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Biomedical subjects

G Masucci

Publications and source records attributed to G Masucci.

At least 19 recordsLinked to original sources

Cytotoxic functions of blood mononuclear cells in patients with colorectal carcinoma treated with mAb 17-1A and granulocyte/macrophage-colony-stimulating factor.

Unconjugated monoclonal antibodies (mAb) may induce tumour regression in patients. The mechanisms of action are complex. Antibody-dependent cellular cytotoxicity (ADCC) is considered one of the effector functions. Augmentation of the killing capacity of cytotoxic cells may thus be a way to increase the therapeutic potential of mAb. Granulocyte/macrophage-colony-stimulating factor (GM-CSF) has been shown to enhance this function in vitro. Eighteen patients with metastatic colorectal carcinoma received GM-CSF (250 micrograms m-2 day-1 s.c.) for 10 days and a single infusion of the anti-(colon carcinoma) mAb 17-1A (mouse IgG2A) (400 mg) on day 3 of the cycle. The cycles were repeated once a month four times. Neutrophils, eosinophils, monocytes and lymphocytes increased significantly in a biphasic way. However, at the fourth cycle the rise in white blood cells was significantly lower compared to the preceding courses. ADCC (SW948, a human CRC cell line,+mAb 17-1A) or peripheral blood mononuclear cells (PBMC) was significantly (P less than 0.05) augmented by day 6 of a cycle and then declined gradually and, at the end of a cycle, the ADCC activity had returned to the pretreatment level. The spontaneous cytotoxicity of PBMC against the natural-killer-resistant cell line, SW948, varied in a similar way. During GM-CSF treatment there was also a significant increase in FcRI+ (CD64), FcRII+ (CD32), FcRIII+ (CD16) and CD14+ cells but not of CD56+ cells.

Adolescent

Diverse effect of cytokine treatment of tumor cells on specific versus non-specific cytotoxicity.

The effect of IFN-gamma and TNF-alpha treatment of an ovarian carcinoma line on the sensitivity to lysis by specific CTL clones and non-specific Tumor Associated Lymphocytes (TAL), isolated from the ascites fluid, was analyzed. The in vitro established TAL line displayed a non-specific lytic activity against the autologous tumor as well as against several allogeneic tumor lines. Pretreatment with IFN-gamma alone, or in combination with TNF-alpha, rendered the carcinoma line less susceptible to lysis by the autologous TAL line. Conversely, susceptibility to lysis by tumor specific T cell clones, isolated from the TAL line, was increased as a result of cytokine pretreatment. Several TCR-alpha/beta+, CD8+ T-cell clones showing a more specific pattern of lysis against the autologous tumor were isolated. Lysis of the autologous tumor by these clones involved the TCR-alpha/beta via a MHC-class I restricted mechanism dependent on the adhesion molecules ICAM-1 and LFA-3, as inferred from antibody blocking studies. The enhanced sensitivity to specific CTL clones seen after cytokine treatment may be related to the enhanced expression of ICAM-1 molecules on the ovarian carcinoma. These results have implications for cytokine based immunotherapy, where IFN-gamma may enhance the effects of tumor associated specific CTL while decreasing that of non-specific effector cells.

Ascitic Fluid

Patients treated with a monoclonal antibody (ab1) to the colorectal carcinoma antigen 17-1A develop a cellular response (DTH) to the "internal image of the antigen" (ab2).

The anti-tumor effector functions of unconjugated MAb in cancer therapy are not fully understood. Direct cytotoxic mechanisms have been demonstrated as well as induction of anti-idiotypic (ab2) and anti-anti-idiotypic (ab3) antibodies. If such a humoral response is induced, then an idiotypic cellular response would also be anticipated. Human monoclonal ab2s which mimic a tumor-associated antigen (TAA) (CO17-1A) of colorectal carcinoma (CRC) cells ("the internal image of the antigen") were produced. These ab2s were injected intradermally to patients with metastatic CRC who had been treated with the anti-colon carcinoma MAb 17-1A (ab1). Five out of 12 patients had a specific DTH (delayed-type hypersensitivity) reaction of the tuberculin type, which was proven by immunohistochemical analysis of skin biopsies. Serum ab3 was demonstrated in 4/4 tested DTH+ patients and also in 4 DTH patients. Control patients did not show any skin reactivity. Generation of an idiotypic response induced by the infused antibody (ab1) might be regarded as an active anti-tumor "vaccination". Induction of an idiotypic cellular and humoral cascade might be an important anti-tumor effector function of MAb and should be considered in future strategies for such therapy in cancer patients.

