scholarly journals Helicobacter felis Infection Is Associated with Lymphoid Follicular Hyperplasia and Mild Gastritis but Normal Gastric Secretory Function in Cats

2000 ◽  
Vol 68 (2) ◽  
pp. 779-790 ◽  
Author(s):  
Kenneth W. Simpson ◽  
Dalit Strauss-Ayali ◽  
Eugenio Scanziani ◽  
Reinhard K. Straubinger ◽  
Patrick L. McDonough ◽  
...  

ABSTRACT The relationship of Helicobacter felis, a bacterium observed in the stomachs of cats, to gastric disease is unclear. The objective of this study was to determine if H. felisinfection alters gastric histopathology, proinflammatory cytokine expression, and secretory function and evokes a humoral immune response in cats. Five specific-pathogen-free (SPF)Helicobacter-free cats were studied before and for 1 year after oral inoculation with H. felis (ATCC 49179). Four SPFH. felis-uninfected cats served as controls. The stomachs of all five H. felis-inoculated cats became colonized, as determined by urease activity, histopathology, PCR, culture, and transmission electron microscopy of serial gastric biopsies at 0, 3, 5, 8, and 12 months. Uninoculated cats remained Helicobacterfree. Lymphoid follicular hyperplasia, atrophy, and fibrosis were observed primarily in the pylorus of infected cats. Mild mononuclear inflammation was detected in both infected and uninfected cats, but was more extensive in infected cats, with pangastric inflammation, eosinophilic infiltrates, and cardia gastritis observed only in infected cats. No upregulation of antral mucosal interleukin 1α (IL-1α), IL-1β, or tumor necrosis factor alpha was detected by reverse transcription-PCR in any cat. The gastric secretory axes, assessed by fasting plasma gastrin, antral mucosal gastrin and somatostatin immunoreactivity, and pentagastrin-stimulated gastric acid secretion, were similar in both infected and uninfected cats. Gradual seroconversion (immunoglobulin G) was observed in four of five infected cats, with enzyme-linked immunosorbent assay values reaching 4× to 12× baseline 12 months postinfection. These findings indicate thatH. felis infection in cats induces lymphoid follicular hyperplasia, mild gastritis, and seroconversion, but is associated with normal gastric secretory function.

2006 ◽  
Vol 74 (3) ◽  
pp. 1916-1923 ◽  
Author(s):  
Chiang W. Lee ◽  
Soumaya Bennouna ◽  
Eric Y. Denkers

ABSTRACT Toxoplasma gondii-infected macrophages are blocked in production of the proinflammatory cytokines interleukin-12 (IL-12) and tumor necrosis factor alpha (TNF-α) upon activation with lipopolysaccharide (LPS). Here, we used pathway-focused cDNA arrays to identify additional T. gondii-regulated transcriptional responses. Parasite infection decreased 57 (inclusive of IL-12 and TNF-α) and increased expression of 7 of 77 LPS-activated cytokine and cytokine-related genes. Interestingly, we found that the LPS-induced transcriptional response of the anti-inflammatory cytokine IL-10 was synergistically increased by T. gondii, results that we validated by conventional reverse transcription-PCR and enzyme-linked immunosorbent assay. Importantly, although the parasite exerted disparate effects in LPS-signaling leading to TNF-α versus IL-10 production, both responses required functional Toll-like receptor 4. We suggest that these effects represent parasite defense mechanisms to avoid or delay induction of antimicrobial activity and/or T-cell-mediated immunity during Toxoplasma infection.


2010 ◽  
Vol 17 (10) ◽  
pp. 1589-1597 ◽  
Author(s):  
Christoph Georg Baums ◽  
Christian Brüggemann ◽  
Christoph Kock ◽  
Andreas Beineke ◽  
Karl-Heinz Waldmann ◽  
...  

