In order to better understand the patho-physiologic role of granulocyte colony-stimulating factor (G-CSF), we estimated its serum levels in healthy persons and patients with various disorders, using a newly developed enzyme immunoassay (Motojima et al). In 49 of 56 normal healthy persons (88%), the levels were beneath the sensitivity of the assay (less than 30 pg/mL), while in the remaining seven healthy persons, the levels ranged from 33 to 163 pg/mL. On the other hand, nine of 11 patients (82%) with idiopathic aplastic anemia (AA), one patient with Fanconi's anemia, six of 12 patients (50%) with myelodysplastic syndrome (MDS), five of 12 patients (42%) with acute leukemia without any blast cells in the blood (M4: one, M5: one, L1: one, and L2: two), six of 18 patients (33%) with chronic myeloid leukemia (CML), one of two patients with chronic lymphoid leukemia (CLL), two of four patients with lung cancer, one patient with cyclic neutropenia, two of seven patients with malignant lymphoma, and four patients with acute infection had G-CSF levels ranging from 46 pg/mL to greater than 2,000 pg/mL. Interestingly, a reverse correlation between blood neutrophil count and serum G-CSF level was clearly demonstrated for aplastic anemia (r = -.8169, P less than .01). Moreover, it was found that the G-CSF level rose during the neutropenic phase of cyclic neutropenia and after chemotherapy or bone marrow transplantation (BMT) in three patients with leukemia; also high G-CSF levels were positively correlated to blood neutrophil counts in some cases of infectious disorders and lung cancer. The cellular sources and the mechanisms for production and secretion of circulating G-CSF were not investigated in this study, but the data presented here strongly indicate that G-CSF plays an important role as a circulating neutrophilopoietin.

We produced lethally irradiated retrovirally GM-CSF-transduced autologous renal tumor cell vaccines (GVAX) from six Japanese patients with stage IV renal cell cancer (RCC). Four patients received GVAX ranging from 1.4 x 10(8) to 3.7 x 10(8) cells on 6-17 occasions. Throughout a total of 48 vaccinations, there were no severe adverse events. After vaccination, DTH skin tests became positive to autologous RCC (auto-RCC) in all patients. The vaccination sites showed significant infiltration by CD4(+) T cells, eosinophils, and HLA-DR-positive cells. The kinetic analyses of cellular immune responses using peripheral blood lymphocytes revealed an enhanced proliferative response against auto-RCC in four patients, and cytotoxicity against auto-RCC was augmented in three patients. T cell receptor beta-chain analysis revealed oligoclonal expansion of T cells in the peripheral blood, skin biopsy specimens from DTH sites, and tumors. Western blot analysis demonstrated the induction of a humoral immune response against auto-RCC. Two of the four patients are currently alive 58 and 40 months after the initial vaccination with low-dose interleukin-2. Our results suggest that GVAX substantially enhanced the antitumor cellular and humoral immune responses, which might have contributed to the relatively long survival times of our patients in the present study.

In order to elucidate molecular events in BCR/ABLinduced transformation, we adopted a polymerase chain reaction (PCR)-based technique of differential display and compared mRNA expression in human factor-dependent cells, TF-1, with that in factor-independent cells, ID-1, which were established from TF-1 cells by transfection of BCR/ABL. Cloning and sequencing of a gene which was upregulated in ID-1 cells revealed that the gene was identical to a melanoma antigen, PRAME. Our present study demonstrated that PRAME was markedly expressed in primary leukemic cells with chronic myeloid leukemia (CML) in blastic crisis and Philadelphia (Ph) + -acute lymphoblastic leukemia (ALL), in which BCR/ABL played an important role as a pathogenic gene. Moreover, comparison of PRAME expression among CD34 + cells with CML in blastic, accelerated, and chronic phases revealed a higher expression in CML in advanced phases. Thus PRAME was considered to be a good candidate for a marker of Ph + -leukemic blast cells as well as a new target antigen of leukemic blast cells that cytotoxic T cells can recognize.z 2000 Federation of European Biochemical Societies.