scholarly journals TLR4 Deficiency Exacerbates Biliary Injuries and Peribiliary Fibrosis Caused by Clonorchis sinensis in a Resistant Mouse Strain

Author(s):  
Chao Yan ◽  
Jing Wu ◽  
Na Xu ◽  
Jing Li ◽  
Qian-Yang Zhou ◽  
...  

Mice with different genetic backgrounds have various susceptibilities to infection with Clonorchis sinensis, although the mechanisms underlying are largely unknown. Toll-like receptor 4 (TLR4) as one of the most important pattern recognition receptors (PPRs) is essential for the invasion, survival, pathogenesis, and elimination of worms. The roles played by TLR4 in C. sinensis infection may vary due to the different genetic backgrounds of mice. In the present study, a relatively resistant mouse strain-C57BL/10 to C. sinensis was used for investigation on the possible roles of TLR4 in the biliary injuries and peribiliary fibrosis. TLR4 wild type (TLR4wild) and TLR4 defective (TLR4def) mice were orally infected with 45 metacercariae of C. sinensis, and all C. sinensis-infected mice and non-infected groups were anesthetized on day 28 post-infection. The liver and serum from each mouse were collected for assessment of the biliary injuries and biliary fibrosis. Meanwhile, hepatic leukocytes were isolated and detected for the activation of M1 or M2 macrophage using flow cytometry. The hepatic type 1 immune response and type 2 immune responses -relative molecules were also evaluated using ELISA and quantitative PCR. The data showed that TLR4def aggravated liver inflammatory cell infiltrations, bile duct proliferation, biliary and hepatocellular injuries, and ECM deposition in C. sinensis-infected mice, compared with TLR4wild mice when they were intragastrically administered with the same amounts of C. sinensis metacercaria. Furthermore, the M2-like macrophages and type 2 immune responses were significantly predominant induced in TLR4def mice, compared with that of TLR4wild mice following C. sinensis infection. But the type 1 immune response were significantly decreased in TLR4def mice, compared with TLR4wild mice after C. sinensis infection. These data demonstrate that TLR4 deficiency exacerbates biliary injuries and peribiliary fibrosis caused by C. sinensis in C57BL/10 strain mice, which is contributed by augments of type 2 immune responses and decrease pro-inflammatory responses.

2006 ◽  
Vol 74 (11) ◽  
pp. 6280-6286 ◽  
Author(s):  
Matthew L. deSchoolmeester ◽  
Harinder Manku ◽  
Kathryn J. Else

ABSTRACT Trichuris muris resides in intimate contact with its host, burrowing within cecal epithelial cells. However, whether the enterocyte itself responds innately to T. muris is unknown. This study investigated for the first time whether colonic intestinal epithelial cells (IEC) produce cytokines or chemokines following T. muris infection and whether divergence of the innate response could explain differentially polarized adaptive immune responses in resistant and susceptible mice. Increased expression of mRNA for the proinflammatory cytokines gamma interferon (IFN-γ) and tumor necrosis factor and the chemokine CCL2 (MCP-1) were seen after infection of susceptible and resistant strains, with the only difference in expression being a delayed increase in CCL2 in BALB/c IEC. These increases were ablated in MyD88−/− mice, and NF-κB p65 was phosphorylated in response to T. muris excretory/secretory products in the epithelial cell line CMT-93, suggesting involvement of the MyD88-NF-κB signaling pathway in IEC cytokine expression. These data reveal that IEC respond innately to T. muris. However, the minor differences identified between resistant and susceptible mice are unlikely to underlie the subsequent development of a susceptible type 1 (IFN-γ-dominated) or resistant type 2 (interleukin-4 [IL-4]/IL-13-dominated) adaptive immune response.