ABSTRACT Streptococcus suis is an important porcine pathogen causing meningitis and other invasive diseases in piglets of different ages. Application of S. suis serotype 2 bacterins to specific-pathogen-free (SPF) weaning piglets has been demonstrated to protect against the homologous serotype. However, autogenous S. suis bacterins are also applied to sows and suckling piglets in the field. Therefore, comparative evaluation of different bacterin immunization regimes, including sow vaccination, was performed in this study. The main objectives were to determine the immunogenicity of an S. suis bacterin in sows prepartum and its influence on active immunization of piglets. Experimental infection of 6- and 8-week-old weaning piglets was performed to elucidate protective efficacies. Humoral immune responses were investigated by an enzyme-linked immunosorbent assay (ELISA) measuring muramidase-released protein (MRP)-specific IgG titers and by opsonophagocytosis assays. Bacterin application elicited high MRP-specific IgG titers in the serum and colostrum of sows, as well as opsonizing antibodies. Piglets from vaccinated sows had significantly higher MRP-specific titers than respective piglets from nonvaccinated sows until 6 weeks postpartum. Vaccination of suckling piglets did not result in high MRP-specific titers nor in induction of opsonizing antibodies. Furthermore, neither vaccination of suckling nor of weaning piglets from immunized sows was associated with a prominent active immune response and protection at 8 weeks postpartum. However, protection was observed in respective 6-week-old weaning piglets, most likely because of protective maternal immunity. In conclusion, this study provides the first results suggesting protective passive maternal immunity for S. suis serotype 2 after bacterin vaccination of sows and a strong inhibitory effect on active immunization of suckling and weaning piglets, leading to highly susceptible growers.


Viruses ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 784 ◽  
Author(s):  
Krzysztof Śmietanka ◽  
Jolanta Tyborowska ◽  
Monika Olszewska-Tomczyk ◽  
Katarzyna Domańska-Blicharz ◽  
Zenon Minta ◽  
...  

Newcastle disease (ND) is responsible for significant economic losses in the poultry industry. The disease is caused by virulent strains of Avian avulavirus 1 (AAvV-1), a species within the family Paramyxoviridae. We developed a recombinant construct based on the herpesvirus of turkeys (HVT) as a vector expressing two genes: F and HN (HVT-NDV-F-HN) derived from the AAvV-1 genotype VI (“pigeon variant” of AAvV-1). This recombinant viral vaccine candidate was used to subcutaneously immunize one group of specific pathogen-free (SPF) chickens and two groups of broiler chickens (20 one-day-old birds/group). Humoral immune response was evaluated by hemagglutination-inhibition test and enzyme-linked immunosorbent assay (ELISA). The efficacy of the immunization was assessed in two separate challenge studies performed at 6 weeks of age with the use of virulent AAvV-1 strains representing heterologous genotypes IV and VII. The developed vaccine candidate elicited complete protection in SPF chickens since none of the birds became sick or died during the 2-week observation period. In the broiler groups, 90% and 100% clinical protection were achieved after challenges with AAvV-1 of IV and VII genotypes, respectively. We found no obvious relationship between antibody levels and protection assessed in broilers in the challenge study. The developed recombinant HVT-NDV-F-HN construct containing genes from a genotype VI AAvV-1 offers promising results as a potential vaccine candidate against ND in chickens.


2005 ◽  
Vol 73 (1) ◽  
pp. 453-458 ◽  
Author(s):  
P. Kelk ◽  
R. Claesson ◽  
L. Hänström ◽  
U. H. Lerner ◽  
S. Kalfas ◽  
...  

