The role of opicapone in the management of Parkinson's disease: an Italian consensus through a combined Nominal Group Technique and Delphi approach

OBJECTIVE

Opicapone (OPC) is a third-generation peripheral catechol-O-methyl transferase inhibitor (COMT-i) approved as add-on therapy to levodopa/DOPA decarboxylase inhibitors (DDCI) combinations in Parkinson's disease (PD) patients with end-of-dose motor fluctuations. While the OPC effectiveness on motor symptoms is well known, there is still uncertainty about the timing of introduction, the management of levodopa dose, and the efficacy on non-motor symptoms (NMS).

SUBJECTS AND METHODS

A group of PD experts participated in a consensus activity composed of the Nominal Group Technique (NGT) and the Delphi method to better define the role of OPC. A list of statements was defined with the NGT and voted on through an online Delphi process by a panel of 85 Italian clinicians.

RESULTS

24 statements were selected for the Delphi voting. Most statements (n=15, 62%) reached a consensus. A wide agreement was reached about the efficacy of OPC in treating motor fluctuations, including early morning akinesia and nocturnal akinesia. The panel widely agreed about the effectiveness of OPC in early fluctuating patients. The long-lasting inhibitory effect of OPC was recognized as an advantage over other COMT-i, resulting in a single daily dose and greater ease of introduction into the levodopa therapeutic regimen.

CONCLUSIONS

The efficacy of OPC observed in the clinical trials for the management of PD patients with motor fluctuations is also experienced in clinical practice. The review of the current positioning of OPC from the late to early stages of the disease may represent an important step in the evolution of the PD therapeutic approach.

Loss of Heterozygosity of Dq Alpha Gene in Human Malignant Melanoma

DNAs from human melanoma cells, used at early in vitro passage, were evaluated by Southern blot analysis for somatic loss of heterozygosity at the DQ alpha gene. A total of 7 melanomas, 3 primary and 4 metastatic derived from 5 different patients were studied; in one case (pt 665) cell lines were derived from two anatomically different subcutaneous metastasis, whereas in a second case (pt 9923) both the primary tumor and a lymph node metastasis were available. Restriction length polymorphism (RFLP) analysis, performed on autologous peripheral blood lymphocyte (PBL) DNA digested with different enzymes, showed a pattern of bands compatible with the constitutional heterozygous typing at DQ alpha gene in 4 cases whereas 1 case revealed an homozygous typing. When melanoma DNAs were analysed, 1 out of the 4 informative cases (pt 1007) showed a loss of a diagnostic fragment for DQ alpha gene when digested with both Taq I and Bgl I enzymes. These results indicate that class II allelic losses detectable by RFLP can be found on malignant melanoma and add further complexity on the involvement of chromosome 6 whose cytogenetic abnormality are the most consistent in this human neoplasia.

Peripheral neuropathy in 30 duodopa patients with vitamins B supplementation

OBJECTIVES

Peripheral neuropathy (PN) is a significant concern and potential cause of withdrawal in patients with Parkinson's disease (PD) treated with Levodopa/Carbidopa Intestinal Gel (LCIG) infusion. Vitamin B deficiency and/or hyperhomocysteinemia levodopa-related are considered possible causative factors. In this study, we evaluated PN incidence in LCIG-PD patients treated since the beginning of infusion with vitamins B supplementation.

MATERIALS & METHODS

In this prospective open-label pilot study, 30 consecutive patients with PD on LCIG infusion were evaluated with clinical, neurophysiological, and biochemical assessments for a mean follow-up of 42.4 months (range 24-72). All evaluations were repeated every 6 months.

RESULTS

At baseline, 21 of 30 presented no signs or symptoms of PN, and 9 of 30 had pre-existing chronic PN. In whole population, a progressive worsening in nerve conduction studies of sural sensory and peroneal motor nerves was observed during the long-term follow-up. 4 of 21 patients, with normal clinical, electrophysiological assessment at baseline, developed distal symmetrical axonal polyneuropathy that remained asymptomatic during the long-term follow-up. Patients with pre-existing PN (9 of 30) showed a mild worsening of electrophysiological features during the period of observation. In none PN was cause of discontinuation of LCIG therapy. No incident cases of acute-subacute PN were documented. No correlation was found with age, sex, Levodopa dosage, duration of levodopa exposure, and homocysteine plasma levels.

CONCLUSION

In this consecutive series of 30 patients with PD on LCIG infusion, with early and continuous vitamins B integration, we observed a low rate (19%) of new onset peripheral polyneuropathy that remained stable after long-term follow-up. Larger studies, controlled, with blinded evaluation, are needed to confirm these findings.

Five-year follow-up of 10 patients treated with globus pallidus internus deep brain stimulation for segmental or multisegmental dystonia

INTRODUCTION

Globus pallidus internus (GPi) deep brain stimulation (DBS) represents a validated, effective, and safe treatment for patients affected by generalized dystonia resistant to conservative treatment. Segmental and multisegmental dystonia have more recently been proposed as further indications for GPi DBS despite the lack of long-term homogenous follow-up. Here we present an original and detailed long-term follow-up (5 years) of a homogeneous population of 11 patients affected by segmental or multisegmental dystonia.

MATERIALS AND METHODS

Ten patients underwent bilateral GPi DBS electrode implantations under a Leksell stereotactic guide, with intraoperative neurophysiological monitoring. The follow-ups at 1, 3 and 5 years were collected using video-BFMDRS for motor and disability scores. The statistical analysis of the results is provided.

RESULTS

We reported a statistically significant improvement in motor and disability overall scores until 5 years after treatment. At the last follow-up, even the single motor subitems were statistically improved.

DISCUSSION

We observed a continuous and statistically significant improvement in all of the motor subitems and in the overall disability score until the 3-year follow-up. These results did not improve any further but they appeared steady at the last follow-up. We also report a significant improvement in the cranial-cervical subitems.

CONCLUSIONS

GPi DBS should definitely be considered a safe and effective treatment also for segmental and multisegmental dystonia even in cases of relevant or prevalent cranial-cervical involvement.

Enhanced nonenzymatic glycation of eye lens proteins in experimental diabetes mellitus: an approach for the study of protein alterations as mediators of normal aging phenomena

The levels of advanced nonenzymatic glycation endproducts (ACE) were investigated by spectrofluorimetry in eye lens proteins obtained from rats with experimental diabetes of 3 and 6 months duration and from normal age-matched control rats. Diabetic animals showed higher AGE levels at both times studied. However the older control animals showed protein ACE levels comparable to those of the experimental 3 months diabetic group. These data suggest that a pathological phenomenon such as enhanced nonenzymatic glycation, associated to diabetic hyperglycemia, can be considered as a process leading to an accelerated aging of proteins. Thus experimental diabetes mellitus may be used as a model to investigate physiological protein senescence.

