Impaired T cell-mediated hepatitis in peroxisome proliferator activated receptor alpha (PPARα)-deficient mice

Abstract Background Peroxisome proliferator activated receptor alpha (PPARα), a regulator of enzymes involved in β oxidation, has been reported to influence lymphocyte activation. The purpose of this study was to determine whether PPARα plays a role in T cell-mediated hepatitis induced by Concanavalin A (ConA). Methods Wild type (wt) or PPARα-deficient (PPARα−/−) mice were treated with ConA (15 mg/kg) by intravenous injection 0, 10 or 24 h prior to sacrifice and serum and tissue collection for analysis of tissue injury, cytokine response, T cell activation and characterization. Results Ten and 24 h following ConA administration, wt mice had significant liver injury as demonstrated by serum transaminase levels, inflammatory cell infiltrate, hepatocyte apoptosis, and expression of several cytokines including interleukin 4 (IL4) and interferon gamma (IFNγ). In contrast, PPARα−/− mice were protected from ConA-induced liver injury with significant reductions in serum enzyme release, greatly reduced inflammatory cell infiltrate, hepatocellular apoptosis, and IFNγ expression, despite having similar levels of hepatic T cell activation and IL4 expression. This resistance to liver injury was correlated with reduced numbers of hepatic natural killer T (NKT) cells and their in vivo responsiveness to alpha-galactosylceramide. Interestingly, adoptive transfer of either wt or PPARα−/− splenocytes reconstituted ConA liver injury and cytokine production in lymphocyte-deficient, severe combined immunodeficient mice implicating PPARα within the liver, possibly through support of IL15 expression and/or suppression of IL12 production and not the lymphocyte as the key regulator of T cell activity and ConA-induced liver injury. Conclusion Taken together, these data suggest that PPARα within the liver plays an important role in ConA-mediated liver injury through regulation of NKT cell recruitment and/or survival.

B Cells Promote Th1- Skewed NKT Cell Response by CD1d-TCR Interaction

CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although alpha-galactosylceramide (alpha-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-gamma by NKT cells, concomitant with a decreased level of IL-4, in the circumstance of co-culture of DCs and B Cells. Remarkably, the response promoted by B cells was dependent on CD1d expression of B cells.

TLR4, 5, and 9 Agonists Inhibit Murine Airway Invariant Natural Killer T Cells in an IL-12-Dependent Manner

PURPOSE: Invariant natural killer T (iNKT) cells may play an important role in the pathogenesis of asthma in mice and humans. Thus, an agent that modulates the function of iNKT cells may have therapeutic potential to control asthma. We hypothesized that lipopolysaccharide (LPS)-, flagellin-, or CpG-induced changes in the cytokine milieu may modify and even inhibit the function of airway iNKT cells in asthma. METHODS: Because increased alpha-galactosylceramide (GalCer)-induced airway hyperreactivity (AHR) reflects the presence of airway iNKT cells, alpha-GalCer-induced AHR, as well as inflammatory cells and cytokines in bronchoalveolar lavage (BAL) fluid, were determined 24 hours after in vivo treatment with LPS, flagellin, or CpG in naive BALB/c mice. Intracellular IL-4 and IFN-gamma were measured in spleen iNKT cells after in vitro treatment with LPS, flagellin, or CpG. A role for IL-12 following the treatments was determined. RESULTS: Intranasal administration of LPS, flagellin, or CpG reduced development of alpha-GalCer-induced AHR, eosinophilic airway inflammation, and Th1 and Th2 cytokine responses in BAL fluid, while producing IL-12 in BAL fluid. Intraperitoneal administration of IL-12 mAb blocked the suppressive effect of LPS, flagellin, or CpG. In vitro treatment with LPS, flagellin, or CpG reduced production of IL-4 and IFN-gamma from alpha-GalCer-stimulated spleen iNKT cells; these effects were ameliorated by addition of anti-IL-12 mAb. CONCLUSIONS: TLR4, 5, and 9 agonists may suppress the function of airway and spleen iNKT cells via IL-12-dependent mechanisms. Anergy of iNKT cells by IL-12 might play a role in suppression by these TLR agonists.

