ABSTRACT
Periprosthetic joint infections (PJIs) are serious complications of prosthetic surgery. The criteria for the diagnosis of PJI integrate clinical and laboratory findings in a complex and sometimes inconclusive workflow. Host immune factors hold potential as diagnostic biomarkers in bone and joint infections. We reported that the humoral pattern-recognition molecule long pentraxin 3 (PTX3) predicts PJI in total hip and knee arthroplasty (THA and TKA, respectively). If and how genetic variation in PTX3 and inflammatory genes that affect its expression (IL-1ß, IL-6, IL-10, and IL-17A) contributes to the risk of PJI is unknown. We conducted a case-control study on a Caucasian historic cohort of THA and TKA patients who had prosthesis explant due to PJI (cases) or aseptic complications (controls). Saliva was collected from 93 subjects and used to extract DNA and genotype PTX3, IL-1ß, IL-6, IL-10, and IL-17A single-nucleotide polymorphisms (SNPs). Moreover, the concentration of IL-1ß, IL-10, and IL-6 was measured in synovial fluid and plasma. No association was found between PTX3 polymorphisms and PJI; however, the AGG haplotype, encompassing rs2853550, rs1143634, and rs1143627 in IL-1ß, was linked to the infection (p = 0.017). Also, synovial levels of all inflammatory markers were higher in cases than in controls, and a correlation emerged between synovial concentration of PTX3 and that of IL-1ß in cases only (Spearman r = 0.67, p = 0.004). We identified a relationship between rs2853550 and the synovial concentration of IL-1ß and PTX3. Our findings suggest that IL-1ß SNPs could be used for the early identification of THA and TKA patients with a high risk of infection.
Subject(s)
Arthroplasty, Replacement, Hip , Arthroplasty, Replacement, Knee , Genetic Predisposition to Disease , Interleukin-1beta , Polymorphism, Single Nucleotide , Prosthesis-Related Infections , Aged , Female , Humans , Male , Middle Aged , Arthroplasty, Replacement, Hip/adverse effects , Arthroplasty, Replacement, Knee/adverse effects , C-Reactive Protein/genetics , C-Reactive Protein/metabolism , Case-Control Studies , Genetic Markers , Interleukin-1beta/genetics , Prosthesis-Related Infections/genetics , Serum Amyloid P-Component/genetics , Serum Amyloid P-Component/metabolismABSTRACT
Streptococcus pneumoniae is a major pathogen in children, elderly subjects, and immunodeficient patients. Pentraxin 3 (PTX3) is a fluid-phase pattern recognition molecule (PRM) involved in resistance to selected microbial agents and in regulation of inflammation. The present study was designed to assess the role of PTX3 in invasive pneumococcal infection. In a murine model of invasive pneumococcal infection, PTX3 was strongly induced in non-hematopoietic (particularly, endothelial) cells. The IL-1ß/MyD88 axis played a major role in regulation of the Ptx3 gene expression. Ptx3-/- mice presented more severe invasive pneumococcal infection. Although high concentrations of PTX3 had opsonic activity in vitro, no evidence of PTX3-enhanced phagocytosis was obtained in vivo. In contrast, Ptx3-deficient mice showed enhanced recruitment of neutrophils and inflammation. Using P-selectin-deficient mice, we found that protection against pneumococcus was dependent upon PTX3-mediated regulation of neutrophil inflammation. In humans, PTX3 gene polymorphisms were associated with invasive pneumococcal infections. Thus, this fluid-phase PRM plays an important role in tuning inflammation and resistance against invasive pneumococcal infection.
Subject(s)
Inflammation , Pneumococcal Infections , Animals , Mice , Inflammation/metabolism , Neutrophils/metabolism , Phagocytosis , Pneumococcal Infections/genetics , Pneumococcal Infections/metabolism , Streptococcus pneumoniaeABSTRACT
The lymphatic vascular system represents a major route for dissemination of several solid tumors, including melanoma. Even though the members of the Vascular Endothelial Growth Factor family VEGF-C and VEGF-A have been shown to drive tumor lymphangiogenesis, experimental evidence indicates that also the pro-angiogenic factor Fibroblast Growth Factor-2 (FGF2) may play a role in the lymphangiogenic switch by triggering the activation of lymphatic endothelial cells (LECs) in cooperation with VEGFs.The soluble pattern recognition receptor Long Pentraxin 3 (PTX3) acts as a natural FGF trap, thus exerting an oncosuppressive role in FGF-dependent tumors. Here, the capacity of PTX3 to modulate lymphangiogenesis was assessed in vitro and in vivo. The results demonstrate that recombinant human PTX3 inhibits the lymphangiogenic activity exerted by the VEGF-A/FGF2/sphingosine-1-phosphate (VFS) cocktail on human and murine LECs. In keeping with in vitro data, a reduced lymphangiogenic response was observed in a lymphangiogenic Matrigel plug assay following the subcutaneous injection of the VFS cocktail in PTX3-overexpressing transgenic TgN(Tie2-hPTX3) mice when compared to wild-type or Ptx3 null animals. Accordingly, the capacity of B16F10-VEGFC-luc melanoma cells to colonize the primary tumor-draining lymph node after grafting into the foot pad was dramatically impaired in PTX3-overexpressing mice.Together with the observation that both the VFS cocktail and melanoma cell conditioned media caused a significant downregulation of PTX3 expression in LECs, these data indicate that the FGF trap activity of PTX3 may exert a key effect in the modulation of lymphangiogenesis and tumor metastatic dissemination.