Diabetes ◽  
2011 ◽  
Vol 60 (4) ◽  
pp. 1354-1359
Author(s):  
J. P. Driver ◽  
Y.-G. Chen ◽  
W. Zhang ◽  
S. Asrat ◽  
D. V. Serreze

2019 ◽  
Vol 20 (21) ◽  
pp. 5493 ◽  
Author(s):  
Meunier ◽  
Chea ◽  
Garrido ◽  
Perchet ◽  
Petit ◽  
...  

Innate lymphoid cells (ILC) are important players of early immune defenses in situations like lymphoid organogenesis or in case of immune response to inflammation, infection and cancer. Th1 and Th2 antagonism is crucial for the regulation of immune responses, however mechanisms are still unclear for ILC functions. ILC2 and NK cells were reported to be both involved in allergic airway diseases and were shown to be able to interplay in the regulation of the immune response. CXCR6 is a common chemokine receptor expressed by all ILC, and its deficiency affects ILC2 and ILC1/NK cell numbers and functions in lungs in both steady-state and inflammatory conditions. We determined that the absence of a specific ILC2 KLRG1+ST2– subset in CXCR6-deficient mice is probably dependent on CXCR6 for its recruitment to the lung under inflammation. We show that despite their decreased numbers, lung CXCR6-deficient ILC2 are even more activated cells producing large amount of type 2 cytokines that could drive eosinophilia. This is strongly associated to the decrease of the lung Th1 response in CXCR6-deficient mice.


1998 ◽  
Vol 6 (3-4) ◽  
pp. 331-342 ◽  
Author(s):  
Christoph Specht ◽  
Hans-Gerd Pauels ◽  
Christian Becker ◽  
Eckehart Kölsch

The involvement of counteractiveCD8+T-cell subsets during tumor-specific immune responses was analyzed in a syngeneic murine plasmacytoma model.CD8+Tc cells against the immunogenic IL-10-producing BALB/c plasmacytoma ADJ-PC-5 can be easily induced by immunization of BALB/c mice with X-irradiated ADJ-PC-5 tumor cellsin vivoandin vitro. However, the failure of recipient mice to mount a protective Tc response against the tumor during early stages of a real or simulated tumor growth is not due to immunological ignorance, but depends on the induction of tumor-specific tolerance, involving a population of tumorinducedCD8+T cells that are able to inhibit the generation of tumor-specific Tc cells in a primary ADJ-PC-5-specific MLTC, using IFN-γas a suppressive factor. Whereas most longterm cultivated CD8+ADJ-PC-5-specific Tc lines produce type-1 cytokines on stimulation, at least two of them, which were derived from a primary MLTC, display a type-2 cytokine spectrum. Furthermore, the primaryin vitroTc response against ADJ-PC-5 cells shows characteristics of a Tc2 response. The Tc response is strictly depending on tumor-derived IL-10.CD8+Tc cells that are induced in a primary MLTC do not produce IFN-γ, and the tumor-specific Tc response is enhanced by IL-4 but suppressed by IFN-γor IL-12. In contrast, ADJ-PC- 5-specificCD8+Tc cells from immunized mice are IFN-γproducing Tc1 cells. Since the primaryin vitroTc response against the tumor is suppressed even by the smallest numbers of irradiated ADJ-PC-5-specific Tc1 cells via IFN-γthese Tc1 cells behave similar to the suppressiveCD8+T cells that are induced during early stages of ADJ-PC-5 tumorigenesis.


2017 ◽  
Vol 86 (1) ◽  
Author(s):  
John Graham-Brown ◽  
Catherine Hartley ◽  
Helen Clough ◽  
Aras Kadioglu ◽  
Matthew Baylis ◽  
...  

