Mechanism of Infantile Feire Kechuan Oral Solution against Mycoplasma pneumoniae infection of A549 cells.

BACKGROUND: Mycoplasma pneumoniae is a leading cause of community-acquired respiratory infections. Infantile Feire Kechuan Oral Solution (IFKOS) is effective for treatment of M. pneumoniae infection. The aim of this study was to explore the potential mechanism of IFKOS against M. pneumoniae infection in basal epithelial human lung adenocarcinoma A549 cells. METHODS: The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine the effects of IFKOS on the viability of A549 cells infected with M. pneumoniae. Optical microscopy was used to observe cell morphology and a Muse cell analyzer was used to assess apoptosis and the cell cycle phase. Enzyme-linked immunosorbent assays were employed to assess the expression levels of interleukin (IL)-4, IL-6, IL-8, IL-17, tumor necrosis factor (TNF)-α, interferon (IFN)-α, and IFN-γ. RESULTS: Under certain conditions, M. pneumoniae infection reduced the viability and inhibited the proliferation of A549 cells, promoted early apoptosis, and arrested cells in the G0/G1 phase, thus shortening the S and G2/M phases (all p < 0.05). M. pneumoniae also upregulated expression of IL-8 and TNF-α and downregulated that of IL-6 (p < 0.05), which switched the immune balance of Th1/Th2 to Th1 cells. IFKOS (5.531 mg/mL) improved the viability and proliferation of M. pneumoniae-infected A549 cells, mitigated early apoptosis, and reversed cell cycle arrest in the G0/G1 phase, thereby extending the S and G2/M phases (all, p < 0.05). IFKOS downregulated expression of IL-8 and TNF-α and upregulated that of IL-6 (p < 0.01), thereby reversing the immune imbalance of Th1/Th2. Secretion of IL-4, IL-17, IFN-α, and IFN-γ was not observed. CONCLUSION: IFKOS played a protective role in the regulation of cell viability, apoptosis, the cell cycle, and Th1/Th2 immune imbalance induced by M. pneumoniae infection and conveyed an anti-inflammatory effect in A549 cells.

Neutrophil-Mediated Lung Injury Both via TLR2-Dependent Production of IL-1α and IL-12 p40, and TLR2-Independent CARDS Toxin after Mycoplasma pneumoniae Infection in Mice.

Mycoplasma pneumoniae (Mp) residing extracellularly in the respiratory tract is the primary cause of bacterial community-acquired pneumonia in humans. However, the detailed pathological mechanism of Mp infection, especially inflammation in the lung, remains unclear. This study examined the role of the neutrophils in the inflammation of Mp-induced pneumonia in mice and the mechanism of neutrophil infiltration into the lungs in the Mp-induced pneumonia. We observed massive infiltration of neutrophils in the bronchoalveolar lavage fluid (BALF) and lung injury after the Mp challenge. The neutrophils were shown to contribute to lung injury in Mp pneumonia but were not involved in eliminating Mp, suggesting that neutrophils are detrimental to the host in Mp pneumonia. Mp also induced the production of inflammatory cytokines and chemokines in the BALF in a toll-like receptor 2 (TLR2)-dependent manner. Particularly, both interleukin (IL)-1α and IL-12 p40 played a crucial role in neutrophil infiltration into the BALF in a coordinated manner. Both IL-1α and IL-12 p40 were released from the alveolar macrophages depending on the TLR2 and reactive oxygen species. In addition, the community-acquired respiratory distress syndrome (CARDS) toxin from Mp were found to induce neutrophil infiltration into BALF in a TLR2-independent and IL-1α-dependent manner. Collectively, the TLR2-dependent production of both IL-1α and IL-12 p40, and CARDS toxin have been elucidated to play an important role in neutrophil infiltration into the lungs subsequently leading to the lung injury upon Mp infection in mice. These data will aid in the development of therapeutics and vaccines for Mp pneumonia. IMPORTANCE Although Mp-induced pneumonia is usually a self-limiting disease, refractory life-threatening pneumonia is often induced. In addition, the development of alternative therapeutic strategies for Mp is expected because of the emergence of antibiotic-resistant Mp. However, the lack of knowledge regarding the pathogenesis of Mp-induced pneumonia, especially inflammation upon the Mp infection, makes it tedious to design novel therapeutics and vaccines. For example, although neutrophil infiltration is widely recognized as one of the characteristics of Mp-induced pneumonia, the precise role of neutrophils in the aggravation of Mp pneumonia remains unclear. This study showed that the infiltration of neutrophils in the lungs is detrimental to the host in Mp-induced pneumonia in mice. Furthermore, the TLR2-dependent IL-1α and IL-12 p40 production, and CARDS toxin play important roles in neutrophil infiltration into the lung, following lung injury. Our findings apply to the rational design of novel therapeutics and vaccines against Mp.