ABSTRACT
Background: Early prognostic stratification of patients with sepsis is a difficult clinical challenge. Aim of this study was to evaluate novel molecules in association with clinical parameters as predictors of 90-days mortality in patients admitted with sepsis at Humanitas Research Hospital. Methods: Plasma samples were collected from 178 patients, diagnosed based on Sepsis-3 criteria, at admission to the Emergency Department and after 5 days of hospitalization. Levels of pentraxin 3 (PTX3), soluble IL-1 type 2 receptor (sIL-1R2), and of a panel of pro- and anti-inflammatory cytokines were measured by ELISA. Cox proportional-hazard models were used to evaluate predictors of 90-days mortality. Results: Circulating levels of PTX3, sIL-1R2, IL-1ß, IL-6, IL-8, IL-10, IL-18, IL-1ra, TNF-α increased significantly in sepsis patients on admission, with the highest levels measured in shock patients, and correlated with SOFA score (PTX3: r=0.44, p<0.0001; sIL-1R2: r=0.35, p<0.0001), as well as with 90-days mortality. After 5 days of hospitalization, PTX3 and cytokines, but not sIL-1R2 levels, decreased significantly, in parallel with a general improvement of clinical parameters. The combination of age, blood urea nitrogen, PTX3, IL-6 and IL-18, defined a prognostic index predicting 90-days mortality in Sepsis-3 patients and showing better apparent discrimination capacity than the SOFA score (AUC=0.863, 95% CI: 0.780-0.945 vs. AUC=0.727, 95% CI: 0.613-0.840; p=0.021 respectively). Conclusion: These data suggest that a prognostic index based on selected cytokines, PTX3 and clinical parameters, and hence easily adoptable in clinical practice, performs in predicting 90-days mortality better than SOFA. An independent validation is required.
Subject(s)
Interleukin-10 , Sepsis , Biomarkers , C-Reactive Protein , Cytokines , Humans , Infant, Newborn , Interleukin 1 Receptor Antagonist Protein , Interleukin-1 , Interleukin-18 , Interleukin-6 , Interleukin-8 , Prognosis , ROC Curve , Serum Amyloid P-Component , Tumor Necrosis Factor-alphaABSTRACT
BACKGROUND: Pentraxin3 (PTX3) is an emerging player in lupus nephritis (LN). Anti-PTX3 antibodies showed to delay LN occurrence in vivo. AIM: To evaluate renal changes following immunization with PTX3 in a murine model of LN. MATERIALS AND METHODS: Twenty-two lupus-prone New Zealand Black/White (NZB/W)F1 mice were divided into two groups (n = 11) and subcutaneously injected with human recombinant (hr)PTX3 100 µg or phosphate buffer saline (PBS) 200 µl, three times 3 weeks apart, starting before development of proteinuria. Five mice from each group were scheduled for sacrifice at week 22 and 6 from each group at week 29. Renal lesions included electron-dense deposits (EDD), glomerular deposition of IgG, complement and PTX3 as markers of renal inflammation. They were evaluated by immunofluorescence (IF), confocal and immunoelectron microscopy (IEM). Validated semiquantitative scores were used when available to score renal lesions. Chi-squared test with Fisher exact test was used for comparison. RESULTS: Nineteen out of 22 mice were sacrificed as scheduled. Only hrPTX3-immunized mice developed anti-PTX3 antibodies. Compared to PBS-injected mice, they displayed a dramatic decrease in glomerular deposits of IgG, C1q and PTX3, as well as in the amount of EDD (p = 0.006) and podocyte effacement (p = 0.043). Importantly, PTX3 was pinpointed inside the EDD and co-localized with nuclear material. CONCLUSIONS: Immunization with PTX3 prevented progression from the preclinical to the clinical stage of LN, inciting anti-PTX3 antibodies and preventing renal PTX3 deposition. PTX3 is a novel component of EDD, submitting it as one initiating autoantigen in LN and as potential target for early treatment.
