bluuebunny/crossref_metadata_2025_split huggingface dataset:
Humoral response againstCryptococcus neoformansmannoprotein antigens in HIV-infected patients
Authors: PITZURRA L , PERITO S , BALDELLI F , BISTONI F , VECCHIARELLI A 
Published: December 2004

SUMMARYTwenty-four sera from healthy donors, 18 from HIV-positive patients (&lt; 200 CD4+/mm3) and 18 sera collected before and during cryptococcosis from HIV-positive patients were analysed for the presence of humoral response to C. neoformans mannoproteins. Our results show that samples from healthy subjects and from HIV-positive patients had one of three antibody response profiles: (i) presence of reactive antibodies against both 105 and 80 kilodalton mannoproteins; (ii) presence of reactive antibodies against one of the two mannoproteins; or (iii) absence of reactive antibodies. Importantly the percentage of unreactive sera increased 6-fold in HIV-positive patients and more than 10-fold in patients with cryptococcosis. In addition, in the latter patients no variation of humoral response before and during cryptococcosis was observed. These results suggest that HIV-positive patients show a marked difficulty in mounting or maintaining antibody response to mannoprotein and this could contribute to predisposition to cryptococcosis.
Dysregulated expression of IFN-γand IL-10 and impaired IFN-γ-mediated responses at different disease stages in patients with genital herpes simplex virus-2 infection
Authors: SINGH R , KUMAR A , CREERY W D , RUBEN M , GIULIVI A , DIAZ-MITOMA F 
Published: December 2004

SUMMARYCell-mediated T-helper type-1 (Th1) responses play a vital role in the immunopathogenesis of genital infections caused by herpes simplex virus 2 (HSV-2). We investigated the role of Th responses in HSV-2 infection at different disease stages by analysing the production of Th cytokines in HSV-stimulated peripheral blood mononuclear cells (PBMCs). IFN-γ production decreased over time following a recurrence, whereas levels of IL-10, and to a lesser extent IL-2, remained elevated during this period. In addition, PBMCs from asymptomatic seropositive individuals produced high levels of IFN-γ and low levels of IL-10, in contrast to individuals with a history of genital ulcers. Following a recurrence, virus copy number in the genital lesions decreased progressively over time, in a manner similar to IFN-γ production by HSV-2-stimulated PBMCs. Enhanced production of IFN-γ may modulate HSV replication and B7 expression on monocytic cells of HSV-infected individuals. In contrast to seronegative controls, IFN-γ failed to enhance B7 expression on monocytic cells of HSV-infected individuals. In addition, monocytic cells from HSV-2-infected individuals with recurrent disease supported greater HSV replication than did those of HSV-infected asymptomatic individuals or seronegative controls. Furthermore, addition of IFN-γ resulted in enhanced HSV replication in monocytic cells of HSV-infected individuals with recurrent disease, in contrast to the inhibition observed in HSV-seropositive asymptomatic individuals and seronegative controls. Taken together, our results suggest that dysregulated production of IFN-γ at different disease stages and the impaired ability of monocytic cells to respond to IFN-γ may play a role in the pathogenesis of recurrent genital herpes disease.
Three novel mutations reflect the variety of defects causing phenotypically diverse X-linked hyper-IgM syndrome
Authors: LÓPEZ-GRANADOS E , CAMBRONERO R , FERREIRA A , FONTÁN G , GARCÍA-RODRÍGUEZ M C 
Published: December 2004

SUMMARYX-linked hyper-IgM syndrome (HIGM1) (MIM♯308230), is a severe primary immunodeficiency caused by mutations in the gene coding for CD40 ligand (CD40L or CD154), a member of the tumour necrosis factor (TNF) superfamily. The interaction of this protein with its ligand, CD40, mediates crucial processes in the immune response. The variety of defects that have been described in HIGM1 patients range from a complete lack of CD40L protein expression to missense mutations that interfere with its interaction with CD40L. In this study we describe three families – a total of seven HIGM1 patients and carriers, presenting a spectrum of severity in clinical evolution. In two of these families, patient DNA samples were available for genetic studies. In the third, carrier detection was performed on female family members. The results of immunological studies – the different patterns of CD40L expression and binding capacity as measured by flow cytometry – and molecular diagnosis are presented. Three novel mutations were identified: an intron mutation that partially interferes with the splicing process (intron 3, position + 5 G/T); a missense mutation (Ser222 Phe) located in the molecular region which interacts with the receptor and which abrogates binding capacity; and a 14 base pair deletion leading to a frameshift and a premature truncated mutation (del I 171 X 195). An attempt to correlate protein expression and function of the CD40L mutants with clinical disease evolution is described.
HIV-1 infection is facilitated in T cells by decreasing p56lck protein tyrosine kinase activity
Authors: YOUSEFI S , MA X-Z , SINGLA R , ZHOU Y-C , SAKAC D , BALI M , LIU Y , SAHAI B M , BRANCH D R 
Published: December 2004

