scholarly journals Avian Macrophage Responses to Virulent and Avirulent Clostridium perfringens

Pathogens ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 100
Author(s):  
Raveendra R. Kulkarni ◽  
Carissa Gaghan ◽  
Javid Mohammed

The present study evaluated the avian macrophage responses against Clostridium perfringens that varied in their ability to cause necrotic enteritis in chickens. Strains CP5 (avirulent-netB+), CP1 (virulent-netB+), and CP26 (highly virulent-netB+tpeL+) were used to evaluate their effect on macrophages (MQ-NCSU cells) and primary splenic and cecal tonsil mononuclear cells. The bacilli (whole cells) or their secretory products from all three strains induced a significant increase in the macrophage transcription of Toll-like receptor (TLR)21, TLR2, interleukin (IL)-1β, inducible nitric oxide synthase (iNOS), and CD80 genes as well as their nitric oxide (NO) production and major histocompatibility complex (MHC)-II surface expression compared to an unstimulated control. The CP1 and CP26-induced expression of interferon (IFN)γ, IL-6, CD40 genes, MHC-II upregulation, and NO production was significantly higher than that of CP5 and control groups. Furthermore, splenocytes and cecal tonsillocytes stimulated with bacilli or secretory products from all the strains showed a significant increase in the frequency of macrophages, their surface expression of MHC-II and NO production, while CP26-induced responses were significantly higher for the rest of the groups. In summary, macrophage interaction with C. perfringens can lead to cellular activation and, the ability of this pathogen to induce macrophage responses may depend on its level of virulence.

1993 ◽  
Vol 265 (2) ◽  
pp. L110-L116 ◽  
Author(s):  
M. W. Owens ◽  
M. B. Grisham

The close proximity of pleural mesothelial cells (PMC) and mononuclear cells during pleural inflammation suggests that leukocyte-derived products (e.g., cytokines) may play an important role in modulating PMC function. The purpose of this study was to determine whether certain cytokines and bacterial products induce PMC to produce nitric oxide (NO). Confluent monolayers of rat PMC were exposed to tumor necrosis factor (TNF), interleukin-1 beta (IL-1), gamma-interferon (IFN), or lipopolysaccharide (LPS) individually and in various double and triple combinations for 6–72 h. Concentrations of nitrite and nitrate were quantified and used as indirect indices of NO production. Nitrite/nitrate accumulation was maximal at 72 h, with most of the increase occurring from 48 to 72 h. Maximal nitrite/nitrate production was observed with triple combinations with the combination of LPS, IL-1, and TNF giving the highest concentration (137.4 +/- 2.8 microM). Nitrite/nitrate production was significantly inhibited by NG-nitro-L-arginine methyl ester, suggesting that nitrite and nitrate were derived from the L-arginine-dependent formation of NO. These data indicate that PMC can be induced to produce large amounts of NO in response to specific combinations of proinflammatory cytokines and LPS.


2005 ◽  
Vol 288 (2) ◽  
pp. G261-G267 ◽  
Author(s):  
John D. Linehan ◽  
George Kolios ◽  
Vassilis Valatas ◽  
Duncan A. F. Robertson ◽  
John Westwick

Nitric oxide (NO) production is increased in the human colonic mucosa in intestinal inflammation. We examined the effect of corticosteroids and the role of mononuclear cells in this production. Colonic biopsies from patients with ulcerative colitis and normal controls were cultured with either budesonide or prednisolone in the presence of proinflammatory cytokines. Human mixed mononuclear cells (MMCs) were cocultured with HT-29 cells stimulated with IFN-γ and LPS in the presence or absence of corticosteroids. Nitrite production was measured in supernatants by a modification of the Griess reaction, and inducible NO synthase (iNOS) mRNA expression was studied in colonic tissue by RT-PCR. Both steroids significantly suppressed the nitrite production and iNOS mRNA expression in inflamed colonic biopsies from ulcerative colitis patients and in cytokine-stimulated normal colonic biopsies but not in cytokine-stimulated HT-29 cells. Nitrite production by HT-29 cells was significantly increased ( P < 0.01) in cocultures with MMCs stimulated with IFN-γ and LPS. The presence of either prednisolone or budesonide significantly ( P < 0.01) suppressed nitrite production from cocultures of HT-29 cells and MMCs but not from cultures of HT-29 cells stimulated with conditioned media from activated MMCs. Interestingly, stimulation of HT-29 with conditioned media from MMCs pretreated with steroids before stimulation with LPS and IFN-γ induced a significantly ( P < 0.01) lower nitrite production. These results suggest that the inhibitory effect of corticosteroids on the NO production in the intestinal inflammation might be via the inhibition of MMC-produced mediators responsible for NO production by colonic epithelial cells.


