Fresh living Bacillus Calmette-Guerin (BeG), injected i.v. into (C57BI/ 6xDBA/2)FI mice, activated peritoneal macrophages rendering them highly cytotoxic for tumor cells in vitro. This cytotoxic activity w~s already maximal 14 days after injection of 1 mg of BCG and remained stable when 3 or 5 mg of BCG were given. At the same time spleen cells of the BCG-treat~d mice showed strongly depressed responses to the T-cell mitogens,PHA and Con A, irrespective of the dose of BCG injected. The inhibitory effect was shown to be mediated by suppressor cells which had characteristics of macrophages since they could be removed by carbonyl iron and magnet treatment and were adherent to plastic. In contrast to it was observed after injec­ tion of 1 mg of BCG, these suppressor cells alone did not account for the depression of T-cell re.sponses induced by higher doses of BCG. Nylon-nonadherent cell populations obtained from spleen cells treated with 3 or 5 mg BCG partially retained the inhibitory activity suggesting that suppressor T cells were also induced after injection of high doses of BCG. In contrast, the responses to the B-cell mitogen LPS of unfractionated and macrophage-depleted spleen cells were not affected or significantly enhanced depending on the dose of BCG injected.

Inhalt

1. Morphological Recognition of Lymphocytes and Macrophages.- 2. Revised Semiology of the Different Mononuclear Cells Under Scanning Electron Microscopy.- 3. Immunologic Definition of Lymphocytes: Functions and Markers.- 4. In vitro Interactions Between Tumor Cells and Immune Lymphoid Cells.- 5. Activation and Cytotoxic Activity of Macrophages.- 6. Cell-Membrane Activation of Macrophage Function.- 7. Lymphocyte-Macrophage Interactions in BCG-Treated Mice.- 8. Liposomes as Immunological Adjuvants.- 9. Nonspecific Immunodepression Induced by Tumor-Cell Extracts.- 10. Increase in "Null" Cells in Acute Lymphocytic Leukemia in Remission on Long-Term Immunotherapy.- 11. Participation of Leukemia Cells in Immune Responses.- 12. Morphological Characterisation of Adult Acute Leukaemia in Short-Term Liquid Culture.- 13. Surface Cell Markers in Human Lymphoid Malignancies.- 14. An Immunological Classification of Leukemias and Hematosarcomas Based on Cell Membrane Markers with Special Reference to Null Cell Disorders.- 15. Hodgkin's Disease: A War Between T-Lymphocytes and Transformed Macrophages?.- 16. The Significance of the Macrophage Content of Human Tumours.- 17. Search for Correlations Between Immunological and Morphological Criteria Used to Classify Lymphoid Leukemias and Non-Hodgkin's Hematosarcomas with Special Reference to Scanning Electron Microscopy and T and B Membrane Markers.- 18. Non-Hodgkin's Hematosarcoma ("Lymphomas"): Classification of the W. H. O. Reference Center for Neoplastic Diseases of Hemopoietic and Lymphoid Tissues.