The in vitro proliferation and cytokine production of Vα24+Vβ11+ natural killer T cells in patients with systemic lupus erythematosus / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Activation in vitro of natural killer T (NKT) cells in systemic lupus erythematosus (SLE) with α-galactosylceramide (α-GalCer) and dendritic cells (DC) may affect the immunoregulatory role of NKT cells. This study was designed to compare the number of NKT cells in patients with SLE to the number in healthy volunteers and measure the cytokines secreted from these NKT cells in vitro.</p><p><b>METHODS</b>Three sets of culture conditions using (i) α-GalCer, (ii) DC, or (iii) both α-GalCer and DC (α-GalCer+DC) were adopted to expand NKT cells from peripheral blood mononuclear cells (PBMC) of patients with SLE and healthy volunteers. Flow cytometry was used to assess the levels of interleukin (IL)-4, IL-10, interferon (IFN)-γ and tumor necrosis factor (TNF)-α produced by the Vα24(+)Vβ11(+) NKT cells.</p><p><b>RESULTS</b>After 14 days in culture, the total cell count and percentage of Vα24(+)Vβ11(+) NKT cells were increased under all conditions but were highest in the α-GalCer+DC group. The level of IL-4 and IL-10 secreted by Vα24(+)Vβ11(+) NKT cells from patients with active SLE was found to be higher than that of inactive patients and the control group (P < 0.05), while the levels of IFN-γ and TNF-α were lower than those found in the inactive and control groups (P < 0.05).</p><p><b>CONCLUSIONS</b>Vα24(+)Vβ11(+) NKT cells showed the greatest expansion in vitro with α-GalCer and DC. Th2-type cytokines from Vα24(+)Vβ11(+) NKT cells are the predominant type in patients with SLE, while Th1 cytokines predominate in the control group. This evolution of NKT cell function during the progression of the disease may have important implications in understanding the mechanism of SLE and for the development of possible therapies using NKT cell agonists.</p>

α-GalCer administration after allogeneic bone marrow transplantation improves immune reconstitution in mice / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To explore the effect of α- galactosyleramide( α-GalCer ) on immune reconstitution under acute graft-versus-host disease (aGVHD).</p><p><b>METHODS</b>BALB/c mice were transplanted wit hallogeneic C57BL/6 bone marrow cells and splenocytes (both 1×10(7))after receiving lethal total-body irradiation. α-GalCer (100 ug/kg) or vehicle (dimethylsulfoxide) was administered intraperitoneally immediately after transplantation. The effects of α-GalCer on immune reconstitution,proliferation of T cells and B cells, hematopoiesis,and thymic microenvironment were assessed.</p><p><b>RESULTS</b>The α-GalCer group exhibited higher percentages of CD3(+),CD4(+), CD8(+), B220(+), CD40(+), and CD86(+)cells compared with the vehicle group . The number of colony forming unit per 1000 CD34(+) cells in the α-GalCer group was higher than in the vehicle group ( P=0.0012).In vitro proliferation assays showed that the α-GalCer group had higher percentages of CD3(+), CD4(+), CD8(+),and B220(+) cells compared with the vehicle group. As for the results of in vivo proliferation assays, the numbers of CD3(+), CD4(+), CD8(+), and B220(+)cells were higher in the α-GalCer group than in the normal group ,especially the number of B220(+) cells ( P=0.007).Significant difference was not found in thymocyte count between the α-GalCer group and the vehicle group, nor in the percentages of CD3(+), CD4(+), and CD8(+) cells.</p><p><b>CONCLUSION</b>Administration of α-GalCer after allogeneic bone marrow transplantation may promote immune reconstitution in the presence of aGVHD.</p>