Author(s):  
Manu Kupani ◽  
Smriti Sharma ◽  
Rajeev Kumar Pandey ◽  
Rajiv Kumar ◽  
Shyam Sundar ◽  
...  

Nitric oxide (NO) is an anti-microbial effector of the innate immune system which plays major role in non-specific killing of various pathogens including protozoan parasites. However, due to subversion of the host’s immune processes by pathogens, suboptimal production of NO is frequently found in many infection models. Previous studies have shown suppressed NO production during Leishmania donovani infection, the causative agent of visceral leishmaniasis (VL). Availability of L-Arginine, a semi-essential amino acid is required for inducible nitric oxide synthase (iNOS) mediated NO production. However, arginase is another enzyme, which if expressed concomitantly, may strongly compete for L-Arginine, and suppress NO production by iNOS. In the present study, plasma nitrite and arginase levels were measured in VL patients before and after successful drug treatment, endemic and non-endemic healthy donors. We observed significantly lower NO levels in the plasma of VL patients as compared to endemic controls, which improved significantly post-treatment. Significantly elevated arginase activity was also observed in the plasma of VL patients, which may be associated with NO deficiency. VL patients also showed significantly higher levels of IL-10 and TGF-β, which are known to regulate expression of arginase in various immune cells. In vitro studies with human peripheral blood mononuclear cells (PBMCs) further corroborated the role of IL-10 and TGF-β in arginase mediated suppression of NO production.


1999 ◽  
Vol 67 (9) ◽  
pp. 4977-4981 ◽  
Author(s):  
Douglas J. Perkins ◽  
Peter G. Kremsner ◽  
Daniela Schmid ◽  
Mary A. Misukonis ◽  
Meghan A. Kelly ◽  
...  

ABSTRACT Plasmodium falciparum malaria is an important cause of morbidity and mortality in children. Factors that determine the development of mild versus severe malaria are not fully understood. Since host-derived nitric oxide (NO) has antiplasmodial properties, we measured NO production and NO synthase (NOS) activity in peripheral blood mononuclear cells (PBMC) from healthy Gabonese children with a history of prior mild malaria (PMM) or prior severe malaria (PSM) caused by P. falciparum. The PMM group had significantly higher levels of NOS activity in freshly isolated PBMC and higher NO production and NOS activity in cultured PBMC. The investigation of NO-modulating cytokines (e.g., interleukin 12, gamma interferon, tumor necrosis factor alpha [TNF-α], and transforming growth factor β1) as an explanation for differing levels of NOS activity revealed that plasma levels of TNF-α were significantly higher in the PSM group. Our results suggest that NOS/ NO and TNF-α are markers for prior disease severity and important determinants of resistance to malaria.


2020 ◽  
Vol 295 (28) ◽  
pp. 9513-9530 ◽  
Author(s):  
Cory Q. Wenzel ◽  
Dominic C. Mills ◽  
Justyna M. Dobruchowska ◽  
Jiri Vlach ◽  
Harald Nothaft ◽  
...  

