Human cytotoxic T-cell lines with restricted specificity for squamous cell carcinoma of the head and neck.

Human cytotoxic T-lymphocyte (CTL) lines with specificity restricted for autologous squamous cell carcinoma of the head and neck (SCCHN) were established from peripheral blood lymphocytes obtained at the time of surgery and again at two different times after surgery from a patient with cancer of the tongue. The CTL lines were cultured in the presence of interleukin (IL) 2, IL4, and autologous tumor (AuTu) cell monolayers. All three lines were CD3+CD8+CD11b-HLA-DR+ T-cell receptor alpha/beta+. They were tested in 4-h51Cr release assays against SCCHN cell lines (n = 5) and a variety of nonsquamous human tumor (n = 5) and normal (n = 5) cell targets and was found to lyse only AuTu (PCI-50) and three allogenic SCCHN cell lines. Lysis of AuTu and the three allogenic SCCHN targets by the established CTL lines appeared to be major histocompatibility complex class I restricted, since it was blocked by monoclonal antibodies to class I histocompatibility complex antigens. The CTL lines proliferated in vitro in response to autologous PCI-50 or an allogenic SCCHN cell line (PCI-1). The lines have been maintained in culture in the presence of AuTu monolayers and retained cytotoxicity against AuTu for over 20 weeks. The AuTu (PCI-50) cell line was tested for in vitro sensitivity to cytotoxic or cytostatic effects of various effector cells, including the CTL lines. PCI-50 targets were resistant to lysis by resting human mononuclear cells but sensitive to IL2-activated natural killer cells in 4-h 51Cr release assays. In comparison with IL2-activated natural killer cells, the CTL line mediated lower levels of lysis against AuTu. Growth of PCI-50 cells in culture was significantly inhibited by a combination of gamma-interferon and IL2 or by high concentrations of tumor necrosis factor alpha. While supernants of IL2-activated natural killer cells were growth inhibitory, those of the CTL line were not. On the other hand, lysis of AuTu targets by the CTL line was increased by preincubation of the tumor cells with tumor necrosis factor alpha or gamma-interferon. These cytokines augmented expression of HLA-class I, HLA-class II, and intercellular adhesion molecule I, but not squamous cell carcinoma-associated antigens, E7 and A9, on PCI-50 cells. The CTL lines described are the first with restricted specificity for autologous SCCHN ever reported and their availability will facilitate studies of the AuTu T-cell response in head and neck cancer.

MAGE-1-specific precursor cytotoxic T-lymphocytes present among tumor-infiltrating lymphocytes from a patient with breast cancer: characterization and antigen-specific activation.

A potential target for development of tumor-specific immunotherapeutic strategies is the MAGE-1 gene. We have utilized a recently developed recombinant canarypox (ALVAC) virus vector containing the MAGE-1 gene (vCP235) to activate CTLs from a breast cancer patient bearing a MAGE-1+ tumor. Tumor-infiltrating lymphocytes (TILs) obtained from the tumor of a patient were stimulated in vitro with irradiated autologous peripheral blood mononuclear cells acutely infected with the vCP235 construct. These TILs preferentially expanded approximately 6-fold over a 16-day culture period and specifically recognized an allogeneic transformed B-cell line acutely infected with a vaccinia-MAGE-1 recombinant targeting vector (vP1188) in the context of HLA-A2 and/or B7. TCR V beta analysis of in vitro expanded T cells by a quantitative multiprobe RNase protection assay revealed preferential expansion of TCR V beta 6.3 and V beta 6.4. In addition, homologous T-cell receptor beta CDR3 joining sequences were found in the in vitro stimulated cultures. These results suggest that tumor antigen-specific, MHC-restricted CTLs may be derived from precursor CTLs present in TILs obtained from patients with MAGE-1+ tumors by in vitro stimulation with recombinant avipox MAGE-1 virus-infected autologous cells. Collectively, these findings provide a rationale for tumor-associated antigen-based immunization as a means of activating precursor CTLs residing in patients with tumors expressing defined tumor-associated antigens such as MAGE-1.

Efficient gene transfer to human peripheral blood monocyte-derived dendritic cells using human immunodeficiency virus type 1-based lentiviral vectors.

