scholarly journals Interleukin-17A Exacerbates Disease Severity in BALB/c Mice Susceptible to Lung Infection withMycoplasma pulmonis

2018 ◽  
Vol 86 (9) ◽  
Author(s):  
Maximillion T. Mize ◽  
Xiangle L. Sun ◽  
Jerry W. Simecka

ABSTRACTMycoplasmas are atypical bacteria that disrupt the immune response to promote respiratory tract infections and secondary complications. However, not every immunologic response that protects or damages the host during mycoplasma infection is known. Interleukin-17A (IL-17A) is elevated in individuals infected with mycoplasmas, but how IL-17A and its cellular sources dictate disease outcome remains unclear. Here, IL-17A is hypothesized to worsen disease in individuals susceptible to mycoplasma infection. Thus, monoclonal anti-IL-17A antibodies were given to disease-susceptible BALB/c mice and disease-resistant C57BL/6 mice infected withMycoplasma pulmonis. Neutralizing the function of IL-17A using anti-IL-17A antibodies reduced disease severity duringM. pulmonisinfection in BALB/c, but not C57BL/6, mice. Neutralizing IL-17A also reduced the incidence of neutrophilic lung lesions during infection in BALB/c mice. Reduced pathology occurred without impacting the bacterial burden, demonstrating that IL-17A is not required for mycoplasma clearance. The main source of IL-17A throughout infection in BALB/c mice was CD4+T cells, and neutralizing IL-17A after infiltration of the lungs by T cells reduced disease severity, identifying the Th17 response as a herald of late mycoplasma pathology in susceptible mice. Neutralizing IL-17A did not further reduce disease duringM. pulmonisinfection in BALB/c mice depleted of neutrophils, suggesting that IL-17A requires the presence of pulmonary neutrophils to worsen respiratory pathology. IL-17A is a pathological element of murine respiratory mycoplasma infection. Using monoclonal antibodies to neutralize IL-17A could reduce disease severity during mycoplasma infection in humans and domesticated animals.

2011 ◽  
Vol 79 (11) ◽  
pp. 4503-4510 ◽  
Author(s):  
Takashi Dejima ◽  
Kensuke Shibata ◽  
Hisakata Yamada ◽  
Hiromitsu Hara ◽  
Yoichiro Iwakura ◽  
...  

ABSTRACTInterleukin-17A (IL-17A)-producing γδ T cells differentiate in the fetal thymus and reside in the peripheral tissues, such as the lungs of naïve adult mice. We show here that naturally occurring γδ T cells play a protective role in the lung at a very early stage after systemic infection withCandida albicans.Selective depletion of neutrophils byin vivoadministration of anti-Ly6G monoclonal antibody (MAb) impaired fungal clearance more prominently in the lung than in the kidney 24 h after intravenous infection withC. albicans.Rapid and transient production of IL-23 was detected in the lung at 12 h, preceding IL-17A production and the influx of neutrophils, which reached a peak at 24 h after infection. IL-17A knockout (KO) mice showed reduced infiltration of neutrophils concurrently with impaired fungal clearance in the lung after infection. The major source of IL-17A was the γδ T cell population in the lung, and Cδ KO mice showed little IL-17A production and reduced neutrophil infiltration after infection. Early IL-23 production in a TLR2/MyD88-dependent manner and IL-23-triggered tyrosine kinase 2 (Tyk2) signaling were essential for IL-17A production by γδ T cells. Thus, our study demonstrated a novel role of naturally occurring IL-17A-producing γδ T cells in the first line of host defense againstC. albicansinfection.


2019 ◽  
Vol 88 (1) ◽  
Author(s):  
Brian S. Learman ◽  
Aimee L. Brauer ◽  
Kathryn A. Eaton ◽  
Chelsie E. Armbruster