Mycoplasma pneumoniae Seroprevalence and Total IgE Levels in Patients with Juvenile Idiopathic Arthritis.

BACKGROUND: Mycoplasma pneumoniae (M. pneumoniae) is implicated in several immune-mediated extrapulmonary manifestations, including reactive arthritis. Recently, increased total serum IgE were reported in children developing M. pneumoniae-related extrapulmonary diseases (MpEPDs). Here, we aimed at analyzing these aspects in children affected with rheumatic disorders and, in detail, Juvenile Idiopathic Arthritis (JIA). METHODS: M. pneumoniae serology (IgG and IgM) and total serum IgE were concomitantly analyzed in 139 pediatric patients diagnosed with: JIA (Group 1, n = 85), or any rheumatic disease other than JIA (Group 2, n = 27), or non-inflammatory endocrinological disorders (Group 3, n = 27). RESULTS: Overall, 19.4% M. pneumoniae seroprevalence was observed in this hospitalized pediatric population, without signicant differences among the three groups. No significant differences in total serum IgE levels were noted among these groups; however, a second analysis excluding children with very high (and clearly abnormal) IgE levels suggested that JIA patients and, in detail, those with oligopolyarticular forms may have higher serum IgE concentrations. This relative difference among groups in serum IgE level seems to be more pronounced in M. pneumoniae seropositive children. CONCLUSIONS: M. pneumoniae infection should be actively sought in children developing immune-mediated diseases, including patients affected with JIA and, especially, in oligopolyarticular forms. There is some evidence that total serum IgE levels may tend to be increased in patients with oligopolyarticular JIA subtype and especially in those resulting as M. pneumoniae seropositive. However, further and focused research is needed to confirm these preliminary results and to clarify the relation between M. pneumoniae infection, atopic status, and immune-mediated arthritis.

Ribosomal RNA­depleted RNA sequencing reveals the pathogenesis of refractory Mycoplasma pneumoniae pneumonia in children.

Pneumonia caused by Mycoplasma pneumoniae (M. pneumoniae) is a major cause of community­acquired pneumonia in children. In some cases, M. pneumoniae pneumonia (MPP) can develop into refractory MPP (RMPP), which shows no clinical or radiological response to macrolides, and can progress to severe and complicated pneumonia. However, the pathogenesis of RMPP remains poorly understood. The present study aimed to identify target genes that could be used as biomarkers for the clinical diagnosis of early­stage RMPP through high­throughput sequencing technology. The differences in long non­coding (lnc)RNAs, mRNAs and circular (circ)RNAs were examined between whole­blood samples from two patients with non­refractory MPP (NRMPP), two patients with RMPP and three healthy children using ribosomal (r)RNA­depleted RNA­sequencing techniques and an integrated mRNA/circRNA analysis. A total of 17 lncRNAs (four upregulated and 13 downregulated), 18 mRNAs (six upregulated and 12 downregulated) and 24 circRNAs (12 upregulated and 12 downregulated) were the most significantly differentially expressed (P<0.05) between the NRMPP and RMPP groups. Upon functional analysis, the significantly differentially expressed genes encoded by the targeting mRNAs (prostaglandin­endoperoxide synthase 2, IL­8 and fos­like antigen 1) were screened and identified to be enriched in the 'IL­17 signaling pathway'. Furthermore, the key circRNAs in the NRMPP and RMPP comparative groups were primarily enriched in 'herpes simplex virus 1 infection', 'viral carcinogenesis' and 'RNA transport'. In the present study, a comprehensive analysis of the differences between the NRMPP and RMPP cases was performed based on rRNA­depleted RNA­sequencing techniques, and the selected genes and circRNAs may be closely associated with the complex pathogenesis of RMPP.

