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Rheumatoid arthritis (RA) is a multisystem disorder. Various studies have shown the important role of inflammatory factors tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-22, MYD88, and toll-like receptor 2 (TLR2) in this disease. In this study, we investigated the anti-inflammatory effects of B-D-Mannuronic acid (M2000), as a new immunosuppressive drug, on the expression of these inflammatory markers in peripheral blood mononuclear cells (PBMCs) of RA patients. The blood samples of active RA patients and healthy volunteers were used for PBMCsl separation. The cells were cultured with LPS (1 µg/mL), low (5 µg/mL), moderate (25 µg/mL), and high (50 µg/mL) doses of M2000 and a single dose of diclofenac (1 µg/mL) to evaluate TNF-α, IL-6, IL-22, MYD88, and TLR2 genes expression by quantitative real-time (qRT-PCR). Cell surface expression and MFI of TLR2 were assessed; using flow cytometry. Our findings exhibited a significant reduction of TNF-α, IL-6, and MYD88 gene expressions after treatment with three doses of M2000 and an optimum dose of diclofenac. TLR2 gene expression was significantly diminished by moderate and high doses of M2000 and a single dose of diclofenac. Moreoversurface expression of TLR2 was significantly downregulated by moderate and high doses of M2000, while MFI of this receptor was significantly reduced by three doses of M2000. The results of this research showed that M2000 was able to significantly reduce the gene expression of inflammatory molecules  TNF-α, IL-6, MYD88, and TLR2 in patients PBMCs. factor-alpha; Rheumatoid arthritis. These data revealed a part of the molecular mechanisms of M2000 in the treatment process. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a multisystem disorder. Various studies have shown the important role of inflammatory factors tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-22, MYD88, and toll-like receptor 2 (TLR2) in this disease. In this study, we investigated the anti-inflammatory effects of B-D-Mannuronic acid (M2000), as a new immunosuppressive drug, on the expression of these inflammatory markers in peripheral blood mononuclear cells (PBMCs) of RA patients. The blood samples of active RA patients and healthy volunteers were used for PBMCsl separation. The cells were cultured with LPS (1 µg/mL), low (5 µg/mL), moderate (25 µg/mL), and high (50 µg/mL) doses of M2000 and a single dose of diclofenac (1 µg/mL) to evaluate TNF-α, IL-6, IL-22, MYD88, and TLR2 genes expression by quantitative real-time (qRT-PCR). Cell surface expression and MFI of TLR2 were assessed; using flow cytometry. Our findings exhibited a significant reduction of TNF-α, IL-6, and MYD88 gene expressions after treatment with three doses of M2000 and an optimum dose of diclofenac. TLR2 gene expression was significantly diminished by moderate and high doses of M2000 and a single dose of diclofenac. Moreoversurface expression of TLR2 was significantly downregulated by moderate and high doses of M2000, while MFI of this receptor was significantly reduced by three doses of M2000. The results of this research showed that M2000 was able to significantly reduce the gene expression of inflammatory molecules TNF-α, IL-6, MYD88, and TLR2 in patients PBMCs. factor-alpha; Rheumatoid arthritis. These data revealed a part of the molecular mechanisms of M2000 in the treatment process.

Growing evidence indicates a link between persistent infections and the development of autoimmune diseases. For instance, the inability to control Salmonella infection due to defective toll-like receptor (TLR)/myeloid differentiation primary response 88 (MyD88) signaling has linked the development of persistent infections to a breakdown in B cell tolerance. However, the extent of immune dysregulation in the absence of TLR-MyD88 signaling remains poorly characterized. Here, we show that MyD88−/− mice are unable to eliminate attenuated Salmonella enterica serovar Typhimurium, even when challenged with a low-dose inoculum (200 CFUs/mouse), developing a persistent and progressive infection when compared to wild-type (MyD88+/+) animals. The splenic niche of MyD88−/− mice revealed increased counts of activated, Sca-1-positive, myeloid subpopulations highly expressing BAFF during persistent Salmonella infection. Likewise, the T cell compartment of Salmonella-infected MyD88−/− mice showed increased levels of CD4+ and CD8+ T cells expressing Sca-1 and CD25 and producing elevated amounts of IL-4, IL-10, and IL-21 in response to CD3/CD28 stimulation. This was associated with increased Tfh cell differentiation and the presence of CD4+ T cells co-expressing IFN-γ/IL-4 and IFN-γ/IL-10. Noteworthy, infected MyD88−/− mice had enhanced serum titers of both anti-Salmonella antibodies as well as autoantibodies directed against double-stranded DNA, thyroglobulin, and IgG rheumatoid factor, positive nuclear staining with HEp-2 cells, and immune complex deposition in the kidneys of MyD88−/− mice infected with live but not heat-killed Salmonella. Infection with other microorganisms (Acinetobacter baumanii, Streptococcus agalactiae, or Escherichia coli) was unable to trigger the autoimmune phenomenon. Our findings suggest that dysregulation of the immune response in the absence of MyD88 is pathogen-dependent and highlight potentially important genotype–environmental factor correlations.