Immunogenicity of advanced glycation end products in diabetic patients and in nephropathic non-diabetic patients on hemodialysis or after renal transplantation

Advanced glycation end products (AGE) increase as a consequence of diabetic hyperglycemia and, in nephropathic patients, following renal function loss. Protein-bound AGE behave as immunogens, inducing formation of specific antibodies (Ab-AGE). In this work AGE immunogenicity was studied in 42 diabetic patients, 26 nephropathic patients on hemodialysis and 26 patients with end-stage renal disease who underwent kidney transplantation and in 20 normal subjects. Non-oxidation-derived AGE (nox-AGE), oxidation-derived AGE (ox-AGE) and Ab-AGE were measured by competitive or direct enzyme-linked immunosorbent assay (ELISA) and circulating immune complexes (CIC) by C1q ELISA. Nox- AGE increased significantly in all patient groups (p < or = 0.05 to < or = 0.0001) except in patients on hemodialysis for less than 6 yr. Ox-AGE were only significantly increased in patients transplanted more than 3 yr previously (p < 0.05). Ab-AGE were significantly lower than controls in both diabetic groups and in patients on hemodialysis for more than 6 yr (p < 0.005 to < 0.0001) and not unlike controls in the other groups. These results demonstrate that hemodialysis or renal transplantation can, initially, reduce either nox- or ox-AGE levels, which however go back to being high in time. Renal transplantation fails to normalize nox-AGE. More importantly, plasma Ab-AGE levels are reduced or unchanged in all patient groups in comparison with controls, despite higher circulating AGE levels. This suggests the importance of tissue-bound AGE as Ab-AGE targets. Additional interventions are needed to control AGE levels in treated nephropathic patients. The search and quantification of specific Ab-AGE would give more meaningful results if performed over specific tissue specimens.

Angiotensin blockade and matrix synthesis by glomerular epithelial cells in high glucose: a further experimental insight into the pathophysiology of diabetic nephropathy

AIMS

Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin II receptor-1 (AT-1) antagonists are used in the treatment of proteinuria of diabetic nephropathy. One of the major pathogenic events in this condition is represented by the alteration of the extracellular matrix protein synthesis by glomerular epithelial cells.

MATERIALS AND METHODS

We evaluated the effects of the angiotensin converting enzyme inhibitor, Enalaprilat, and the AT-1 receptor antagonist, Losartan, on mRNA fibronectin and laminin synthesis by glomerular epithelial cells, in conditions mimicking hyperglycemia.

RESULTS

In high glucose conditions, Enalaprilat reduced significantly the mRNA expression of fibronectin (p 0.03), but not significantly that of laminin. Losartan addition to high glucose incubated cells reduced (-30%) mRNA expression of fibronectin, and significantly (p 0.05) the mRNA expression of laminin.

CONCLUSIONS

In addition to the known hemodynamic effects, the improvement of renal function in diabetic patients treated with these compounds may also be due to a modulator effect on extracellular matrix content and composition.

Dientamoeba fragilis in swine population: A preliminary investigation

Dientamoeba fragilis, a protozoan with worldwide distribution is considered to be responsible for enteric disease in humans. A wide spectrum of clinical symptoms including; diarrhoea (acute or prolonged), flatulence, abdominal pains and other unspecific bowel symptoms have been ascribed to this parasite. Asymptomatic infection has also been reported. Dientamoeba fragilis is as its name indicates an extremely delicate protozoon and only the trophozoite has ever been demonstrated in stool samples. The definitive diagnosis of this infection is based on demonstration in permanently stained stool samples. In Italy examination of ova and parasite (O&P) samples are not currently performed. This protozoan is extremely difficult to cultivate but molecular techniques such as the Polymerase Chain Reaction offer promise as a means of diagnosing infection. The epidemiology of Dientamoebiasis is not clear. This paper will present preliminary results from a study looking for the parasite's presence in swine faeces. The possible role of pigs as a reservoir of infection was studied; 121 faecal samples from breeding and fattening pigs were examined using a Giemsa permanent stain. Dientamoeba fragilis was found in 53 (43.8%) of the stool samples examined.

Mutually exclusive NRASQ61R and BRAFV600E mutations at the single-cell level in the same human melanoma

Activating BRAF or NRAS mutations have been found in 80% of human sporadic melanomas, but only one of these genetic alterations could be detected in each tumour. This suggests that BRAF and NRAS 'double mutants' may not provide advantage for tumour growth, or may even be selected against during tumorigenesis. However, by applying mutant-allele-specific-amplification-PCR method to short-term melanoma lines, one out of 14 tumours was found to harbour both BRAFV600E and the activating NRASQ61R mutations. On the other hand, analysis of 21 melanoma clones isolated by growth in soft agar from this tumour indicated that 16/21 clones harboured a BRAFV600E, but were wild-type for NRAS, whereas the remaining had the opposite genotype (NRASQ61R/wild-type BRAF). When compared to BRAFV600E clones, NRASQ61R clones displayed reduced growth in soft agar, but higher proliferative ability in vitro in liquid medium and even in vivo after grafting into SCID/SCID mice. These data suggest that NRAS and BRAF activating mutations can coexist in the same melanoma, but are mutually exclusive at the single-cell level. Moreover, the presence of NRASQ61R or BRAFV600E is associated with distinct in vitro and in vivo growth properties of neoplastic cells.

Explosive-aggressive behavior related to bilateral subthalamic stimulation

We describe a patient with Parkinson's Disease who underwent bilateral subthalamic nucleus deep brain stimulation and later presented with episodes of aggressive behavior disorder with disturbed impulse control and an inability to control anger likely related to the deep brain stimulation "switch-on stimulation". We hypothesize that increasing voltage intensity could influence neighboring passing fibers coming from basal limbic system that are involved in the regulation of affect and emotional behavior. We suggest investigating these neuropsychological disturbances considering their influence on quality of life after surgery.

The impairment of renal function is not associated to altered circulating vascular endothelial growth factor in patients with Type 2 diabetes and hypertension

BACKGROUND

Metabolic and haemodynamic factors concur in the development of diabetic nephropathy. Moreover, in diabetes, the presence of hypertension may accelerate the development of renal damage. Vascular endothelial growth factor (VEGF) stimulates microvascular permeability, endothelium-dependent vasodilation and angiogenesis and its synthesis is enhanced by hyperglycaemia, advanced glycation end-products (AGEs), tissue hypoxia and hypertension. VEGF appears to play a central role in mediating diabetic vasculopathy, and although VEGF and its receptors are expressed at renal level, its action in renal pathophysiology is unknown. The aim of this study was to elucidate whether presence and/or severity of renal dysfunction is related to circulating VEGF in patients with Type 2 diabetes and hypertension.

DESIGN AND METHODS

Fifty hypertensive Type 2 diabetic patients and 20 non-diabetic patients were included in the study. Renal function parameters such as albumin excretion rate (AER), and glomerular filtration rate (GFR), and VEGF plasma levels were analysed in all subjects, whereas %HbA1c and AGEs levels were evaluated in diabetic patients.

RESULTS

GFR was significantly decreased in diabetic patients compared with the control subjects (74.36 +/- 15.95 vs 111.5 +/- 17.0 ml/min, p<0.0001). Three diabetic patients showed AER abnormalities (53.8 +/- 2.3 mg/24h). VEGF in diabetic patients was higher than in the control group (77.95 +/- 65.98 vs 49.30 +/- 40.8 pg/ml), but not significantly. %HbA1c and AGE levels were 6.6 +/- 1.5% and 11.59 +/- 8.09 UAGE/ml, respectively. No correlation was found between renal function, circulating VEGF levels and metabolic control.

CONCLUSION

Diabetes, in association with hypertension, significantly decreases renal function, but circulating VEGF may not reflect its concentration and action at renal level.

Angiotensin-converting enzyme inhibition modulates high-glucose-induced extracellular matrix changes in mouse glomerular epithelial cells

BACKGROUND/AIM

Extracellular matrix alterations are involved in the pathogenesis of diabetic nephropathy. We evaluated the effects of high glucose concentrations and inhibition of angiotensin-converting enzyme on the laminin and fibronectin production by glomerular epithelial cells.

METHODS

Glomerular epithelial cells were cultured in 5 and 30 mmol/l glucose, with and without enalaprilat (0.3 mmol/l). Laminin and fibronectin were measured (35S-methionine, immunoprecipitation), and their mRNA expression was evaluated (RT-PCR).