SUMMARYSeveral studies have suggested an important role for the protein tyrosine kinase p56lck (Lck) in HIV infection; however, the exact nature of this role remains unclear. Using a series of well characterized Jurkat-derived cell lines having a wide range of Lck kinase activity, our results showed that, while the entry of HIV-1 into these cell lines was similar, the kinetics of virus production by these cells were very different. Cells expressing a kinase-inactive Lck showed accelerated viral replication, whereas, cells expressing Lck with normal or elevated enzymatic activity showed a delay in virus replication that was proportional to the initial level of endogenous Lck activity. The cell line having the highest initial Lck kinase activity showed the slowest rate of productive HIV-1 infection. Analysis of 2-LTR circles revealed that this inhibitory effect of Lck was not due to inhibition of reverse transcription of HIV-1 genome or migration of the proviral DNA into the nuclei. This affect of Lck was confirmed in additional studies that used either the S1T cell line lacking completely Lck or where the Lck activity was altered in Jurkat cells prior to infection. S1T cells showed a 3- to 12-fold increase in the level of infection compared to Jurkat cells despite similar CD4 and chemokine coreceptor expression and cell doubling times. Pretreatment of Jurkat with an antisense lck oligodeoxynucleotide inhibited the synthesis of functional Lck and facilitated the viral replication by the cells as did expressing a dominant-negative mutant Lck which increased the productive infection&gt;3-fold. Conversely, whereas IL-16 had no affect on productive infection in S1T cells that lack Lck, IL-16 pretreatment of Jurkat cells resulted in an immediate (within 5 min) and sustained and gradual (over 5 h) increase in Lck activity that resulted in a reduction of HIV-1 replication that paralleled the increasing Lck kinase activity. These results show that the enzymatic activity of Lck kinase can affect viral replication, that a lack of, or decreased Lck activity facilitates viral replication. Conversely, Lck can mediate a delay in HIV-1 infection that is proportional to the initial endogenous Lck enzyme activity.
Participation of the interstitium in acute immune-complex nephritis: interstitial antigen accumulation, cellular infiltrate, and MHC class II expression
Authors: PARRA G , HERNÁNDEZ S , MORENO P , RODRÍGUEZ-ITURBE B 
Published: December 2004

SUMMARYBovine serum albumin (BSA) injected into the rabbits induces acute immune complex glomerulonephritis. Since albumin is filtered and reabsorbed in the tubules, we investigated whether tubulointerstitial cells participate in the pathogenesis of this experimental condition. For this purpose, we induced immune-complex nephritis in 45 rabbits with the injection of 125I-BSA and urinary BSA excretion, glomerular and tubulointerstitial BSA accumulation, lymphocyte infiltration, proliferative activity and MHC class II antigens were examined 2, 4–5 and 6–8 days after immunization.Proteinuria developed day 6–8. BSA was found in urine from day 2 (mean ± SE; 1089 ± 339 µg/24 h) and peaked on day 4 after immunization (2249 ± 1106). BSA content (cpm/g tissue) in tubulointerstitium (TI) and glomeruli were similar at day 2 (457 ± 45 and 407 ± 75, respectively), but afterward increased significantly in TI, reaching a peak level on day 5 (1026 ± 406) while remained unchanged in glomeruli (388 ± 95). At the same time, preceding the onset of proteinuria, maximal intensity of the lymphocyte infiltration, proliferative activity and MHC class II antigen expression in tubular cells, monocytes/macrophages and interstitial cells were observed.Our study shows that antigen is excreted in the urine and concentrated in TI in association with overexpression of MHC class II molecules and lymphocyte infiltration. These findings occur prior to the development of proteinuria and suggest that the tubulointerstitial cells play a critical role in the pathogenesis of this model.
Role of leptin as an immunomodulator of blood mononuclear cells: mechanisms of action
Authors: SÁNCHEZ-MARGALET V , MARTÍN-ROMERO C , SANTOS-ALVAREZ J , GOBERNA R , NAJIB S , GONZALEZ-YANES C 
Published: December 2004