ABSTRACT Catheter-associated urinary tract infections (CAUTIs) are common hospital-acquired infections and frequently polymicrobial, which complicates effective treatment. However, few studies experimentally address the consequences of polymicrobial interactions within the urinary tract, and the clinical significance of polymicrobial bacteriuria is not fully understood. Proteus mirabilis is one of the most common causes of monomicrobial and polymicrobial CAUTI and frequently cocolonizes with Enterococcus faecalis, Escherichia coli, Providencia stuartii, and Morganella morganii. P. mirabilis infections are particularly challenging due to its potent urease enzyme, which facilitates formation of struvite crystals, catheter encrustation, blockage, and formation of urinary stones. We previously determined that interactions between P. mirabilis and other uropathogens can enhance P. mirabilis urease activity, resulting in greater disease severity during experimental polymicrobial infection. Our present work reveals that M. morganii acts on P. mirabilis in a contact-independent manner to decrease urease activity. Furthermore, M. morganii actively prevents urease enhancement by E. faecalis, P. stuartii, and E. coli. Importantly, these interactions translate to modulation of disease severity during experimental CAUTI, predominantly through a urease-dependent mechanism. Thus, products secreted by multiple bacterial species in the milieu of the catheterized urinary tract can directly impact prognosis.


2012 ◽  
Vol 80 (12) ◽  
pp. 4398-4408 ◽  
Author(s):  
Jessalyn H. Nishimori ◽  
Tiffanny N. Newman ◽  
Gertrude O. Oppong ◽  
Glenn J. Rapsinski ◽  
Jui-Hung Yen ◽  
...  

ABSTRACTThe Toll-like receptor 2 (TLR2)/TLR1 receptor complex responds to amyloid fibrils, a common component of biofilm material produced by members of the phylaFirmicutes,Bacteroidetes, andProteobacteria. To determine whether this TLR2/TLR1 ligand stimulates inflammatory responses when bacteria enter intestinal tissue, we investigated whether expression of curli amyloid fibrils by the invasive enteric pathogenSalmonella entericaserotype Typhimurium contributes to T helper 1 and T helper 17 responses by measuring cytokine production in the mouse colitis model. AcsgBAmutant, deficient in curli production, elicited decreased expression of interleukin 17A (IL-17A) and IL-22 in the cecal mucosa compared to theS. Typhimurium wild type. In TLR2-deficient mice, IL-17A and IL-22 expression was blunted duringS. Typhimurium infection, suggesting that activation of the TLR2 signaling pathway contributes to the expression of these cytokines. T cells incubated with supernatants from bone marrow-derived dendritic cells (BMDCs) treated with curli fibrils released IL-17A in a TLR2-dependent mannerin vitro. Lower levels of IL-6 and IL-23 production were detected in the supernatants of the TLR2-deficient BMDCs treated with curli fibrils. Consistent with this, three distinct T-cell populations—CD4+T helper cells, cytotoxic CD8+T cells, and γδ T cells—produced IL-17A in response to curli fibrils in the intestinal mucosa duringS. Typhimurium infection. Notably, decreased IL-6 expression by the dendritic cells and decreased IL-23 expression by the dendritic cells and macrophages were observed in the cecal mucosa of mice infected with the curli mutant. We conclude that TLR2 recognition of bacterial amyloid fibrils in the intestinal mucosa represents a novel mechanism of immunoregulation, which contributes to the generation of inflammatory responses, including production of IL-17A and IL-22, in response to bacterial entry into the intestinal mucosa.


2013 ◽  
Vol 82 (3) ◽  
pp. 937-948 ◽  
Author(s):  
Benjamin J. Murdock ◽  
Gary B. Huffnagle ◽  
Michal A. Olszewski ◽  
John J. Osterholzer

ABSTRACTInfection of C57BL/6 mice with the moderately virulentCryptococcus neoformansstrain 52D models the complex adaptive immune response observed in HIV-negative patients with persistent fungal lung infections. In this model, Th1 and Th2 responses evolve over time, yet the contribution of interleukin-17A (IL-17A) to antifungal host defense is unknown. In this study, we show that fungal lung infection promoted an increase in Th17 T cells that persisted to 8 weeks postinfection. Our comparison of fungal lung infection in wild-type mice and IL-17A-deficient mice (IL-17A−/−mice; C57BL/6 genetic background) demonstrated that late fungal clearance was impaired in the absence of IL-17A. This finding was associated with reduced intracellular containment of the organism within lung macrophages and deficits in the accumulation of total lung leukocytes, including specific reductions in CD11c+CD11b+myeloid cells (dendritic cells and exudate macrophages), B cells, and CD8+T cells, and a nonsignificant trend in the reduction of lung neutrophils. Although IL-17A did not alter the total number of CD4 T cells, decreases in the total number of CD4 T cells and CD8 T cells expressing gamma interferon (IFN-γ) were observed in IL-17A−/−mice. Lastly, expression of major histocompatibility complex class II (MHC-II) and the costimulatory molecules CD80 and CD86 on CD11c+CD11b+myeloid cells was diminished in IL-17A−/−mice. Collectively, these data indicate that IL-17A enhances host defenses against a moderately virulent strain ofC. neoformansthrough effects on leukocyte recruitment, IFN-γ production by CD4 and CD8 T cells, and the activation of lung myeloid cells.