RESULTS

The laminin concentration was higher in the cells than in the medium, where an increase of its content was observed under high-glucose conditions (p < 0.01). Fibronectin, found only in the medium, was not modified by the high glucose concentration. Following enalaprilat administration, the laminin concentration was decreased under high-glucose conditions, both in the cell and in the medium (p < 0.001), whereas the fibronectin concentration was increased under high-glucose conditions (p < 0.001). The mRNA expression of laminin and fibronectin under high-glucose conditions only slightly increased. Enalaprilat decreased the fibronectin mRNA synthesis dramatically (>50%, p < 0.0001) under high-glucose conditions.

CONCLUSIONS

Enalaprilat normalizes the abnormal, high-glucose-induced concentration of laminin, while it decreases the fibronectin synthesis. The improvement of the renal function in diabetic patients treated with angiotensin-converting enzyme inhibitors may, in part, be due to a modulator effect on extracellular matrix content and composition.

Two polyclonal antisera detect different AGE epitopes in human plasma samples

Advanced glycation end products (AGEs), involved in the pathogenesis of diabetic complications, comprise a series of related chemical structures which might possess dissimilar immunogenic characteristics. In this study the levels of AGE in plasma samples from normal subjects (N=41) and diabetic patients (N=44) were measured by ELISA using two polyclonal antisera (named CF5 and CF199, respectively, and immunologically characterized) raised using two different immunogens and immunization techniques. Age levels were significantly higher in diabetic than in normal plasma samples (P<0.0001) with both antisera. However, CF199 detected higher AGE levels than CF5 both in normal (P<0.0001) and diabetic (P<0.005) samples. Pre-incubation with AGE-bovine serum albumin (BSA) caused the loss of most the reactivity of both antisera. Pre-incubation with carboxy-methyl-lysine-BSA (an oxidation-derived AGE) induced the loss of nearly all CF5 reactivity while CF199 retained a significant amount of activity against AGE antigens. Moreover, CF5 lost over 90% of its reactivity against BSA incubated with high glucose under non-oxidative conditions, suggesting its recognition of mainly oxidation-derived AGE epitopes. The different AGE levels measured by the two antisera suggests, therefore, that one single antiserum is unable to recognize all the various AGE epitopes which might be present, at any time, in tissues and body fluids in health and disease.

Identification of a novel gp100/pMel17 peptide presented by HLA-A*6801 and recognized on human melanoma by cytolytic T cell clones

Melanoma-associated peptides recognized by cytolytic T lymphocytes (CTL) in the context of several histocompatibility leukocyte antigens (HLA) are required for the development of specific immunotherapies. Using a transient transfection assay into COS-7 cells, we identified the gp100/pMel17 melanosomal protein as the shared antigen recognized by three independent CD8+ CTL clones in HLA-A*6801-restricted fashion. This finding was confirmed by the correlation between lack of gp100/pMel17 protein in a number of HLA-A*6801-positive melanomas and their resistance to lysis/cytokine production by the specific effectors. The gp100/pMel17 antigenic epitope was identified based on recognition of subfragments and on a computer-based prediction algorithm. Among a panel of gp100/pMel17-derived synthetic peptides only the 10-mer HTMEVTVYHR (gp100/pMel17182-191) induced tumor necrosis factor (TNF) release by CTL clones when pulsed on suitable target cells whereas both the 10-mer and the shorter 9-mer gp100/pMel17183-191 sensitized the same antigen-pulsed cells to lysis. In conclusion, the identification of the HTMEVTVYHR peptide will extend to HLA-A*6801 melanoma patients the possibility to exploit gp100/pMel17 melanosomal protein for experimental and clinical studies.

Advanced glycation end product levels in eye lenses, aorta, and tail tendon in transplanted diabetic inbred Lewis rats

BACKGROUND

Pancreatic islet transplantation in diabetes, by restoring euglycemia, should in time correct the abnormal accumulation of advanced glycation end products (AGEs) over target tissues, thus delaying the development of late diabetic complications.

METHODS

Homologous islet transplantation was performed in inbred Lewis rats 15 days (TA), 4 months (TB), and 8 months (TC) after streptozotocin diabetes. Group TA was studied for 12 months and groups TB and TC were studied for 4 months after transplantation. Normal (N) and diabetic (D) rats formed the control groups. Metabolic control in the transplant (T) groups was evaluated by oral glucose tolerance test. Blood glucose, glycated hemoglobin, and body weight were determined in all groups. AGE levels were determined by spectrofluorometry in eye lens proteins and by ELISA in aortic and tail tendon collagen.

RESULTS

T groups showed normal oral glucose tolerance tests and metabolic parameters. The latter were altered in all D groups (P<0.005 to P<0.0001 versus N and T groups). AGEs were increased in the D groups (P<0.05 to P<0.001) versus the N groups. AGEs in the TA and TB groups were not different from those of the N groups but were significantly reduced (P<0.05 to P<0.001) when compared with those of the D groups. In the TC group, eye lens AGEs were significantly elevated (P<0.001) or significantly reduced (P<0.01) when compared with those of the N or D groups, respectively. Aortic collagen AGEs were elevated (P<0.01) by comparison with those of the N groups and not statistically different from those of the D groups. Tail tendon collagen AGE levels lay between those of the N and D groups, without reaching a statistical significance.

CONCLUSIONS

These results indicate that primary and early secondary (groups TA and TB) but not late secondary (group TC) islet transplantations are capable of blocking or reducing an abnormal accumulation of AGEs, thus confirming the importance of preventive transplantation therapies.

Human melanocytes and melanomas express novel mRNA isoforms of the tyrosinase-related protein-2/DOPAchrome tautomerase gene: molecular and functional characterization

We previously reported that a melanoma antigen, recognized by tumor-specific cytotoxic T lymphocytes, was encoded by intron sequences retained in a partially spliced transcript of the tyrosinase-related protein-2/DOPAchrome tautomerase gene. At difference with the mRNA encoding tyrosinase-related protein-2, this anomalous transcript was not expressed in melanocytes. This study examined whether neoplastic and/or normal cells of the melanocytic lineage could express additional forms of tyrosinase-related protein-2 mRNA. Screening of a melanoma-derived cDNA library with a tyrosinase-related protein-2 probe allowed identification of two novel isoforms. The first, tyrosinase-related protein-2-long tail, corresponds to the dominant transcript detected on melanomas and melanocytes by northern blot analysis. Tyrosinase-related protein-2-long tail is identical to the tyrosinase-related protein-2-encoding published cDNA sequence except for an extended 3'-untranslated region and is originated by alternative polyadenylation. This novel 3'-untranslated region contains an alternatively spliced, tyrosinase-related protein-2 last exon in the second isoform (tyrosinase-related protein-2-8b). The protein encoded by tyrosinase-related protein-2-8b is identical to tyrosinase-related protein-2 in its first 460 amino acids but possesses a different carboxyl-terminus devoid of transmembrane domain. Tyrosinase-related protein-2-long tail exhibited DOPA-chrome tautomerase activity, when transiently transfected into COS-7 cells. On the contrary, no detectable activity was exhibited by tyrosinase-related protein-2-8b. Reverse transcription-polymerase chain reaction analysis indicated that tyrosinase-related protein-2-long tail and tyrosinase-related protein-2-8b are expressed by tyrosinase-related protein-2-positive melanomas and normal melanocytes. Moreover all cell lines positive for tyrosinase-related protein-2 isoforms expressed tyrosinase and, all but one, tyrosinase-related protein-1. These data show that the human tyrosinase-related protein-2/DOPAchrome tautomerase gene can yield different isoforms by alternative poly(A) site usage or by alternative splicing. The pattern of expression of these isoforms suggest that they might play a part in the normal pathway of melanin biosynthesis.