SUMMARYLeptin is a an adipocyte-secreted hormone that regulates weight centrally. However, the leptin receptor is expressed not only in the central nervous system, but also in peripheral tissues, such as haematopoietic and immune systems. Therefore, the physiological role of leptin should not be limited to the regulation of food intake and energy expenditure. Moreover, the leptin receptor bears homology to members of the class I cytokine family, and recent data have demonstrated that leptin is able to modulate the immune response. Thus, the leptin receptor is expressed in human peripheral blood mononuclear cells, mediating the leptin effect on proliferation and activation. In vitro activation and HIV infection in vivo induce the expression of the long isoform of the leptin receptor in mononuclear cells. Also, leptin stimulates the production of proinflammatory cytokines from cultured monocytes and enhances the production of Th1 type cytokines from stimulated lymphocytes. Moreover, leptin has a trophic effect on monocytes, preventing apoptosis induced by serum deprivation. Leptin stimulation activates JAK–STAT, IRS-1-PI3K and MAPK signalling pathways. Leptin also stimulates Tyr-phosphorylation of the RNA-binding protein Sam68 mediating the dissociation from RNA. In this way, leptin signalling could modulate RNA metabolism. These signal transduction pathways provide possible mechanisms whereby leptin may modulate activation of peripheral blood mononuclear cells. Therefore, these data support the hypothesis regarding leptin as a proinflammatory cytokine with a possible role as a link between the nutritional status and the immune response. Moreover, these immunoregulatory functions of leptin could have some relevance in the pathophysiology of obesity.
Modulation of cytokine release from colonic explants by bacterial antigens in inflammatory bowel disease
Authors: DIONNE S , LABERGE S , DESLANDRES C , SEIDMAN E G 
Published: December 2004

SUMMARYThe intestinal flora play an important role in experimental colitis and inflammatory bowel disease (IBD). Using colonic explant cultures from 132 IBD and control subjects, we examined tumour necrosis factor-alpha (TNF-α), interleukin (IL)-1 and interleukin-1 receptor antagonist (IL-1RA) production in vitro in response to bacterial activators. Unstimulated TNF-α release was increased significantly in rectal biopsies from involved IBD tissue, correlating with inflammation severity. Whereas lipopolysaccharide (LPS) only moderately stimulated TNF-α production from inflamed tissue, pokeweed mitogen (PWM) induced its release in all groups, with a stronger response in involved IBD tissue. Superantigen staphylococcal enterotoxin A (SEA) had a similar, but weaker effect. SEB was observed to be the strongest inducer of TNF-α for all groups, again with a more marked response in inflamed tissue. Stimulated release of IL-1 was considerably less than for TNF-α. The superantigens’ superior potency over LPS was not as marked for IL-1 as it was for TNF-α. In addition to IL-1, IL-1RA release was also triggered by the bacterial products. The net effect of activation on the IL-1RA/IL-1 ratio was relatively modest. Release of the proinflammatory cytokines TNF-α and IL-1, as well as that of the anti-inflammatory cytokine IL-1RA was increased by incubation of colonic tissue with bacterial factors. TNF-α production and release was increased significantly in involved colonic explants from IBD. SEB was even capable of inducing TNF-α release from uninvolved colonic tissue.
Gliadin, endomysial and thyroid antibodies in patients with latent autoimmune diabetes of adults (LADA)
Authors: KUČERA P , NOVÁKOVÁ D , BĚHANOVÁ M , NOVÁK J , TLASKALOVÁ-HOGENOVÁ H , ANDĚL M 
Published: December 2004

SUMMARY
Latent autoimmune diabetes of adults (LADA) manifested after the age of 35 is characterized by the presence of disease-specific autoantibodies (anti-glutamate decarboxylase GADAb, anti-IA2Ab). However, autoimmunity in Type 1 diabetes mellitus is not targeted only to pancreatic beta-cells. No data have so far been published concerning the antibodies associated with other autoimmune disease in LADA patients. The presence of anti-thyroglobulin (TGAb), anti-thyroid peroxidase (TPOAb), anti-gliadin IgA (AGAAb) and IgG (AGGAb) and endomysial antibodies (EMAb) in sera of 68 diabetics typed as LADA was compared with the antibody presence in sera of 85 patients with Type 2 diabetes. We found a significantly higher occurrence of gliadin antibodies in LADA patients: the rate of AGGAb was 19·1% in comparison with 3·5% in the T2DM group (P = 0·0026), the rate of AGAAb was 13·2% in comparison with 3·5% (P = 0·035). The prevalence of EMAb was very low in both groups (1·5% and 0). The two groups differed significantly in the TPOAb rate: 22·1% in LADA compared to 9·4% in T2DM (P = 0·04), whereas no significant difference was found in the presence of TGAb (8·8% and 3·5%, P = 0·187). In comparison with T2DM patients, LADA patients were found to express higher antibody activity against gluten-related antigens and against TPO.
Pimecrolimus does not affect the differentiation, maturation and function of human monocyte-derived dendritic cells, in contrast to corticosteroids
Authors: KALTHOFF F S , CHUNG J , MUSSER P , STUETZ A 
Published: December 2004