2013 ◽  
Vol 81 (10) ◽  
pp. 3923-3934 ◽  
Author(s):  
Ying Guo ◽  
Xun Sun ◽  
Kensuke Shibata ◽  
Hisakata Yamada ◽  
Hiromi Muta ◽  
...  

ABSTRACTInterleukin-17A (IL-17A)-producing γδ T cells are known to be activated followingMycobacterium bovisbacillus Calmette-Guérin (BCG) infection. Here, we show that CD30, a member of the tumor necrosis factor (TNF) receptor superfamily, is important for activation of IL-17A-producing γδ T cells after BCG infection. Vγ1−Vγ4−γδ T cells preferentially expressing Vγ6/Vδ1 genes were identified as the major source of IL-17A in the peritoneal cavity during the early stage of BCG infection. The number of IL-17A-producing Vγ1−Vγ4−γδ T cells bearing Vγ6 increased in peritoneal exudate cells (PEC) of wild-type (WT) mice but not in those of CD30 knockout (KO) mice in response to BCG infection. Consistently, CD30 ligand (CD30L) or CD30 expression, predominantly by Vγ1−Vγ4−γδ T cells, was rapidly upregulated after BCG infection. Inhibition of CD30L/CD30 signaling byin vivoadministration of a soluble CD30 and immunoglobulin fusion protein (CD30-Ig) severely impaired activation of IL-17A-producing Vγ1−Vγ4−γδ T cells in WT mice, while stimulating CD30L/CD30 signaling byin vivoadministration of agonistic anti-CD30 monoclonal antibody (MAb) restored IL-17A production by Vγ1−Vγ4−γδ T cells in CD30L KO mice after BCG infection. These results suggest that CD30 signaling plays an important role in the activation of IL-17A-producing Vγ1−Vγ4−γδ T cells bearing Vγ6 at an early stage of BCG infection.


2011 ◽  
Vol 79 (8) ◽  
pp. 3131-3140 ◽  
Author(s):  
A. Marijke Keestra ◽  
Ivan Godinez ◽  
Mariana N. Xavier ◽  
Maria G. Winter ◽  
Sebastian E. Winter ◽  
...  

ABSTRACTThe development of T helper 17 (TH17) cells is a well-established adaptive mechanism for the production of interleukin-17A (IL-17A), a cytokine involved in neutrophil recruitment. However, pathways contributing to mucosal expression of IL-17A during the initial phase of a bacterial infection have received less attention. Here we used the mouse colitis model ofSalmonella entericaserotype Typhimurium infection to investigate the contribution of myeloid differentiation primary response protein 88 (MyD88) to inflammation and mucosal IL-17A expression. Expression of IL-23 in the cecal mucosa duringS.Typhimurium colitis was dependent on the presence of MyD88. Furthermore, initial expression of IL-17A at 24 h afterS.Typhimurium infection was dependent on MyD88 and the receptor for IL-1β. IL-23 and IL-1β synergized in inducing expression of IL-17A in splenic T cellsin vitro. In the intestinal mucosa, IL-17A was produced by three distinct T cell populations, including δγ T cells, TH17 cells, and CD4−CD8−T cells. The absence of IL-1β signaling or IL-17 signaling reduced CXC chemokine expression but did not alter the overall severity of pathological lesions in the cecal mucosa. In contrast, cecal pathology and neutrophil recruitment were markedly reduced in Myd88-deficient mice during the initial phases ofS.Typhimurium infection. Collectively, these data demonstrate that MyD88-dependent mechanisms, including an initial expression of IL-17A, are important for orchestrating early inflammatory responses duringS.Typhimurium colitis.