Dendritic cells (DCs) are potent antigen-presenting cells and are capable of activating naive T cells. Gene transfer of tumor antigen and cytokine genes into DCs could be an important strategy for immunotherapeutic applications. Dendritic cells derived from peripheral blood monocytes do not divide and are therefore poor candidates for gene transfer by Moloney murine leukemia virus (Mo-MuLV)-based retroviral vectors. Lentiviral vectors are emerging as a powerful tool for gene delivery into dividing and nondividing cells. A three-plasmid expression system pseudotyped with the envelope from vesicular stomatitis virus (VSV-G) was used to generate lentiviral vector particles expressing enhanced green fluorescent protein (EGFP). Peripheral blood monocyte-derived DCs were cultured in the presence of GM-CSF and IL-4 and transduced with lentiviral or Mo-MuLV-based vectors expressing EGFP. FACS analysis of lentiviral vector-transduced DCs derived either from normal healthy volunteers or from melanoma patients demonstrated transduction efficiency ranging from 70 to 90% compared with 2-8% using Mo-MuLV-based vectors pseudotyped with VSV-G. Comparison of lentiviral vectors expressing EGFP driven by CMV or human PGK promoters showed similar levels of transgene expression. Lentiviral vector preparations produced in the absence of HIV accessory proteins transduced DCs at efficiencies equal to vectors produced with accessory proteins. Alu-HIV-1 LTR PCR demonstrated the genomic integration of the lentiviral vector in the transduced DCs. Transduced cells showed characteristic dendritic cell phenotype and strong allostimulatory capacity and maintained the ability to respond to activation signals such as CD40 ligand and lipopolysaccharide. These results provide evidence that lentiviral vectors are efficient tools for gene transfer and expression in monocyte-derived DCs that could be useful for immunotherapeutic applications.

C-reactive protein in patients with COPD, control smokers and non-smokers.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) have raised serum levels of C reactive protein (CRP). This may be related directly to COPD and its associated systemic inflammation or secondary to other factors such as concomitant ischaemic heart disease (IHD) or smoking status. The aim of this study was to evaluate IHD and smoking as potential causes of raised CRP levels in COPD and to test the association between inhaled corticosteroid (ICS) use and serum CRP levels. METHODS: Cross sectional analyses comparing cohorts of 88 patients with COPD, 33 smokers (S), and 38 non-smoker (NS) controls were performed. Clinical assessments included a complete medical history, pulmonary function, 6 minute walk test (6MWT), cardiopulmonary exercise test, and high sensitivity serum CRP measurements. RESULTS: Serum CRP levels were significantly higher in patients with COPD (5.03 (1.51) mg/l) than in controls (adjusted odds ratio 9.51; 95% confidence interval 2.97 to 30.45) but were similar in the two control groups (S: 2.02 (1.04) mg/l; NS: 2.24 (1.04) mg/l). There was no clinical or exercise evidence of unstable IHD in any of the subjects. CRP levels were lower in COPD patients treated with ICS than in those not treated (3.7 (3.0) mg/l v 6.3 (3.6) mg/l); this association was confirmed in an adjusted regression model (p<0.05). CONCLUSION: CRP levels are raised in COPD patients without clinically relevant IHD and independent of cigarette smoking, and reduced in patients with COPD using ICS. CRP may be a systemic marker of the inflammatory process that occurs in patients with COPD.

Association of alpha interferon production with natural killer cell lysis of U937 cells infected with human immunodeficiency virus.

Mononuclear leukocytes from human immunodeficiency virus (HIV)-seronegative and -seropositive homosexual men lysed HIV-infected U937 cells to a significantly greater degree than uninfected U937 cells. Depletion of cell subsets with monoclonal antibodies and complement indicated that the effector cells were primarily of the CD16+ phenotype. Acid-stable alpha interferon (IFN-alpha) production induced by the HIV-infected cells correlated with, although was not an absolute requisite for, preferential lysis of the infected targets. The activity of these CD16+, natural killer (NK) cells decreased in relation to the duration of HIV infection and the presence of acquired immunodeficiency syndrome. Pretreatment of peripheral blood mononuclear cells from HIV-seronegative subjects, but not HIV-seropositive men, with IFN-alpha or recombinant interleukin-2 enhanced lysis of both uninfected and HIV-infected U937 cells. These results suggest that IFN-alpha-associated, NK-like mechanisms are active in the cytotoxic response against HIV-infected cells and that HIV infection results in an early and progressive depression of such responses. Prospective investigations may be useful in determining the role of this NK cell response in the natural history and pathogenesis of HIV infection and the efficacy of therapeutic modalities.