IL-17 stimulates neutrophils to release S100A8/A9 to promote lung epithelial cell apoptosis in Mycoplasma pneumoniae-induced pneumonia in children.

Mycoplasma pneumoniae-induced pneumonia (MPP) is a common cause of community-acquired respiratory tract infections, increasing risk of morbidity and mortality, in children. However, diagnosing early-stage MPP is difficult owing to the lack of good diagnostic methods. Here, we examined the protein profile of bronchoalveolar lavage fluid (BALF) and found that S100A8/A9 was highly expressed. Enzyme-linked immunosorbent assays used to assess protein levels in serum samples indicated that S100A8/A9 concentrations were also increased in serum obtained from children with MPP, with no change in S100A8/A9 levels in children with viral or bacterial pneumonia. In vitro, S100A8/A9 treatment significantly increased apoptosis in a human alveolar basal epithelial cell line (A549 cells). Bioinformatics analyses indicated that up-regulated S100A8/A9 proteins participated in the interleukin (IL)-17 signaling pathway. The origin of the increased S100A8/A9 was investigated in A549 cells and in neutrophils obtained from children with MPP. Treatment of neutrophils, but not of A549 cells, with IL-17A released S100A8/A9 into the culture medium. In summary, we demonstrated that S100A8/A9, possibly released from neutrophils, is a new potential biomarker for the clinical diagnosis of children MPP and involved in the development of this disease through enhancing apoptosis of alveolar basal epithelial cells.

Comparison of Mycoplasma pneumoniae IgM and IgE Antibody Levels in Asthmatic and Non-Asthmatic Adults.

OBJECTIVE: Mycoplasma pneumoniae (M. pneumoniae), an extracellular pathogen lacking a cell wall, causes respiratory infection in adults and children and has been implicated in asthma exacerbation; immunoglobulin (Ig) E may be involved in these exacerbations. Specific IgM and IgG immune response to M. pneumoniae has been reported, but less is known about IgE M. pneumoniae antibody (Ab) responses in asthma. Previous studies in our laboratory demonstrated that asthmatic children have increased IgM M. pneumoniae levels, but not IgE. Thus, we sought to investigate whether past M. pneumoniae infection triggers production of M. pneumoniae-specific IgE Abs in adult subjects with/without asthma. METHODS: M. pneumoniae- IgE and -IgM Ab responses were studied in adult asthmatic (N=22) and non-asthmatic (N=22) subjects (ELISA). Data are reported as antibody index. Threshold detection levels: IgE, IgM: 0.2, 0.9, respectively. RESULTS: M. pneumoniae-IgE Ab levels were low and below the threshold of detection in both asthmatic and non-asthmatics (0.002±0.008 vs. 0.02±0.03; P=0.021). However, specific-IgM levels were slightly higher in non-asthmatics compared with asthmatics (0.96±0.37 vs. 0.79±0.31; P=0.054). M. pneumoniae-IgM Ab positivity was similar in both groups (P=1.0). CONCLUSION: IgM M. pneumoniae Abs may play an important role in non-asthma and persist for months after acute infection. IgE M. pneumoniae Abs may play a less important role in both groups.

miR-509-5p anti-infection response for mycoplasma pneumonia in sheep by targeting NF-κB pathway.