Differential loss of T cell signaling molecules in metastatic melanoma patients' T lymphocyte subsets expressing distinct TCR variable regions

In this study we tested the hypothesis that loss of T cell signaling molecules in metastatic melanoma patients' T cells may affect differently T cell subsets characterized by distinct TCR variable regions. By a two-color immunofluorescence technique, expression of zeta-chain, lck, and ZAP-70 was evaluated in CD3+ T cells and in three representative T cell subsets expressing TCRAV2, TCRBV2, or TCRBV18. Partial loss of lck and ZAP-70 was found in CD3+ T cells from PBL of most melanoma patients, but not of healthy donors. The extent of zeta-chain, lck, and ZAP-70 loss depended on the TCRV region expressed by the T cells, and this association was maintained or increased during progression of disease. Coculture of patients' or donors' T cell with melanoma cells, or with their supernatants, but not with normal fibroblasts or their supernatants, down-modulated expression of zeta-chain, lck, and ZAP-70 in a TCRV region-dependent way. Immunodepletion of soluble HLA class I molecules present in tumor supernatants, but not of soluble ICAM-1, blocked the suppressive effect on T cell signaling molecule expression. T cell activation with mAbs to a single TCRV region and to CD28 led to significant and TCRV region-specific re-induction of zeta-chain expression. These findings indicate that extent of TCR signaling molecules loss in T lymphocytes from metastatic melanoma patients depends on the TCRV region and suggest that tumor-derived HLA class I molecules may contribute to induce such alterations.

Effect of islet transplantation on neuroelectrophysiological abnormalities in diabetic inbred Lewis rats: comparison of primary versus secondary prevention

BACKGROUND

Neuroelectrophysiological abnormalities in diabetes indicate nervous function failure. Restoration of euglycemia by islet transplantation may prevent or reverse these abnormalities.

METHODS

Pancreatic islets were transplanted in inbred Lewis rats after 15 days (Ta12, primary prevention) or 8 months (Tb12, secondary prevention) from streptozotocin-induced diabetes. Transplanted and control (normal and diabetic) rats were followed for a total period of 12 months. Metabolic parameters, somato-sensory, brain-stem auditory, and visual evoked potentials were determined at the beginning and at the end of the study and before transplantation for secondary prevention.

RESULTS

The metabolic parameters in transplanted animals were similar to those of normal animals. Ta12 and normal group somato-sensory conduction velocities did not vary and were always significantly higher than those of diabetic animals. By contrast, Tb12 group conduction velocities showed only a partial improvement, values lying between those of diabetic and normal rats. Brain-stem auditory (waves I, II, and III) latencies in Ta12 group were similar to those of normal rats and significantly lower than those of diabetic animals (wave I: P<0.01; waves II and III: P<0.05). Tb12 group wave I and II latency values remained altered (P<0.005 and P<0.01 versus normal values respectively). Visual evoked potentials-P1 wave latencies in transplanted rats were always higher than those of normal and diabetic animals.

CONCLUSIONS

After primary prevention, central and peripheral neurological alterations were abolished. After secondary prevention, transplantation beneficial effects were partial, occurring mainly at peripheral level. These results highlight the importance of early transplantation to prevent hyperglycemia-dependent neuroelectrophysiological alterations.

Autoimmune markers and neurological complications in non-insulin-dependent diabetes mellitus

To verify whether autoimmune markers related to nervous system structures and other autoimmunity indexes present in diabetes mellitus are associated with subclinical neuropathy, we examined 48 non-insulin-dependent diabetic patients with and without neuroelectrophysiological alterations. Nerve conduction velocity at the external sciatic-popliteal nerve, at the sural nerve, at the median and ulnar nerves level has been evaluated. Autoimmunity was investigated by evaluating glutamic acid decarboxylase (GAD-Ab), insulin (IAA), GM3, GD3 and GT1b gangliosides, pancreatic islet cell (IC-A) and anti-nervous-tissue autoantibody presence. Nerve conduction velocities were decreased in 72.9% of diabetic patients. Anti-insulin antibodies were detected in seven non-insulin created diabetic patients and in higher amount in subjects with (17.1%) than in those without (7.7%) asymptomatic neuropathy. Anti-GM3 antibodies were detected in four diabetic patients all of whom presented neurological complication. A significant correlation has been found between neurological damage and presence of anti-insulin antibodies (p<0.05). In the case of GM3 autoantibody, a similar result was obtained, but the data failed to reach statistical significance. Our data demonstrate that autoimmunity might play a role in the development of peripheral neuropathy.

Leber's Hereditary Optic Neuropathy (LHON) with 14484/ND6 mutation in a North African patient

We report the clinical and genetic study of a Leber's Hereditary Optic Neuropathy (LHON) patient of North African origin harboring the 14484/ND6 mutation of mtDNA. For over a year we followed the ophthalmological course of this 24-year-old male with LHON treated with idebenone and vitamin B12. Serum lactate after effort was evaluated before, during and after therapy. Muscle biopsy was obtained for morphological study. Homo/heteroplasmy of 14484/ND6 mutation was studied in different tissues. Recovery of visual acuity was documented 6 months after onset and 3 months after therapy was established. Baseline serum lactate was elevated but normalized after 3.5 months of therapy. Muscle biopsy demonstrated only a few fibers with a slightly increased subsarcolemmal SDH activity. Genetic analysis showed homoplasmic 14484/ND6 mutation in all tissues investigated. The clinical phenotype of LHON/14484 in this patient closely resembles that commonly found in European patients. Even if LHON/14484 patients are reported to have a better prognosis for visual recovery, it is possible that the evolution of visual recovery in this patient could have been influenced by therapy as suggested by changes in serum lactate levels. Bioenergetic impairment of skeletal muscle was documented by lactate levels and muscle morphology. The 14484/ND6 mutation behaves as a primary mutation regardless of mtDNA population-specific backgrounds.

Translation of a retained intron in tyrosinase-related protein (TRP) 2 mRNA generates a new cytotoxic T lymphocyte (CTL)-defined and shared human melanoma antigen not expressed in normal cells of the melanocytic lineage

We report here the identification of a new shared human melanoma antigen recognized by a human leukocyte antigen (HLA)-A*68011-restricted cytotoxic T lymphocyte clone (CTL 128). The cDNA encoding this antigen is composed of a partially spliced form of the melanocyte differentiation antigen tyrosinase-related protein (TRP)-2, containing exons 1-4 with retention of intron 2 and part of intron 4 (TRP-2-INT2). The sequence coding for the antigenic epitope is located at the 5' end of intron 2 and is available for translation in the same open reading frame of the fully spliced TRP-2 mRNA. This peptide is also recognized by CTL 128 when presented by the HLA-A*3301, a member of the HLA-A3-like supertype that includes the HLA-A*68011. Quantitative reverse transcription PCR analysis carried out on total and/or cytoplasmic mRNA demonstrated that, in contrast to the fully spliced TRP-2 mRNA expressed in melanomas, normal skin melanocytes, and retina, the TRP-2-INT2 mRNA could be detected at significant levels in melanomas but not in normal cells of the melanocytic lineage. Instead, in these normal samples, both the spliced and the unspliced transcript of gp100 were expressed at high levels. Absence of endogenous TRP-2-INT2 expression in melanocytes was also confirmed by lack of recognition of HLA-A*68011-transduced, TRP-2(+) melanocyte lines by CTL 128. These results indicate that a partially spliced form of a differentiation antigen mRNA, present in the cytoplasmic compartment of neoplastic but not normal cells of the melanocytic lineage, can be the source of a melanoma-restricted T cell epitope.

