The mechanism of the delayed type of hypersensitivity

Инкубационный пром ытого клетки hypersensitive кроли ков (лейкоциты, селез енки клеток, лимфоцит ов) в разбавленном туб еркулина в vitro приводит к появлению веществ с pyrogenic действий. Эти веще ств не фигурирует в к онтроля эксперимен тов, в которых клетки hypersensitive Были инкубировали без туберкулина или в которых клетки от н ормальных, не hypersensitive крол иков были инкубиров али.     

The mechanism of the delayed type of hypersensitivity

Кролики были ознак омл ены с БЦЖ вакцины, и посл е гиперчувств ительно сть кожи вак цины, и посл е гиперчу вствительно сть кожи дозе 5 μ (itg) очищ ен ного туберкулина (PT), веде нии внутривен но. Систе мные реакци и туберкули на hypersensitive от кроликов до 5 μ г PT состоит из лихор адка, и lymphopenia изменения в число гра нулоцитов (leucocytosis или leucopenia). Эта доза не производит т ем пературы или карт ина кр ови изменения в контро ля. Гиперчув ствительн ость был переведен пас сивно по клеток (200 до 500 млн.) hypersensitive от кроликов. Она прош ла успешно на использо вании клеток селезенки, перитонеального exudate (сол еных течение четырех ч асов или минеральное нефти в течение 48 часов) и белые клетки перифери ческой крови. В пассивн ом передача гиперчувс твительности в клетка х нормальных получате лей, все проявлений сист емных туберкулина Реа кция может быть вызвал, как в активном сенсибил изированная кроликов. Передача плазмы сенсиб илизированная кролик ов. Передача плазмы раз работка системного зад ерживается гиперчувс твительность в получат елями. Он сделал вывод о том, что результаты туб еркулина системные ре акции в первую очередь вызвала реакцию на hypersenstive клеток с туберкулина.     

The mechanism of the delayed type of hypersensitivity

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   Простой метод демон страции цитостатиче ские воздействия раз бавленных туберкул ина и ПТ) на лейкоциты от hypersensitive кролики описана. О пределенный артикль Метод состоит в пятн а и мертвых живых кле ток (лейкоциты, мыть в четыре раза и приост ановлено в Tyrode раствор а) с 1% Конго красного и 0,2% после голубого Нила в течение четырех ча сов инкубации в vitro. Нес колько сто эксперим енты проводились и сто эксперименты пр оводились и гиперсс ылок чувствительно сти кроликов испыта ниям.     
   
   

Study on systemic reaction of delayed type hypersensitivity

Effectiveness of two different samples of PPD tuberculins was studied quantitatively. No differences were found in the effect on skin test in rabbits, extent of skin reaction in guinea pigs, edema of foot-pad in rats and inhibition of spleen cell migration in guinea pigs. Differences were observed in the systemic febrile reaction in rabbits and in examinations of the thickness of infiltrated skin in guinea pig tests. The results may serve as a basis for standardization of systemic reaction in rabbits.     

Study of systemic fever reaction of the delayed type hypersensitivity

The possibility of elaborating a model of fever reaction to a simple protein antigen, ovalbumin, was investigated. Administration of the antigen in adjuvants into the foot-pads or intravenously proved unsatisfactory and did not sensitize the animal to induction of a fever reaction to a challenging dose of antigen. Sensitization by the simultaneous intravenous administration of ovalbumin together with living BCG vaccine yielded positive results. The fever response to ovalbumin is specific, since rabbits sensitized with BCG vaccine only did not respond to the administration of ovalbumin. The degree of fever reactions to tuberculin and ovalbumin in the individual rabbits was more or less proportional. The given model is reproducible and is useful for experimental studies. Further experiments will be necessary, however, for detailed characterization and for analysis of the mechanism (antibody-mediated or delayed type hypersensitivity).     