Subject(s)
Antibody Formation/immunology , Antigen-Antibody Complex/ultrastructure , C-Reactive Protein/metabolism , Kidney Glomerulus/ultrastructure , Lupus Nephritis/immunology , Serum Amyloid P-Component/metabolism , Animals , C-Reactive Protein/genetics , C-Reactive Protein/immunology , Complement System Proteins/metabolism , Disease Models, Animal , Disease Resistance , Female , Humans , Immunization , Kidney Glomerulus/metabolism , Mice , Mice, Inbred Strains , Microscopy, Electron , Serum Amyloid P-Component/genetics , Serum Amyloid P-Component/immunologyABSTRACT
Background: Pentraxin3 (PTX3) is overexpressed in kidneys of patients developing lupus nephritis (LN). Active LN is associated with reduced anti-PTX3 antibodies. However, abnormalities of B cell differentiation against PTX3 have not been characterized in systemic lupus erythematosus (SLE). Objective: Characterization of PTX3-specific (PTX3+) B cells in peripheral blood of SLE patients with or without LN and healthy donors (HD). Patients and Methods: SLE patients without LN, biopsy-proven LN and matched HD were analyzed. Active LN was defined as proteinuria>0.5 g/day or CrCl<60 ml/min/1.73 m2 with active urinary sediment. Peripheral B cells were analyzed for direct PTX3 binding by flow cytometry using PTX3 labeled with cyanine 5 (Cy5) and phycoerythrin (PE). Results: Initially, a flow cytometry based assay to identify PTX3+ B cells was developed by demonstrating simultaneous binding of PTX3-Cy5 and PTX3-PE. Specificity of B cells was validated by blocking experiments using unlabeled PTX3. We could identify circulating PTX3+ B-cells in HD and patients. Notably, LN patients showed a significantly diminished number of PTX3+ B cells (SLE vs. LN p = 0.033; HD vs. LN p = 0.008). This decrease was identified in naïve and memory B cell compartments (naïve: SLE vs. LN p = 0.028; HD vs. LN p = 0.0001; memory: SLE vs. LN p = 0.038, HD vs. LN p = 0.011). Conclusions: Decreased PTX3+ B cells in LN within the naïve and memory compartment suggest their negative selection at early stages of B cell development potentially related to a decreased regulatory function. PTX3+ B cells could candidate for autoantigen-defined regulatory B cells as a striking abnormality of LN patients.
Subject(s)
B-Lymphocytes/metabolism , C-Reactive Protein/metabolism , Lupus Erythematosus, Systemic/blood , Lupus Nephritis/blood , Serum Amyloid P-Component/metabolism , Adult , Autoantibodies/blood , Autoantigens/metabolism , Biomarkers/metabolism , C-Reactive Protein/chemistry , C-Reactive Protein/immunology , Carbocyanines/chemistry , Female , Flow Cytometry/methods , Humans , Male , Middle Aged , Phycoerythrin/chemistry , Serum Amyloid P-Component/chemistry , Serum Amyloid P-Component/immunology , Staining and LabelingABSTRACT
Control of synapse number and function in the developing central nervous system is critical to the formation of neural circuits. Astrocytes play a key role in this process by releasing factors that promote the formation of excitatory synapses. Astrocyte-secreted thrombospondins (TSPs) induce the formation of structural synapses, which however remain post-synaptically silent, suggesting that completion of early synaptogenesis may require a two-step mechanism. Here, we show that the humoral innate immune molecule Pentraxin 3 (PTX3) is expressed in the developing rodent brain. PTX3 plays a key role in promoting functionally-active CNS synapses, by increasing the surface levels and synaptic clustering of AMPA glutamate receptors. This process involves tumor necrosis factor-induced protein 6 (TSG6), remodeling of the perineuronal network, and a ß1-integrin/ERK pathway. Furthermore, PTX3 activity is regulated by TSP1, which directly interacts with the N-terminal region of PTX3. These data unveil a fundamental role of PTX3 in promoting the first wave of synaptogenesis, and show that interplay of TSP1 and PTX3 sets the proper balance between synaptic growth and synapse function in the developing brain.