Reduction of advanced glycation end-product (AGE) levels in nervous tissue proteins of diabetic Lewis rats following islet transplants is related to different durations of poor metabolic control

Advanced glycation end-products (AGEs) are irreversible compounds which, by abnormally accumulating over proteins as a consequence of diabetic hyperglycaemia, can damage tissues and thus contribute to the pathogenesis of diabetic complications. This study was performed to evaluate whether restoration of euglycaemia by islet transplantation modifies AGE accumulation in central and peripheral nervous tissue proteins and, as a comparison, in proteins from a non-nervous tissue. Two groups of streptozotocin diabetic inbred Lewis rats with 4 (T1) or 8 (T2) months disease duration were grafted into the liver via the portal vein with 1200-1500 islets freshly isolated from normal Lewis rats. Transplanted rats, age-matched control and diabetic rats studied in parallel, were followed for a further 4-month period. At study conclusion, glycaemia, glycated haemoglobin and body weight were measured in all animals, and an oral glucose tolerance test (OGTT) performed in transplanted rats. AGE levels in cerebral cortex, spinal cord, sciatic nerve proteins and tail tendon collagen were measured by enzyme-linked immunosorbent assay (ELISA). Transplanted animal OGTTs were within normal limits, as were glycaemia and glycated haemoglobin. Diabetic animal AGEs were significantly higher than those of control animals. Protein AGE values were reduced in many transplanted animals compared to diabetic animals, reaching statistical significance in spinal cord (P < 0.05), sciatic nerve (P < 0.02) and tail tendon collagen (P < 0.05) of T1 animals. Thus, return to euglycaemia following islet transplantation after 4 months of diabetes with poor metabolic control reduces AGE accumulation rate in the protein fractions of the mixed and purely peripheral nervous tissues (spinal cord and sciatic nerve, respectively). However, after a double duration of bad metabolic control, a statistically significant AGE reduction has not been achieved in any of the tissues, suggesting the importance of an early therapeutic intervention to prevent the possibly pathological accumulation of AGEs in nervous and other proteins.

Levels of advanced glycosylation end-products (AGE) in sera of pregnant diabetic women: comparison between type 1, type 2 and gestational diabetes mellitus

The chronic hyperglycemia can lead to an increase of the advanced glycosylation end-products (AGE) levels on proteins and macromolecules. Abnormal levels of AGE in several tissues has been associated with the pathogenesis of late diabetic complications. In diabetic pregnant women, high AGE levels might influence the delicate maternal-fetal balance and therefore alter the pregnancy outcome. In this preliminary study, we have measured the AGE in sera of 44 diabetic women in two trimester. Sixteen sera from non diabetic pregnant women have been used as controls. The AGE have been analyzed by means of an ELISA method with an antiserum anti-RNAse-AGE, produced in the Laboratory of Clinical Biochemistry of the Istituto Superiore di Sanità. Diabetic patients type 1 and type 2, in good metabolic control, showed normal AGE levels at both trimester. Patients with gestational diabetes showed significantly high serum AGE levels (p < 0.05). A more extended study will give better insight on the association between AGE levels and a physiopathology of diabetic pregnancy.

Intralesional selection of T cell clonotypes in the immune response to melanoma antigens occurring during vaccination

T cells infiltrating pre- and postvaccine metastases obtained from melanoma patients vaccinated with either dinitrophenyl (DNP)-modified autologous tumor or with the MAGE-3.A1 peptide display selective T cell receptor (TCR) beta chain variable region (BV) repertoire changes at the tumor site as a consequence of vaccination. Restricted sets of BV families expand in all postvaccine lesions when compared with prevaccine specimens and often contain dominant clones. A protocol devised to obtain T cell lines highly enriched for expression of a given BV region through the use of anti-BV monoclonal antibodies was used to understand whether responses to specific antigen(s) accounted for these clonal expansions. In one of the patients vaccinated with DNP-modified tumor cells, BV-driven selection of the T lymphocytes expanded in two infiltrated postvaccine metastases resulted in T cell lines able to exert HLA class I-restricted lysis of the autologous tumor. These results indicate that TCR repertoire analysis at the tumor site facilitates the detection of T cell responses elicited by a vaccine and potentially cytotoxic for the autologous tumor.

Immunohistochemical analysis of the T-cell receptor beta-chain variable regions expressed by T lymphocytes infiltrating primary human melanoma

The T-cell receptor beta-chain variable (TCRBV) region repertoire expressed by tumor-infiltrating lymphocytes was characterized by immunohistochemical analysis using a panel of 18 monoclonal antibodies on cryosectioned specimens of 14 primary vertical growth phase (VGP) melanomas with a T-cell infiltrate histopathologically defined as brisk or nonbrisk. T lymphocytes present in the VGP of all patients displayed a restricted T-cell receptor usage, with a pattern of reactivity similar in brisk versus nonbrisk infiltrates. No evidence of restriction was found in the extra-VGP lymphocytic infiltrates, when available, within the same specimen. Furthermore, the repertoire of TCRBV expressed in nodal metastases was similar to that of the corresponding primary melanomas in the two cases tested. The results obtained by this in situ analysis indicate that the TCRBV repertoire in VGP is determined by a preferential migration of T lymphocytes, possibly indicative of an immune response to melanoma-associated antigens.

Cerebellar ataxia, hypogonadism and chorioretinopathy: molecular analysis of an Italian family

This study aimed to determine if cerebellar ataxia, hypogonadism and chorioretinopathy (AHCR) is associated with mutations in mitochondrial DNA or in genes responsible for spinocerebellar ataxias (SCA1, SCA2, SCA3 and Friedreich's ataxia). Two brothers with cerebellar ataxia, hypogonadism and chorioretinopathy and their unaffected parents underwent molecular analysis for duplications and deletions in mitochondrial DNA (mtDNA), point mutations in the ATP ase 6 gene, and expansions of CAG repeats (at 6p22-p23, 12q24.1, 14q32.1) and of GAA repeats (at gene X25 on chromosome 9q13). The research was negative for all mutations. Our findings confirm that AHCR is a distinct disease within the inherited cerebellar ataxias.

TCR beta-chain variable region-driven selection and massive expansion of HLA-class I-restricted antitumor CTL lines from HLA-A*0201+ melanoma patients

Recognition of a given melanoma Ag involves a limited array of T cell clones bearing a structurally defined TCR. The aim of this study was to verify whether this information can be used to isolate and expand such anti-tumor effectors from fresh lymphocyte populations. We found that one to three different TCR beta-chain variable (TCRBV) regions were significantly expanded in 4-wk mixed lymphocyte-tumor cultures (MLTC) from six HLA-A*0201+ melanoma patients, and that the T cells expressing the expanded TCRBV regions were involved in HLA class I-restricted lysis of the tumor. T cell activation by mAbs to MLTC-selected TCRBV region and CD28 resulted in large scale expansion (1-10 x 10(9) cells) of T cell lines, highly enriched for the expression of a single TCRBV region and for CD8+ T cells. The TCRBV-driven selection was equally effective when applied to patients' or healthy donors' lymphocytes, and the T cell lines isolated from melanoma patients exerted HLA class I-restricted lysis of the autologous tumor. MLTC and TCRBV-selected lines recognized allogeneic melanomas sharing HLA-A and -B alleles with the autologous tumor, but only two of the HLA-A2-restricted lines were directed to a known peptide from melanoma-associated Ags. Single-strand conformation polymorphism analysis indicated a polyclonal composition of both MLTC and TCRBV-selected lines, but expansion of clonotypes with identical CDR3 length was observed only in the MLTC lines. Thus, TCRBV-driven selection can be exploited to obtain large scale expansion of antitumor CTL lines from melanoma patients.