Natural killer T cell and pathophysiology of asthma / 소아과

Natural killer T (NKT) cell is a special type of T lymphocytes that has both receptor of natural killer (NK) cell (NK1.1, CD161c) and T cell (TCR) and express a conserved or invariant T cell receptor called Valpha14Jalpha18 in mice or Va24 in humans. Invariant NKT (iNKT) cell recognizes lipid antigen presented by CD1d molecules. Marine-sponge-derived glycolipid, alpha-galactosylceremide (alpha-GalCer), binds CD1d at the cell surface of antigen-presenting cells and is presented to iNKT cells. Within hours, iNKT cells become activated and start to secrete Interleukin-4 and interferon-gamma. NKT cell prevents autoimmune diseases, such as type 1 diabetes, experimental allergic encephalomyelitis, systemic lupus erythematous, inflammatory colitis, and Graves' thyroiditis, by activation with alpha-GalCer. In addition, NKT cell is associated with infectious diseases by mycobacteria, leshmania, and virus. Moreover NKT cell is associated with asthma, especially CD4+ iNKT cells. In this review, I will discuss the characteristics of NKT cell and the association with inflammatory diseases, especially asthma.

NK-T cell activator (α-GalCer) accelerates immune and hematological reconstitution after murine allo-bone marrow transplantation / 中国实验血液学杂志

Immune reconstitution is crucially relevant for patients receiving hematopoietic stem cell transplantation (HSCT). This study was purposed to investigate the ability of α-GalCer (α-galactosylceramide), a well-known activator of natural killer T cells (NK-T), to enhance immune and hematological reconstitution. Lethally irradiated BALB/c mice were transplanted with allogeneic C57BL/6 bone marrow cells and splenocytes. α-GalCer was administered immediately after HSCT. After transplantation, the weight, activity, hairs, diarrhea and survival time of mice were observed daily; the blood routine test was performed once weekly; the donor chimeras, amount of mononuclear cells in spleen (MNC) and relative levels of CD3(+), CD4(+), CD8(+), B220(+), CD11c(+), CD40(+), CD86(+) and CD80(+) cells were detected by FACS on day 2, 7, 14, 27, 70 after transplantation. The results indicated that the MNC counts and relative levels of CD3(+) and CD4(+) in group treated with α-GalCer on day 2 after transplantation were higher than those in control group; at the same time, the detected donor chimeras were complete recipient type chimeras, then gradually transformed into donor type, on day 7 - 14 donor chimeras in α-GalCer group were enhanced significantly as compared with control group, on day 27 the chimeras in two groups were complete donor type chimeras thereafter to day 70, the MNC count and relative levels of CD3(+), CD4(+), CD8(+), B220(+), CD40(+), CD86(+) cells in α-GalCer group were obviously higher than those in control group, at the same time, the hematopoietic reconstitution in α-GalCer group was accelerated as compared with control group. It is concluded that the α-GalCer administration after allogeneic bone marrow transplantations accelerates immune and hematological reconstitution.

Expansion and cytokine secretion profile of human valpha24(+) NKT cells from different sources / 中国实验血液学杂志