Subject(s)
C-Reactive Protein/physiology , Extracellular Matrix/metabolism , Integrin beta1/metabolism , Nerve Tissue Proteins/physiology , Receptors, AMPA/metabolism , Synapses/physiology , Animals , Astrocytes/metabolism , Brain/growth & development , Brain/metabolism , C-Reactive Protein/genetics , CHO Cells , Cells, Cultured , Cricetinae , Cricetulus , Extracellular Matrix/genetics , Mice , Mice, Inbred C57BL , Nerve Tissue Proteins/genetics , Neuronal Plasticity/genetics , Protein Transport/genetics , Thrombospondin 1/metabolismABSTRACT
Pentraxin 3 (PTX3) is an inflammatory mediator acting as a fluid-phase pattern recognition molecule and playing an essential role in innate immunity and matrix remodeling. Inflammatory mediators also contribute to skeletal homeostasis, operating at multiple levels in physiological and pathological conditions. This study was designed to investigate the role of PTX3 in physiological skeletal remodeling and bone healing. Micro-computed tomography (µCT) and bone histomorphometry of distal femur showed that PTX3 gene-targeted female and male mice (ptx3-/- ) had lower trabecular bone volume than their wild-type (ptx3+/+ ) littermates (BV/TV by µCT: 3.50 ± 1.31 vs 6.09 ± 1.17 for females, p < 0.0001; BV/TV 9.06 ± 1.89 vs 10.47 ± 1.97 for males, p = 0.0435). In addition, µCT revealed lower trabecular bone volume in second lumbar vertebra of ptx3-/- mice. PTX3 was increasingly expressed during osteoblast maturation in vitro and was able to reverse the negative effect of fibroblast growth factor 2 (FGF2) on osteoblast differentiation. This effect was specific for the N-terminal domain of PTX3 that contains the FGF2-binding site. By using the closed transversal tibial fracture model, we found that ptx3-/- female mice formed significantly less mineralized callus during the anabolic phase following fracture injury compared to ptx3+/+ mice (BV/TV 17.05 ± 4.59 vs 20.47 ± 3.32, p = 0.0195). Non-hematopoietic periosteal cells highly upregulated PTX3 expression during the initial phase of fracture healing, particularly CD51+ and αSma+ osteoprogenitor subsets, and callus tissue exhibited concomitant expression of PTX3 and FGF2 around the fracture site. Thus, PTX3 supports maintenance of the bone mass possibly by inhibiting FGF2 and its negative impact on bone formation. Moreover, PTX3 enables timely occurring sequence of callus mineralization after bone fracture injury. These results indicate that PTX3 plays an important role in bone homeostasis and in proper matrix mineralization during fracture repair, a reflection of the function of this molecule in tissue homeostasis and repair.
Subject(s)
C-Reactive Protein/metabolism , Fractures, Bone/metabolism , Osteoblasts/physiology , Serum Amyloid P-Component/metabolism , Animals , Bone Remodeling/genetics , C-Reactive Protein/genetics , Cell Differentiation , Cells, Cultured , Disease Models, Animal , Female , Fibroblast Growth Factor 2/metabolism , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Serum Amyloid P-Component/genetics , Tibia/surgery , Wound Healing/genetics , X-Ray MicrotomographyABSTRACT
BACKGROUND: Anti-pentraxin 3 (PTX3) antibodies were associated with the absence of lupus glomerulonephritis in humans. AIM: To explore the effects of anti-PTX3 antibodies in New Zealand Black/White (NZB/NZW F1) mice and their inherent mechanisms of action. MATERIALS AND METHODS: 30 NZB/NZW F1 mice were subdivided into 3 groups of 10 mice each and subcutaneously injected with PTX3, alum and PBS (group 1), alum and PBS (group 2) or PBS alone (group 3), 3 times 3 weeks apart, before development of renal disease. Mice were followed until natural death. Histological analysis and immunohistochemistry were performed on harvested kidneys. Effects of anti-PTX3 antibodies on C1q binding to immobilized PTX3-anti-PTX3 immune complexes were evaluated in vitro using human SLE sera. Qualitative characterization of human IgG anti-PTX3 was performed. RESULTS: Only group 1 mice developed anti-PTX3 antibodies. Anti-dsDNA and anti-C1q antibodies appeared significantly later and at lower levels in group 1 mice vs. controls (p < 0.0001). Proteinuria-free and overall survival were significantly increased in group 1 mice vs. controls (p < 0.05 and p = 0.03, respectively). Histopathological analysis showed that glomerular and tubular PTX3 staining and renal lesions were increased in controls compared with immunized mice. Addition of human SLE sera positive for anti-PTX3 antibodies to C1q and fixed PTX3 interfered with C1q binding to PTX3-anti-PTX3 immune complexes. Qualitative characterization of human IgG anti-PTX3 showed an increased proportion of IgG4. CONCLUSIONS: Anti-PTX3 antibodies delay lupus-like nephritis and prolong survival of NZB/NZW F1 mice. In vitro observations suggest anti-PTX3 antibodies may dampen complement activation via their Fc fragment, likely hindering renal inflammation.
