PubMed Health⌕ Search

Biomedical subjects

G Consogno

Publications and source records attributed to G Consogno.

14 recordsLinked to original sources
PubMed2001

Inhibition of caspases maintains the antineoplastic function of gammadelta T cells repeatedly challenged with lymphoma cells.

T lymphocytes recognizing tumor antigens eventually undergo anergy or Fas-mediated death. V gamma9/V delta2+ T cells recognize poorly characterized ligand moieties on human B-cell lymphomas. Here we show that gammadelta T cells, a model for the study of activation-induced apoptosis, activate on repeated in vitro antigen-recognition caspase 3 and 8 and dramatically down-regulate their cytotoxic and secretory function. Caspase hindrance enhanced gammadelta T cell survival and sustained the killing of neoplastic cells and the release of IFN-gamma and tumor necrosis factor alpha. Caspases of tumor-specific T cells represent a candidate target to complement adoptive immunotherapy strategies.

Antigens, Neoplasm↗
PubMed2001

Cytokine secretion associated with the clearance of apoptotic bodies in renal cell carcinoma patients.

The factors determining the outcome of immunotherapy in metastatic renal cell carcinoma (RCC) patients remain elusive. Macrophages from normal donors that phagocytose apoptotic cells secrete the immunosuppressive cytokine IL-10 in vitro. Conversely, IL-10 genetic deletion enhances the immunogenicity of apoptotic tumor cells in vivo. Elevated pre-treatment levels of IL-10 are associated with an unfavorable outcome of RCC. We examined whether the ability to release IL-10 by macrophages from RCC patients that phagocytosed apoptotic cells correlated with the outcome of immunotherapy. To this aim, we derived macrophages from 30 patients with metastatic RCC and from 21 healthy subjects (11 sex- and age-matched healthy controls and 10 younger donors). Patients either had a clinical response after immunotherapy, with a median survival after treatment of more than 18 months (n = 16), or were beginning immunotherapy after diagnosis of metastatic disease (n = 14). Macrophages from responding patients challenged with apoptotic cells released significantly less IL-10 than controls (p = 0.0075) and recently diagnosed patients (p = 0.0198), as ascertained by a 2-sided Student's t-test. This was not because macrophages from responding patients lost the ability to secrete IL-10, because antibody opsonization of apoptotic cells rescued IL-10 secretion. In contrast, macrophages from all groups of donors released similar amounts of TNF-alpha. The failure in IL-10 secretion by engulfing macrophages of responding subjects may exalt the immunogenicity of dying tumor cells, contributing to the success of immunotherapy.

Adult↗
PubMed1999

Major histocompatibility complex class I restricted cytotoxic T cells specific for natural melanoma peptides recognize unidentified shared melanoma antigen(s).

CTLs were generated in vitro from two healthy donors and one melanoma patient by stimulation of CD8+ T cells with autologous dendritic cells pulsed with natural melanoma peptides (NMPs), obtained by acid treatment of HLA-matched melanoma cells. CTLs showed MHC class I-restricted melanoma-specific cytolytic activity. Importantly, CTLs from the patient, induced with NMPs obtained from an allogeneic HLA-A-matched melanoma, killed the autologous tumor. COS-7 cells cotransfected with the cDNA of 13 melanoma antigens and the HLA-A1-restricting allele did not induce cytokines release from NMP-specific CTLs, suggesting that they recognize unidentified shared melanoma antigens and that they may be valuable for identification of new tumor antigens. These results strongly support the use of autologous and/or allogeneic NMP-pulsed dendritic cells as cancer vaccines in patients whose neoplasms do not express or have lost expression of known tumor antigens.

Alleles↗
PubMed1998

Human melanoma cells transfected with the B7-2 co-stimulatory molecule induce tumor-specific CD8+ cytotoxic T lymphocytes in vitro.