MicroRNAs play a key role in Mannan-binding lectin-mediated resistance to Mycoplasma ovipneumoniae pneumonia, by regulating the translation of mRNAs of target genes, thereby regulating the immune response. Additionally, TRAF6 is a key molecule in Toll-like receptor signal transduction, which mediates inflammation and apoptosis signaling pathways and is widely involved in inflammation and immune response. While the molecular regulation mechanism has not been reported. In this study, we screened differentially expressed miRNAs and genes of Anti-infection for M. pneumonia on Sheep, through relevant bioinformatics analysis. Further, the effect of differential expression of NF-κB signaling pathway related genes on the molecular mechanism of M. pneumonia was detected. We used miRNA-mRNA integrated analysed, the target gene TRAF6 of miR-509-5p was selected. TRAF6 dual luciferase reporter vector was co-transfected into HEK 293T cells and primary sheep respiratory mucosal epithelial cells to detect changes in luciferase activity. qRT-PCR was used to analyze the effect of miR-509-5p on the expression and regulation of TRAF6 and other genes related to the NF-κB signaling pathway. The result confirmed that TRAF6 was a target gene of miR-509-5p. Compared with miR-509-5p-NC group, the luciferase activity of miR-509-5p group was significantly down-regulated (P < 0.01). Further, in sheep respiratory mucosal epithelial cells, miR-509-5p mimic could significantly down-regulate the fold change value of TRAF6 (P < 0.01). On the contrary, miR-509-5p-inhibitor up-regulated the fold change value of TRAF6 (P < 0.05). Interestingly, the expression levels of other genes were different. Among them, miR-509-5p mimic significantly up-regulated TLR4 and IRAK4 (P < 0.05), significantly down-regulated TAK1 (P < 0.05) and NF-κB (P < 0.01). miR-509-5p-inhibitor significantly up-regulated NF-κB (P < 0.05) and TAK1 (P < 0.01). miR-509-5p targets TRAF6 to affect the expression of downstream genes, which negatively regulates the NF-κB pathway, thereby affecting the inflammatory response.

T-B cell epitope peptides induce protective immunity against Mycoplasma pneumoniae respiratory tract infection in BALB/c mice.

Mycoplasma pneumoniae is the most common pathogen of community-acquired pneumonia in humans. Due to its high rates of antibiotic resistance, vaccination has become the best method to control the dissemination of M. pneumoniae. The recombinant carboxyl terminus of the P1 (P1C) protein is an immunodominant antigen, but it has negative effects such as poor stability and lower purity. In the current study, T-B epitopes of the P1C protein were predicted according to bioinformatics analysis and assessed for efficacy in peptide vaccination. BALB/c mice were subcutaneously inoculated with the T-B epitope peptides four times and then infected with M. pneumoniae through the respiratory tract. The results showed that the T-B epitope peptides of the P1C protein (P1C103-117, P1C155-169, P1C224-238 and P1C244-258) induced strong antigen-specific serum antibody responses and cellular immune responses with high levels of serum IgG, IgA antibodies and Th1-biased (IFN-γ and IL-2) cytokines. Immunization with T-B epitope peptides significantly reduced the M. pneumoniae burden and the degree of inflammation in the challenged mice. Furthermore, the levels of IFN-γ and TNF-α in the supernatants of lung homogenates were observably reduced compared to those in the PBS group. Overall, our findings demonstrate that T-B epitopes (P1C103-117, P1C155-169, P1C224-238 and P1C244-258) play significant roles in the P1C protein and can be used to induce powerful humoral and cellular immune responses to provide significant protection against M. pneumoniae pulmonary infection, which provides new insight into the design of potential multiepitope vaccines to prevent host infection by M. pneumoniae.

Comparative profiling of the resistance of different genotypes of mannose-binding lectin to Mycoplasma pneumoniae infection in Chinese Merino sheep based on high-throughput sequencing technology.

Mannose-binding lectin (MBL) glycoproteins in blood can selectively recognise lectins on the surface of bacteria, and play an important role in natural immunity. Micro RNAs (miRNAs) are key molecules that regulate gene expression at the post-transcriptional level in vivo, and their pathways are specific and effective. Previous studies indicate that small RNAs such as miRNAs perform regulatory roles in immunology. Herein, we investigated differential expression of miRNAs during MBL protein immunotherapy in sheep following treatment with different MBL genotypes (resistant and susceptible), and identified miRNAs linked to different target genes and pathways. RNA was extracted from liver tissue of resistant and susceptible sheep, miRNAs were identified by high-throughput sequencing, and differentially expressed miRNAs were analysed by SOAP to predict target genes and biological pathways. Results: Some miRNAs (oar-mir-143, oar-mir-10b, oar-mir-382, oar-mir-432 and oar-mir-379) were up-regulated, while others were down-regulated. GPATCH3 and DNAJC5 were predicted target genes of oar-mir-379, DMRT1 and GATA4 were linked to oar-mir-382, and oar-mir-432 was associated with STAT2, DMRT1 and ATG16L1. Identification of miRNAs differentially expressed in resistant and susceptible sheep may expand our understanding of miRNAs in immune regulation, and the role of MBL in innate immunity.