Subject(s)
Autoantibodies/immunology , C-Reactive Protein/immunology , Lupus Nephritis/immunology , Serum Amyloid P-Component/immunology , Animals , Anti-Inflammatory Agents/immunology , Anti-Inflammatory Agents/pharmacology , Autoantibodies/blood , Autoantibodies/pharmacology , Biomarkers , Biopsy , C-Reactive Protein/genetics , C-Reactive Protein/metabolism , Complement Activation/immunology , Complement C1q/immunology , Disease Models, Animal , Female , Humans , Immunization , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunohistochemistry , Kidney Function Tests , Lupus Nephritis/diagnosis , Lupus Nephritis/metabolism , Lupus Nephritis/mortality , Mice , Mice, Inbred NZB , Protective Agents , Serum Amyloid P-Component/genetics , Serum Amyloid P-Component/metabolism , Time FactorsABSTRACT
Pentraxin 3 (PTX3) is a fluid-phase pattern recognition molecule and a key component of the humoral arm of innate immunity. In four different models of tissue damage in mice, PTX3 deficiency was associated with increased fibrin deposition and persistence, and thicker clots, followed by increased collagen deposition, when compared with controls. Ptx3-deficient macrophages showed defective pericellular fibrinolysis in vitro. PTX3-bound fibrinogen/fibrin and plasminogen at acidic pH and increased plasmin-mediated fibrinolysis. The second exon-encoded N-terminal domain of PTX3 recapitulated the activity of the intact molecule. Thus, a prototypic component of humoral innate immunity, PTX3, plays a nonredundant role in the orchestration of tissue repair and remodeling. Tissue acidification resulting from metabolic adaptation during tissue repair sets PTX3 in a tissue remodeling and repair mode, suggesting that matrix and microbial recognition are common, ancestral features of the humoral arm of innate immunity.
Subject(s)
C-Reactive Protein/metabolism , Immunity, Humoral/physiology , Nerve Tissue Proteins/metabolism , Animals , Arteries/pathology , Blood Coagulation , Cell-Free System , Collagen/metabolism , Female , Fibrin/metabolism , Fibrinolysis , Gene Expression Regulation , Hydrogen-Ion Concentration , Immunity, Innate , Leukocytes/cytology , Liver/injuries , Lung Injury/pathology , Male , Mice , Mice, Inbred C57BL , Microscopy, Confocal , Phenotype , Plasminogen/metabolism , Protein Structure, Tertiary , Skin/immunology , Skin/pathology , Surface Plasmon Resonance , Thrombosis/pathology , Wound HealingABSTRACT
Long pentraxin 3 (PTX3) is a non-redundant component of the humoral arm of innate immunity. The present study was designed to investigate the interaction of PTX3 with Neisseria meningitidis. PTX3 bound acapsular meningococcus, Neisseria-derived outer membrane vesicles (OMV) and 3 selected meningococcal antigens (GNA0667, GNA1030 and GNA2091). PTX3-recognized microbial moieties are conserved structures which fulfil essential microbial functions. Ptx3-deficient mice had a lower antibody response in vaccination protocols with OMV and co-administration of PTX3 increased the antibody response, particularly in Ptx3-deficient mice. Administration of PTX3 reduced the bacterial load in infant rats challenged with Neisseria meningitidis. These results suggest that PTX3 recognizes a set of conserved structures from Neisseria meningitidis and acts as an amplifier/endogenous adjuvant of responses to this bacterium.