TCR beta-chain variable region-driven selection and massive expansion of HLA-class I-restricted antitumor CTL lines from HLA-A*0201+ melanoma patients

Recognition of a given melanoma Ag involves a limited array of T cell clones bearing a structurally defined TCR. The aim of this study was to verify whether this information can be used to isolate and expand such anti-tumor effectors from fresh lymphocyte populations. We found that one to three different TCR beta-chain variable (TCRBV) regions were significantly expanded in 4-wk mixed lymphocyte-tumor cultures (MLTC) from six HLA-A*0201+ melanoma patients, and that the T cells expressing the expanded TCRBV regions were involved in HLA class I-restricted lysis of the tumor. T cell activation by mAbs to MLTC-selected TCRBV region and CD28 resulted in large scale expansion (1-10 x 10(9) cells) of T cell lines, highly enriched for the expression of a single TCRBV region and for CD8+ T cells. The TCRBV-driven selection was equally effective when applied to patients' or healthy donors' lymphocytes, and the T cell lines isolated from melanoma patients exerted HLA class I-restricted lysis of the autologous tumor. MLTC and TCRBV-selected lines recognized allogeneic melanomas sharing HLA-A and -B alleles with the autologous tumor, but only two of the HLA-A2-restricted lines were directed to a known peptide from melanoma-associated Ags. Single-strand conformation polymorphism analysis indicated a polyclonal composition of both MLTC and TCRBV-selected lines, but expansion of clonotypes with identical CDR3 length was observed only in the MLTC lines. Thus, TCRBV-driven selection can be exploited to obtain large scale expansion of antitumor CTL lines from melanoma patients.

Clonal expansion of T lymphocytes in human melanoma metastases after treatment with a hapten-modified autologous tumor vaccine

Metastatic melanoma patients treated with an autologous DNP-modified tumor cell vaccine develop inflammatory responses in metastatic tumors characterized by infiltration of CD8+ T cells. To further define this immune response, we analyzed T cell receptor beta-chain variable (TCRBV) region repertoire in biopsy specimens and peripheral blood lymphocytes of six patients. After administration of DNP vaccine, a restricted set of TCRBV gene families was found to be expanded compared with prevaccine metastases. In several postvaccine lesions of one patient, obtained over a 2-yr period, TCRBV14+ T cells were clonally expanded and identical T cell clonotypes could be detected. Two major recurring clones were biased toward the use of TCRBJ1S5. Furthermore, T cell lines derived from two such infiltrated skin lesions and, enriched in TCRBV14+ T cells, displayed HLA-class I-restricted lysis of the autologous melanoma cells. Clonal expansion of T cells was demonstrated in the T cell-infiltrated, postvaccine metastasis of a second patient as well. These results indicate that vaccination with autologous, DNP-modified melanoma cells can expand selected clones of T cells at the tumor site and that such clones are potentially destructive to the tumor.

Conserved TCR usage by HLA-Cw* 1601-restricted T cell clones recognizing melanoma antigens

In this study we determined TCR alpha and beta chain nucleotide sequences of HLA-Cw* 1601-restricted cytoxic T lymphocyte (CTL) clones obtained from the peripheral blood lymphocytes (PBL) of a melanoma patient. These clones were previously shown to be involved in the recognition of melanoma-associated antigenic epitopes SAYGEPRKL and AARAVFLAL encoded by gene MAGE-1 and BAGE respectively. All (3/3) anti-MAGE-1 CTL clones displayed TCRBV5 usage and one clonotype was found twice, > 1 year apart, in patient's PBL. Two out of three anti-BAGE CTL clones showed the same TCRAV/AJ and TCRBV/BJ combinations and differed in the alpha chain CDR3 for two residues and in the beta chain CDR3 for a single nucleotide which, however, did not change translation. These results suggest a pattern of TCR conservation in CTL selected for recognition of MAGE-1 or BAGE peptides on the autoiogous melanoma.

Peripheral, but not central, nervous system abnormalities are reversed by pancreatic islet transplantation in diabetic Lewis rats

Neuroelectrophysiological recordings represent a non-invasive and reproducible method of detecting central and peripheral nervous system alterations in diabetes mellitus. In order to evaluate whether the normalization of metabolic control obtained by pancreatic islet transplantation could reverse diabetic neuroelectrophysiological alterations, or prevent further deterioration, we used an experimental model in which pancreatic islets (n = 1200) were injected into the portal vein of inbred Lewis rats (used as islet donors as well as recipients). Islets were injected 4 months after diabetes induction, since previous work had shown functional but not morphological damage at the nervous tissue level at this stage of the disease. Visual (V), brainstem auditory (BA) and somatosensory (S) evoked potentials (EPs) were measured in streptozotocin-induced, islet-recipient diabetic rats (n = 7), streptozotocin-induced diabetic rats (n = 16) and non-diabetic control rats (n = 12). Metabolic parameters and electrophysiological recordings were evaluated before diabetes induction, before transplantation and 4 months later. After transplantation, glycaemic levels returned to normal values within 1 week and remained so until the end of the study, as confirmed by a normal oral glucose tolerance test and by an increase in body weight. Electrophysiological recordings were altered in diabetic animals before transplantation. Four months after transplantation EP recordings improved, with a detectable gradient from the peripheral to the central structures. SEPs were significantly improved in the peripheral tarsus-L6 tract and the L6-cortex tract (P < 0.005 and P < 0.01 versus diabetic rats) and were ameliorated without achieving statistical significance in the central L6-cortex tract. BAEP latency values tended to improve in transplanted rats, but the differences versus non-transplanted diabetic animals failed to reach significance. VEP values remained clearly pathological and even deteriorated after transplantation. These results show that normalization of metabolic control by pancreatic islet transplantation can reverse some of the already established neuroelectrophysiological alterations at the peripheral nervous system level, but does not affect other alterations at the central nervous system level.

Interaction with fibronectin regulates cytokine gene expression in human melanoma cells

Our study was aimed at investigating whether interaction of human melanoma cells with the extracellular matrix (ECM) protein fibronectin (FN) could regulate lymphokine gene expression. Serum-deprived cells (quiescent condition) of a metastatic melanoma cloned line were cultured either on uncoated or on FN- or BSA-coated surfaces. By means of reverse transcriptase- polymerase chain reaction (RT-PCR), we analyzed mRNA expression of 4 cytokines interleukin (IL)-1alpha, IL, 1beta, IL-6 and IL-8-and 9 growth factors-endothelial cell growth factor (ECGF), basic fibroblast growth factor (bFGF), fibroblast growth factor (FGF)-5, HST, keratinocyte growth factor (KGF), transforming growth factor (TGF)-alpha TGF-beta1, TGF-beta2 and TGF-beta3. When cultured on FN, melanoma cells expressed IL-1beta and IL-6 transcripts in addition to IL-1beta, IL-8, ECGF, TGF-beta1, TGF-beta2 and TGF-beta3, already present in quiescent cells. Amplification parameters to achieve semi-quantitative RT-PCR were then determined for each detectable factor, thus allowing us to measure a selective enhancement of mRNA levels for IL-1alpha, IL-6, IL-8 and TGF-beta2 upon interaction with FN by quiescent melanoma cells. This augmented expression was inhibited by an anti-integrin beta1 chain monoclonal antibody (MAb). Moreover, the amounts of IL-6, IL-8 and IL-beta produced in the supernatants, as assessed by ELISA, correlated with the corresponding mRNA expression. Extension of this analysis to the other 5 human primary and metastatic melanoma lines confirmed the ability of FN to selectively up-regulate only IL-6 and IL-8 secretion. Our data indicate that FN is able to modulate expression and secretion of a defined subset of lymphokines in human melanoma.