Neoplastic cells express tumor-associated antigens, but tumor rejection seldom occurs in vivo. The absence of an effective immune response may be explained by the inability of tumor cells to deliver co-stimulatory signals. Indeed, transfection of either B7-1 or B7-2 co-stimulatory molecules into mouse tumor cells enhances antitumor immune responses. In this study, we stably transfected human melanoma cells with the cDNA encoding the B7-2 molecule to evaluate in vitro: (i) the induction of anti-melanoma cytotoxic T lymphocytes (CTL) by stimulation of CD8+ T cells, purified from healthy donors and a melanoma patient, with B7-2 transfected allogeneic HLA-matched melanoma cells; (ii) the tumor specificity and the HLA restriction of the induced CTL; and (iii) the feasibility to propagate long-term antimelanoma CTL lines. We found that B7-2 transfected, but not untransfected or mock-transfected, melanoma cells activated MHC-class I-restricted, melanoma-specific CD8+ CTL from healthy donors. More importantly, CD8+ tumor-associated lymphocytes, purified from a tumor-invaded lymph node of a melanoma patient and stimulated with B7-2-transfected melanoma cells, acquired a strong reactivity toward the autologous tumor. CTL lines with specific cytolytic activity could be propagated in long-term culture. These results indicate that: (i) the expression of the B7-2 molecule into human melanoma cells makes them immunogenic and able to act as antigen-presenting cells and (ii) purified CD8+ cells, stimulated with B7-2+ allogeneic HLA-matched melanoma cells, preferentially recognize melanoma-specific rather than allogeneic antigens. This study may have clinical implications for passive and/or active immunotherapy in melanoma patients.

Antigens, Neoplasm↗
PubMed1996

Increased interleukin-10 serum levels in patients with solid tumours.

In 40 out of 99 patients (40.4%) with solid tumours of different tissue, but the same stage (IV), elevated serum levels of interleukin-10 were observed. The mean levels of the cytokine in patients with malignant melanoma (24.3 ng/ml), pancreatic (6.8 ng/ml) or gastric (6.3 ng/ml) adenocarcinoma were significantly higher than in healthy subjects (3.4 ng/ml) or in patients with uterine fibroma (1.7 ng/ml). Patients with colon (6.8 ng/ml) and renal (5.7 ng/ml) carcinoma had similar values of interleukin-10 but did not significantly differ from controls. Interleukin-10 is known to suppress the functions of both T lymphocytes and macrophages, working as a general dampener of the immune and inflammatory responses. The observation of increased circulating levels of interleukin-10 in cancer patients may have important implications for future investigations, immunological monitoring and therapeutic intervention on neoplastic patients, and suggests a mechanism for tumour cells escaping from immune surveillance.

Adult↗
PubMed1996

Particulate naturally processed peptides prime a cytotoxic response against human melanoma in vitro.

For an efficient antitumor cytotoxic response, tumor antigenic peptides need to be presented by professional antigen-presenting cells in association with MHC class I molecules. We established in vitro short-term human CTL lines from healthy and melanoma-bearing subjects, using as antigen-presenting cells autologous adherent cells after phagocytosis of latex beads coated with melanoma peptides. Melanoma peptides were obtained by acid extraction of melanoma cells that matched with donor peripheral blood mononuclear cells, at least for one HLA-A allele. The cytotoxic activity of the lines was specific for the melanoma from which peptides were obtained and for melanoma sharing HLA alleles. These results demonstrate that a complex mixture of naturally processed melanoma peptides conjugated to a phagocytic substrate that targets them into the MHC class I pathway of adherent cells can prime a CTL response in healthy subjects in vitro, and that peptides from allogeneic tumors may be used to propagate CTL in melanoma patients. Our data support the feasibility of active and passive vaccination procedures with nonliving vaccines in cancer patients.

Animals↗
PubMed1996

Thymopentin modulates Th1 and Th2 cytokine response and host survival in experimental injury.

OBJECTIVE: To investigate the impact of thymopentin (Thy) on mortality and in vivo cytokine release in an animal model of gut-derived sepsis which includes different combinations of allogeneic blood transfusion (T) and burn injury plus bacterial gavage (BG). DESIGN: Randomly controlled experiments. MATERIAL: Two hundred sixteen Balb/c (H-2d) and 50 C3H/HeJ (H-2k) mice. INTERVENTIONS: In the first study 60 Balb/c mice were given Thy (1 mg/kg). The same day of therapy onset, 40 mice were transfused with allogeneic blood (from C3H/HeJ mice). The remaining 20 mice received aliquots of saline. Five days post-T, 20 of the 40 transfused mice were subjected to a 20% TBSA thermal injury and simultaneous gavage with 1 x 10(9) Escherichia coli and the other 20 mice underwent a sham burn. The 20 nontransfused mice also received a 20% burn plus bacterial gavage. In all animals Thy was administered for 15 days. Three control groups (n = 20 each) entered the same protocol design, but they did not receive Thy. In the second study 96 animals were randomized to six groups (n = 16 each) according to the above experimental design. Animals were sacrificed by exsanguination after burn or 5 days post-T in nonburned mice to measure TNF-alpha, IL-2, and IL-4 plasma levels. RESULTS: The highest mortality (70%) occurred when T was combined with BG. Thy significantly reduced mortality in both groups that underwent BG, regardless of the association with T. TNF-alpha was detectable in 30% of the tested samples, IL-2 in 50%, and IL-4 in 70%. Thy significantly reduced the levels of IL-4 and increased the production of IL-2. CONCLUSIONS: The protective effect of Thy in this experimental model may be mediated by modulation of cytokine release.

