Characterization of a granule-independent lytic mechanism used by CTL hybridomas

The mechanism(s) by which CTL induce target cell lysis have not been clearly elucidated. Perforin and the cytotoxic cell proteinases (granzymes) contained within the granules of CTL and NK, have been implicated, but abundant evidence for the existence of alternate lytic pathways has accumulated. In this report we characterize the mechanism of killing used by two cytolytic hybridomas (PMM-1 and MD90) that express neither perforin nor the granzymes. These characteristics are compared with results obtained by using a representative Ag-dependent, granule-containing T cell clone in cytolysis assays. The major differences were that the granule-negative hybridomas could lyse a variety of target cells in the presence of cyclosporin and the absence of calcium. All the effectors could kill in the presence of protein synthesis inhibitors (cycloheximide and emetine) and induced DNA fragmentation in the target cells. The cytolytic hybridomas had to be stimulated to be cytolytic and this activation required the presence of calcium, was dependent on protein synthesis, and inhibited by the addition of cyclosporin. Although TNF was shown not be involved, the sensitivity of the target cells to lysis by the granule-negative killers correlated with the level of expression of Fas Ag. With the use of L1210 and an L1210 cell line transfected with Fas cDNA we demonstrated that these MD90 and PMM-1 kill the latter much more effectively and that this increase was effectively inhibited with anti-Fas Ab. Furthermore the lack of sensitivity to cyclosporin, cycloheximide, emetine, and EGTA was confirmed with these targets. We conclude that these two cytolytic hybridomas use the Fas lytic pathway to induce lysis in target cells.

Characterization of a granule-independent lytic mechanism used by CTL hybridomas

The mechanism(s) by which CTL induce target cell lysis have not been clearly elucidated. Perforin and the cytotoxic cell proteinases (granzymes) contained within the granules of CTL and NK, have been implicated, but abundant evidence for the existence of alternate lytic pathways has accumulated. In this report we characterize the mechanism of killing used by two cytolytic hybridomas (PMM-1 and MD90) that express neither perforin nor the granzymes. These characteristics are compared with results obtained by using a representative Ag-dependent, granule-containing T cell clone in cytolysis assays. The major differences were that the granule-negative hybridomas could lyse a variety of target cells in the presence of cyclosporin and the absence of calcium. All the effectors could kill in the presence of protein synthesis inhibitors (cycloheximide and emetine) and induced DNA fragmentation in the target cells. The cytolytic hybridomas had to be stimulated to be cytolytic and this activation required the presence of calcium, was dependent on protein synthesis, and inhibited by the addition of cyclosporin. Although TNF was shown not be involved, the sensitivity of the target cells to lysis by the granule-negative killers correlated with the level of expression of Fas Ag. With the use of L1210 and an L1210 cell line transfected with Fas cDNA we demonstrated that these MD90 and PMM-1 kill the latter much more effectively and that this increase was effectively inhibited with anti-Fas Ab. Furthermore the lack of sensitivity to cyclosporin, cycloheximide, emetine, and EGTA was confirmed with these targets. We conclude that these two cytolytic hybridomas use the Fas lytic pathway to induce lysis in target cells.

Hyperzincuria in individuals with insulin-dependent diabetes mellitus: concurrent zinc status and the effect of high-dose zinc supplementation

The urinary excretion of zinc in individuals with insulin-dependent diabetes mellitus (IDDM) is approximately doubled. In the absence of a compensatory mechanism, this hyperzincuria should induce a deficient or marginal Zn status. We examined parameters of Zn status in plasma and in blood cells with respect to urinary Zn losses and Zn supplementation. We measured Zn levels in the urine, plasma, and erythrocytes of 14 IDDM subjects and 15 nondiabetics who kept dietary records for 3 consecutive days. Subsequently, six IDDM subjects and seven nondiabetics were supplemented with 50 mg Zn daily for 28 days. We measured the above parameters, as well as mononuclear leukocyte Zn (MNL-Zn) and the plasma subfraction of albumin-bound Zn (alb-Zn). The total plasma Zn-binding capacity was also assessed. Plasma copper and erythrocyte Cu were monitored as indicators of potential Zn toxicity. Individuals with IDDM displayed the expected hyperzincuria, but had normal blood Zn parameters. Zincuria increased by a similar amount in both groups during supplementation, as did the MNL-Zn content. However, erythrocyte Zn (e-Zn) was refractory, so a trend toward lower e-Zn among IDDM subjects persisted during Zn supplementation. Hemoglobin A1c (HbA1c) increased markedly in the Zn-supplemented IDDM group. Despite their chronic hyperzincuria, individuals with IDDM appear not to be Zn-deficient. Large-dose Zn supplementation increases MNL-Zn and induces an undesirable elevation of HbA1c in all individuals. This is especially disconcerting for those with IDDM, and may reflect an exacerbation of a chronic "Zn diabetes." These data suggest a potential for toxicity from large-dose Zn supplementation.