Clostridium perfringens is a leading cause of food-poisoning and causes avian necrotic enteritis, posing a significant problem to both the poultry industry and human health. No effective vaccine against C. perfringens is currently available. Using an antiserum screen of mutants generated from a C. perfringens transposon-mutant library, here we identified an immunoreactive antigen that was lost in a putative glycosyltransferase mutant, suggesting that this antigen is likely a glycoconjugate. Following injection of formalin-fixed whole cells of C. perfringens HN13 (a laboratory strain) and JGS4143 (chicken isolate) intramuscularly into chickens, the HN13-derived antiserum was cross-reactive in immunoblots with all tested 32 field isolates, whereas only 5 of 32 isolates were recognized by JGS4143-derived antiserum. The immunoreactive antigens from both HN13 and JGS4143 were isolated, and structural analysis by MALDI-TOF-MS, GC-MS, and 2D NMR revealed that both were atypical lipoteichoic acids (LTAs) with poly-(β1→4)-ManNAc backbones substituted with phosphoethanolamine. However, although the ManNAc residues in JGS4143 LTA were phosphoethanolamine-modified, a few of these residues were instead modified with phosphoglycerol in the HN13 LTA. The JGS4143 LTA also had a terminal ribose and ManNAc instead of ManN in the core region, suggesting that these differences may contribute to the broadly cross-reactive response elicited by HN13. In a passive-protection chicken experiment, oral challenge with C. perfringens JGS4143 lead to 22% survival, whereas co-gavage with JGS4143 and α-HN13 antiserum resulted in 89% survival. This serum also induced bacterial killing in opsonophagocytosis assays, suggesting that HN13 LTA is an attractive target for future vaccine-development studies.


2020 ◽  
Vol 7 (3) ◽  
pp. 115
Author(s):  
Michel B. Verwoolde ◽  
Robin H. G. A. van den Biggelaar ◽  
Jürgen van Baal ◽  
Christine A. Jansen ◽  
Aart Lammers

Beta-glucan-stimulated mammalian myeloid cells, such as macrophages, show an increased responsiveness to secondary stimulation in a nonspecific manner. This phenomenon is known as trained innate immunity and is important to prevent reinfections. Trained innate immunity seems to be an evolutionary conserved phenomenon among plants, invertebrates and mammalian species. Our study aimed to explore the training of primary chicken monocytes. We hypothesized that primary chicken monocytes, similar to their mammalian counterparts, can be trained with β-glucan resulting in increased responses of these cells to a secondary stimulus. Primary blood monocytes of white leghorn chickens were primary stimulated with β-glucan microparticulates (M-βG), lipopolysaccharide (LPS), recombinant chicken interleukin-4 (IL-4) or combinations of these components for 48 h. On day 6, the primary stimulated cells were secondary stimulated with LPS. Nitric oxide (NO) production levels were measured as an indicator of pro-inflammatory activity. In addition, the cells were analyzed by flow cytometry to characterize the population of trained cells and to investigate the expression of surface markers associated with activation. After the secondary LPS stimulation, surface expression of colony stimulating factor 1 receptor (CSF1R) and the activation markers CD40 and major histocompatibility complex class II (MHC-II) was higher on macrophages that were trained with a combination of M-βG and IL-4 compared to unstimulated cells. This increased expression was paralleled by enhanced NO production. In conclusion, this study showed that trained innate immunity can be induced in primary chicken monocytes with β-glucan, which is in line with previous experiments in mammalian species. Innate immune training may have the potential to improve health and vaccination strategies within the poultry sector.


2021 ◽  
Vol 8 ◽  
Author(s):  
Zipeng Jiang ◽  
Wentao Li ◽  
Weifa Su ◽  
Chaoyue Wen ◽  
Tao Gong ◽  
...  