Subject(s)
Adjuvants, Immunologic/genetics , Antibodies, Bacterial/biosynthesis , Antigens, Bacterial/immunology , C-Reactive Protein/immunology , Meningitis, Meningococcal/prevention & control , Meningococcal Vaccines/immunology , Neisseria meningitidis/immunology , Serum Amyloid P-Component/immunology , Adjuvants, Immunologic/administration & dosage , Adjuvants, Immunologic/deficiency , Animals , Animals, Newborn , Antibodies, Bacterial/immunology , Antigens, Bacterial/genetics , Bacterial Load/drug effects , C-Reactive Protein/administration & dosage , C-Reactive Protein/deficiency , C-Reactive Protein/genetics , Female , Gene Expression , Immunity, Humoral/drug effects , Immunity, Innate/drug effects , Male , Meningitis, Meningococcal/immunology , Meningitis, Meningococcal/virology , Meningococcal Vaccines/administration & dosage , Meningococcal Vaccines/genetics , Mice , Mice, Knockout , Neisseria meningitidis/drug effects , Neisseria meningitidis/genetics , Ovalbumin/administration & dosage , Rats , Rats, Wistar , Serum Amyloid P-Component/administration & dosage , Serum Amyloid P-Component/deficiency , Serum Amyloid P-Component/genetics , VaccinationABSTRACT
A new immunoassay based on surface plasmon resonance (SPR) for the rapid, reproducible and sensitive determination of pentraxin-3 (PTX3) levels in human plasma has been developed and characterized. The method involves a 3-min flow of plasma over a sensor chip pre-coated with a monoclonal anti-PTX3 antibody (MNB4), followed by a 3-min flow of a polyclonal anti-PTX3 antibody (pAb), required for specific recognition of captured PTX3. The SPR signal generated with this secondary antibody linearly correlates with the plasma PTX3 concentration, in the range of 5-1500 ng/mL, with a lowest limit of detection of 5 ng/mL. The PTX3 concentrations determined with the SPR-based immunoassay in the plasma of 21 patients with sepsis, ranging 15-1600 ng/mL, were superimposable to those found in a classic ELISA immunoassay. Since the PTX3 concentration in the plasma of healthy subjects is <2 ng/mL, but markedly rises in certain medical conditions, the method is useful to quantify pathological levels of this important biomarker, with important diagnostic applications. In comparison with the classic ELISA, the SPR-based approach is much faster (30 min versus 4-5 h) and could be exploited for the development of new cost-effective SPR devices for point-of-care diagnosis.
Subject(s)
Biosensing Techniques/instrumentation , Blood Chemical Analysis/instrumentation , C-Reactive Protein/analysis , Immunoassay/instrumentation , Serum Amyloid P-Component/analysis , Surface Plasmon Resonance/instrumentation , Computer Systems , Equipment Design , Equipment Failure Analysis , Humans , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
Immunity in the urinary tract has distinct and poorly understood pathophysiological characteristics and urinary tract infections (UTIs) are important causes of morbidity and mortality. We investigated the role of the soluble pattern recognition molecule pentraxin 3 (PTX3), a key component of the humoral arm of innate immunity, in UTIs. PTX3-deficient mice showed defective control of UTIs and exacerbated inflammation. Expression of PTX3 was induced in uroepithelial cells by uropathogenic Escherichia coli (UPEC) in a Toll-like receptor 4 (TLR4)- and MyD88-dependent manner. PTX3 enhanced UPEC phagocytosis and phagosome maturation by neutrophils. PTX3 was detected in urine of UTI patients and amounts correlated with disease severity. In cohorts of UTI-prone patients, PTX3 gene polymorphisms correlated with susceptibility to acute pyelonephritis and cystitis. These results suggest that PTX3 is an essential component of innate resistance against UTIs. Thus, the cellular and humoral arms of innate immunity exert complementary functions in mediating resistance against UTIs.
Subject(s)
C-Reactive Protein/metabolism , Escherichia coli Infections/immunology , Escherichia coli/immunology , Neutrophils/immunology , Pyelonephritis/immunology , Receptors, Pattern Recognition/metabolism , Serum Amyloid P-Component/metabolism , Urinary Tract Infections/immunology , Animals , C-Reactive Protein/genetics , Cell Line , Child , DNA Mutational Analysis , Disease Models, Animal , Escherichia coli Infections/complications , Female , Genetic Predisposition to Disease , Genotype , Humans , Immunity, Innate , Mice , Mice, Inbred C57BL , Mice, Knockout , Myeloid Differentiation Factor 88/genetics , Myeloid Differentiation Factor 88/metabolism , Neutrophils/microbiology , Phagocytosis , Polymorphism, Genetic , Pyelonephritis/etiology , Receptors, Pattern Recognition/genetics , Serum Amyloid P-Component/genetics , Sweden , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/metabolism , Urinary Tract Infections/complicationsABSTRACT
Long pentraxin 3 (PTX3) is a conserved pattern-recognition secreted protein and a host-defence-related component of the humoral innate immune system. The aim of the present study was to characterize swine PTX3 (SwPTX3) protein expression in influenza virus infected pigs. First, we performed in silico studies to evaluate the cross-reactivity of PTX3 human antibodies against SwPTX3. Secondly, we used in vitro analysis to detect SwPTX3 presence in swine bone marrow dendritic cells (SwBMDC) upon stimulation with different agents by Western blot and immunofluorescence. Finally, the levels of SwPTX3 were assessed in experimental infection of pigs with different strains of influenza virus. This is a novel study where the expression of SwPTX3 was evaluated in the context of a pathogen infection. The initial characterization of SwPTX3 in influenza virus infected pigs contributes to understand the role of PTX proteins in the immune response.