ABSTRACT Actinobacillus actinomycetemcomitans produces a leukotoxin that selectively kills human leukocytes. Recently, we reported that macrophages are highly sensitive to leukotoxin and that their lysis involves activation of caspase 1. In this study, we show that leukotoxin also induces the production and release of proinflammatory cytokines from human macrophages. The macrophages were challenged with leukotoxin or lipopolysaccharide (LPS) from A. actinomycetemcomitans or LPS from Escherichia coli, and the production and secretion of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α) were determined at the mRNA and protein levels by reverse transcription-PCR and enzyme-linked immunosorbent assay, respectively. Leukotoxin (1 to 30 ng/ml) induced abundant production and secretion of IL-1β, while the effects on IL-6 and TNF-α production were limited. Leukotoxin (1 ng/ml) caused a 10-times-higher release of IL-1β than did LPS (100 ng/ml). The secreted IL-1β was mainly the bioactive 17-kDa protein. At higher concentrations (>30 ng/ml), leukotoxin caused secretion of mainly inactive cytokine, the 31-kDa pro-IL-1β. The presence of specific antibodies to IL-1β or of a caspase 1 inhibitor blocked the secretion and production of the cytokine. Supernatants of leukotoxin-challenged macrophages stimulated bone resorption when tested in a mouse calvarial model. The activity could be blocked by an IL-1 receptor antagonist or specific antibodies to IL-1β. We concluded that A. actinomycetemcomitans leukotoxin can trigger abundant production and secretion of bioactive IL-1β by human macrophages, which is mediated by activation of caspase 1.


2007 ◽  
Vol 75 (4) ◽  
pp. 1870-1877 ◽  
Author(s):  
Kirti V. Sawant ◽  
David N. McMurray

ABSTRACT The early influx of neutrophils to the site of infection may be an important step in host resistance against Mycobacterium tuberculosis. In this study, we investigated the effect of M. tuberculosis infection on the ability of guinea pig neutrophils to produce interleukin-8 (IL-8; CXCL8) and tumor necrosis factor alpha (TNF-α) and to activate alveolar macrophages. Neutrophils and alveolar macrophages were isolated from naïve guinea pigs, cultured together or alone, and infected with virulent M. tuberculosis for 3, 12, and 24 h. IL-8 protein production in cocultures, as measured by using an enzyme-linked immunosorbent assay, was found to be additive at 24 h and significantly greater in M. tuberculosis-infected cocultures than in uninfected cocultures and in cultures of the infected neutrophils or macrophages alone. The IL-8 mRNA levels, determined by real-time reverse transcription-PCR, were elevated at 24 h in infected cocultures and infected cells cultured alone. In order to elucidate the contributions of neutrophils and their soluble mediators to the activation of alveolar macrophages, neutrophils and alveolar macrophages were cultured in a contact-independent manner by using a Transwell insert system. Neutrophils were infected with virulent M. tuberculosis in the upper wells, and alveolar macrophages were cultured in the lower wells. The release of hydrogen peroxide from alveolar macrophages exposed to soluble products from infected neutrophils was significantly increased compared to that from unexposed alveolar macrophages. Significant up-regulation of IL-1β and TNF-α mRNA levels in alveolar macrophages was observed at 24 and 30 h, respectively, compared to those in cells not exposed to soluble neutrophil products. Treatment with anti-guinea pig TNF-α polyclonal antibody completely abolished the response of alveolar macrophages to neutrophil products. This finding suggests that TNF-α produced by infected neutrophils may be involved in the activation of alveolar macrophages and hence may contribute to the containment of M. tuberculosis infection during the early period of infection.


2021 ◽  
Vol 6 (1) ◽  
pp. e000733
Author(s):  
Astrid Muyldermans ◽  
Maria Bjerke ◽  
Thomas Demuyser ◽  
Deborah De Geyter ◽  
Ingrid Wybo ◽  
...  