ABSTRACTFasciola hepaticais a parasitic trematode of global importance in livestock. Control strategies reliant on anthelmintics are unsustainable due to the emergence of drug resistance. Vaccines are under development, but efficacies are variable. Evidence from experimental infection suggests that vaccine efficacy may be affected by parasite-induced immunomodulation. Little is known about the immune response toF. hepaticafollowing natural exposure. Hence, we analyzed the immune responses over time in calves naturally exposed toF. hepaticainfection. Cohorts of replacement dairy heifer calves (n= 42) with no prior exposure toF. hepatica, on three commercial dairy farms, were sampled over the course of a grazing season. Exposure was determined through anF. hepatica-specific serum antibody enzyme-linked immunosorbent assay (ELISA) and fluke egg counts. Concurrent changes in peripheral blood leukocyte subpopulations, lymphocyte proliferation, and cytokine responses were measured. Relationships between fluke infection and immune responses were analyzed by using multivariable linear mixed-effect models. All calves from one farm showed evidence of exposure, while cohorts from the remaining two farms remained negative over the grazing season. A type 2 immune response was associated with exposure, with increased interleukin-4 (IL-4) production, IL-5 transcription, and eosinophilia. Suppression of parasite-specific peripheral blood mononuclear cell (PBMC) proliferation was evident, while decreased mitogen-stimulated gamma interferon (IFN-γ) production suggested immunomodulation, which was not restricted to parasite-specific responses. Our findings show that the global immune response is modulated toward a nonproliferative type 2 state following natural challenge withF. hepatica. This has implications in terms of the timing of the administration of vaccination programs and for host susceptibility to coinfecting pathogens.


Author(s):  
Matthew J. Simmonds ◽  
Stephen C. L. Gough

Dysfunction within the endocrine system can lead to a variety of diseases with autoimmune attack against individual components being some of the most common. Endocrine autoimmunity encompasses a spectrum of disorders including, e.g., common disorders such as type 1 diabetes, Graves’ disease, Hashimoto’s thyroiditis, and rarer disorders including Addison’s disease and the autoimmune polyendocrine syndromes type 1 (APS 1) and type 2 (APS 2) (see Table 1.6.1). Autoimmune attack within each of these diseases although aimed at different endocrine organs is caused by a breakdown in the immune system’s ability to distinguish between self and nonself antigens, leading to an immune response targeted at self tissues. Investigating the mechanisms behind this breakdown is vital to understand what has gone wrong and to determine the pathways against which therapeutics can be targeted. Before discussing how self-tolerance fails, we first have to understand how the immune system achieves self-tolerance.


2019 ◽  
Vol 34 (4) ◽  
pp. 764-775 ◽  
Author(s):  
Elizabeth C Townsend ◽  
Grace Y Zhang ◽  
Rabab Ali ◽  
Marian Firke ◽  
Mi Sun Moon ◽  
...  

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Qin Zhao ◽  
Miusi Shi ◽  
Chengcheng Yin ◽  
Zifan Zhao ◽  
Jinglun Zhang ◽  
...  

AbstractThe immune response of a biomaterial determines its osteoinductive effect. Although the mechanisms by which some immune cells promote regeneration have been revealed, the biomaterial-induced immune response is a dynamic process involving multiple cells. Currently, it is challenging to accurately regulate the innate and adaptive immune responses to promote osteoinduction in biomaterials. Herein, we investigated the roles of macrophages and dendritic cells (DCs) during the osteoinduction of biphasic calcium phosphate (BCP) scaffolds. We found that osteoinductive BCP directed M2 macrophage polarization and inhibited DC maturation, resulting in low T cell response and efficient osteogenesis. Accordingly, a dual-targeting nano-in-micro scaffold (BCP loaded with gold nanocage, BCP-GNC) was designed to regulate the immune responses of macrophages and DCs. Through a dual-wavelength photosensitive switch, BCP-GNC releases interleukin-4 in the early stage of osteoinduction to target M2 macrophages and then releases dexamethasone in the later stage to target immature DCs, creating a desirable inflammatory environment for osteogenesis. This study demonstrates that biomaterials developed to have specific regulatory capacities for immune cells can be used to control the early inflammatory responses of implanted materials and induce osteogenesis.


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