This study was purposed to investigate the phenotype, in vitro expansion and cytokine secretion profile of Valpha24(+) NKT cells from cord blood (CB), peripheral blood (PB), and granulocyte colony stimulating factor-mobilized peripheral blood mononuclear cells (G-PBMNCs). Fresh mononuclear cells (MNCs) were isolated by the method of gradient centrifugation and then cultured with alpha-GalCer (100 ng/ml), IL-2 (50 U/ml), IL-15 (50 ng/ml) for 12 days. Valpha24(+) NKT cells were purified by anti-Vbeta11 TCR McAb and goat anti-mouse IgG magnetic beads. The phenotype and purity of Valpha24(+) NKT cells were determined by flow cytometry. Cytokine production was analyzed by ELISA. The results showed that Valpha24(+) NKT cells in CB, PB and G-PBMNCs were expanded by 221.5 (95 - 501), 456.5 (101 - 2207), and 756.38 (82 - 20373)-fold respectively. After stimulation by phorbol-12-myristate-13-acetate (PMA) for 24 hours, IL-4 and IFN-gamma produced by Valpha24(+) NKT cells from CB and PB were 180.33 (144.67 - 2253.48) vs 190.67 (110.07 - 6060.16) ng/ml, 864.33 (401.33 - 3386.67) vs 508.49 (253.82 - 8840.00) ng/ml respectively, with IL-4/IFN-gamma ratio of 0.503 +/- 0.642 vs 0.455 +/- 0.562 respectively. After expansion of Valpha24(+) NKT cells from G-PBMNCs, IL-4 and IFN-gamma produced by Valpha24(+) NKT cells at day 9 and day 12 were 139.08 (7.62 - 606) vs 89.3 (0 - 729.2) ng/ml, 14264.8 (1168 - 18059) vs 14488 (1041 - 18261) ng/ml respectively, with IL-4/IFN-gamma ratio of 0.0531 +/- 0.1081 vs 0.0376 +/- 0.1148 respectively. It is concluded that in presence of IL-2 and IL-15, alpha-GalCer can facilitate the rapid short-term expansion of Valpha24(+) NKT cells from CB, PB, and G-PBMNCs. Valpha24(+) NKT cells from G-PBMNCs show much high potential of expansion in comparison to the counterparts from CB or PB (p < 0.05). The activated Valpha24(+) NKT cells can secrete IFN-gamma and IL-4 in large amounts, with IFN-gamma in particular.

The presence of CD8+ invariant NKT cells in mice

Invariant natural killer T (iNKT) cells develop in the thymus upon recognition of CD1d expressed on developing thymocytes. Although CD4 and CD8 coreceptors are not directly involved in the interaction between CD1d and the T cell receptors (TCRs) of iNKT cells, a conspicuous lack of CD8+ iNKT cells in mice raised the question of whether CD8+ iNKT cells are excluded due to negative selection during their thymic development, or if there is no lineage commitment for the development of murine CD8+ iNKT cells. To address this question, we analyzed iNKT cell-specific TCR Valpha14+ transgenic mice, where the Valpha14 transgene forces the generation of iNKT cells. This allows detailed study of the iNKT cell repertoire. We were able to identify CD8+ iNKT cells which respond to the NKT cell-specific glycolipid ligand alpha-galactosylceramide. Unlike conventional iNKT cells, CD8+ iNKT cells produce predominantly IFN-gamma but not IL-4 upon antigen stimulation. We also confirmed the presence of CD8+ iNKT cells in wild type mice. Our results suggest that CD8+ NKT cells do exist in mice, although their population size is quite small. Their Th1-skewed phenotype might explain why the population size of this subtype needs to be controlled tightly.

Papel de las células nkt invariantes en la respuesta inmune anti-viral: [revisión] / Role of invariant nkt cells in the anti-viral immune response: [review]

Las células T asesinas naturales con receptor de células T invariante y restringidas por la molécula CD1d (iNKT) son un subgrupo de linfocitos con potente actividad inmunorreguladora; su respuesta casi inmediata y la capacidad de producir citoquinas tanto Th1 como Th2 son factores determinantes en el desarrollo de la respuesta inmune innata y adaptativa. El papel fisiológico de las células iNKT se ha documentado ampliamente en la respuesta anti-tumoral, el desarrollo de la tolerancia en los órganos inmunoprivilegiados y el control de las reacciones autoinmunes. A pesar de la demostrada potencia inmunomoduladora de las células iNKT, hasta el momento se conoce poco de su acción en la respuesta inmune anti-infecciosa, en particular en el ser humano y contra los virus patógenos. Este artículo sintetiza los resultados de una búsqueda en las principales bases de datos biomédicas (Pubmed, Medline y OVID), e incluye los estudios realizados para caracterizar estas células y evaluar su papel en la interacción del hospedero con los virus. Las células iNKT participan en la respuesta inmune antiviral, aunque de una manera diferente según el tipo de virus; incluso, podrían estar comprometidas en los daños mediados por mecanismos inmunes. En el ser humano, las células iNKT son aparentemente esenciales en la respuesta inmune contra el virus Varicela Zoster, mientras que todavía hay controversia sobre su función en el control de otros virus. Los modelos animales han aportado las primeras evidencias sobre el potencial de la manipulación terapéutica específica de este subgrupo de linfocitos.

