The colony-stimulating factors (CSFs) promote the proliferation and differentiation of hematopoietic precursors and more recently have been shown to amplify the functions of mature phagocytes in vitro. In this study recombinant human granulocyte/macrophage colony-stimulating factor (rGM-CSF) was administered to cancer patients to determine whether the cytotoxic and secretory activity of their blood monocytes could be enhanced. Patients with refractory neoplastic disease were treated with rGM-CSF either as a single bolus or as a constant infusion for 14 days at either 100 or 500 micrograms/m2 per day. As has been reported by others, the number of peripheral blood monocytes and granulocytes rose markedly in a dose-response fashion during infusion with rGM-CSF. The functional capacity of monocytes was increased by rGM- CSF, since the cytotoxicity of monocytes against antibody-coated xenogeneic cells was increased during the constant infusion compared to baseline. In addition, monocytes harvested during the constant infusion and stimulated with lipopolysaccharide (LPS) in vitro secreted increased quantities of tumor necrosis factor alpha (TNF-alpha) and interferon (IFN). These data indicate that rGM-CSF can enhance both the number and the function of peripheral blood monocytes in vivo.
Cytolytic T lymphocytes play an important role in host defense against viral infections, including human immunodeficiency virus (HIV). In a phase I clinical trial (protocol 080 of the AIDS Clinical Trials Group), generation of CD8+ effector cells from peripheral blood of patients with acquired immunodeficiency syndrome (AIDS)-related complex (ARC) or AIDS and safety of autologous adoptive transfer of these cells were evaluated. For therapeutic infusions, CD8+ T cells were purified by positive selection on anti-CD8 monoclonal antibody-coated flasks from leukapheresed peripheral blood of seven patients. These CD8+ T cells were cultured in the presence of interleukin-2 and phytohemagglutinin for up to 3 weeks to obtain cells sufficient for therapeutic infusions (10(8) to 10(10)). All 31 cell cultures established from the seven patients and used for therapy were highly enriched in CD8+ (mean, 97%), CD8+HLA-DR+ (50%), cytotoxic CD8+CD11b- (82%), and memory CD29+ (78%) T lymphocytes. In vitro expanded CD8+ cells had excellent cytotoxic function at the time they were used for therapy, including HIV-specific activity against autologous targets infected with vaccinia vectors expressing HIV-IIIb antigens, gag, pol, and env. Anti-HIV activity of cultured CD8+ cells was significantly higher than that of autologous fresh peripheral blood lymphocytes. Our results show that CD8+ T lymphocytes obtained from peripheral blood of symptomatic HIV-infected patients can be purified, cultured to obtain large numbers of cells with enhanced anti-HIV activity, and safely infused into patients with AIDS as a form of immunotherapy.
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