Adjuvants, Immunologic↗
PubMed1995

Serum levels of soluble cell adhesion molecules (ICAM-1, VCAM-1, E-selectin) and of cytokine TNF-alpha increase during interleukin-2 therapy.

Circulating levels of soluble intracellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin were measured in 20 advanced cancer patients at different times during recombinant interleukin-2 immunotherapy. The concentration of all three molecules progressively increased as did the levels of circulating tumor necrosis factor-alpha (TNF-alpha), which is known to induce endothelial cell activation. A fair direct relationship (but not statistically significant) between the raised concentration of soluble cell adhesion molecules and TNF-alpha was observed. We suggest that elevated levels of soluble adhesion molecules and TNF-alpha in the blood of IL-2-treated patients may arise from a systemic inflammatory reaction producing endothelial cell activation.

Adult↗
PubMed1994

Reversible anergy in circulating lymphocytes of cancer patients during interleukin-2 therapy.

Interleukin-2 plays a crucial role in enhancing the antitumor immune response. Clinical trials, mainly in renal cell carcinoma and melanoma patients, have been carried out with encouraging results. Recent reports demonstrated that interleukin-2 therapy may depress the immune response either in vitro or in vivo. We decided to monitor, in nine renal cancer patients, the proliferative responses and the parallel variations in Ca2+ homeostasis of peripheral blood lymphocytes collected before, during and after the first cycle of a 3-day interleukin-2 systemic administration. The proliferative response to phytohemagglutinin or concanavalin A significantly dropped early during interleukin-2 infusion. Consistently, an impairment in mobilizing Ca2+, either from internal stores or via influx from outside, was observed. Results obtained with a mAb-alpha CD3 molecular complex strongly suggested that the TCR/CD3 signal transduction pathway was defective. In contrast, no major variations were observed in the general machinery controlling Ca2+ homeostasis nor in the total Ca(2+)-releasable pool. Patients' lymphocytes, cultured in vitro for 3 days in medium alone, showed an almost complete recovery in their ability to respond to mitogens. In conclusion, we show that interleukin-2 administration in cancer patients induces a reversible state of anergy in circulating lymphocytes, assessed both by the reduction in the proliferative response and the block of the mitogen-activated intracellular Ca2+ signalling.

Calcium↗
PubMed1976

Complement profile and anticomplementary potential in mixed cryoglobulinemia.

In six mixed cryoglobulinemias we have found the indications of a complement classic pathway activation and the fall of the total hemolytic activity (CH50): cryoprecipitate anticomplementary power was always proportional to the respective serum CH50 fall, while no correlation with its own immunoglobulin constitution was found.

Animals↗
PubMed1975

[Immune complexes DNA-anti-DNA during the course of mixed cryoglobulinemia].

Plasma and isolated cryoglobulins from ten patients with mixed cryoglobulinemia were studied for the presence of DNA using the diphenylamine reagent test. DNA-like material was detected in all the plasmas tested and it was also present in nine of the isolated cryoglobulins. IgM and IgG components of three cryoglobulins were purified by gel-filtration: anti-DNA activity was detected in IgG fraction (two cases), in IgM and IgG (one case); antigammaglobulin activity was always found in IgM fraction.

Antibodies, Anti-Idiotypic↗
PubMed1975

Anti-IgA antibodies in two brothers with selective serum IgA deficiency.

A selective serum IgA deficiency with anti-IgA antibodies at high titer were found in a patient who suffered severe transfusion reactions. The same abnormalities were detected in his brother, a 72-year-old-man in good general condition. Anti-IgA antibodies were found in the IgG fraction and were directed against alpha-chains. A deficiency of isoagglutinins and an absence of heteroagglutinins in the propositus' serum could be shown.

Aged↗