Natural killer T cells with an invariant T-cell receptor and restricted by CD1d (iNKT) are a subgroup of lymphocytes with a very strong immunoregulatory potential; their quick response and their ability to produce Th1 and Th2 cytokines are determinant factors that influence the development of innate and adaptive immune responses. The physiological role of iNKT cells has been well documented in anti-tumor immune responses, the development of tolerance in immune-privileged organs and the control of autoimmune diseases. Despite the fact that the immunoregulatory potential of these cells has been well documented, less is known regarding their role in the immune response against infectious agents, in particular to human pathogenic viruses. This paper synthesizes the search in the most important biomedical data bases (Pubmed, Medline, OVID), including studies on the phenotypic characterization of these cells and functional studies that evaluated their role in the interaction between hosts and viruses. iNKT cells have a heterogeneous participation during the anti-viral immune responses, depending on the type of virus; indeed, in some instances the iNKT-cell responses can be involved in the tissue damage associated to the anti-viral responses. In humans, iNKT cells are apparently essential for an effective immune response against Varicella Zoster virus, while it is still controversial their role in the control of other viral infections. Studies in animal models have shown the first evidences on the therapeutic potential of this lymphocyte subpopulation.

Prevalence of some lipidosis among Egyptian children with neurodegenerative disorders

The present work comprised 30 patients belonging to 27 families. The age of the studied patients ranged from 7 months to 10 years [mean 43.9 +/- 27.69 months]. The age of onset of the disease ranged from 7 months to 5 years [mean 17.26 +/- 13.3 months]. All patients suffered from developmental delay or progressive loss of previously acquired milestones, with no coarse facial features, organomegaly or ectodermal abnormality. For all patients the following was done: - Full medical history, thorough clinical examination and family pedigree construction. - Fundus examination and nerve conduction velocity [NCV]. - MRI of brain and IQ assessment. - Measurement of arylsulphatase A, galactocerebroside: beta-galactosidase activity in peripheral leucocyte was also done together with chitotriosidase level in plasma. Twenty two patients [73.33%] had normal fundus examination, and eight patients [26.66%] had various fundus findings [three patients [10%] had pale optic disc, and five patients [16.66%] had optic atrophy] - Twenty five patients [83.33%] had normal NCV, and five patients [16.66%] had demyelination. - All patients had +ve MRI findings, 19 patients [63.33%] had dysmyelination and 11 patients [36.33%] had brain atrophy. - Twenty six patients had normal value of Aryl sulphatase A activity [ASA] [51-200 micro mol/g- p/h], while three cases demonstrated decreased activity [one case had pseudodeficiency value [10-50 micro mol/g-p/h], and two cases had actual deficiency of enzyme activity [<10 micro mol/g -p/h] and diagnosed as metachromatic leukodystrophy]. - Twenty eight patients had normal value of Chitotriosidase activity [CT] [4-80 micro mol/l/h] and one patient had high value. - Galactocerebroside beta-galactosidase activity [GALC] was measured in leukocytes for 29 index cases. Normal value was detected in all cases [0.5-4 micro mol/g-p/h]. One case [3.33%] had Gaucher disease, another had aryl sulfatase A pseudodeficiency and a third case had most probably Pelizaeus Merzbach disease, two cases had infantile Metachromatic leukodystrophy [6.66%], while another two had congenital muscular dystrophy. All other patients need further follow up and further investigations

Proliferation of natural killer T cells in umbilical cord blood and peripheral blood and their different phenotypes / 中国实验血液学杂志