Antibodies, Anti-Idiotypic

Interleukin-4 augments the cytotoxic capacity of lymphocytes and monocytes in antibody-dependent cellular cytotoxicity.

Human peripheral blood mononuclear cells (lymphocytes and monocytes) (PBMC) were preincubated for 0-24 h with human recombinant interleukin-4 (IL-4) and used as effector cells in an 18 h antibody-dependent cellular cytotoxicity (ADCC) assay with mAb 17-1A (mouse IgG2A) against SW948 (a human colorectal carcinoma cell line). A statistically significant increase in the lytic capability was noted after 2-24 h of preactivation. IL-4 at 1 ng/ml induced the highest cell lysis while higher and lower concentrations were inferior or had no effect at all. Preactivation for 24 h induced a more effective lytic cell population than 2 h prestimulation: 63 LU (lytic units)/10(6) cells vs 42 LU/10(6) cells. Pretreatment with 1 ng/ml IL-4 for 2 h induced a statistically significant increase in the ADCC activity of PBMC (P less than 0.05), of monocytes (P less than 0.01) and E-rosette-negative cells (natural killer cells) (P less than 0.05) compared to non-activated cells. IL-4 did not induce lymphokine-activated killer activity of PBMC against SW948. The spontaneous cytotoxicity against K562 was, however, increased after stimulation with 1 ng/ml IL-4 for 2 h of E-rosette-negative non-adherent cells.

Antibodies, Monoclonal

Chemotherapy and immunotherapy of colorectal cancer.

More than 50% of the patients with large bowel cancer develop disseminated disease and invariably succumb. Adjuvant chemotherapy with 5-FU and levamisole have been shown to be more efficient than 5-FU alone or in combination with cytostatics. The combination of 5-FU, leukovorin and methotrexate induces prolonged survival with a good quality of life in metastatic colorectal cancer (CRC). During the last decade tumor immunotherapy has been an alternative facilitated by isolation and large scale production of cytokines and monoclonal antibodies. The mouse monoclonal antibody (MAb) 17-1A recognizes a tumor-associated antigen (TAA), present in high concentrations on the surface of gastrointestinal tumor cells. Injections of MAb 17-1A in patients with metastatic CRC induced generation of anti-idiotypic (ab2) in 90% and anti-anti-idiotypic (ab3) antibodies in 47% of the treated patients. The development of ab3 correlated significantly with survival (mean 80 weeks) while ab3- patients survive only 38 weeks. One of 52 patients treated with MAb 17-1A is a complete remission after 66 months, 3 had minor regression and 6 had a stable disease (19% RR). Based on in vitro findings showing increased antibody-dependent cellular cytotoxicity (ADCC) by the combination of granulocyte-macrophage colony stimulating factor (GM-CSF) and MAb 17-1A, 16 CRC patients have been treated with subcutaneously injections of GM-CSF for 10 days and intravenous infusions of MAb 17-1A at day 3. Two of 16 are in CR, 1 in MR and 3 in SD (37.5% RR). Minor side-effects were registered. A further development of immunotherapy of CRC might imply vaccination by injection of specific human anti-idiotypic antibodies (ab2) which mimics the nominal antigen, in order to induce a specific immunity.

Antibodies, Monoclonal

Induction of anti-idiotypic (ab2) and anti-anti-idiotypic (ab3) antibodies in patients treated with the mouse monoclonal antibody 17-1A (ab1). Relation to the clinical outcome--an important antitumoral effector function?