Background/aimsSARS-CoV-2 is highly contagious. More evidence concerning extrapulmonary transmission routes such as the eyes is urgently needed. Although the humoral immune response is important in the viral containment, the local response in tears has not yet been studied. The aim of our study was twofold: to assess the prevalence of both SARS-CoV-2 RNA and antibodies in tear fluid.MethodsIn a first series, nasopharyngeal sampling and tear sampling by Schirmer test strips were performed in 26 acutely ill patients with COVID-19 to assess the presence of SARS-CoV-2 RNA by reverse transcription PCR. In a second series, IgG and IgA responses to SARS-CoV-2 spike protein in serum and tear fluid of convalescent individuals (n=22) were compared with control individuals (n=15) by ELISA.ResultsSARS-CoV-2 RNA was detected in tears of 7/26 (26.9%) patients with COVID-19. None of them had ocular symptoms. Convalescent individuals displayed a significant higher ratio of IgG (p<0.0001) and IgA (p=0.0068) in tears compared with control individuals. A sensitivity of 77.3% and specificity of 93.3% was observed for IgG, and 59.1% and 100% for IgA.ConclusionsOur results demonstrate the presence of SARS-CoV-2 RNA and a local IgG and IgA immune response in tear fluid. These data confirm the possibility of SARS-CoV-2 transmission through tear fluid and the importance of the eye as a first defence against SARS-CoV-2, indicating the potential of tears as a non-invasive surrogate for serum in monitoring the host immune response.


2003 ◽  
Vol 10 (1) ◽  
pp. 103-107 ◽  
Author(s):  
I. Portig ◽  
J. C. Goodall ◽  
R. L. Bailey ◽  
J. S. H. Gaston

ABSTRACT Detection of antibodies to an outer membrane protein 2 (OMP2) by enzyme-linked immunosorbent assay (ELISA) by using either the Chlamydia trachomatis- or the Chlamydia pneumoniae-specific protein was investigated. OMP2 is an immunodominant antigen giving rise to antibody responses in humans infected with different C. trachomatis serovars (A to C and D to K) or with C. pneumoniae, which could be detected by OMP2 ELISA. OMP2 ELISA is not species specific, but antibody titers were usually higher on the homologous protein. The sensitivity of this assay was high but varied according to the “gold standard” applied. Levels of antibody to C. pneumoniae OMP2 as detected by ELISA seem to return to background or near-background values within a shorter period of time compared to antibodies to C. pneumoniae detected by microimmunofluorescence (MIF), making it more likely that positive results in ELISA reflect recent infection. Thus, OMP2 ELISA has distinct advantages over MIF and commercially available ELISAs and might be a useful tool for the serodiagnosis of chlamydial infection.


2010 ◽  
Vol 18 (2) ◽  
pp. 298-304 ◽  
Author(s):  
E. K. Hoebe ◽  
S. H. Hutajulu ◽  
J. van Beek ◽  
S. J. Stevens ◽  
D. K. Paramita ◽  
...  

ABSTRACTWHO type III nasopharyngeal carcinoma (NPC) is highly prevalent in Indonesia and 100% associated with Epstein-Barr virus (EBV). NPC tumor cells express viral proteins, including BARF1, which is secreted and is considered to have oncogenic and immune-modulating properties. Recently, we found conserved mutations in the BARF1 gene in NPC isolates. This study describes the expression and purification of NPC-derived BARF1 and analyzes humoral immune responses against prototype BARF1 (B95-8) and purified native hexameric BARF1 in sera of Indonesian NPC patients (n= 155) compared to healthy EBV-positive (n= 56) and EBV-negative (n= 16) individuals. BARF1 (B95-8) expressed inEscherichia coliand baculovirus, as well as BARF1-derived peptides, did not react with IgG or IgA antibodies in NPC. Purified native hexameric BARF1 protein isolated from culture medium was used in enzyme-linked immunosorbent assay (ELISA) and revealed relatively weak IgG and IgA responses in human sera, although it had strong antibody responses to other EBV proteins. Higher IgG reactivity was found in NPC patients (P= 0.015) than in regional Indonesian controls or EBV-negative individuals (P< 0.001). IgA responses to native BARF1 were marginal. NPC sera with the highest IgG responses to hexameric BARF1 in ELISA showed detectable reactivity with denatured BARF1 by immunoblotting. In conclusion, BARF1 has low immunogenicity for humoral responses and requires native conformation for antibody binding. The presence of antibodies against native BARF1 in the blood of NPC patients provides evidence that the protein is expressed and secreted as a hexameric protein in NPC patients.