Purpose of this study was to establish an effective method in vitro to proliferate natural killer T (NKT) cells from umbilical cord blood (UCB) and peripheral blood (PB), and to study their different phenotype. Mononuclear cells (MNC) from UCB and PB were cultured in the presence of IL-2 (100 U/ml), with or without alpha-Galcer. TCR Valpha24 Vbeta11 double positive natural killer T-cells (NKT cells) and their other phenotypes were determined by flow cytometry. The results showed that after expansion for 7 days, TCRValphabeta(+) NKT cells from UCB-MNCs increased by (8.74 +/- 4.37) x 10(2) times as much, but most of them did not express NK1.1 and its TCR Vbeta11(+) was higher than TCR Valpha24(+). After expansion for 14 days, TCR Valphabeta(+) NKT cells from PB-MNCs increased by (3.72 +/- 2.01) x 10(2) times, the expression of NK1.1 was high and its TCR Vbeta11(+) was almost equal to TCR Valpha24(+). It is concluded that human TCR Valpha24 Vbeta11 double positive NKT cells can expand by addition of alpha-Galcer. The proliferation efficiency in UCB-MNCs is greater than that in PB-MNCs. Most of the UCB-NKT is NK1.1(-), while the PB-NKT is NK1.1(+), a new subset of NKT cells.

Ex vivo expansion of Valpha24 natural killer T cells with alpha-galactosylceramide / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the method for expanding Valpha24 natural killer T (NKT) cells with alpha-galactosylceramide (alpha-GalCer) ex vivo.</p><p><b>METHODS</b>Mononuclear cells (MNCs) isolated from adult peripheral blood or umbilical cord blood (UCB) were divided into three groups. In Group A1 (n = 5), CD34+ progenitorderived dendritic cells were differentiated in a cytokine-supplemented culture system from cord blood and acted as antigen presenting cells (APC) to induce the expansion of cord blood Valpha24 NKT cells in presence of alpha-GalCer; in Group A2 (n = 5), adult peripheral monocyte-derived dendritic cells (Mo-DC) were used as APC to induce the expansion of adult peripheral NKT cells in presence of alpha-GalCer; whereas in Group B (n = 16), alpha-GalCer was added into adult peripheral MNCs culture system without additional DCs. Cytokine-produce were measured by ELISA, and NKT cells' proliferation ability, cytotoxicity, and suppressive effect on mixed lymphocyte reaction (MLR) were examined by MTT assays.</p><p><b>RESULTS</b>Valpha24 NKT cells in Group A1, A2, and B were expanded up to 128 (95-207), 250.5 (179.6-790.6), and 326 (101-2 136) -fold by day 12, respectively. Adult NKT cells expanded in Group B were markedly better than those in Group A1 (P = 0.038). When stimulating by PMA, the NKT cells had a 3-day stimulate index of 1.80 +/- 0.41; and the secretion ratio of IL-4 to IFN-gamma of UCB or adult peripheral blood NKT cells were 0.30 +/- 0.13 and 0.28 +/- 0.18; and the ex vivo antitumor effect of expanded NKT cells were found in cell line HL60, KG1a, and Raji except for K562; and the suppressive effect of expanded NKT cells or the culture supernatant on MLR were confirmed.</p><p><b>CONCLUSIONS</b>Alpha-GalCer can facilitate the rapid shorttime expansion of Valpha24 NKT cells in presence of IL-2 and IL-15. These expanded NKT cells, kill tumor cell lines, and inhibit can massively excret IL-4 and IFN-gamma allogeneic T-cell response.</p>

Differentiation of rat neural stem cells and its relationship with environment / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To explore the differentiation fates of rat neural stem cells (NSCs) in different environmental conditions.</p><p><b>METHODS</b>NSCs derived from 16-day-old rat embryo were proliferated in vitro and implanted into the brain of rats with intra-cerebral hemorrhage. At the same time some NSCs were co-cultured in vitro with Schwann cells derived from newborn rats. MAP-2, GFAP and GalC (which are the specific markers of neural cells, astrocytes and oligodendrocytes respectively), BrdU and beta-tubulin were detected by immunohistochemical and immunofluorescent methods.</p><p><b>RESULTS</b>BrdU positive cells that were implanted into the brain distributed around the hemorrhagic area. The majority of them were GFAP positive astrocytes while a few of them were beta-tubulin positive neural cells or GalC positive oligodendrocytes. After being co-cultured with Schwann cells in vitro, NSCs are predominately shown beta-tubulin and MAP-2 positive, and only a minority of them were GFAP or GalC positive.</p><p><b>CONCLUSIONS</b>The hemorrhagic environment in vivo induces NSCs to differentiate mainly into astrocytes while co-culture with Schwann cells in vitro induce the majority of NSCs to differentiate into neural cells.</p>

No inhibition of urinary bladder carcinogenesis in rats with intravesical instillation of alpha-galactosylceramide.