Altered chemokine profile in Refractory Mycoplasma pneumoniae pneumonia infected children.

BACKGROUND: Mycoplasma pneumoniae is one of the major pathogens causing community-acquired pneumonia in children. Although usually self-limited, Mycoplasma pneumoniae pneumonia (MPP) may lead to complicated morbidity that can even be life-threatening. Upon MPP infection, alveolar macrophage becomes attracted and activated and will induce subsequent cytokine and chemokine reaction. Refractory Mycoplasma pneumoniae pneumonia (RMPP) is manifested by clinical or radiological deterioration despite proper antibiotic therapy. RMPP is characterized with excessive inflammation and may need subsequent glucocorticoid treatment. AIM: The aim of this study was to investigate the change of plasma chemokines in non-refractory Mycoplasma pneumoniae pneumonia (NRMPP) and RMPP before and after antibiotic or methylprednisolone treatment. METHOD: A total of 42 children with MPP were enrolled in this study. Plasma specimens were collected at admission and one to two weeks after antibiotic or methylprednisolone treatment with declined fever. Plasma specimens were then indicated to chemokines detection. RESULTS: Mycoplasma pneumoniae pneumonia altered the chemokine profile through the observation of decreased plasma M1 related chemokines (CCL2, CCL8 and CXCL10) and increased M2 related chemokines (CCL17 and CCL22) after treatment.When the patients were divided into RMPP and NRMPP groups and the chemokines before treatment were compared, the RMPP group showed higher CXCL10 but lower CCL3 and CCL11 than the NRMPP group. CONCLUSION: Unique changes in macrophage related chemokines is observed in the course of MPP infection. NRMPP and RMPP infection in children showed distinct manifestation in chemokine profiles.

Monocyte-Independent and -Dependent Regulation of Regulatory T-Cell Development in Mycoplasma Infection.

BACKGROUND: Although Mycoplasma pneumoniae (MP) infection has been implicated in the pathogenesis of allergic diseases, the mechanism of this trigger remains unknown. We explored the mechanism for how MP infection could tilt the balance between regulatory T cells (Tregs) and Th17 cells. METHODS: We analyzed the frequency, phenotype, and function of Tregs in patients at the different stages of MP and various virus infections over a period of more than 1 year. We examined the effect of monocytes to elucidate signals that can regulate the balance between Treg and Th17 cells. RESULTS: The functional activity of Tregs was profoundly impaired during the acute stage of MP as well as viral infections. Upon resolution, however, the Treg function remained impaired even 1 year after MP infection. In the resolution stage, the impaired Treg function was associated with an increase in interleukin (IL) 17A+ Tregs and Th17 cells. Development of Th17 cells was dependent on the "aberrant" proinflammatory monocytes (pMOs), characterized by potent ability to produce IL-6 in a Toll-like receptor 2-dependent manner. CONCLUSIONS: Depending on the prevalence of the pMOs, Tregs and Th17 cells could mutually regulate the number and function of the other. The pMOs/IL-6 could be crucial therapeutic targets against MP-induced allergic diseases.

Immunodominant proteins P1 and P40/P90 from human pathogen Mycoplasma pneumoniae.

Mycoplasma pneumoniae is a bacterial human pathogen that causes primary atypical pneumonia. M. pneumoniae motility and infectivity are mediated by the immunodominant proteins P1 and P40/P90, which form a transmembrane adhesion complex. Here we report the structure of P1, determined by X-ray crystallography and cryo-electron microscopy, and the X-ray structure of P40/P90. Contrary to what had been suggested, the binding site for sialic acid was found in P40/P90 and not in P1. Genetic and clinical variability concentrates on the N-terminal domain surfaces of P1 and P40/P90. Polyclonal antibodies generated against the mostly conserved C-terminal domain of P1 inhibited adhesion of M. pneumoniae, and serology assays with sera from infected patients were positive when tested against this C-terminal domain. P40/P90 also showed strong reactivity against human infected sera. The architectural elements determined for P1 and P40/P90 open new possibilities in vaccine development against M. pneumoniae infections.

