ocular squamous cell carcinoma. A pilot study

Five cows bearing bovine ocular squamous cell carcinoma (BOSCC) were treated with low doses of recombinant human interleukin-2 (rhIL-2). A dose of 2500 U rhIL-2 was injected intralesionally and another 2500 U were injected into the subparotid regional lymph node once a day during a period of 5 consecutive days. This cycle of 5 days was repeated after an interval of 2 days. Total regression of the tumor was observed in three out of five animals. One cow showed tumor regression (greater than 80%) accompanied by metastases to the regional lymph node that were observed from the fifth week after the beginning of the treatment. Growth of the tumor of the fifth animal was retarded after treatment. In vitro proliferation of peripheral blood lymphocytes was investigated in two animals and tumor-infiltrating lymphocytes in one animal during incubation in various rhIL-2 concentrations. Cytotoxic activity of both cell populations against P815, Yac-1 and BOSCC-derived cell lines increased during incubation with rhIL-2. Cultured BOSCC-infiltrating lymphocytes showed predominant killing of the BOSCC-derived autologous cell line after 4 weeks of culture. Preliminary phenotype analysis did not give conclusive results with respect to the types of cells responsible for killing.