ABSTRACT
OBJECTIVE: To characterize dendritic cell (DC) numbers, subset distribution, phenotype, and costimulation molecule expression in a normal pediatric population and in a lymphoblastic malignant pretherapy pediatric population. DC are potent antigen-presenting cells and are crucial for initiating specific immune responses. MATERIALS AND METHODS: We first analyzed peripheral blood samples of healthy pediatric controls (n=72). Once a range of normal parameters was established, we compared these to newly diagnosed pediatric leukemia and lymphoma patients prior to receiving therapy (n=69). Using flow cytometry, we examined blood DC cell-surface expression of CD80, CD86, CD40, CD18, CD50, CD83, CD123, CD58, CD54, and CD11c. RESULTS: Expression of each of these molecules was significantly altered except for CD80, CD83, and CD58. When compared to healthy children, absolute blood DC were reduced in children with leukemia or lymphoblastic lymphoma (p<0.0001) and children with Hodgkin's disease (p=0.0028). Additionally, lymphocyte function in vitro, was impaired (p=0.0489) for children with lymphoblastic malignancies, while patients with Hodgkin's disease had normal proliferative function. CONCLUSIONS: Our results show that peripheral blood DC from children with newly diagnosed leukemia or lymphoma are significantly altered in number, subset distribution, and costimulation molecule expression, and that lymphocyte function is impaired compared to healthy pediatric controls.
Subject(s)
Antigens, CD/blood , Dendritic Cells/metabolism , Gene Expression Regulation, Leukemic , Leukemia/blood , Lymphoma/blood , Neoplasm Proteins/blood , Adolescent , Child , Child, Preschool , Dendritic Cells/pathology , Female , Humans , Infant , Leukemia/diagnosis , Lymphoma/diagnosis , MaleABSTRACT
BACKGROUND: A Phase I study of 11 pediatric patients with newly diagnosed, Stage 4 neuroblastoma was conducted using monocyte-derived dendritic cells (DC) pulsed with tumor RNA to produce antitumor vaccines (DC(RNA)). METHODS: Patients received two courses of induction with carboplatin followed by standard chemotherapy, surgery, radiation, high-dose therapy, stem cell rescue, and DC(RNA) vaccine therapy. RESULTS: The results showed that this method for producing and administering DC(RNA) from a single leukapheresis product was both feasible and safe in this pediatric neuroblastoma population. Two courses of carboplatin maintained lymphocyte counts at normal levels. However, immune function 6 weeks after high-dose chemotherapy and stem cell rescue and prior to receiving DC(RNA) was impaired in all patients tested. There was an alteration in the ratio of CD4-positive and CD80-positive T cells. CD4-positive cell numbers were below normal, whereas CD8-positive cell numbers were above normal for all patients. In addition, CD19-positive cell numbers were below normal for all but one patient. It was found that humoral responses to recall antigens (diphtheria and tetanus) and cellular responses to mitogen and recall antigens were below normal in most patients. Despite this, two of three patients tested showed a tumor-specific humoral immune response to DC(RNA). Among the patients who had measurable disease at the time of DC(RNA) vaccine, none showed any objective tumor response. CONCLUSIONS: DC(RNA) vaccines were both safe and feasible in children with Stage 4 neuroblastoma. Humoral responses to tumor were detected, although remained immunosuppressed at the time of administration, limiting efficacy.
Subject(s)
Adrenal Gland Neoplasms/pathology , Cancer Vaccines/therapeutic use , Dendritic Cells/immunology , Neuroblastoma/pathology , Neuroblastoma/therapy , RNA, Neoplasm/immunology , Adrenal Gland Neoplasms/immunology , Adrenal Gland Neoplasms/mortality , Adrenal Gland Neoplasms/therapy , Child , Child, Preschool , Female , Humans , Immunotherapy/methods , Leukapheresis/methods , Male , Neoplasm Staging , Neuroblastoma/immunology , Neuroblastoma/mortality , Probability , Retroperitoneal Neoplasms/immunology , Retroperitoneal Neoplasms/mortality , Retroperitoneal Neoplasms/pathology , Retroperitoneal Neoplasms/therapy , Risk Assessment , Sensitivity and Specificity , Survival Analysis , Treatment OutcomeABSTRACT
We conducted a phase 1 study of 9 pediatric patients with recurrent brain tumors using monocyte-derived dendritic cells pulsed with tumor RNA to produce antitumor vaccine (DCRNA) preparations. The objectives of this study included (1) establishing safety and feasibility and (2) measuring changes in general, antigen-specific, and tumor-specific immune responses after DCRNA. Dendritic cells were derived from freshly isolated monocytes after 7 days of culture with IL-4 and granulocyte-macrophage colony-stimulating factor, pulsed with autologous tumor RNA, and then cryopreserved. Patients received at least 3 vaccines, each consisting of an intravenous and an intradermal administration at biweekly intervals. The study showed that this method for producing and administering DCRNA from a single leukapheresis product was both feasible and safe in this pediatric brain tumor population. Immune function at the time of enrollment into the study was impaired in all patients tested. While humoral responses to recall antigens (diphtheria and tetanus) were intact in all patients, cellular responses to mitogen and recall antigens were below normal. Following DCRNA vaccine, 2 of 7 patients showed stable clinical disease and 1 of 7 showed a partial response. Two of 7 patients who were tested showed a tumor-specific immune response to DCRNA. This study showed that DCRNA vaccines are both safe and feasible in children with tumors of the central nervous system with a single leukapheresis.
Subject(s)
Brain Neoplasms/drug therapy , Cancer Vaccines/administration & dosage , Dendritic Cells/metabolism , Immunotherapy, Adoptive/methods , Monocytes/metabolism , RNA, Neoplasm/administration & dosage , Adolescent , Adult , Antibodies, Neoplasm/biosynthesis , Brain Neoplasms/immunology , Brain Neoplasms/pathology , Cancer Vaccines/adverse effects , Cancer Vaccines/immunology , Child , Dendritic Cells/immunology , Female , Humans , Immunity, Cellular , Immunotherapy, Adoptive/adverse effects , Interleukin-10/biosynthesis , Lymphocyte Count , Male , Monocytes/immunology , RNA, Neoplasm/adverse effects , RNA, Neoplasm/immunology , Statistics, NonparametricABSTRACT
The number of dendritic cells (DC) circulating in the peripheral blood of cancer patients were monitored at multiple time points during chemotherapy and granulocyte colony-stimulating factor (G-CSF) support. DC were identified via the lack of expression of standard lineage markers and high expression of HLA-DR (LN-/DR+). The expression of DC-associated markers, including CD83, CD11c, IL-3Ralpha (CDw123) and CD86, within this LN-/DR+ population was also monitored. Maximal mobilization occurred during recovery on d 12, with a mean 32-fold increase in LN-/DR+ numbers. The most striking increase was observed in the LN-/DR+/CD83+ cell population: 12 d after commencement of treatment, the proportion of these cells had increased by approximately 120-fold when compared with baseline. Peripheral blood mononuclear cell (PBMC) and CD34+ cell numbers also peaked 12 d into the treatment regimen in most patients. These data suggest that it should be possible to acquire substantial numbers of DC from leukapheresis products collected from cancer patients undergoing a standard treatment regimen of chemotherapy and G-CSF. This strategy may be a feasible, low-risk means of acquiring cells for DC-based vaccine studies.
