Human malanoma antigens and their epitopes recognized by T cells have been identified using a variety of methods. These antigens are classified as 1) melanocyte specific melanosomal proteins (MART-1, gp100, tyrosinase, TRP-1 and TRP-2), 2) proteins expressed in testis and a variety of cancers (MAGE-1, MAGE-3, BAGE and GAGE), 3) tumor specific mutated proteins (β-catenin, MUM-1 and CDK4), and 4) others (p15, GnT-V, PRAME). The HLA-A2 binding unmutated melanosomal epitopes were found to have a tendency to contain non-dominant anchor amino acids and have relatively low HLA-A2 binding affinity, suggesting that these epitopes are likely to be subdominant or cryptic self determinants. In addition, a variety of mechanisms for generating T cell epitopes on growing tumor cells have been discovered. Since a significant correlation between vitiligo development and tumor regression in the IL2 based immunotherapy was observed, autoreactive T cells specific for these self peptides may be involved in in vivo melanoma regression. Adoptive transfer of CTL recognizing these epitopes into patients resulted in tumor regression. Immunization with the MART-1, gp100 or tyrosinase peptides in conjunction with incomplete Freund adjuvant or GM-CSF also resulted in tumor regression in some patients. These observations suggest that these molecules may function as tumor rejection antigens.
Melanoma reactive CTL were efficiently induced from PBL of patients by in vitro stimulation with PBMC pulsed with these epitopes and may be useful for the adoptive transfer protocol for treatment of melanoma patients. Therefore, these identified antigens may be useful for development of new immunotherapies for melanoma patients as well as for understanding the mechanisms of T cell recognition of autologous tumor cells.

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Macrophage colony-stimulating factor (M-CSF) was found in 1978 by our group as a homodimeric glycoprotein with a molecular weight of 85kDa in human urine which stimulated macrophage colony formation in in vitro culture system of human and mouse bone marrow cells, and its gene was cloned by our group in collaboration with Genetics Institute in 1987. In vitro studies showed that M-CSF stimulated proliferation and differentiation of macrophage progenitor cells, and activated functions of mature macrophages such as killing of bacteria and fungi, production of granulocyte-macrophage CSF, granulocyte CSF, interleukin 6 and 8, tumor necrosis factor and reactive nitrogen intermediates, and cholesterol metabolism. In addition to the effects on macrophages, M-CSF was also found to stimulate proliferation and differentiation of trophoblasts and osteoclasts. Based on these basic studies, we conducted a large scale double blind clinical study using M-CSF and placebo, and found that administration of M-CSF to patients with acute myeloid leukemia after intensive chemotherapies accelerates recovery of neutrophils and platelets, reduces incidence and period of febrile neutropenia, total volumes of platelets transfused, and period requied to finish three courses of consolidation therapies with a statistic significances. It was also found that administration of M-CSF reduced relapse rate and increased disease-free survival rate of younger AML patients (15-29 years old) with statistic significances. More recently, it was found that administration of M-CSF to patients with ovarian cancers after intensive chemotherapies following operations in which tumors were completely removed, shortened periods required to finish two courses of chemotherapies and increased survival rate with statistic significances. These results indicate that administration of M-CSF not only stimulates hematopoiesis after cancer chemotherapy, but also induces anti-tumor immunity against cancer cells.

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We examined immunohistochemically the expression of cytokines in Hodgkin's disease and non-Hodgkin's lymphomas utilizing formalin-fixed, paraffin-embedded tissues.
In 29 cases of Hodgkin's disease, TNF-α, IL-6, IL-4, IL-1 and IL-5 were positive in RS cells in 18 (62.1%), 13 (44.8%), 11 (31.9%), 9 (31.0%) and 4 (13.8%) cases, respectively. MC and NS type cases showed more frequent cytokine expression than other type cases. These findings were comparable to those reported previously.
In 32 cases of non-Hodgkin's lymphoma, TNF-α (18 cases, 56.3%), IL-6 (17 cases, 53.1%) and IL-4 (15 cases, 46.9%) were the cytokines frequently expressed, as were in Hodgkin's disease. T and B cell lymphomas showed similar frequency of cytokine expression. ALCL most closely resembled in cytokine expression to Hodgkin's disease.
There were statistically positive corelation between expression of IL-1 α and IL-5 as well as non-expression of IL-1 α and IL-2. These findings suggested active cytokine network operative in the lymphomatous tissue. There were also evidences that cytokine activity influenced the morphological complexity of the lymphomatous tissue.

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