Low Concentration of the Neutrophil Proteases Cathepsin G, Cathepsin B, Proteinase-3 and Metalloproteinase-9 Induce Biofilm Formation in Non-Biofilm-Forming Staphylococcus epidermidis Isolates.

Neutrophils play a crucial role in eliminating bacteria that invade the human body; however, cathepsin G can induce biofilm formation in a non-biofilm-forming Staphylococcus epidermidis 1457 strain, suggesting that neutrophil proteases may be involved in biofilm formation. Cathepsin G, cathepsin B, proteinase-3, and metalloproteinase-9 (MMP-9) from neutrophils were tested on the biofilm induction in commensal (skin isolated) and clinical non-biofilm-forming S. epidermidis isolates. From 81 isolates, 53 (74%) were aap+, icaA−, icaD− genotype, and without the capacity of biofilm formation under conditions of 1% glucose, 4% ethanol or 4% NaCl, but these 53 non-biofilm-forming isolates induced biofilm by the use of different neutrophil proteases. Of these, 62.3% induced biofilm with proteinase-3, 15% with cathepsin G, 10% with cathepsin B and 5% with MMP -9, where most of the protease-induced biofilm isolates were commensal strains (skin). In the biofilm formation kinetics analysis, the addition of phenylmethylsulfonyl fluoride (PMSF; a proteinase-3 inhibitor) showed that proteinase-3 participates in the cell aggregation stage of biofilm formation. A biofilm induced with proteinase-3 and DNAse-treated significantly reduced biofilm formation at an early time (initial adhesion stage of biofilm formation) compared to untreated proteinase-3-induced biofilm (p < 0.05). A catheter inoculated with a commensal (skin) non-biofilm-forming S. epidermidis isolate treated with proteinase-3 and another one without the enzyme were inserted into the back of a mouse. After 7 days of incubation period, the catheters were recovered and the number of grown bacteria was quantified, finding a higher amount of adhered proteinase-3-treated bacteria in the catheter than non-proteinase-3-treated bacteria (p < 0.05). Commensal non-biofilm-forming S. epidermidis in the presence of neutrophil cells significantly induced the biofilm formation when multiplicity of infection (MOI) 1:0.01 (neutrophil:bacteria) was used, but the addition of a cocktail of protease inhibitors impeded biofilm formation. A neutrophil:bacteria assay did not induce neutrophil extracellular traps (NETs). Our results suggest that neutrophils, in the presence of commensal non-biofilm-forming S. epidermidis, do not generate NETs formation. The effect of neutrophils is the production of proteases, and proteinase-3 releases bacterial DNA at the initial adhesion, favoring cell aggregation and subsequently leading to biofilm formation.

Human Proteinase 3, an important autoantigen of c-ANCA associated vasculitis, shares cross-reactive epitopes with serine protease allergens from mites: an in silico analysis.

Background: In autoimmune vasculitis, autoantibodies to Human Proteinase 3 (PR3), a human serine protease, seems to have a role on the inception of c-ANCA associated vasculitis. The origin of this autoreactive response remains unclear. However, for several autoreactive responses, molecular mimicry between environmental antigens and human proteins is key to trigger autoantibodies and finally autoimmunity manifestations. Considering that PR3 is a serine protease and house dust mite (HDM) group 3 allergens share this biochemical activity, the aim of this study was to identify cross-reactive epitopes between serine proteases from human and mites using an in silico approach. Methods: Multi alignment among amino acid sequences of PR3 and HDM group 3 allergens was performed to explore identity and structural homology. ElliPro and BepiPred  in silico tools were used to predict B and T cell epitopes. Consurf tool was used to conduct identification of conserved regions in serine proteases family. Results: PR3 and HDM group 3 allergens shared moderate identity and structural homology (root mean square deviation < 1). One B cell cross reactive epitope among serine proteases was identified (29I, 30V, 31G, 32G, 34E, 36K, 37A, 38L, 39A and 54C) and two T cell epitopes. Conclusions: PR3 have structural homology and share cross reactive epitopes with HDM group 3 allergens.