Analysis of TCR usage in human tumors: a new tool for assessing tumor-specific immune responses

Tumor-infiltrating lymphocytes (TILs), through displaying a T-cell receptor (TCR) repertoire as heterogeneous as that of normal peripheral blood T cells, show overexpression of TCR variable-gene segments that include clonally expanded TCR sequences. Here, Marialuisa Sensi and Giorgio Parmiani analyze the available information on TCR usage by T cells present in the infiltrate of histologically different tumors and suggest that the analysis of TCR sequences represents a powerful new tool to assess the in vivo immune response to growing tumors. Ultimately, this strategy may lead to the identification and manipulation of T-cell populations endowed with antitumor reactivity.

Cytotoxic T-lymphocyte clones from different patients display limited T-cell-receptor variable-region gene usage in HLA-A2-restricted recognition of the melanoma antigen Melan-A/MART-1

To determine whether T-cell-receptor (TCR) usage by T cells recognizing a defined human tumor antigen in the context of the same HLA molecule is conserved, we analyzed the TCR diversity of autologous HLA-A2-restricted cytotoxic T-lymphocyte (CTL) clones derived from five patients with metastatic melanoma and specific for the common melanoma antigen Melan-A/MART-1. These clones were first identified among HLA-A2-restricted anti-melanoma CTL clones by their ability to specifically release tumor necrosis factor in response to HLA-A2.1+ COS-7 cells expressing this tumor antigen. A PCR with variable (V)-region gene subfamily-specific primers was performed on cDNA from each clone followed by DNA sequencing. TCRAV2S1 was the predominant alpha-chain V region, being transcribed in 6 out of 9 Melan-A/MART-1-specific CTL clones obtained from the five patients. beta-chain V-region usage was also restricted, with either TCRBV14 or TCRBV7 expressed by all but one clone. In addition, a conserved TCRAV2S1/TCRBV14 combination was expressed in four CTL clones from three patients. None of these V-region genes was found in a group of four HLA-A2-restricted CTL clones recognizing different antigens (e.g., tyrosinase) on the autologous tumor. TCR joining regions were heterogeneous, although conserved structural features were observed in the complementarity-determining region 3 sequences. These results indicate that a selective repertoire of TCR genes is used in anti-melanoma responses when the response is narrowed to major histocompatibility complex-restricted antigen-specific interactions.

Role of advanced glycation end-products (AGE) in late diabetic complications

To evaluate accumulation of advanced glycation end-products (AGE) in diabetes and its possible correlation with late diabetic complications, AGE levels were measured by spectrofluorimetry in eye lens and sciatic nerve proteins and isolated tail tendon collagen of rats with experimental diabetes of 3- and 6-month duration. The values obtained were compared to those from age-matched control rats and correlated with cataract presence and somatosensory evoked potential (SEP) alterations. Diabetic animals had increased AGE levels in all tissues at both times; cataract developed in 29% of diabetic rats at 3 months and in 57% at 6 months; SEP conduction velocity was reduced in diabetic animals both at 3 (54.5 +/- 1.8 S.E.M. m/s vs. 73.9 +/- 1.0, P < 0.0001) and 6 months (59.5 +/- 1.4 vs. 71.5 +/- 1.6, P < 0.0001) from diabetes induction. No eye lens AGE level differences were observed when cataract presence was considered. Interestingly, in diabetic rats, increased sciatic nerve AGE levels were associated with reduced SEP. These data show that: (1) AGE levels are increased as early as 3 months from development of hyperglycemia; (2) other factors, in addition to an enhanced rate of fluorescent AGE formation, might play important roles in the pathogenesis of diabetic cataract; (3) increased peripheral nerve AGE levels are associated with SEP alterations.

Characteristics of proteinuria in experimental diabetes mellitus

An impairment of protein charge selectivity has been invoked to explain the initial anionic proteinuria in diabetic nephropathy. The aims of this work were to investigate charge and size protein perm-selectivity abnormalities in experimental diabetes and to monitor these changes over time after diabetes induction. Diabetes was induced in 56 Sprague-Dawley male rats by streptozotocin; the control group was represented by 38 normal rats. Blood glucose, body weight, urine volumes, and proteinuria in 24-h urine collections were evaluated at 3, 6, 9, and 12 months of diabetes. The Bradford method and mono- and bidimensional gel electrophoresis were used to determine and characterize proteinuria. Body weight increase was lower (P < 0.05, P < 0.0001, P < 0.05 at 3, 6, and 12 months, respectively), urine volumes were greater (P < 0.001, P < 0.005, P < 0.05 at 6, 9, and 12 months, respectively) and the proteinuria was significantly increased (P < 0.05 at 3 months, P < 0.001 at 6 months, P < 0.01 at 9 months, and P < 0.05 at 12 months) in diabetic rats compared with the control group. When the charge and the size of urine proteins were considered, small (30 kDa) and anionic proteins were found to be mainly excreted in diabetic rats, at 3 months of the disease; at 6 months, higher amounts of albumin and cationic proteins with higher molecular weight (50 kDa) were also found in the urine; at 9 and 12 months the changes previously described were associated with an excretion of proteins weighing about 75 kDa.(ABSTRACT TRUNCATED AT 250 WORDS)

H-2Kb and H-2Db gene transfections in B16 melanoma differently affect non-immunological properties relevant to the metastatic process. Involvement of integrin molecules

Modification of non-immunological cell adhesion properties plays a major role in the decrease in metastatic ability observed after transfection of the H-2Kb gene in H-2-negative B16-derived melanoma clone cells. To investigate the role played by different class-I major histocompatibility complex (MHC) genes on non-immunological properties relevant for metastasis, transfection with the H-2Db gene alone or in conjunction with the H-2Kb gene was performed. H-2Db gene transfection did not modify either metastatic potential or non-immunological cell adhesion properties. Double KbDb transfectants showed a decreased metastatic ability when compared to control clones and to Db transfectants; a decrease in homotypic adhesive ability was also observed, even though not in all clones studied: therefore expression of the Db gene is also relevant. The mechanisms of homotypic cell adhesion were studied and found to be dependent upon temperature and divalent cations. Adhesion was partially inhibited by an antiserum directed against the beta 1 integrin subunit, whereas anti-alpha IIb beta 3 was ineffective. Cell pre-treatment with anti-beta 1 serum reduced metastatic ability. A decreased expression of alpha 4 and alpha 6 integrin subunits was observed in Kb clones, whereas no difference in the levels of some homophilic cell adhesion molecules, such as N-CAM and alpha IIb beta 3, was found. Adhesion required the activity of tyrosine kinases, as suggested by the decreased adhesive properties and impaired metastatic ability of cells pre-treated with the tyrosine-kinase-inhibitor genistein. These results are compatible with involvement of integrin molecules of the beta 1 family in the adhesive ability of these cells. Our data show that: (a) immunological and non-immunological effects of MHC transfection are correlated and depend on the class-I gene used, suggesting that MHC gene therapy can be highly successful only if appropriate MHC genes are transfected; (b) non-immunological cell-adhesion properties modified after MHC transfection could be related to an impairment of integrin-mediated adhesive interactions.