Forty-three patients with metastatic colorectal carcinoma (CRC) were treated with the unconjugated mouse monoclonal antibody (MAb) 17-1A (ab1) only. The presence of antiidiotypic antibodies (ab2) and anti-antiidiotypic antibodies (ab3) were analyzed using an ELISA technique and a mixed hemadsorption assay respectively. Ninety-five percent (41/43) of the patients developed ab2 both of the IgM and the IgG classes. Forty-seven percent (20/43) of the patients had detectable ab3 after therapy, two of them also before administration of MAb 17-1A. Binding in vitro of ab3 (ab1) to CRC cells could be specifically inhibited by ab1. Ab3 bound to human monoclonal antiidiotypic antibodies and to a goat antiidiotypic antibody (ab2). Both these ab2 were directed against MAb 17-1A (ab1). There was a strong correlation between the presence of ab3 and the clinical outcome. Ab3+ patients survived significantly longer than those who did not develop ab3 antibodies, 80 weeks vs 38 weeks (p less than 0.001). A statistically significant correlation was found between the presence of ab3 and the anti-tumor response (CR + PR + MR + SD) (p = 0.01). Thus, induction of an antiidiotypic cascade seems to be an important antitumor effector function of MAb in the treatment of cancer patients.

Antibodies, Anti-Idiotypic

Therapy of colorectal carcinoma with monoclonal antibodies (MAb17-1A) alone and in combination with granulocyte monocyte-colony stimulating factor (GM-CSF).

A mouse monoclonal antibody (MAb17-1A) (IgG2A) against colorectal carcinoma cells was used to treat patients with metastatic disease. Major direct effector functions of MAb seem to be ADCC (antibody dependent cellular cytotoxicity), CDC (complement dependent cytolysis) and apoptosis ('programmed cell death'). Thus, a high tumor cell saturation of the MAb should be achieved. Increasing doses of MAb to the patients increased the total area under the concentration curve and thus the exposure of tumor cells to MAb. However, the response rate (with complete + partial + minor response + stable disease defined as response) was not augmented. In total, 10/52 (19%) patients responded and in fact lower doses (less than 2 g) might induce a higher response frequency (9/52) than higher doses (greater than 2 g) (1/52). During treatment, the numbers of cytotoxic cells (lymphocytes and monocytes) increases in the tumor lesion and complement components were deposited. As ADCC may be important, effector mechanism attempts were made to augment the cytolytic capability of the effector cells by simultaneously giving the patients GM-CSF. The combination of MAb17-1A + GM-CSF augmented the ADCC activity of blood mononuclear cells and a heavy infiltration of monocytes could be noted in the tumor. Out of 15 available patients 6 (40%) showed a response.

Antibodies, Monoclonal

Granulocyte-monocyte colony-stimulating-factor augments the interleukin-2-induced cytotoxic activity of human lymphocytes in the absence and presence of mouse or chimeric monoclonal antibodies (mAb 17-1A).

Blood lymphocytes stimulated for 96 h with interleukin-2 (IL-2; 100 BRMP U/ml) (lymphokine-activated killer, LAK, cells) or granulocyte-monocyte colony-stimulating-factor (GM-CSF) (10 ng/ml) became cytotoxic for Daudi cells. IL-2 was significantly more effective than GM-CSF. Only IL-2-activated cells killed SW948 (a human colorectal carcinoma cell line) while GM-CSF-stimulated cell did not. GM-CSF and IL-2 acted synergistically in a dose-dependent fashion for induction of a highly effective cytotoxic cell population (IL-2/GM-CSF cells). Il-2/GM-CSF cells were statistically significantly more effective than LAK cells in lysing Daudi cells and SW948 (P less than 0.05). The enhancing effect was most pronounced during the first 48-96 h of activation. Incubation periods longer than 192 h did not contribute to augmented cytotoxicity. The combination of IL-2 and GM-CSF significantly increased the number of CD25+ cells compared to IL-2 and GM-CSF alone. Furthermore, IL-2/GM-CSF cells were significantly more effective in antibody-dependent cellular cytotoxicity assays (SW948 + mAb 17-1A) than LAK cells. The chimeric mAb 17-1A was significantly more effective in tumor cell lysis than the mouse mAb. Thus, combination of various biological therapeutics might be a way to enhance their antitumoral effects.

Animals

Simplified long term large scale production of highly active human LAK cells for therapy.