Interleukin-23 derived from CD16+ monocytes drives IL-17 secretion by TLR4 pathway in children with mycoplasma pneumoniae pneumonia.

AIMS: The study aimed to investigate whether IL-23 is amplified in monocyte subsets of MP pneumonia and to determine its relevant pathway. MATERIALS AND METHODS: We firstly analyze the IL-23p19 expression in monocyte subgroups in MP pneumonia patients and healthy controls subjects by using flow cytometry. Then, we also analyzed the percentage of IL-17+γδT cells and Th17 cells in patients with MP pneumonia and controls subjects. At the same time, the relation between IL-23 and IL-17 were also assessed. Furthermore, we constructed the recombinant community-acquired respiratory distress syndrome (CARDS) toxin and intend to stimulate peripheral blood mononuclear cells and RAW264.7 cells in vitro. IL-23p19 was detected by flow cytometry and the mRNA levels were measured by real-time PCR. Finally, TLR4 pathway was also investigated by TAK242 inhibitor. KEY FINDINGS: It turned out that the expression of IL-23p19 was increased in CD14brightCD16+ monocyte of MP pneumonia patients than controls subjects. The patients with MP pneumonia had significantly higher the percentage of IL-17+γδT cells and Th17 cells than controls subjects. Interestingly, the levels of IL-23 were positively related to IL-17 in MP pneumonia patients. CD16+ monocytes and RAW264.7 cells, respectively can be induced by CARDS toxin to secrete IL-23 by TLR4 pathway in vitro. SIGNIFICANCE: These results indicated that IL-23-IL-17+γδT/Th17 axis may play a role in the pathogenesis of MP pneumonia, whereas IL-23 derived from CD16+ monocytes was expanded in MP pneumonia by TLR4 pathway.

A 20-Mer Peptide Derived from the Lectin Domain of SP-A2 Decreases Tumor Necrosis Factor Alpha Production during Mycoplasma pneumoniae Infection.

Human surfactant protein-A2 (hSP-A2) is a component of pulmonary surfactant that plays an important role in the lung's immune system by interacting with viruses, bacteria, and fungi to facilitate pathogen clearance and by downregulating inflammatory responses after an allergic challenge. Genetic variation in SP-A2 at position Gln223Lys is present in up to ∼30% of the population and has been associated with several lung diseases, such as asthma, pulmonary fibrosis, and lung cancer (M. M. Pettigrew, J. F. Gent, Y. Zhu, E. W. Triche, et al., BMC Med Genet 8:15, 2007, https://bmcmedgenet.biomedcentral.com/articles/10.1186/1471-2350-8-15; Y. Wang, P. J. Kuan, C. Zing, J. T. Cronkhite, et al., Am J Hum Genet 84:52-59, 2009, https://www.cell.com/ajhg/fulltext/S0002-9297(08)00595-8). Previous work performed by our group showed differences in levels of SP-A binding to non-live mycoplasma membrane fractions that were dependent on the presence of a lysine (K) or a glutamine (Q) at amino acid position 223 in the carbohydrate region of SP-A2. On the basis of these differences, we have derived 20-amino-acid peptides flanking this region of interest in order to test the ability of each to regulate various immune responses to live Mycoplasma pneumoniae in SP-A knockout mice and RAW 264.7 cells. In both models, the 20-mer containing 223Q significantly decreased both tumor necrosis factor alpha (TNF-α) mRNA levels and protein levels in comparison to the 20-mer containing 223K during M. pneumoniae infection. While neither of the 20-mer peptides (223Q and 223K) had an effect on p38 phosphorylation during M. pneumoniae infection, the 223Q-20mer peptide significantly reduced NF-κB p65 phosphorylation in both models. Taken together, our data suggest that small peptides derived from the lectin domain of SP-A2 that contain the major allelic variant (223Q) maintain activity in reducing TNF-α induction during M. pneumoniae infection.

miR-143-3p impacts on pulmonary inflammatory factors and cell apoptosis in mice with mycoplasmal pneumonia by regulating TLR4/MyD88/NF-κB pathway.