Expression of interleukin 1 alpha, interleukin 6, and tumor necrosis factor alpha genes in human melanoma clones is associated with that of mutated N-RAS oncogene

To assess whether RAS oncogenes may affect the expression of cytokines in tumor cells, the presence of interleukins (IL) 1 alpha, 1 beta, 4, 6, 7, and 8, tumor necrosis factor (TNF) alpha and interferon gamma mRNA has been analyzed by reverse transcriptase-polymerase chain reaction in 19 melanoma clones derived from the metastatic cell line 665/2 and previously characterized for RAS mutation and expression. Five of these clones and the parental cell line showed a mutation at codon 61 of N-RAS that resulted in Gln-->Arg substitution (N-RAS/61+), while in the remaining 14, only the wild-type allele for N-RAS was present (N-RAS/61-). With the exception of interferon gamma and IL-4, all the cytokines tested were expressed by the parental 665/2 cell line, whereas IL-1 alpha, IL-6, and TNF-alpha were coordinately transcribed only in the subset of the clones bearing the mutated N-RAS gene. The other cytokine genes studied (IL-1 beta, IL-4, IL-7, and IL-8) displayed a variable degree of expression, and such an heterogeneity was not correlated to the N-RAS phenotype of the clones. The association between N-RAS oncogene and IL-1 alpha, IL-6, and TNF-alpha expression was also found in a 665/2 subline (665/2/5) in which loss of mutated N-RAS genes simultaneously occurred with the loss of IL-1 alpha, IL-6, and TNF-alpha expression. Direct evidence that N-RAS oncogene could influence the pattern of cytokine expression was provided by the coordinate induction of IL-1 alpha, IL-6, and TNF-alpha messenger RNA achieved in N-RAS/61+ transfectants of the N-RAS wild-type melanoma clone 2/21. Furthermore, IL-1 alpha, IL-6, and TNF-alpha could be detected by enzyme-linked immunosorbent assay in the culture medium obtained from N-RAS/61+ melanoma clones as well as from positive transfectants, indicating that lymphokine mRNA expression triggered by the activated N-RAS oncogene lead to a secreted protein. In an N-RAS/61+ melanoma clone, by adding specific antibodies against each cytokine, it was found that soluble IL-1 alpha exerted a positive control on IL-6 mRNA and a negative one on its own expression. In addition, IL-1 alpha and IL-6 were negatively regulated by soluble IL-6 and TNF-alpha.

Autologous cytolytic T lymphocytes recognize a MAGE-1 nonapeptide on melanomas expressing HLA-Cw*1601

Human melanoma cell line MZ2-MEL expresses several antigens recognized by autologous cytolytic T lymphocyte (CTL) clones. We reported previously the identification of a gene, named MAGE-1, which codes for antigen MZ2-E which is presented by HLA-A1. Gene MAGE-1 is expressed in many tumors of several types but not in normal tissues except for testis. We show here that gene MAGE-1 directs the expression of another antigen recognized by CTL on the MZ2-MEL cells. This antigen, which was named MZ2-Bb, consists of MAGE-1-encoded peptide SAYGEPRKL bound to major histocompatibility molecule HLA-Cw*1601. The HLA-Cw*1601 allele was found to be expressed by 7 out of 99 individuals from a Caucasian population. Our results extend the range of tumor patients who could be eligible for immunization against MAGE antigens.

Cytotoxic T lymphocytes recognize tumor antigens of a murine colonic carcinoma by using different T-cell receptors

To see whether different antigens expressed by the same tumor are recognized by distinct T-cell receptors (TCR), we used cytotoxic T-lymphocyte (CTL) lines known to lyse in vitro the syngeneic BALB/c adenocarcinoma C-26. Four of these CD3+ CD8+ lines showed 4 different patterns of lysis on a panel of MHC-class-I-compatible targets. The activity was H-2d-restricted and could be blocked by anti-CD3 and anti-TCR-alpha/beta monoclonal antibodies (MAbs). The CTL lines were also effective, although to a different extent, in adoptive immunotherapy of mice bearing lung metastases. Phenotypic analysis revealed in all the lines a high frequency of cells positive for CD45, asialo GM1 (ASGM1), lymphocyte-function-associated antigen-1 (LFA-1), intercellular adhesion molecule-1 (ICAM-1) and CD44, but negligible expression of L-selectin (LAM-1) and very late antigen-4 (VLA-4); 2 lines expressed the vitronectin-receptor (VN-R). Analysis of TCR V beta-chains used by the 4 lines showed selective presence of V beta 6, V beta 8.2, V beta 8.3 and of V beta 13 chains. MAbs directed to these V beta chains blocked their lytic activity in vitro. V alpha-chain transcripts of the lines were identified by polymerase chain reaction (PCR) as V alpha ITT11 and V alpha 52 in 2 lines, while one could not be identified. Analysis of V beta s in mixed lymphocyte-tumor-cell cultures (MLTC) of T cells deriving from tumor-infiltrating lymphocytes (TIL) or from spleen of C-26 tumor-bearing or immune animals indicated that the TCR of the CTL lines were representatives of the TCR repertoire recognizing C-26 tumor, since their V beta s were shown to be selectively expanded in MLTC.

Effect of protein kinase C inhibitors on invasiveness of human melanoma clones expressing different levels of protein kinase C isoenzymes

The involvement of protein kinase C (PKC) in the mechanism of chemotaxis and invasiveness of human melanoma has been studied in 6 clones of 665/2 cell line characterized by a different integrin profile, differentiation grade and in vitro invasive ability. The levels of total protein kinase C activity revealed a direct correlation with the chemotactic and invasive ability of these clones. Protein kinase C inhibitors, sphingosine and staurosporine, reduced chemotaxis and invasiveness of the highly invasive clone 2/60, while 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H7) was ineffective. Immunofluorescence analysis revealed high levels of protein kinase C alpha in clone 2/60, while the less invasive clone 2/21 expressed low levels of protein kinase C alpha and beta, but surprisingly appreciable levels of protein kinase C gamma. Downregulation with phorbol 12-myristate 13-acetate (TPA) did not affect invasiveness of clone 2/60 unless the compound was present during the assay. H7 strongly increased invasiveness of clone 2/21 and was able to reverse the inhibitory effect of TPA on clone 2/60. Preliminary experiments showed higher levels of diacylglycerol in clones with lower protein kinase C, suggesting a constitutive downregulation of the enzyme in low invasive clones. Our results support a role for protein kinase C in the invasion process, but point out the complexity of the mechanism which might involve the proteolytic fragment of the enzyme, protein kinase M.

N-RAS mutations and susceptibility to lymphokine-activated killer (LAK) cells in human melanoma

RAS oncogene expression has been reported to affect several biological features of rodent tumours cells, including lysability by activated natural killer cells. In order to examine whether expression of mutated RAS genes in human melanoma cells alters their susceptibility to lysis by LAK cells, seven melanoma lines were assessed for the presence of Ki- and N-RAS genes bearing all possible mutations at codons 12, 13 and 61. A panel of 21 clones deriving from the metastatic lesion Me665/2, which had a Gln-->Arg substitution at codon 61 of N-RAS (N-RAS/61+), were also examined. Melanoma cells and clones were used as targets of allogeneic LAK in a 4-h 51Cr-release assay. LAK showed a higher lysis on melanoma lines and clones harbouring a mutated RAS compared with counterparts bearing no RAS mutations. In addition, LAK-mediated lysis drastically decreased on Me665/2 sublines progressively selected by exposure to LAK. This loss was paralleled by a reduction or even disappearance of N-RAS/61+ mRNA signal in Me665/2 sublines. To evaluate whether N-RAS could directly modulate LAK susceptibility to lysis, N-RAS/61+ gene was transfected in two N-RAS wild type (N-RAS/61-) 665/2 melanoma clones by a cosmid vector. In contrast to the high lysability of melanoma cells constitutively expressing the mutationally active N-RAS oncogene, N-RAS/61+ transfectants did not show a consistent high lysability by LAK, compared with some control pSV2neo transfectants.(ABSTRACT TRUNCATED AT 250 WORDS)