Transfer of osteosarcoma-specific cell-mediated immunity in hamsters by rabbit dialyzable leukocyte extracts

Dialysable leukocyte extracts modify the course of experimental paracoccidioidomycosis in the Syrian hamster

The effect of dialysable leukocyte extracts (DLE) obtained from hamsters immunized with Paracoccidioides brasiliensis (immune DLE) and from non-immunized hamsters (non-immune DLE) was studied in hamsters inoculated with P. brasiliensis by the intratesticular route. Treatment with immune or non-immune DLE was started during the third week of infection and was repeated at 7, 11, 15 and 19 weeks. A group of untreated infected animals was used as control. Animals were submitted to the delayed hypersensitivity skin test to P. brasiliensis antigen (PbAg) in vivo and assayed in vitro by the macrophage migration inhibition test in the presence of Phytohemagglutinin (PHA) and PbAg and by immunodiffusion for specific antibody. The animals were sacrificed at 4, 8, 12, 16 and 20 weeks. The morphology and extension of the lesions were studied at the inoculation site, and in lymph nodes, lungs, liver, spleen and kidneys. In contrast to the controls, animals treated with both DLEs maintained a positive cell-mediated immune response throughout the experiment and developed less extensive infection with a significantly lower number of fungi in the lesions. The results suggest that immune and non-immune DLE preparations modified the evolution of experimental paracoccidioidomycosis with equal efficiency. This similarity may be explained by the immunoregulatory activities of both extracts.

Spleen cell dialyzable extracts (SCDE) mediated immunotherapy for patients with myasthenia gravis

We studied 14 cases of myasthenia gravis (MG) with regard to their anti-acetylcholine receptor antibody (AChR-Ab) production, peripheral blood CD4+/CD8+ ratio, and responses of peripheral lymphocytes to PHA and PWM stimulations. We found that the clinical severity was not proportional to AChR-Ab level in serum in terms of whole myasthenic population, whereas in one individual patient there was a close correlation between clinical severity and the AChR-Ab level in serum. The CD4+/CD8+ ratio in myasthenic patients was significantly higher than that of normal controls. The responses of T- and B-cells to mitogenic stimulations were impaired in myasthenic patients. The immune abnormalities found in the majority of the patients were restored to about normal after spleen cell dialyzable extracts (SCDE) therapy was applied to all patients. The results implicated that SCDE, working as an immunomodulator, could serve as a promising agent to normalize the abnormal immune functions of MG patients or other autoimmune diseases.

An animal model for evaluation of antigen-specific dialyzable leukocyte extracts therapy of osteosarcoma

The effects of human osteosarcoma (OS)-specific dialyzable leukocyte extracts (DLE) in hamsters bearing human OS were investigated. The DLE used in this investigation was prepared from rabbits immunized with human osteosarcoma-associated antigens (DLE-OSAA). Tuberculin (DLE-PPD) and control DLE were prepared from rabbits injected with tuberculin or 0.85% NaCl (DLE-NaCl). DLE was administered subcutaneously into inbred hamsters (each injection contained DLE derived from 10(7) rabbit leukocytes). Four groups of animals were studied: group 1, amputation alone; group 2, amputation plus DLE-OSAA; group 3, amputation plus DLE-PPD; group 4, amputation plus DLE-NaCl. Of the DLE-OSAA-treated animals (group 2), 60% were still alive at 300 days postamputation; whereas in animals in groups 1, 3, and 4, all died within 90 days postamputation. In separate experiments, we found that 100% of the animals in groups 1, 3, and 4 developed pulmonary metastases within 30-60 days postamputation, whereas only 20% of the animals in group 2 developed metastases at the same time; indeed 40% of the DLE-OSAA-treated animals were free of metastases in 240-300 days postamputation. Both the leukocyte adherence inhibition assay (LAI) and lymphocyte DNA synthesis assay (LDS) were used to monitor the transfer of antigen-specific cell-mediated immunity in each group of tumor-bearing hamsters. All surviving hamsters in group 2 had high LAI and LDS activity. Our results suggest that DLE-OSAA is effective in preventing pulmonary metastases and death of OS-bearing hamsters (after amputation) as compared with amputation alone, amputation plus DLE-NaCl, and amputation plus DLE-PPD, and that its effect is via an antigen-specific mechanism.