[Responsiveness of lymphocytes from patients with M. avium-intracellulare complex (MAC) infection to PPDs as measured by IFN-gamma production]

We investigated the responsiveness of peripheral blood lymphocytes (PBLs) from patients with M. avium-intracellulare complex (MAC) infection to the stimulation with PPDs by measuring their IFN-gamma producing ability. PBLs were obtained from MAC patients at active stage (culture-positive after three-month chemotherapy), those at inactive stage (culture-negative for three months after or during chemotherapy), and healthy donors. PPDs used were PPD-S prepared from M. tuberculosis, PPD-B from M. intracellulare, and PPD-Y from M. kansasii. PBLs from active MAC patients did not produce IFN-gamma to a significant extent by stimulation with any of three PPDs, while PBLs from inactive MAC patients showed higher responses to each PPD compared to those from active patients. In inactive MAC patients, the maximal response was observed to PPD-B among three PPDs. On the other hand, PBLs from healthy controls produced different levels of IFN-gamma in response to three different PPDs, and their response was most remarkable to PPD-S. These results indicated that the responsiveness of patients' PBLs to PPDs was impaired during active stage of MAC infection and restored on recovery from the disease.

[Relationship between nutritional depletion and cell-mediated immune function in active pulmonary tuberculosis]

A survey on the nutritional status and cell-mediated immune function of 47 hospitalized patients with active pulmonary tuberculosis and healthy controls was conducted. In the patients group: 1) Anthropometric measurements, such as %ideal body weight (%IBW), %arm circumference (%AC), %arm muscle circumference (%AMC) and %triceps skin fold (%TSF), were significantly reduced. 2) Visceral proteins including serum albumin (Alb), transferrin (Tf), prealbumin (PA) and retinol binding protein (RBP) were significantly reduced. 3) The imbalance of plasma amino acids, which was characterized by the depression of Fischer ratio, a molar ratio of branched chain amino acids (BCAA) to aromatic amino acids (AAA), was observed. Fischer ratio was significantly correlated with anthropometric measurements (%IBW, %AC and %AMC). Delayed-type hypersensitivity to DNCB (2,4-dinitrochlorobenzene) and lymphocyte transformation to phytohemagglutinin (PHA) and concanavalin A (Con A) were significantly impaired in the patients group, whereas NK cell activity was higher than that of controls. Alb, PA, RBP and Fischer ratio were significantly lower in the patients with reduced DNCB reaction than in those with normal responses. Lymphocyte transformation was significantly correlated with Fischer ratio, and NK cell activity was significantly correlated with Alb, PA, RBP. These data may suggest that the imbalance of plasma amino acids represented by the reduction of Fischer ratio and the depletion of visceral proteins are closely related to the impairment of lymphocyte function in the patients with active pulmonary tuberculosis.

[Tumor necrosis factor alpha in bronchoalveolar lavage fluid and its production by alveolar macrophages with asbestos exposure]

It is generally accepted that asbestos exposure causes pulmonary fibrosis and carcinogenesis. Several studies have suggested that TNF alpha is produced principally by mononuclear phagocytes and that it may play a role in inflammation, fibrosis and anti-tumor activity. We studied TNF alpha production by alveolar macrophages and the TNF alpha concentration in bronchoalveolar lavage fluid harvested from asbestos-exposed subjects and healthy controls. TNF alpha production by alveolar macrophages was significantly higher in the asbestos-exposed subjects than in healthy controls (3696 +/- 1606, 1938 +/- 753 pg/ml; p < 0.01). The period from first exposure correlated inversely with TNF alpha production (r = -0.6; p < 0.05). The TNF alpha concentration in bronchoalveolar lavage fluid was also significantly higher in the asbestos-exposed subjects than in healthy controls. These results suggest that abnormal TNF alpha production by alveolar macrophages may be related to fibrosis and carcinogenesis due to asbestos.