The immunostimulatory a-galactosylceramide, KRN 7000 ((2S,3S,4R)-1-O-(a-D-galactopyranosyl)-2-(N-hexacosnoylamino)-1,3,4-octadecatrienol), may be anticipated to have antitumor activity in vivo apart from any direct toxicity to cancer cells. In this experiment, inhibition of rat bladder carcinogenesis by intravesically instillated KRN7000 was investigated. Male Fischer 344 rats, 6-weeks-old at the start, were divided into 4 groups, all first receiving the carcinogen, 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine, in their drinking water for 12 weeks. Then groups 1 and 2 respectively were administered 500 and 50 mg/kg of KRN7000 intravesically once weekly for 17 weeks. Group 3 similarly received only 0.3 micro/l of saline (vehicle control). Group 4 did not undergo bladder catheterization. On macroscopic examination at 30 weeks, multiplicities and sizes of bladder tumors in the KRN 7000 high and low-dose groups were not significantly different from those of the vehicle control group. Histologic examination confirmed no significant variation in incidences of carcinomas or preneoplastic lesions in the bladder among groups 1 to 4. Thus the results indicate that intravesical instillation of KRN7000 does not inhibit bladder carcinogenesis in rats.

Doença de Krabbe (leucodistrofia célula globóide): relato de um caso / Krabbe disease (globoid cell leukodystrophy): a case report

Objetivo: Os autores relatam um caso de Doença de Krabbe. Métodos: Os autores relatam um caso de um paciente com involuçäo psicomotora e irritabilidade logo nos primeiros meses de vida sendo suspeitada e confirmada a hipótese de Leucodistrofia de células globóides através dos exames subsidiários e dosagem enzimática. Resultados: O caso apresentava sinais e sintomas compatíveis com a forma infantil precoce da Doença de Krabbe sendo confirmado pela dosagem de enzima galactosilceramida beta galactosidase em cultura de fibroblastos. Conclusöes: A doença de Krabbe é uma patologia rara de caracter autossômico recessivo sendo que a suspeita muitas vezes näo chega a ser levantada, näo chegando ao especialista para o diagnóstico. Apesar de näo haver tratamento específico, a orientaçäo genética é necessária...

Molecular mimicry between Trypanosoma cruzi and host nervous tissues

Increasing evidence suggests that in Chagas' disease chronic-phase pathology is autoimmune in nature. There are at least two nonexclusive explanations for the generation of autoimmunity in Chagas disease: a) infection with the parasite perturbs immunoregulation, leading to loss of tolerance for self-antigens; b) immune recognition of T. cruzi antigens is crossreactive with selected mammalian antigens, leading to autoimmunity (molecular mimicry). Through this latter mechanism, T. cruzi antigens that share epitopes with mammalian nervous tissue may drive autoreactive B- or T-cell clones to expand and cause autoimmune lesions in chronic chagasic patients. Several different antigens sharing this characteristic have been studied, as for example the 160-kDa flagellum-associated surface protein (Fl-160), which has a nervous tissue crossreactive epitope composed by twelve amino acids. Additionally, it has been demonstrated that a trypomastigote stage-specific 85kDa surface glycoprotein (Gp85) has terminal galactosyl(alpha 1-3)galactose terminal residues, which are reactive with chronic chagasic sera. Common glycolipid antigens have also been reported, as for example galactocerebroside, sulfogalactocerebroside and sulfoglucuronylcerebroside, all of them specifically present at high concentrations in mammalian nervous system and in T. cruzi trypomastigotes. Chronic chagasic patients produce elevated levels of antibodies against these three glycolipid antigens. They also do against terminal galactosyl(alpha 1-3)galactose residues present on several acid and neutral glycolipids common either to nervous system or parasite. These antibodies are powerful lytic for circulating T. cruzi trypomastigotes. Another common strongly immunogenic residues are galactosyl(alpha 1-2)galactose, galactosyl(alpha 1-6)galactose and galactofuranosyl(beta 1-3)mannose residues present on several glycoinositolphospholipids (GIPL), against which chronic chagasic patients have elevated levels of specific antibodies. In brief, very specific host-parasite relationships existing only in Chagas' disease may explain the particular peripheral nervous tissue damage seen in acute or chronic stages of this disease. This specificity could depend either on invasion of autonomic ganglia by T. cruzi trypomastigotes and modification of nervous cell surface structures by some of the several mechanisms of acquired molecular mimicry

