scholarly journals Modulation of Paired Immunoglobulin-Like Type 2 Receptor Signaling Alters the Host Response to Staphylococcus aureus-Induced Pneumonia

2010 ◽  
Vol 78 (3) ◽  
pp. 1353-1363 ◽  
Author(s):  
Antara Banerjee ◽  
Frederik Stevenaert ◽  
Kalyan Pande ◽  
Erik Haghjoo ◽  
Svetlana Antonenko ◽  
...  

ABSTRACT Paired immunoglobulin-like type 2 receptors (PILRs) inhibitory PILRα and activating PILRβ are predominantly expressed on myeloid cells. Their functions in host defense and inflammation are largely unknown, and in this study, we evaluated their roles in an acute Staphylococcus aureus pneumonia model. Compared to their respective controls, Pilrb −/− mice or mice in which PILRα was activated with an agonistic antibody showed improved clearance of pulmonary staphylococci and improved survival. These mice had reduced serum or bronchoalveolar lavage fluid levels of interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α), and IL-6 and elevated levels of gamma interferon (IFN-γ), IL-12, and IL-10. In contrast, mice in which PILRβ was activated had increased lung bacterial burdens and higher mortality coupled with an intense proinflammatory response with highly elevated levels of IL-1β, TNF-α, and IL-6. Treatment groups with reduced bacterial burdens had higher levels of Keratinocyte-derived chemokine (KC), macrophage inflammatory protein 2 (MIP-2), and MIP-1α in bronchoalveolar lavage fluid and an increased influx of neutrophils and macrophages to the lungs. Consistent with our in vivo findings, bone marrow-derived macrophages from Pilrb −/− mice released significantly less IL-1β and TNF-α and more IFN-γ and IL-12 than did the wild-type macrophages when directly stimulated with heat-killed S. aureus. To our knowledge, this is the first evidence that S. aureus directly interacts with PILRβ. It provides a mechanism by which manipulating the balance in favor of an inhibitory PILR signal, by activation of PILRα or deletion of PILRβ, helps to control acute S. aureus-mediated pneumonia and attenuate the inflammatory response. These results highlight the importance of PILRs in innate immunity and the control of inflammation.

2005 ◽  
Vol 49 (10) ◽  
pp. 4128-4136 ◽  
Author(s):  
Monica Fonseca-Aten ◽  
Christine M. Salvatore ◽  
Asunción Mejías ◽  
Ana M. Ríos ◽  
Susana Chávez-Bueno ◽  
...  

ABSTRACT Mycoplasma pneumoniae is a major cause of community-acquired pneumonia. We evaluated the efficacy of LBM415, a novel peptide deformylase inhibitor antimicrobial agent, for the treatment of M. pneumoniae pneumonia in a mouse model. Eight-week-old BALB/c mice were intranasally inoculated once with 107 CFU of M. pneumoniae. Groups of mice were treated with LBM415 (50 mg/kg of body weight) or placebo subcutaneously daily for 13 days, starting 24 h after inoculation. Groups of mice were evaluated at the baseline; at days of treatment 1, 3, 6, and 13; and at 7 days after treatment. The MIC of LBM415 against M. pneumoniae was <0.005 μg/ml. LBM415-treated mice had significantly lower bronchoalveolar lavage fluid M. pneumoniae concentrations than placebo-treated mice on days 6 and 13 of treatment. Compared with placebo treatment, therapy with LBM415 significantly decreased lung histopathology scores at days 3, 6, and 13 of treatment and at 7 days after treatment. Airway obstruction was significantly lower in LBM415-treated mice than in placebo-treated mice on days 1, 3, and 6 of treatment and after 7 days of therapy, while airway hyperresponsiveness was significantly lower only on day 3 of therapy. The bronchoalveolar lavage fluid concentrations of tumor necrosis factor alpha, gamma interferon (IFN-γ), interleukin-6 (IL-6), IL-12, KC (functional IL-8), monocyte chemotactic protein 1, macrophage inflammatory protein 1α, monokine induced by IFN-γ, and IFN-inducible protein 10 were significantly reduced in LBM415-treated mice compared with the levels in placebo-treated mice. There were no differences in the bronchoalveolar lavage fluid concentrations of granulocyte-macrophage colony-stimulating factor, IL-1β, IL-2, IL-4, IL-5, and IL-10 between the two groups of mice. LBM415 therapy had beneficial microbiologic, histologic, respiratory, and immunologic effects on acute murine M. pneumoniae pneumonia.


2010 ◽  
Vol 88 (10) ◽  
pp. 1010-1016 ◽  
Author(s):  
Qiang Du ◽  
Gan-Zhu Feng ◽  
Li Shen ◽  
Jin Cui ◽  
Jian-Kang Cai

Paeonol, the main active component isolated from Moutan Cortex, possesses extensive pharmacological activities such as anti-inflammatory, anti-allergic, and immunoregulatory effects. In the present study, we examined the effects of paeonol on airway inflammation and hyperresponsiveness in a mouse model of allergic asthma. BALB/c mice sensitized and challenged with ovalbumin were administered paeonol intragastrically at a dose of 100 mg/kg daily. Paeonol significantly suppressed ovalbumin-induced airway hyperresponsiveness to acetylcholine chloride. Paeonol administration significantly inhibited the total inflammatory cell and eosinophil count in bronchoalveolar lavage fluid. Treatment with paeonol significantly enhanced IFN-γ levels and decreased interleukin-4 and interleukin-13 levels in bronchoalveolar lavage fluid and total immunoglobulin E levels in serum. Histological examination of lung tissue demonstrated that paeonol significantly attenuated allergen-induced lung eosinophilic inflammation and mucus-producing goblet cells in the airway. These data suggest that paeonol exhibits anti-inflammatory activity in allergic mice and may possess new therapeutic potential for the treatment of allergic bronchial asthma.