2021 ◽  
Vol 9 (7) ◽  
pp. 1446
Author(s):  
Ivo Hoefnagels ◽  
Josephine van de Maat ◽  
Jeroen J.A. van Kampen ◽  
Annemarie van Rossum ◽  
Charlie Obihara ◽  
...  

Lower respiratory tract infections (LRTIs) in children are common and, although often mild, a major cause of mortality and hospitalization. Recently, the respiratory microbiome has been associated with both susceptibility and severity of LRTI. In this current study, we combined respiratory microbiome, viral, and clinical data to find associations with the severity of LRTI. Nasopharyngeal aspirates of children aged one month to five years included in the STRAP study (Study to Reduce Antibiotic prescription in childhood Pneumonia), who presented at the emergency department (ED) with fever and cough or dyspnea, were sequenced with nanopore 16S-rRNA gene sequencing and subsequently analyzed with hierarchical clustering to identify respiratory microbiome profiles. Samples were also tested using a panel of 15 respiratory viruses and Mycoplasma pneumoniae, which were analyzed in two groups, according to their reported virulence. The primary outcome was hospitalization, as measure of disease severity. Nasopharyngeal samples were isolated from a total of 167 children. After quality filtering, microbiome results were available for 54 children and virology panels for 158 children. Six distinct genus-dominant microbiome profiles were identified, with Haemophilus-, Moraxella-, and Streptococcus-dominant profiles being the most prevalent. However, these profiles were not found to be significantly associated with hospitalization. At least one virus was detected in 139 (88%) children, of whom 32.4% had co-infections with multiple viruses. Viral co-infections were common for adenovirus, bocavirus, and enterovirus, and uncommon for human metapneumovirus (hMPV) and influenza A virus. The detection of enteroviruses was negatively associated with hospitalization. Virulence groups were not significantly associated with hospitalization. Our data underlines high detection rates and co-infection of viruses in children with respiratory symptoms and confirms the predominant presence of Haemophilus-, Streptococcus-, and Moraxella-dominant profiles in a symptomatic pediatric population at the ED. However, we could not assess significant associations between microbiome profiles and disease severity measures.


2021 ◽  
Vol 233 ◽  
pp. 2-10
Author(s):  
Yan Long ◽  
Changsheng Xia ◽  
Yuanyuan Sun ◽  
Yinting Ma ◽  
Lijuan Xu ◽  
...  

2014 ◽  
Vol 81 (2) ◽  
pp. 713-725 ◽  
Author(s):  
John W. Schmidt ◽  
Getahun E. Agga ◽  
Joseph M. Bosilevac ◽  
Dayna M. Brichta-Harhay ◽  
Steven D. Shackelford ◽  
...  

ABSTRACTSpecific concerns have been raised that third-generation cephalosporin-resistant (3GCr)Escherichia coli, trimethoprim-sulfamethoxazole-resistant (COTr)E. coli, 3GCrSalmonella enterica, and nalidixic acid-resistant (NALr)S. entericamay be present in cattle production environments, persist through beef processing, and contaminate final products. The prevalences and concentrations of these organisms were determined in feces and hides (at feedlot and processing plant), pre-evisceration carcasses, and final carcasses from three lots of fed cattle (n= 184). The prevalences and concentrations were further determined for strip loins from 103 of the carcasses. 3GCrSalmonellawas detected on 7.6% of hides during processing and was not detected on the final carcasses or strip loins. NALrS. entericawas detected on only one hide. 3GCrE. coliand COTrE. coliwere detected on 100.0% of hides during processing. Concentrations of 3GCrE. coliand COTrE. colion hides were correlated with pre-evisceration carcass contamination. 3GCrE. coliand COTrE. coliwere each detected on only 0.5% of final carcasses and were not detected on strip loins. Five hundred and 42 isolates were screened for extraintestinal pathogenicE. coli(ExPEC) virulence-associated markers. Only two COTrE. coliisolates from hides were ExPEC, indicating that fed cattle products are not a significant source of ExPEC causing human urinary tract infections. The very low prevalences of these organisms on final carcasses and their absence on strip loins demonstrate that current sanitary dressing procedures and processing interventions are effective against antimicrobial-resistant bacteria.


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