SUMMARYClinically, corticosteroids (CS) are among the first line drugs in the therapy of autoimmune and allergic diseases and potently inhibit the activation of immune cells. However, due to their pleiotropic mode of action, the prolonged use of CS is generally associated with a range of undesirable side-effects. In this study, we compared the activity of pimecrolimus, a novel immunomodulatory drug for the treatment of inflammatory skin disorders, and the CS dexamethasone (Dex) and beta-methasone-valerate (β-MSV) in different in vitro assays addressing the cytokine-induced differentiation and maturation of monocyte-derived dendritic cells (M-DC), the susceptibility of M-DC to drug-induced apoptosis and the potency of differentiated M-DC to induce primary T cell activation. In contrast to pimecrolimus, Dex and β-MSV strongly induced apoptosis of M-DC precursors if added at the start of the DC differentiation culture. Flow cytometric analysis of surviving cells on day 6 of culture showed that the expression of several DC-specific antigens such as CD1a, CD40 and CD80 was inhibited by 50% to 80% at concentrations between 1 nm and 10 nm of either Dex or β-MSV. Furthermore, the presence of CS during the final maturation of M-DC inhibited the synthesis of IL-12p70, the expression of critical DC costimulatory molecules, such as CD83 and CD86 and impaired their ability to activate primary CD4+ T cell proliferation. In contrast, pimecrolimus did not inhibit the LPS-induced secretion of IL-12, surface expression of costimulatory molecules or the maturation of M-DC into potent stimulators of T cells. Taken together, these data indicate that pimecrolimus does not interfere with the differentiation and viability of dendritic cells and their precursors or with the function of mature M-DC to prime naïve T lymphocytes, and thus may have a lower potential than CS to interfere with DC-mediated immunosurveillance.
Mimicry between the hepatitis C virus polyprotein and antigenic targets of nuclear and smooth muscle antibodies in chronic hepatitis C virus infection
Authors: GREGORIO G V , CHOUDHURI K , MA Y , PENSATI P , IORIO R , GRANT P , GARSON J , BOGDANOS D P , VEGNENTE A , MIELI-VERGANI G , VERGANI D 
Published: December 2004

SUMMARYAutoantibodies to smooth muscle (SMA) and nuclear components (ANA) arise in the natural course of chronic infection with hepatitis C virus. In view of the growing evidence for ‘molecular mimicry’ as a mechanism of autoimmunity we investigated whether cross-reactive immune reactions between host smooth muscle/nuclear components and HCV antigens may contribute to the formation of SMA and ANA in chronic HCV infection. Computer-assisted protein database search methods were used to identify three smooth muscle (smoothelin698−717, myosin1035−1054, vimentin69−88) and three nuclear (matrin722−741, histone H2A11-30, replication protein A133-152) host antigens with the highest local sequence similarity to the HCV polyprotein and 20-mer peptides corresponding to these regions were constructed. Sera from 51 children with chronic HCV infection [median age: 8 (2–16); 27 boys], 26 SMA positive and five ANA positive, were tested for reactivity to the synthesized HCV peptides and their human homologues by enzyme linked immunosorbent assay (ELISA). Sera from patients with HBV infection and chronic liver disease of different aetiologies were used as controls. ‘Double reactivity’ to HCV peptides and smooth muscle/nuclear homologues was associated strongly with HCV infection (P &lt; 0·001 for both). Humoral cross-reactivity was established as the basis for double recognition by competition ELISA. Double-reactivity to smooth muscle and HCV peptide antigens correlated with SMA positivity by indirect immunofluouresence (P = 0·05). Of 15 patients double-reactive to myosin1035−1054 and its HCV homologue, 13 recognized whole myosin by immunoblot. These results suggest that ANA and SMA in chronic HCV infection may arise, at least in part, as a consequence of cross-reactive immune responses to HCV and host smooth muscle/nuclear antigens.
Antibody-mediated glomerulonephritis in mice: the role of endotoxin, complement and genetic background
Authors: ROBSON M G , COOK H T , PUSEY C D , WALPORT M J , DAVIES K A 
Published: December 2004