2007 ◽  
Vol 76 (1) ◽  
pp. 270-277 ◽  
Author(s):  
Takashi Shimizu ◽  
Yutaka Kida ◽  
Koichi Kuwano

ABSTRACT The pathogenesis of Mycoplasma pneumoniae infection is considered to be in part attributable to excessive immune responses. In this study, we investigated whether synthetic lipopeptides of subunit b of F0F1-type ATPase (F0F1-ATPase), NF-κB-activating lipoprotein 1 (N-ALP1), and N-ALP2 (named FAM20, sN-ALP1, and sN-ALP2, respectively) derived from M. pneumoniae induce cytokine and chemokine production and leukocyte infiltration in vivo. Intranasal administration of FAM20 and sN-ALP2 induced infiltration of leukocyte cells and production of chemokines and cytokines in bronchoalveolar lavage fluid, but sN-ALP1 failed to do so. The activity of FAM20 was notably higher than that of sN-ALP2. FAM20 and sN-ALP2 induced tumor necrosis factor alpha (TNF-α) through Toll-like receptor 2 in mouse peritoneal macrophages. Moreover, in the range of low concentrations of lipopeptides, FAM20 showed relatively high activity of inducing TNF-α in mouse peritoneal macrophages compared to synthetic lipopeptides such as MALP-2 and FSL-1, derived from Mycoplasma fermentans and Mycoplasma salivarium, respectively. These findings indicate that the F0F1-ATPase might be a key molecule in inducing cytokines and chemokines contributing to inflammatory responses during M. pneumoniae infection in vivo.


2010 ◽  
Vol 84 (17) ◽  
pp. 8790-8798 ◽  
Author(s):  
Debbie C. P. Lee ◽  
James A. E. Harker ◽  
John S. Tregoning ◽  
Sowsan F. Atabani ◽  
Cecilia Johansson ◽  
...  

ABSTRACT Regulatory CD4+ T cells have been shown to be important in limiting immune responses, but their role in respiratory viral infections has received little attention. Here we observed that following respiratory syncytial virus (RSV) infection, CD4+ Foxp3+ CD25+ natural regulatory T-cell numbers increased in the bronchoalveolar lavage fluid, lung, mediastinal lymph nodes, and spleen. The depletion of CD25+ natural regulatory T cells prior to RSV infection led to enhanced weight loss with delayed recovery that was surprisingly accompanied by increased numbers of activated natural killer cells in the lung and bronchoalveolar lavage fluid on day 8 postinfection. Increased numbers of neutrophils were also detected within the bronchoalveolar lavage fluid and correlated with elevated levels of myeloperoxidase as well as interleukin-6 (IL-6) and gamma interferon (IFN-γ). CD25+ natural regulatory T-cell depletion also led to enhanced numbers of proinflammatory T cells producing IFN-γ and tumor necrosis factor alpha (TNF-α) in the lung. Despite these increases in inflammatory responses and disease severity, the viral load was unaltered. This work highlights a critical role for natural regulatory T cells in regulating the adaptive and innate immune responses during the later stages of lung viral infections.


1998 ◽  
Vol 66 (1) ◽  
pp. 65-69 ◽  
Author(s):  
J. K. Brieland ◽  
D. G. Remick ◽  
M. L. LeGendre ◽  
N. C. Engleberg ◽  
J. C. Fantone

ABSTRACT The in vivo role of endogenous interleukin 12 (IL-12) in modulating intrapulmonary growth of Legionella pneumophila was assessed by using a murine model of replicative L. pneumophila lung infection. Intratracheal inoculation of A/J mice with virulent bacteria (106 L. pneumophilacells per mouse) resulted in induction of IL-12, which preceded clearance of the bacteria from the lung. Inhibition of endogenous IL-12 activity, via administration of IL-12 neutralizing antiserum, resulted in enhanced intrapulmonary growth of the bacteria within 5 days postinfection (compared to untreated L. pneumophila-infected mice). Because IL-12 has previously been shown to modulate the expression of cytokines, including gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and IL-10, which regulate L. pneumophila growth, immunomodulatory effects of endogenous IL-12 on intrapulmonary levels of these cytokines during replicative L. pneumophila lung infection were subsequently assessed. Results of these experiments demonstrated that TNF-α activity was significantly lower, while protein levels of IFN-γ and IL-10 in the lung were similar, in L. pneumophila-infected mice administered IL-12 antiserum, compared to similarly infected untreated mice. Together, these results demonstrate that IL-12 is critical for resolution of replicativeL. pneumophila lung infection and suggest that regulation of intrapulmonary growth of L. pneumophila by endogenous IL-12 is mediated, at least in part, by TNF-α.


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