Cells obtained by leukapheresis and separated without or with a Ficoll-Isopaque (FIP) gradient were cultured for 4 or 20 days to determine whether a more effective LAK cell population could be obtained compared to LAK cells generated by the commonly used method (FIP separated cells cultured for 4 days). After leukapheresis the cells were separated on a FIP gradient (FIP cells) or only washed to minimize platelet contamination (non-FIP cells). In some experiments, the cells were also pretreated with phenylalanine-methylester (PheOMe) to reduce monocytes. After culturing for 20 days in the presence of IL-2 (100 BRMP U ml-1) a significantly higher total number of CD3+ and CD56+ cells was noted in the non-FIP fraction compared to the FIP fraction. The total lytic activity of non-FIP cells (LU/tot. no. of cells) against Daudi targets after 4 days of culture was 11,820 +/- 624 versus 4770 +/- 550 of FIP cells (P less than 0.05). After 20 days of culture the non-FIP fraction exhibited a higher cytotoxic activity than the FIP cell fraction, 76,291 +/- 20,053 compared to 7169 +/- 1148 LU (P less than 0.05). Pretreatment of the cells with PheOMe induced a significantly more effective cytotoxic population when cultured for 4 days. However, at 20 days PheOMe did not enhance the LAK cell activity. Large scale production of LAK cells can be accomplished without FIP separation with an increased cell yield and cytotoxicity compared to FIP separated cells both in short and long time cultures.

Cells, Cultured

Generation of human LAK cells in tissue culture bags using recombinant IL-2 and serum free medium. Effects of pretreatment with phenylalanine-methylester.

A technique for processing and culturing of human LAK cells using an automated closed system and tissue culture bags is described. To circumvent the inhibitory effects of monocytes on LAK cells the peripheral blood mononuclear cells (PBMC) were pretreated with phenylalanine-methylester (PheOMe). PBMC were obtained from healthy donors by leukapheresis of whole blood. After pretreatment with PheOMe and culturing with IL-2 for 96 h, 60% of the cells remained. PheOMe significantly reduced the number of monocytes (Leu-M3+ cells) from 20-12%. The lytic activity (against K562 and Daudi) of non-PheOMe-treated cells reached a plateau at 72-96 h while PheOMe-treated cells reached maximum activity at 96 h. The total lytic activity/tissue culture bag at 96 h of PheOMe-pretreated cells was significantly augmented in comparison to non-PheOMe-pretreated cells. The present technique allows rapid and simple generation of LAK cells without serum in sterile receptacles suitable for therapy. Additionally, the LAK cell efficacy was improved by reducing the inhibitory effects of monocytes.

Cell Count

Relationship between clinical stage, histopathology and antibody titers against the second Epstein-Barr virus nuclear antigen (EBNA-2) in non-Hodgkin's lymphoma patients.

Non-Hodgkin lymphoma (NHL) patients with centroblastic (Cb) or centroblastic-centrocytic (Cb/Cc)-diffuse lymphomas, immunocytoma (IC) and chronic lymphocytic leukemia (CLL) in clinical stages III-IV and with active disease (highly malignant group) were compared to NHL patients with CLL, IC, and centrocytic (Cc) or centroblastic-centrocytic (Cb-Cc)-diffuse/follicular lymphomas, in clinical stages I-II and with inactive disease (low malignant group) based on the presence of antibodies to Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1) and 2 (EBNA-2). In the highly malignant group, anti-EBNA-1 geometric mean titers (GMT) were 13.2 (range less than 2-80) and anti-EBNA-2 60.6 (range: 20-320). The ratio between the logarithms of anti-EBNA-1 and anti-EBNA-2 antibody titers was less than 1.0 (mean: 0.32) in all the patients examined. In 6 out of 8 patients of the low malignant group, anti-EBNA-1 titers were higher (mean: 30.1; range 10-160) than anti-EBNA-2 titers (mean: 4.3; range less than 2-80) and the EBNA 1/2 ratio was greater than 1.0. In healthy EBV-seropositive individuals, anti-EBNA-1 GMT were 49 (range: 10-320) and only 5 out of 17 individuals had detectable anti-EBNA-2 titers (GMT: 3; range less than 5-20). The EBNA-1/2 ratio was in all cases greater than 1. Among patients of the highly and low malignant groups, patients with follicular-cell-derived lymphomas had elevated antibody titers against the restricted component of early antigens (EA-R), whereas all patients with IC and 2 out of 4 CLL patients had elevated antibody titers against the diffuse component of early antigens (EA-D). The results indicate that the ratio between anti-EBNA-1 and anti-EBNA-2 antibody titers may be of diagnostic importance in patients with immunodeficiencies.