miR-143-3p is correlated with inflammatory pain responses, such as hsa-miR-143-3p expression reduction in fibromyalgia. The present study aimed to explore the effects of miR-143-3p and Toll-like receptor (TLR) 4/myeloid differentiation factor 88 (MyD88)/NF-κB signaling pathway on pulmonary inflammatory factors levels and alveolar epithelial cell apoptosis in mycoplasmal pneumonia mice. Twenty mice were selected as normal group. The 120 successfully modeled Mycoplasma pneumoniae (MP) infection mice were randomly divided into model group (without any treatment), negative control (NC) group (injected with NC mimic), miR-143-3p mimic group (injected with miR-143-3p mimic), miR-143-3p inhibitor group (injected with miR-143-3p inhibitor), TAK-242 group (treatment with TAK-242), and miR-143-3p inhibitor + TAK-242 group (treatment with miR-143-3p inhibitor + TAK-242). Compared with model group, model mice had up-regulated miR-143-3p expression and decreased MyD88 and p-NF-κB p50 protein expressions (all P<0.05); Model mice treated with miR-143-3p mimic and TAK-242 had reduced interleukin (IL)-2 and tumor necrosis factor (TNF)-α contents and protein expressions of MyD88, p-NF-κB p50, increased IL-10 content, fewer alveolar epithelial cell apoptosis, lower Bax expression and higher Bcl-2 expression (all P<0.05); however, mice with miR-143-3p inhibitor treatment showed opposite trends in terms of above indicators. The exacerbation of mycoplasmal pneumonia caused by miR-143-3p inhibitor was partly improved by miR-143-3p inhibitor + TAK-242 combination treatment (all P<0.05). Therefore, up-regulation of miR-143-3p expression may ameliorate pulmonary inflammatory factors levels and reduce alveolar epithelial cell apoptosis in mycoplasmal pneumonia mice by inhibiting TLR4/MyD88/NF-κB signaling pathway.

Serum Cytokines and FeNO in School-Aged Children with Mycoplasma pneumoniae Pneumonia.

BACKGROUND Mycoplasma pneumoniae is a major cause of community-acquired pneumonia (CAP) that is particularly prevalent in school-aged children. This study explored the potential involvement of cytokines in children with Mycoplasma pneumoniae pneumonia (MPP) infection. MATERIAL AND METHODS Children aged 3-7 years who were hospitalized due to CAP infection were enrolled and divided into 2 groups: an MPP group (n=33) and a NMPP group (n=38), along with 21 age-matched healthy controls. Clinical characteristics and laboratory data were recorded. Serum levels of IL-18, IL-33, IFN-γ, IL-5, IL-6, IL-8, and IL-13 were assessed using Luminex xMAP technology. Correlation analysis and ROC curves analysis were also performed to further explore the role of these detected cytokines in CAP. RESULTS Compared with the healthy controls, the serum expression of IL-18, IL-33, IFN-γ, IL-5, IL-6, IL-8, and IL-13 were significantly higher in the MPP and NMPP groups. Furthermore, serum IL-18 expression was found to be significantly correlated with lgE, FeNO, IL-5, IL-8, and IL-13 concentrations. Significant differences were also observed between the MPP group and NMPP group patients in levels of IL-18, IL-5, and IL-6, and further ROC analysis showed that the area under the curve (AUC) of IL-18 and IL-5 were 0.813 (95% CI: 0.710-0.917; P<0.01) and 0.844 (95% CI: 0.756-0.933; P<0.01), respectively. CONCLUSIONS IL-18, IL-33, IFN-γ, IL-5, IL-6, IL-8, and IL-13 serum levels showed significant differences in children with CAP. IL-18 and IL-5 were much higher in the MPP group compared to the NMPP group patients, whereas IL-6 levels were significantly lower in these 2 groups.

Bronchoalveolar lavage T cell cytokine profiles and their association with lung function in children with Mycoplasma pneumoniae -associated bronchiolitis obliterans.