Expression of Mycobacterium smegmatis pyrazinamidase in Mycobacterium tuberculosis confers hypersensitivity to pyrazinamide and related amides

A pyrazinamidase (PZase)-deficient pncA mutant of Mycobacterium tuberculosis, constructed by allelic exchange, was used to investigate the effects of heterologous amidase gene expression on the susceptibility of this organism to pyrazinamide (PZA) and related amides. The mutant was highly resistant to PZA (MIC, >2,000 microg/ml), in accordance with the well-established role of pncA in the PZA susceptibility of M. tuberculosis (A. Scorpio and Y. Zhang, Nat. Med. 2:662-667, 1996). Integration of the pzaA gene encoding the major PZase/nicotinamidase from Mycobacterium smegmatis (H. I. M. Boshoff and V. Mizrahi, J. Bacteriol. 180:5809-5814, 1998) or the M. tuberculosis pncA gene into the pncA mutant complemented its PZase/nicotinamidase defect. In both pzaA- and pncA-complemented mutant strains, the PZase activity was detected exclusively in the cytoplasm, suggesting an intracellular localization for PzaA and PncA. The pzaA-complemented strain was hypersensitive to PZA (MIC, /=20 microg/ml) and was also sensitive to benzamide (MIC, 20 microg/ml), unlike the wild-type and pncA-complemented mutant strains, which were highly resistant to this amide (MIC, >500 microg/ml). This finding was consistent with the observation that benzamide is hydrolyzed by PzaA but not by PncA. Overexpression of PzaA also conferred sensitivity to PZA, nicotinamide, and benzamide on M. smegmatis (MIC, 150 microg/ml in all cases) and rendered Escherichia coli hypersensitive for growth at low pH.     

牛型纯化蛋白衍生物皮内变态反应试验阳性牛中分枝杆菌的分离与鉴定

为评价牛分枝杆菌纯化蛋白衍生物(purified protein derivative,PPD)单纯颈部皮内变态反应试验(single intradermal cervical tuberculin,SICT)在奶牛结核病检测中的特异性,采集54头SICT阳性牛的118份组织样品进行病原分离和鉴定。结果显示,14头SICT阳性牛样品中分离到抗酸阳性菌,占SICT阳性牛总数的25.9%(14/54)。其中,10头阳性牛样品中分离到分枝杆菌,占18.5%(10/54);1头阳性牛样品中分离到牛分枝杆菌,占1.9%(1/54)。从118份组织样品中分离到16株抗酸阳性菌,其中12株为分枝杆菌,分枝杆菌分离率为10.2%(12/118)。12株分枝杆菌中,1株为牛分枝杆菌,其余11株为禽分枝杆菌、土地分枝杆菌等非结核分枝杆菌。牛分枝杆菌与非结核分枝杆菌分别占分枝杆菌分离株的8.3%(1/12)和91.7%(11/12)。病原分离和鉴定结果表明,SICT阳性牛的牛分枝杆菌分离率较低,为确保检测结果的准确性,有必要采用其他检测方法进行验证。同时,可将分枝杆菌快速分离培养及菌种鉴定检测技术引入对皮内变态反应试验阳性牛的实验室诊断,进一步提高牛结核病检测的特异性。     

Effect of thyroid hormones on delayed type hypersensitivity reaction

The effect of long term administration of thyroid hormones and its deprivation on delayed type hypersensitivity (DTH) reaction to 2-4 dinitrochlorobenzene (DNCB) was studied. Animals were either pre-treated with thyroid hormones (T3 or T4) for 15 days and then subjected to DNCB skin test or the animals received thyroid hormones and simultaneously subjected to DNCB skin test. In both the cases DTH reaction was found to be increased significantly. When DNCB skin test was performed in the thyroidectomized animals, DNCB skin reaction was significantly decreased and the reaction was restored to normal following supplementation of thyroid hormones to the thyroidectomized animals. TLC and ALC were increased significantly following hormone treatment and thyroidectomized animals. TLC hand, induced significant depression in the count which was restored by hormone administration to the thyroidectomized animals.     

Allergic encephalomyelitis: characterization of the determinants for delayed type hypersensitivity

Three non-encephalitogenic peptides derived from the encephalitogenic myelin basic protein of the central nervous system, produce delayed type hypersensitivity responses and elicit delayed skin reaction in guinea pigs sensitized with either peptide, the encephalitogenic tryptophan region (peptide E) or the basic protein. The amino acid sequence of the peptides is N-Acetyl-Ala-Ser-Ala-Gln-Lys-OH, forming the N-terminal region of the basic protein molecule, H-Gly-Ser-Leu-Pro-Gln-Lys-OH and H-Gly-Ala-Glu-Gly-Gln-Lys-OH representing residues number 69–74 and 117–122 of the basic protein respectively.     