Antibodies, Viral

Granulocyte-monocyte-colony-stimulating factor augments the cytotoxic capacity of lymphocytes and monocytes in antibody-dependent cellular cytotoxicity.

Human peripheral blood mononuclear cells (lymphocytes and monocytes) were preincubated for 0-24 h with human recombinant granulocyte-monocyte-colony-stimulating factor (GM-CSF) and used as effector cells in an 18 h antibody-dependent cellular cytotoxicity (ADCC) assay with SW948 (a human colorectal carcinoma cell line) as target cells and mAb 17-1A. A significant increase in the lytic capability was noted after 0.5-2 h of preactivation while longer preincubation times did not significantly increase the lytic potential. GM-CSF at 0.01 microgram/ml induced the best tumor cell lysis while higher concentrations were inhibitory. GM-CSF pretreatment induced a statistically significant increase in the lytic capacity of both monocytes and lymphocytes in ADCC as well as in the spontaneous cytotoxicity.

Antibodies, Monoclonal

The clinical use of monoclonal antibodies, MAb 17-1A, in the treatment of patients with metastatic colorectal carcinoma.

Increasing doses of MAb 17-1A (mouse IgG2A) have been given for therapy of patients with metastatic colorectal carcinoma (n = 28). Serum half-life (T beta 1/2) of MAb 17-1A after a single infusion was about 24 h. A constant serum level of MAb 17-1A could be maintained for a long time period by infusions every 2-3 days. Patients received 500 mg 3 days a week for 12 weeks (total dose 12 g). Side effects were mild and dose related but never required medical intervention except for three times (out of 243 infusions) when allergic reactions appeared. All patients developed IgM and IgG antibodies. Two patients experienced immune complex-related symptoms. Six out of 22 evaluable patients (27%) had objective evidence of tumor cell regression/lysis. One of these achieved a complete remission. Median survival for all patients was 12 months, for responding patients 19 months and for non-responding 11 months. 5/17 patients were studied for the development of anti-anti-idiotypic antibodies (Ab3). The presence of Ab3 in serum correlated favourably to the clinical outcome of the disease.

Adult

Lymphokine activated killer (LAK) cells in antibody dependent cellular cytotoxicity (ADCC) using MAb 17-1A: a combination of potential usefulness in tumor therapy.

Peripheral blood lymphocytes (PBL) stimulated by interleukin-2 (IL-2) for 48-96h, generated killer cells against the human colon cancer cell line SW948. The killing capacity increased significantly when the specific mouse monoclonal antibody (MAb) 17-1A was present during the lytic process. The chimeric antibody 17-1A determined a significantly stronger cytotoxicity compared to mouse MAb 17-1A. MAb BR55-2 which recognizes a different antigen on SW948 target cells mediated a similar cytotoxicity as MAb 17-1A. Presence of alpha-interferon (IFN) during the lytic assay significantly enhanced the killing of the tumor by lymphokine activated killer (LAK) cells as well as by LAK cells and mouse MAb 17-1A. However, when chimeric MAb 17-1A and LAK cells were used alpha-IFN failed to increase the lytic activity, probably due to already maximum lysis in the system. Combinations of various biological response modifiers such as monoclonal antibodies, IL-2/LAK cells and alpha-IFN carry great promise to improve this kind of therapy for cancer patients.

Animals

Clinical status of monoclonal antibodies in the treatment of colorectal carcinoma.

MoABs have demonstrated an antitumor effect and, in time, may lead to improved outcome in patients with colorectal cancer. The authors describe their experience in Sweden and summarize the results of other studies. Primarily, unconjugated mouse MoABs have been used--directed against tumor-associated antigens. More promising are hybrid antibodies composed of mouse and human elements (chimeric), or human MoABs. Such antibodies also can be used as carriers of a cytotoxic compound. The authors discuss two mechanisms by which MoABs induce their antitumor effect, and how cytokines combined with a MoAB can contribute to lysis. The potential roles of anti-idiotypic antibodies are outlined and the use of MoABs postoperatively is proposed.

Antibodies, Anti-Idiotypic