2018 ◽  
Vol 44 (4) ◽  
pp. 530-538
Author(s):  
Aysun Çetin ◽  
İhsan Çetin ◽  
Semih Yılmaz ◽  
Ahmet Şen ◽  
Göktuğ Savaş ◽  
...  

Abstract Background Limited research is available concerning the relationship between oxidative stress and inflammation parameters, and simultaneously the effects of rosuvastatin on these markers in patients with hypercholesterolemia. We aimed to investigate the connection between cytokines and oxidative stress markers in patients with hypercholesterolemia before and after rosuvastatin treatment. Methods The study consisted of 30 hypercholesterolemic patients diagnosed with routine laboratory tests and 30 healthy participants. The lipid parameters, interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), paraoxonase-1 (PON1) and malondialdehyde (MDA) levels in controls and patients with hypercholesterolemia before and after 12-week treatment with rosuvastatin (10 mg/kg/day), were analyzed by means of enzyme-linked immunosorbent assay. Results It was found that a 12-week cure with rosuvastatin resulted in substantial reductions in IL-1β, IL-6 and TNF-α and MDA levels as in rising activities of PON1 in patients with hypercholesterolemia. Before treatment, the PON1 levels were significantly negatively correlated with TNF-α and IL-6 in control group, while it was positively correlated with TNF-α in patients. Conclusion Our outcomes provide evidence of protected effect of rosuvastatin for inflammation and oxidative damage. It will be of great interest to determine whether the correlation between PON1 and cytokines has any phenotypic effect on PON1.


2018 ◽  
Vol 51 (6) ◽  
pp. 2575-2590 ◽  
Author(s):  
Gang Zhong ◽  
Ruiming Liang ◽  
Jun Yao ◽  
Jia Li ◽  
Tongmeng Jiang ◽  
...  

Background/Aims: Current drug therapies for osteoarthritis (OA) are not practical because of the cytotoxicity and severe side-effects associated with most of them. Artemisinin (ART), an antimalarial agent, is well known for its safety and selectivity to kill injured cells. Based on its anti-inflammatory activity and role in the inhibition of OA-associated Wnt/β-catenin signaling pathway, which is crucial in the pathogenesis of OA, we hypothesized that ART might have an effect on OA. Methods: The chondro-protective and antiarthritic effects of ART on interleukin-1-beta (IL-1β)-induced and OA patient-derived chondrocytes were investigated in vitro using cell viability assay, glycosaminoglycan secretion, immunofluorescence, quantitative reverse transcription-polymerase chain reaction, and western blotting. We also used OA model rats constructed by anterior cruciate ligament transection and medial meniscus resection (ACLT+MMx) in the joints to investigate the effects of ART on OA by gross observation, morphological staining, immunohistochemistry, and enzyme-linked immunosorbent assay. Results: ART exhibited potent anti-inflammatory effects by inhibiting the expression of proinflammatory chemokines and cytokines, including interleukin (IL)-1β, IL-6, tumor necrosis factor alpha, and matrix metallopeptidase-13. It also showed favorable chondro-protective effect as evidenced by enhanced cell proliferation and viability, increased glycosaminoglycan deposition, prevention of chondrocyte apoptosis, and degeneration of cartilage. Further, ART inhibited OA progression and cartilage degradation via the Wnt/β-catenin signaling pathway, suggesting that it might serve as a Wnt/β-catenin antagonist to reduce inflammation and prevent cartilage degradation. Conclusion: In conclusion, ART alleviates IL-1β-mediated inflammatory response and OA progression by regulating the Wnt/β-catenin signaling pathway. Thereby, it might be developed as a potential therapeutic agent for OA.


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