Growing evidence indicates a link between persistent infections and the development of autoimmune diseases. For instance, the inability to control Salmonella infection due to defective toll-like receptor (TLR)/myeloid differentiation primary response 88 (MyD88) signaling has linked the development of persistent infections to a breakdown in B cell tolerance. However, the extent of immune dysregulation in the absence of TLR-MyD88 signaling remains poorly characterized. Here, we show that MyD88−/− mice are unable to eliminate attenuated Salmonella enterica serovar Typhimurium, even when challenged with a low-dose inoculum (200 CFUs/mouse), developing a persistent and progressive infection when compared to wild-type (MyD88+/+) animals. The splenic niche of MyD88−/− mice revealed increased counts of activated, Sca-1-positive, myeloid subpopulations highly expressing BAFF during persistent Salmonella infection. Likewise, the T cell compartment of Salmonella-infected MyD88−/− mice showed increased levels of CD4+ and CD8+ T cells expressing Sca-1 and CD25 and producing elevated amounts of IL-4, IL-10, and IL-21 in response to CD3/CD28 stimulation. This was associated with increased Tfh cell differentiation and the presence of CD4+ T cells co-expressing IFN-γ/IL-4 and IFN-γ/IL-10. Noteworthy, infected MyD88−/− mice had enhanced serum titers of both anti-Salmonella antibodies as well as autoantibodies directed against double-stranded DNA, thyroglobulin, and IgG rheumatoid factor, positive nuclear staining with HEp-2 cells, and immune complex deposition in the kidneys of MyD88−/− mice infected with live but not heat-killed Salmonella. Infection with other microorganisms (Acinetobacter baumanii, Streptococcus agalactiae, or Escherichia coli) was unable to trigger the autoimmune phenomenon. Our findings suggest that dysregulation of the immune response in the absence of MyD88 is pathogen-dependent and highlight potentially important genotype–environmental factor correlations. [ABSTRACT FROM AUTHOR]

Primary immunodeficiencies are genetic defects of the innate or adaptive immune system, resulting in a propensity to infections. The innate immune system is the first line of defense against pathogens and is critical to recognize microbes and start the inflammatory cascade. Sensing of microbes occurs by a number of pathogen-recognition receptors, resulting in the activation of inflammatory signal transduction pathways, such as the activation of NF-κB. Herein, we describe a case of IRAK4 deficiency, a key signal transduction molecule of toll-like and IL-1 receptors. We highlight the complexities in diagnosis of these disorders and review genetic defects of the NF-κB pathway.

Growing evidence indicates a link between persistent infections and the development of autoimmune diseases. For instance, the inability to control Salmonella infection due to defective toll-like receptor (TLR)/myeloid differentiation primary response 88 (MyD88) signaling has linked the development of persistent infections to a breakdown in B cell tolerance. However, the extent of immune dysregulation in the absence of TLR-MyD88 signaling remains poorly characterized. Here, we show that MyD88 -/- mice are unable to eliminate attenuated Salmonella enterica serovar Typhimurium, even when challenged with a low-dose inoculum (200 CFUs/mouse), developing a persistent and progressive infection when compared to wild-type (MyD88 +/+ ) animals. The splenic niche of MyD88 -/- mice revealed increased counts of activated, Sca-1-positive, myeloid subpopulations highly expressing BAFF during persistent Salmonella infection. Likewise, the T cell compartment of Salmonella -infected MyD88 -/- mice showed increased levels of CD4 + and CD8 + T cells expressing Sca-1 and CD25 and producing elevated amounts of IL-4, IL-10, and IL-21 in response to CD3/CD28 stimulation. This was associated with increased Tfh cell differentiation and the presence of CD4 + T cells co-expressing IFN-γ/IL-4 and IFN-γ/IL-10. Noteworthy, infected MyD88 -/- mice had enhanced serum titers of both anti- Salmonella antibodies as well as autoantibodies directed against double-stranded DNA, thyroglobulin, and IgG rheumatoid factor, positive nuclear staining with HEp-2 cells, and immune complex deposition in the kidneys of MyD88 -/- mice infected with live but not heat-killed Salmonella . Infection with other microorganisms ( Acinetobacter baumanii, Streptococcus agalactiae , or Escherichia coli ) was unable to trigger the autoimmune phenomenon. Our findings suggest that dysregulation of the immune response in the absence of MyD88 is pathogen-dependent and highlight potentially important genotype-environmental factor correlations.

[This corrects the article on p. 83 in vol. 5, PMID: 28503543.].