Subject(s)
C-Reactive Protein/genetics , C-Reactive Protein/immunology , Gene Expression Regulation/immunology , Orthomyxoviridae Infections/veterinary , Orthomyxoviridae/immunology , Serum Amyloid P-Component/genetics , Serum Amyloid P-Component/immunology , Swine Diseases/immunology , Amino Acid Sequence , Animals , Antibodies, Viral/metabolism , Cross Reactions/immunology , Dendritic Cells/virology , Immunity, Innate , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/pathology , Orthomyxoviridae Infections/virology , Sequence Alignment , Swine , Swine Diseases/pathology , Swine Diseases/virologyABSTRACT
Inflammation is a component of glioma microenvironment. PTX3 is a component of the humoral arm of innate immunity and a candidate marker of inflammation. In the present study we assessed the expression of PTX3 in gliomas by immunohistochemistry. PTX3 expression differed across low and high-grade tumors based on histopathological diagnosis and clinical severity, positively correlating with tumor grade and severity. In a multivariate logistic regression model, only the PTX3 score was significantly associated with the presence of a high-grade tumor. Thus, PTX3 may represent a new marker of cancer-related inflammation and glioma malignancy.
Subject(s)
Brain Neoplasms/immunology , C-Reactive Protein/immunology , Encephalitis/immunology , Glioblastoma/immunology , Oligodendroglioma/immunology , Serum Amyloid P-Component/immunology , Adult , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , C-Reactive Protein/genetics , C-Reactive Protein/metabolism , DNA Modification Methylases/genetics , DNA Repair Enzymes/genetics , Encephalitis/metabolism , Encephalitis/pathology , Female , Glioblastoma/metabolism , Glioblastoma/pathology , Humans , Logistic Models , Macrophages/immunology , Male , Middle Aged , Multivariate Analysis , Neoplasm Grading , Oligodendroglioma/metabolism , Oligodendroglioma/pathology , Predictive Value of Tests , Prognosis , Serum Amyloid P-Component/genetics , Serum Amyloid P-Component/metabolism , Severity of Illness Index , Tumor Suppressor Proteins/geneticsABSTRACT
Pattern recognition molecules (PRMs) are components of the humoral arm of innate immunity; they recognize pathogen-associated molecular patterns (PAMP) and are functional ancestors of antibodies, promoting complement activation, opsonization, and agglutination. In addition, several PRMs have a regulatory function on inflammation. Pentraxins are a family of evolutionarily conserved PRMs characterized by a cyclic multimeric structure. On the basis of structure, pentraxins have been operationally divided into short and long families. C-reactive protein (CRP) and serum amyloid P component are prototypes of the short pentraxin family, while pentraxin 3 (PTX3) is a prototype of the long pentraxins. PTX3 is produced by somatic and immune cells in response to proinflammatory stimuli and Toll-like receptor engagement, and it interacts with several ligands and exerts multifunctional properties. Unlike CRP, PTX3 gene organization and regulation have been conserved in evolution, thus allowing its pathophysiological roles to be evaluated in genetically modified animals. Here we will briefly review the general properties of CRP and PTX3 as prototypes of short and long pentraxins, respectively, emphasizing in particular the functional role of PTX3 as a prototypic PRM with antibody-like properties.
Subject(s)
C-Reactive Protein/immunology , Immunity, Humoral , Serum Amyloid P-Component/immunology , Animals , C-Reactive Protein/chemistry , C-Reactive Protein/genetics , Humans , Serum Amyloid P-Component/chemistry , Serum Amyloid P-Component/genetics , Translational Research, BiomedicalABSTRACT
Innate immunity represents the first line of defence against pathogens and plays key roles in activation and orientation of the adaptive immune response. The innate immune system comprises both a cellular and a humoral arm. Components of the humoral arm include soluble pattern recognition molecules (PRMs) that recognise pathogens associated molecular patterns (PAMPs) and initiate the immune response in coordination with the cellular arm, therefore acting as functional ancestors of antibodies. The long pentraxin PTX3 is a prototypic soluble PRM that is produced at sites of infection and inflammation by both somatic and immune cells. Gene targeting of this evolutionarily conserved protein has revealed a non-redundant role in resistance to selected pathogens. Moreover, PTX3 exerts important functions at the crossroad between innate immunity, inflammation and female fertility. Here we review the studies on PTX3, with emphasis on pathogen recognition and crosstalk with other components of the innate immune system.