SUMMARYAntibody-mediated glomerulonephritis in man may be exacerbated by infection and this effect may be mediated by bacterial endotoxin. There is evidence supporting a role for endotoxin in heterologous nephrotoxic nephritis in rats, but the role of endotoxin in this model in mice has not previously been explored. Previous data in mice on the role of complement in this model are conflicting and this may be due to the mixed genetic background of mice used in these studies. We used the model of heterologous nephrotoxic nephritis in mice and explored the role of endotoxin, complement and genetic background. In this study we show a synergy between antibody and endotoxin in causing a neutrophil influx. We also show that C1q-deficient mice have an increased susceptibility to glomerular inflammation but this is seen only on a mixed 129/Sv × C57BL/6 genetic background. On a C57BL/6 background we did not find any differences in disease susceptibility when wildtype, C1q, factor B or factor B/C2 deficient mice were compared. We also demonstrate that C57BL/6 mice are more susceptible to glomerular inflammation than 129/Sv mice. These results show that endotoxin is required in this model in mice, and that complement does not play a major role in glomerular inflammation in C57BL/6 mice. C1q may play a protective role in mixed-strain 129/Sv × C57BL/6 mice, but the data may also be explained by systematic bias in background genes, as there is a large difference in disease susceptibility between C57BL/6 and 129/Sv mice.
IL-17 enhances the susceptibility of U-2 OS osteosarcoma cells to NK cell lysis
Authors: HONORATI M C , NERI S , CATTINI L , FACCHINI A 
Published: December 2004

SUMMARYWe investigated the effect of the proinflammatory cytokine interleukin 17 (IL-17) on the lysis of osteosarcoma cells by human NK cells. NK cells and U-2 OS, MG-63, HOS osteosarcoma cell lines express the IL-17 receptor, the highest amount being found on U-2 OS. Pre-incubation of NK cells with IL-17 did not affect the cytotoxicity against osteosarcomas, that was increased when U-2 OS were pre-incubated with IL-17. In IL-17 treated U-2 OS osteosarcoma cells FACS analysis demonstrated an increased expression of fibronectin among the panel of adhesion molecules assayed, and the treatment with anti-fibronectin antibodies decreased the NK cytotoxicity. The comparison between interferon gamma (IFN-γ) treated and IFN-γ/IL-17-treated U-2 OS showed a decreased susceptibility to NK lysis associated with a reduced expression of CD49f on U-2 OS treated with IFN-γ/IL-17. IL-17 appears to be a modulator of NK adhesion molecules on U-2 OS cells but antagonizes with IFN-γ on NK lysis.
Increased serum levels of interferon-γ-inducible protein 10 and monokine induced by gamma interferon in patients with haemophagocytic lymphohistiocytosis
Authors: TAKADA H , TAKAHATA Y , NOMURA A , OHGA S , MIZUNO Y , HARA T 
Published: December 2004

SUMMARYWe measured serum interferon-gamma-inducible protein 10 (IP-10) and monokine induced by gamma interferon (MIG) levels to investigate the role of these molecules in the pathophysiology of haemophagocytic lymphohistiocytosis (HLH). Serum IP-10 and MIG levels were significantly increased in patients with active HLH compared with those of healthy controls. Serum MIG levels decreased gradually during the course of disease in a patient who recovered without therapy. On the other hand, rapid reduction of MIG and IP-10 levels was observed after chemotherapy in a patient with severe HLH. IP-10 and MIG mRNA expression was enhanced in liver and spleen, and IP-10 mRNA expression was enhanced in bone marrow in the patients, suggesting activated macrophages that infiltrated in these organs as one of the main producers of these cytokines. Serum IP-10 and MIG levels showed a significant correlation with serum IFN-γ levels. In addition, these chemokines had a significant correlation with fever and serum LDH levels, which are clinical indicators of disease activity of HLH. These results suggest that IP-10 and MIG which are produced by activated macrophages by the stimulation of IFN-γ, play an important role in the pathophysiology of HLH, by recruitment of activated Th1 cells into the tissues or organs.