[Anorexia nervosa complicated with pulmonary tuberculosis]

A study was made on a patient with anorexia nervosa complicated with pulmonary tuberculosis treated with intravenous hyperalimentation (IVH). A 24-year-old female was admitted to our hospital because of progressive loss of body weight during medication for pulmonary tuberculosis at another hospital. She was diagnosed as having anorexia nervosa. After the nutritional assessment IVH was performed. As a result of IVH, her body weight increased and her nutritional deprivation, (i.e., low visceral proteins, low branched amino acids, etc.) recovered. Nutritional support was effective upon treating pulmonary tuberculosis.

[An autopsy case of atypical mycobacteriosis accompanied with chest wall deformity]

An autopsy case of 63-year old male of atypical mycobacteriosis with severe scoliosis was reported. He was diagnosed as atypical mycobacteriosis in 1981 and controlled by antimycobacterial treatment. But since 1989, dyspnea and sputum have been increasing, new abnormal shadow in company with progression of curvature of the scoliosis was revealed on the chest roentgenogram. In spite of various treatments for mycobacteriosis, he died of respiratory failure. The aggravation of this mycobacteriosis brought on advancement of malnutrition and impairment of cell mediated immunity. Findings of autopsy showed the remarkable chest wall deformity and tuberculous change of the lung parenchyma. In this case, chest deformity was thought as the major risk factor of onset of mycobacterial mycobacteriosis.

[Clinical features of primary and secondary atypical mycobacteriosis]

A clinical investigation was carried out in 39 patients with atypical mycobacteriosis (AM). The patients at our hospital diagnosed as having AM during an 11-year period from 1981 to 1991 were reviewed in this study. The incidence of AM among all of mycobacterial infections has been increasing since 1988. The atypical mycobacteria detected included M. avium complex (MAC) in 79%, M. kansasii in 26%, and other organisms in 5%. Patients who had primary infection without underlying respiratory disease were compared with those who had secondary infection. In secondary infection, MAC was detected in the sputum of a high percentage of patients and was positive for more than 6 months despite therapy. Gamma globulin levels were also increased in patients with secondary infection. Cell mediated immunity was examined by the DNCB reaction and the detection of CD4- and CD8- positive T lymphocytes. The DNCB skin reaction was positive in 6 out of 26 patients with secondary infection. The percentage of CD8- positive T lymphocytes was higher in patients with secondary disease. Fischer's ratio (indicating the balance of plasma amino acids) was also examined as an index of the nutritional status. It was significantly lower in secondary infection compared with primary infection. Moreover, secondary infection was associated with a lower positive rate for the DNCB skin reaction and a lower Fischer's ratio when compared with pulmonary tuberculosis. Thus impairment of cell-mediated immunity, malnutrition, and a poor prognosis were significantly more common in secondary infection compared with primary infection.

[Case study of interleukin-1 beta, tumor necrosis factor alpha and interleukin-6 production peripheral blood monocytes in patients with diabetes mellitus complicated by pulmonary tuberculosis]

Patients with diabetes mellitus (DM) show an increased susceptibility to bacterial infections due to the presence of neutrophil dysfunction. Susceptibility to tuberculosis has also been reported in such patients, however, the reason remains unclear. This study measured the production of interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF alpha) and interleukin-6 (IL-6) by the peripheral monocytes of patients diagnosed with pulmonary tuberculosis accompanied by DM (TB+DM) and patients without DM complications (TB) using age-matched, healthy control subjects for comparison. Also examined was the relationship between cytokine production and DM control. The results were as follows: (1) The production of IL-1 beta, TNF alpha and IL-6 in TB patients was significantly higher than that observed in the healthy control subjects. (2) The production of IL-1 beta, TNF alpha and IL-6 in TB+DM patients was significantly lower than that observed in the TB patients. (3) The production of IL-1 beta and TNF alpha in TB+DM patients with poor control was significantly lower than that observed in the patients with good control. (4) The TNF alpha production had a significant inverse correlation to HbA1c in the TB+DM patients. This study demonstrated that the production of cytokines is impaired in TB+DM patients and suggests a close correlation between tuberculosis immunity and DM.