This study aimed to investigate the protective effects of Bacillus amyloliquefaciens (BA40) against Clostridium perfringens (C. perfringens) infection in mice. Bacillus subtilis PB6 was utilized as a positive control to compare the protective effects of BA40. In general, a total of 24 5-week-old male C57BL/6 mice were randomly divided into four groups, with six mice each. The BA40 and PB6 groups were orally dosed with resuspension bacteria (1 × 109 CFU/ml) once a day, from day 1 to 13, respectively. In the control and infected groups, the mice were orally pre-treated with phosphate-buffered saline (PBS) (200 μl/day). The mice in the infected groups, PB6 + infected group and BA40 + infected group, were orally challenged with C. perfringens type A (1 × 109 CFU/ml) on day 11, whereas the control group was orally dosed with PBS (200 μl/day). The results showed that the BA40 group ameliorated intestinal structure damage caused by the C. perfringens infection. Furthermore, the inflammatory responses detected in the infected groups which include the concentrations of IL-1β, TNF-α, IL-6, and immunoglobulin G (IgG) in the serum and secretory immunoglobulin (SigA) in the colon, and nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) activity in the jejunum, were also alleviated (P &lt; 0.05) by BA40 treatment. Similarly, cytokines were also detected by quantitative PCR (qPCR) in the messenger RNA (mRNA) levels, and the results were consistent with the enzyme-linked immunosorbent assay (ELISA) kits. Additionally, in the infected group, the mRNA expression of Bax and p53 was increasing and the Bcl-2 expression was decreasing, which was reversed by BA40 and PB6 treatment (P &lt; 0.05). Moreover, the intestinal microbiota imbalance induced by the C. perfringens infection was restored by the BA40 pre-treatment, especially by improving the relative abundance of Verrucomicrobiota (P &lt; 0.05) and decreasing the relative abundance of Bacteroidetes (P &lt; 0.05) in the phyla level, and the infected group increased the relative abundance of some pathogens, such as Bacteroides and Staphylococcus (P &lt; 0.05) in the genus level. The gut microbiota alterations in the BA40 group also influenced the metabolic pathways, and the results were also compared. The purine metabolism, 2-oxocarboxylic acid metabolism, and starch and sucrose metabolism were significantly changed (P &lt; 0.05). In conclusion, our results demonstrated that BA40 can effectively protect mice from C. perfringens infection.


2006 ◽  
Vol 290 (5) ◽  
pp. F1044-F1054 ◽  
Author(s):  
Caigan Du ◽  
Qiunong Guan ◽  
Hong Diao ◽  
Ziqin Yin ◽  
Anthony M. Jevnikar

The susceptibility or resistance of tubular epithelial cells (TEC) to apoptosis is pivotal to the long-term maintenance of kidney function following episodes of inflammation, such as graft rejection. TEC apoptosis can occur with ischemia as well as with proinflammatory cytokines and nitric oxide (NO), produced by infiltrating mononuclear cells. TEC can also produce abundant amounts of NO during inflammation but the role and regulation of NO-induced injury of TEC are not well understood. Apoptosis in TEC in vitro was determined by FACS analysis with annexin-V and propidium iodide staining. NO in culture supernatants was measured by Greiss reagent, and protein expression of inducible NO synthetase (NOS2/iNOS) and caspase-8 was examined by Western blot analysis. Here, we showed that murine TEC produced abundant amounts of NO in response to proinflammatory cytokines (IFN-γ/TNF-α) through upregulation of NOS2, and inhibition of endogenous NO production by l-NMMA reduced TEC apoptosis in cytokine-stimulated cultures. Addition of exogenous NO (sodium nitroprusside) induced TEC apoptosis as well as caspase-8 activation in a dose-dependent manner. The key role of caspase-8 in NO-induced TEC apoptosis was demonstrated by that NO-induced TEC apoptosis can be blocked by caspase-8 inhibition using z-IETD-fmk, caspase-8 silencing with shRNA or by overexpressing the endogenous caspase-8 inhibitor c-FLIP (cellular Flice-inhibitory protein). In conclusion, endogenous NO from NOS2 activity as well as exogenous NO can contribute to renal injury through apoptosis of TEC. Activation of caspase-8 plays a central role in NO-induced apoptosis and caspase-8 inhibition may be an important therapeutic target during renal inflammation.