Subject(s)
C-Reactive Protein/genetics , C-Reactive Protein/immunology , Immunity, Humoral/immunology , Immunity, Innate/immunology , Inflammation/immunology , Serum Amyloid P-Component/genetics , Serum Amyloid P-Component/immunology , HumansABSTRACT
Chronic lung infections by Pseudomonas aeruginosa strains are a major cause of morbidity and mortality in cystic fibrosis (CF) patients. Although there is no clear evidence for a primary defect in the immune system of CF patients, the host is generally unable to clear P. aeruginosa from the airways. PTX3 is a soluble pattern recognition receptor that plays nonredundant roles in the innate immune response to fungi, bacteria, and viruses. In particular, PTX3 deficiency is associated with increased susceptibility to P. aeruginosa lung infection. To address the potential therapeutic effect of PTX3 in P. aeruginosa lung infection, we established persistent and progressive infections in mice with the RP73 clinical strain RP73 isolated from a CF patient and treated them with recombinant human PTX3. The results indicated that PTX3 has a potential therapeutic effect in P. aeruginosa chronic lung infection by reducing lung colonization, proinflammatory cytokine levels (CXCL1, CXCL2, CCL2, and IL-1ß), and leukocyte recruitment in the airways. In models of acute infections and in in vitro assays, the prophagocytic effect of PTX3 was maintained in C1q-deficient mice and was lost in C3- and Fc common γ-chain-deficient mice, suggesting that facilitated recognition and phagocytosis of pathogens through the interplay between complement and FcγRs are involved in the therapeutic effect mediated by PTX3. These data suggested that PTX3 is a potential therapeutic tool in chronic P. aeruginosa lung infections, such as those seen in CF patients.
Subject(s)
C-Reactive Protein/therapeutic use , Immunologic Factors/therapeutic use , Pseudomonas Infections/drug therapy , Pseudomonas aeruginosa/immunology , Respiratory Tract Infections/drug therapy , Serum Amyloid P-Component/therapeutic use , Animals , Chronic Disease , Fluorescent Antibody Technique , Humans , Male , Mice , Mice, Inbred C57BL , Pseudomonas Infections/immunology , Respiratory Tract Infections/immunologyABSTRACT
Acute lung injury and acute respiratory distress syndrome (ALI/ARDS) are severe forms of bilateral lung inflammation with poor clinical outcomes. However, the pathophysiology of ALI/ARDS remains largely obscure. Soluble receptor for advanced glycation endproducts (sRAGE) plays a key regulatory role during the acute phase of inflammation, and baseline plasma levels of sRAGE were recently found to be associated with severity of ALI/ARDS. We analyzed, in ALI/ARDS patients, plasma and alveolar levels of sRAGE over time and the association with severity of lung injury. We enrolled 21 ALI/ARDS patients admitted to our intensive care unit (ICU) and assayed plasma sRAGE on the first 2 days after diagnosis, every three days for the first month and then once a week, until ICU discharge or death. We also measured sRAGE levels in bronchoalveolar lavage fluids, obtained when clinically indicated. At each sampling time, we recorded physiological and clinical data of the patients. Plasma sRAGE levels peaked at day 1 and decreased over time. When all samples were considered, plasma and alveolar sRAGE levels were significantly higher in patients with worse oxygenation and higher need for ventilatory support (i.e., patients with more severe lung dysfunction). Moreover, the presence of lung infection yielded higher alveolar sRAGE levels. In conclusion, we show that the plasma and alveolar levels of sRAGE in ALI/ARDS patients are correlated to lung injury severity and to lung infection. Our findings may, in time, lead to the development of more effective therapies against ALI/ARDS.
Subject(s)
Pulmonary Alveoli/metabolism , Receptors, Immunologic/metabolism , Respiratory Distress Syndrome/metabolism , Aged , Biomarkers/analysis , Biomarkers/metabolism , Bronchoalveolar Lavage Fluid/chemistry , C-Reactive Protein/analysis , Female , Humans , Male , Middle Aged , Pulmonary Alveoli/physiopathology , Receptor for Advanced Glycation End Products , Receptors, Immunologic/analysis , Respiratory Distress Syndrome/physiopathology , Respiratory Function Tests , Serum Amyloid P-Component/analysis , Severity of Illness IndexABSTRACT
Pentraxins are a superfamily of conserved proteins involved in the acute-phase response and innate immunity. Pentraxin 3 (PTX3), a prototypical member of the long pentraxin subfamily, is a key component of the humoral arm of innate immunity that is essential for resistance to certain pathogens. A regulatory role for pentraxins in inflammation has long been recognized, but the underlying mechanisms remain unclear. Here we report that PTX3 bound P-selectin and attenuated neutrophil recruitment at sites of inflammation. PTX3 released from activated leukocytes functioned locally to dampen neutrophil recruitment and regulate inflammation. Antibodies have glycosylation-dependent regulatory effect on inflammation. Therefore, PTX3, which is an essential component of humoral innate immunity, and immunoglobulins share functional outputs, including complement activation, opsonization and, as shown here, glycosylation-dependent regulation of inflammation.