BACKGROUND: Mycoplasma pneumoniae (M. pneumoniae) infection may progress to bronchiolitis obliterans (BO), with an underlying chronic inflammatory process. The aim of this study was to investigate the cytokine profiles in pulmonary T-lymphocytes and their associations with lung function in patients with BO following M. pneumoniae infection. METHODS: Bronchoalveolar lavage (BAL) samples were obtained from 10 controls and 18 children with M. pneumoniae-associated BO. We analyzed the BAL T cells for interferon (IFN)-γ, interleukin (IL)-4, IL-9, IL-17, CD25, and Foxp3 by intercellular flow cytometry. The associations with T-cell subpopulations and lung function parameters were determined. RESULTS: In BAL fluid, significantly increased proportions of T-helper 1 (Th1), Th17, and Tc1 cells were found in M. pneumoniae-associated BO patients when compared with controls. The percentages of Th17 cells showed correlations with forced expiratory volume in 1 second % predicted value (r = -0585; P < .05) and forced expiratory flow at 25% to 75% (FEF25%-75% ) % predicted value (r = -.618; P < .01). Higher proportions of Tc1 (r = -.488; P < .05) and Tc17 (r = -.542; P < .05) were significantly correlated with a reduced FEF25%-75% % predicted value in M. pneumoniae-associated BO patients. CONCLUSIONS: Our comprehensive cytokines analysis of BAL T cells revealed correlations of IL-17-producing and IFN-γ-producing T cells with lung function, suggesting that increased T-cell subpopulations may play a role in M. pneumoniae-associated BO progression.

Comprehensive RNA-Seq profiling of the lung transcriptome of Argali hybrid sheep in response to experimental Mycoplasma ovipneumoniae infection.

BACKGROUND: An experiment was conducted to reveal why the Argali hybrid sheep are susceptible to Mycoplasma ovipneumoniae infection, the causative agent of mycoplasma ovipneumonia, a chronic respiratory disease that is harmful to the sheep industry. RESULTS: After nine Argali hybrid sheep, divided into three groups, were experimentally infected with an M. ovipneumoniae strain at 0, 4 and 14 days, transcriptome profiling of lung tissues was performed by deep RNA sequencing, using the Illumina platform. Analysis of differentially expressed genes was performed to determine concomitant gene-specific temporal patterns of mRNA expression in the lungs after M. ovipneumoniae infection. 156 differentially expressed genes (44 up-regulated, 112 down-regulated) were found when comparing transcriptomic data at 4 and 0 days post-infection, and 367 (35 up-regulated, 332 down-regulated) when comparing 14 versus 0 days post-infection. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the differentially expressed genes at 4 and 14 versus 0 days post-infection were enriched in 109 and 150 pathways, respectively, and the Primary immunodeficiency pathway was considered most closely related to MO infection (p < .01). Hyper-IgM syndrome was identified based on the B-cell Immunodeficiency signaling pathway from differentially expressed genes related to M. ovipneumoniae infection. Gene Ontology analysis showed that differentially expressed genes in different groups were enriched for 497 and 928 terms, where those most closely related to M. ovipneumoniae infection are ciliated motor damage (p < .01). CONCLUSIONS: The situation that ciliary movement is significantly inhibited and B cells in immunodeficiency are possibly the most important reason why Argali hybrid sheep are susceptible to MO.

Seropositive anti-MOG antibody-associated acute disseminated encephalomyelitis (ADEM): a sequelae of Mycoplasma pneumoniae infection.

Acute disseminated encephalomyelitis (ADEM) is a demyelinating, autoimmune disease of the central nervous system (CNS). It causes motor and sensory deficits, altered mental status and other neurological symptoms. Though rarely fatal, it has been associated with residual motor and neurocognitive deficits. Our case consisted of a 4-year-old girl who presented with fatigue and unsteady gait after a respiratory illness. During her hospital course, she became progressively weaker and experienced seizures. Imaging showed sections of demyelination in the CNS, and appropriate treatment was started. Additional labs resulted in positive Mycoplasma pneumoniae serum serology. Antimyelin oligodendrocyte glycoprotein (anti-MOG) antibodies were also found, which is a risk factor for relapsing, multiphasic ADEM. To our knowledge, this is the first case of anti-MOG antibody-associated ADEM due to M. pneumoniae infection. Our patient has made a complete recovery. The parents only report slightly increased fatigue and irritability.