Human dendritic cells require multiple activation signals for the efficient generation of tumor antigen-specific T lymphocytes.

Dendritic cells (DC) are specialized cells of the immune system responsible for the initiation and regulation of both cellular and humoral responses. DC function is highly dependent on their level of maturation. In this study, we postulated that full DC maturation would require a combination of activating signals. When cultured monocyte-derived DC received stimulation with CD40 ligand (CD40L) and lipopolysaccharide (LPS) together, the IL-12 secretion increased 5-60-fold and the IL-10 secretion increased 5-15-fold when compared with either stimulation alone. In addition, poly I.C, a double-stranded RNA analog that mimics viral infection, also synergized with CD40L to stimulate DC to secrete high levels of IL-12 and IL-10. Flow cytometry revealed an up-regulation in the expression of CD80, CD86 and CD83 following activation with a soluble trimeric form of CD40L (CD40Ls) or LPS. However, no further up-regulation was observed when both CD40Ls and LPS were used together compared with a single stimulatory signal, suggesting that there was no correlation between the expression of these markers and the level of IL-12/IL-10 secretion. Finally, specific cytotoxic T lymphocytes (CTL) were generated using DC pulsed with a modified HLA-A2-restricted peptide epitope derived from the melanoma antigen MART-1. DC activated with a combination of CD40Ls and LPS were more efficient in eliciting MART-specific reactivity compared to DC activated with CD40Ls or LPS alone. These results demonstrate that multiple maturational signals have a positive impact on the ability of DC to secrete IL-12 and IL-10 and more importantly, to generate antigen-specific T lymphocytes.

CD4+ blood dendritic cells are potent producers of IFN-alpha in response to in vitro HIV-1 infection.

We determined the relative abilities of cell subpopulations from all major PBMC lineages of normal donors to produce IFN-alpha in response to in vitro stimulation with lymphocytotropic HIV-1 (IIIb and RF), monocytotropic HIV-1 (BaL), Sendai virus, and HSV-1. Active and inactive cell-free preparations of HIV-1 IIIb and cell-associated HIV-1 IIIb, and active cell-free preparations of the other viruses, induced comparable, maximal levels of acid-stable IFN-alpha in PBMC by 18 to 24 h. Negative selection and enrichment experiments indicated that HLA-DR+ "null" cells produced the majority of the IFN-alpha. A positive selection protocol using flow cytometric sorting enriched these HLA-DR+ CD3- CD19- CD16- CD56- CD14- cells to > 95% purity. These were identified as dendritic cells by their phenotype, large size, and veiled and ruffled morphology. The purified dendritic cells produced as much as 60-fold more IFN-alpha compared with purified, HLA-DR+ CD14+ monocytes in response to the viruses. IFN-alpha was not produced by CD3+ T cells or CD56+ NK cells. Purified CD19+ B cells produced a minimal amount of IFN-alpha in response to Sendai virus, and no IFN-alpha in response to the other viruses. Of significance, the dendritic cells expressed CD4 at a density similar to monocytes, and induction of IFN-alpha by HIV-1 could be blocked by HIV-1 gp120 anti-serum or anti-CD4 mAb. We conclude that the production of IFN-alpha constitutes a previously unrecognized major function of blood dendritic cells. This may be a mechanism of innate immunity mediated by dendritic cells against HIV-1 and other viral infections.

Oligoclonal CD8 lymphocytes from persons with asymptomatic human immunodeficiency virus (HIV) type 1 infection inhibit HIV-1 replication.

CD8 lymphocytes from asymptomatic human immunodeficiency virus (HIV) type 1-infected patients can suppress virus production from infected CD4 cells. Suppressive activity is separate and distinct from cytotoxic T lymphocyte (CTL) reactivities and is likely mediated by a soluble factor(s). The majority of HIV-1 suppression studies have been done in the context of bulk CD8 cell cultures. In this study, viral suppression was characterized by clonal populations of CD8 cells derived from HIV-1-infected patients. Most of the suppressive clones were devoid of detectable CTL reactivity against env-, gag-, pol-, and nef-expressing targets. Among the suppressive clones derived from an individual patient, a marked heterogeneity was evident with respect to phenotypic markers, cytokine production, and T cell receptor V beta expression. These results suggest that noncytolytic virus suppression is oligoclonal in nature. Clones provide tools for future studies aimed at understanding the mechanism of suppression and identifying the suppressive factor.