[Relation of airway obstruction and respiratory muscle weakness to energy metabolism in pulmonary emphysema]

Resting energy expenditure (REE) was assessed and its relationship to nutritional status, pulmonary function and respiratory muscle function was studied in 25 patients with pulmonary emphysema. The mean value of REE was 1413 +/- 251 Cal and the ratio of REE/REEpred was 1.398 +/- 0.23, suggesting the existence of a hypermetabolic state in these patients. REE/REEpred ratio was inversely correlated with plasma amino acid BCAA/AAA ratio and body muscle mass; and PImax. REE was inversely correlated with FEV1.0%. REE in the patient subgroup with severe hyperinflation (%RV > or = 200) was significantly higher than that in the subgroup with moderate hyperinflation. Malnourished patients showed significantly more severe hyperinflation than well-nourished patients. These findings suggest that augmented REE contributes to malnutrition in patients with emphysema, and that the increase in REE was related to the increase in mechanical work load on the basis of airway obstruction, respiratory muscle weakness and hyperinflation.

[Nutritional assessment and the effect of supplementary oral nutrition in patients with pulmonary emphysema]

Nutritional status and its relation to respiratory function and respiratory muscle strength were assessed in patients with pulmonary emphysema. Energy metabolism was also examined in order to elucidate the mechanism of their malnutrition. BCAA/AAA ratio of plasma amino acid was positively correlated with FEV1.0%. Resting energy expenditure (REE) was negatively correlated with FEV1.0%, and REE/REEpred ratio was also negatively correlated with BCAA/AAA and PImax. These findings suggest that increased mechanical work load, associated with airway obstruction and reduced respiratory muscle efficiency, contribute to the increased energy expenditure and amino acid imbalance. Oral nutritional supplementation using BCAA enriched-elemental diet was found to be effective, as assessed by nutritional parameters, PImax, D.O.E., and QOL index, in malnourished emphysema patients.

Transcription of the T cell receptor beta-chain gene is controlled by multiple regulatory elements

The cis-acting sequences regulating transcription of the beta-chain of the TCR have been analyzed and multiple elements identified. The minimum 5' upstream sequence displaying promoter activity is a fragment extending 85 bp upstream of the transcriptional start site. Deletion of an additional 43 bp from the 5' end of this fragment abolished promoter activity. The presence of the conserved TCR beta-chain decanucleotide motif, an AP-1 consensus sequence and an inverted repeat in the deleted region, suggests their role as targets for transacting factors regulating transcription of the beta chain gene. Sequences between -343 and -85 increase transcription from the -85 fragment in T cells. The promoter is active in both T cells and fibroblasts. The enhancer was capable of enhancing TCR V beta 2 promoter activity in both T cells and fibroblasts. Sequences further upstream of the V beta 2 promoter down regulate V beta 2 promoter activity in the absence of the enhancer but its repressive influence is overcome in the presence of the TCR beta-chain enhancer.

Transcription of the T cell receptor beta-chain gene is controlled by multiple regulatory elements

The cis-acting sequences regulating transcription of the beta-chain of the TCR have been analyzed and multiple elements identified. The minimum 5' upstream sequence displaying promoter activity is a fragment extending 85 bp upstream of the transcriptional start site. Deletion of an additional 43 bp from the 5' end of this fragment abolished promoter activity. The presence of the conserved TCR beta-chain decanucleotide motif, an AP-1 consensus sequence and an inverted repeat in the deleted region, suggests their role as targets for transacting factors regulating transcription of the beta chain gene. Sequences between -343 and -85 increase transcription from the -85 fragment in T cells. The promoter is active in both T cells and fibroblasts. The enhancer was capable of enhancing TCR V beta 2 promoter activity in both T cells and fibroblasts. Sequences further upstream of the V beta 2 promoter down regulate V beta 2 promoter activity in the absence of the enhancer but its repressive influence is overcome in the presence of the TCR beta-chain enhancer.