1995 ◽  
Vol 182 (4) ◽  
pp. 1143-1151 ◽  
Author(s):  
E K Haddad ◽  
A J Duclos ◽  
M G Baines

In early embryo loss, the fetus may be considered to be an allograft and, therefore, may be rejected by maternal immunocytes. However, the cytotoxic mechanisms involved are still poorly understood. We have previously shown the involvement of natural killer (NK) cells and mononuclear cells expressing Mac-1 (CD11b) and F4/80 in resorbing compared to nonresorbing embryos. In this study, the role of nitric oxide (NO) in the mechanism of early embryo loss was studied. Pregnant CBA/J females mated with DBA/2 males (20-30% early embryo loss) and CD1 females mated with CD1 males (5-10% early embryo loss) were studied on days 8, 10, and 12 of gestation. Cells from the implantation sites of individual embryos were tested for the production of nitrite and nitrate with or without in vitro challenge with lipopolysaccharide (LPS) to determine whether decidual macrophages were primed in situ. On day 12 of gestation, when resorption was clearly visible, resorbing embryos showed more than a fivefold increase in both basal- and LPS-induced nitrite and nitrate production compared to nonresorbing embryos in both mouse strains tested, indicating that the decidual mononuclear cells were primed. Furthermore, more than 20% of CBA/J embryos showed a significant nitrate release on days 8 and 10 of gestation before any signs of embryo cytopathology. This percentage corresponded to the spontaneous resorption rate seen in CBA/J female X DBA/2 male matings. Similarly, 4% of the embryos from pregnant CD1 mice on days 8 and 12 of gestation produced a significant amount of nitrate, which again correlated with the low incidence of resorption observed in these mice. Using immunohistochemistry, the presence of inducible nitric oxide synthase (iNOS) was detected at implantation sites. Furthermore, decidual cells positive for both iNOS and the macrophage marker Mac-1 were demonstrated in implantation sites by double immunostaining. This strongly suggests that decidual macrophages could be the cellular source of NO production. Aminoguanidine, a selective inhibitor of the iNOS, inhibited the in vitro production of nitric oxide by cells isolated from individual implantation sites, and more strikingly, significantly reduced early embryo losses in CBA/J females mated by DBA/2 males when given orally or parenterally to the gravid females starting on day 6 of gestation. In addition, aminoguanidine-treated pregnant mice showed a significant increase in average litter size when the pregnancies were allowed to proceed to term.(ABSTRACT TRUNCATED AT 400 WORDS)


2009 ◽  
Vol 101 (02) ◽  
pp. 345-350 ◽  
Author(s):  
Rosalinda Madonna ◽  
Raffaele De Caterina

SummaryHyperinsulinemia predicts future cardiovascular events, but may also contribute to atherosclerosis. We therefore studied the consequences of prolonged insulin treatment of human umbilical vein endothelial cells (HUVEC) on the phosphatidylinositol-3‘-kinase(PI3K)/Akt/nitric oxide(NO)-dependent insulin signaling, together with the expression of the pro-atherogenic molecule vascular cell adhesion molecule (VCAM)-1. HUVEC were incubated with insulin (10–11 to 10–7 M) in short- (30 min) and long-term (24 h to 3 days) incubations. In short-term incubations, insulin did not affect constitutive Akt and eNOS at any concentration, but significantly increased their active phosphorylated forms, and NO production. In long-term incubations, however, such insulin effects on the phosphorylated forms, as well as NO production, were attenuated, promoting an effect of insulin also at concentrations otherwise ineffective. Such effects were accompanied by a boosting of insulin effect on VCAM-1 surface expression. In contrast, under similar conditions, insulin did not exert any significant effect on the surface expression of ICAM-1 and E-selectin. Therefore, prolonged exposure of HUVEC to high insulin levels induces a downregulation of the PI3K/Akt/eNOS axis. Such impairment of insulin signalling in states of prolonged hyperinsulinemia pontially contributes to detrimental effects on atherogenesis in insulin resistance states, such as the metabolic syndrome and type 2 diabetes.


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