Regulation by the H-2 gene complex of delayed type hypersensitivity

Identity at the major histocompatibility complex (MHC) was essential for successful transfer of delayed type hypersensitivity (DTH) in mice. The regions of the MHC involved differed according to the antigen used for sensitization. In the case of fowl gamma globulin (FGG), identity atI-A was necessary, whereas with dinitrofluorobenzene (DNFB), identity at theK, I, orD region was sufficient. These different genetic constraints probably reflect differences in the mechanisms by which antigens are presented to T lymphocytes. Cells from sensitized (CBA×C57BL)F₁ mice transferred DTH to FGG into parental-strain mice, but transfer was more effective in C57BL than in CBA with the same cell dose. This phenomenon is governed by the MHC, since there was better transfer intoH-2 ^b than intoH-2 ^k mice, regardless of their backgrounds. It may reflect the activity of an Ir gene-dependent process. Cells of one genotype (e.g., CBA), sensitized in chimeric mice derived from two MHC-incompatible strains (CBAC57BL), transferred DTH to both strains. These results do not support the notion that the genetic constraint observed in DTH transfer may be a result of the necessity for sensitized T and stimulator cells to match an identical MHC-coded cell interaction molecule. Rather, they favor the hypothesis that T cells recognize antigen, not as a naked determinant, but in close association with products of genes of the MHC.     

Effect of cyclopiazonic acid on delayed hypersensitivity to Mycobacterium tuberculosis,complement activity,serum enzymes,and bilirubin in guinea pigs

Cyclopiazonic acid (CPA) was given daily to groups of guinea pigs at doses of 0.00625, 0.0125, 0.025, 0.05, 0.1, 0.2, 0.4, 0.8, 1.6, and 1.95 mg/day for 30 days. All guinea pigs were sensitized and survivors were skin tested twenty-five days later with Mycobacterium tuberculosis. Mortalities occurred only in the two greatest dose groups. Signs of disease included anorexia, roughened hair coat, diarrhea and incoordination. The major histopathologic changes occurring in these two groups included hepatocellular vacuolar degeneration and necrosis of the gastric mucosa with infiltration of neutrophils in the deep gastric mucosa. CPA did not affect cutaneous hypersensitivity to M. tuberculosis, complement activity, serum glycocholic acid concentrations or weight gains. There were increases in aspartate aminotransferase, alanine aminotransferase, and sorbitol dehydrogenase concentrations in the serum of guinea pigs in the two greater dose groups, but no changes were found in serum concentrations of SAP. There was a slight increase in the serum bilirubin concentrations in the greater dose groups.Note endorsements are herein implied.     

Phosphoramidon potentiates the endothelin-1-induced bronchopulmonary response in guinea-pigs

We investigated the effect of the endopeptidase-inhibitor, phosphoramidon, on the bronchopulmonary response induced by endothelin-1 in vivo or in isolated perfused lungs. In vivo aerosol administration of 1 or 3 μg/ml endothelin-1 for 2 min provoked no significant bronchopulmonary response. When awake animals were pretreated by an aerosol of phosphoramidon (0.1 mM, for 15 min), the bronchopulmonary response induced by 1 and 3 μg/ml endothelin-1 was markedly enhanced. In isolated guinea-pig lungs, aerosol administration of endothelin-1 (3 μg/ml, for 2 min) evoked a low increase in pulmonary inflation pressure. Treatment of awake animals with an aerosol of phosphoramidon before lung recollection led to a significant potentiation of the endothelin-1-induced increase in pulmonary inflation pressure. These results demonstrate that phosphoramidon potentiates the in vivo and in vitro bronchopulmonary response evoked by low doses of endothelin-1 and suggest that endopeptidase-like enzymes present in the airway tissue modulate the effect of the peptide.     

Systemic immunological reactivity in the absence of delayed type hypersensitivity during murine leprosy

The generation of cell-mediated immunological reactivity has been examined following systemic infection of mice with M. lepraemurium (MLM). It has been found that although delayed-type hypersensitivity to MLM is ablated within 2 weeks of infection, resistance, as determined by a containment of the multiplication of the organism at various sites, persists for at least 7 weeks. During this time it was found that a population of lymphocytes sensitized to MLM antigens appeared within these animals and that DTH could he generated if these cells were focused at a footpad site.The possibility that these changes in immunological status are determined by increasing levels of antigen, resulting from a systemic killing of MLM is discussed. It is postulated that persistent desensitization eventually results in anergy to MLM.