Detecçäo de anticorpos e anticomponentes lipídicos (cardiolipina, gangliosídios e galactocerebrosídios) em pacientes com doença de Behçet / Detection of antibodies and lipid anticomponents (cardiolipin, gangliosides and galactosilceramidas) in patients with Behçet's disease

Os autores avaliam a presença de anticorpos antifraçöes lipídicas (cardiolipina, gangliosídios e galactocerebrosídios) em 13 pacientes com doença de Behcet. Anticorpos séricos anticardiolipina do isotipo IgG foram detectados em 30// dos casos, 50// do isotipo IgM. Em nenhum dos pacientes foi observada presença de isotipo IgA. Antigalactocerebrosídio foram detectados em apenas dois (15//) dos pacientes. Com relaçäo às manifestaçöes clínicas, observou-se que a presença de anticorpos anticardiolipina configura fator de risco para o desenvolvimento do acometimento neurológico

Neuropsychiatric manifestations of systemic lupus erythematosus: the value of anticardiolipin, antigangliosides and antigalactocerebrosides antibodies

In an attempt to find a serological marker for neuropsychiatric manifestations (NPM) of SLE sera from 66 patients (classified in three groups, according to their NPM - defined, probable and without NPM) were analysed by ELISA for IgG and antigalactocerebrosides antibodies. A strong correlation was found between IgM antigangliosides and antigalactocerebrosides antibodies and NPM, but not with IgG class. IgM and IgG antibodies anticardiolipin were not correlated with BPM in this study. Both IgM antigangliosides and seven patients with definid NPM but clinically inactive. The analysis of these autoantibodies showed an important role predictive for NPM in SLE; the negative test decreases the chance of the NPM

A study on demyelinating effect of galactocerebroside in experimental allergic encephalomyelitis

An experimental allergic encephalomyelitis was induced by bovine myelin basic protein (MBP) and bovine galactocerebroside (GC) on male guinea pigs. Animals were divided into five experimental and one control groups. Among the five experimental groups, three were inoculated with 75 micrograms, 150 micrograms and 300 micrograms of MBP, respectively, to see the dose dependency of demyelination. The fourth group was inoculated with mixture of 75 micrograms of MBP and 180 micrograms of GC and the fifth group with 180 micrograms GC. All inocula was injected intradermally in emulsion state mixed with equal amount of complete Freund adjuvant. Control group was injected with adjuvant only. Clinical symptoms began to appear from 15th day after inoculation and animals were sacrificed on maximum neurologic deficit or 4 to 5 days after the onset of symptoms. Demyelination was observed in 6 out of 8 animals inoculated with MBP/GC mixture, while only 3 out of 24 animals inoculated with various dosage of MBP showed demyelination. The difference was statistically significant. Serum antibodies to MBP and GC were measured by ELISA method. All of the eight animals inoculated with MBP/GC mixture and two animals inoculated with GC had low titer of anti-GC antibodies, while all animals inoculated with MBP, MBP alone or MBP/GC mixture, had high titer of anti-MBP antibodies. Therefor it is concluded that the demyelination is augmented by GC and is not significantly dose-dependent on MBP.