Antineutrophil cytoplasmic antibodies in Chinese patients with tuberculosis

Abstract INTRODUCTION: Based on reports, infection with Mycobacterium tuberculosis is believed to induce the development of antibodies that are considered to be biological indicators for the diagnosis of some other diseases. However, conflicting results have been published regarding the presence of antineutrophil cytoplasmic antibodies (ANCAs) in patients with tuberculosis. We aim to study the seroprevalence of ANCA in a population of Chinese patients with tuberculosis, which may lead to the misdiagnosis of vasculitic disorders. METHODS: The study was conducted from January 2016 to May 2017 to evaluate the presence of ANCA in 103 Chinese patients using indirect immunofluorescent assay. An enzyme-linked immunosorbent assay was performed for anti-myeloperoxidase (MPO) and anti-proteinase 3 (PR3) detection. RESULTS: Perinuclear ANCA (p-ANCA) was detected in 4.8% (5/103) of patients, whereas cytoplasmic ANCA (c-ANCA) was not detected; 1.9% (2/103) of patients with tuberculosis was positive for anti-MPO antibodies, and none had anti-PR3 antibodies. Both anti-MPO-positive patients were diagnosed with ANCA-associated vasculitides. CONCLUSIONS: ANCA positivity may be more related to vasculitis and immunological disorders than to a M. tuberculosis infection. Therefore, to improve diagnostic accuracy, patients with M. tuberculosis who are ANCA positive should be investigated for concurrent diseases, including the effects of drugs. Therefore, even in tuberculosis epidemic area, ANCA seropositivity, detected by ELISA, is still more suggestive of ANCA-associated vasculitides.

Functional interrelationships between the kallikrein-related peptidases family and the classical kinin system in the human neutrophil.

In the human neutrophil, kallikrein-related peptidases (KLKs) have a significant functional relationship with the classical kinin system as a kinin B1 receptor agonist induces secretion of KLK1, KLK6, KLK10, KLK13 and KLK14 into the medium. Secretion of KLK1, the kinin-forming enzyme, may perpetuate formation of kinin in the inflammatory milieu by hydrolyzing extravasated kininogens present in tissue edema. Secretion of KLKs into the inflammatory milieu, induced by kinins or other proinflammatory mediators, provides the human neutrophil with a wide range of molecular interactions to hydrolyze different cellular and extracellular matrix components, which may be of critical relevance in different mechanisms involving inflammation.

Using a Caesalpinia echinata Lam. protease inhibitor as a tool for studying the roles of neutrophil elastase, cathepsin G and proteinase 3 in pulmonary edema.

Acute lung injury (ALI) is characterized by neutrophil infiltration and the release of proteases, mainly elastase (NE), cathepsin G (Cat G) and proteinase 3 (PR3), which can be controlled by specific endogenous inhibitors. However, inhibitors of these proteases have been isolated from different sources, including plants. For this study, CeEI, or Caesalpinia echinata elastase inhibitor, was purified from C. echinata (Brazil-wood) seeds after acetone fractionation, followed by ion exchange and reversed phase chromatographic steps. Characterization with SDS-PAGE, stability assays, amino acid sequencing and alignment with other protein sequences confirmed that CeEI is a member of the soybean Kunitz trypsin inhibitor family. Like other members of this family, CeEI is a 20 kDa monomeric protein; it is stable within a large pH and temperature range, with four cysteine residues forming two disulfide bridges, conserved amino acid residues and leucine-isoleucine residues in the reactive site. CeEI was able to inhibit NE and Cat G at a nanomolar range (with K(i)s of 1.9 and 3.6 nM, respectively) and inhibited PR3 within a micromolar range (K(i) 3.7 µM), leading to hydrolysis of specific synthetic substrates. In a lung edema model, CeEI reduced the lung weight and pulmonary artery pressure until 180 min after the injection of zymosan-activated polymorphonuclear neutrophils. In experiments performed in the presence of a Cat G and PR3, but not an NE inhibitor, lung edema was reduced only until 150 min and pulmonary artery pressure was similar to that of the control. These results confirm that NE action is crucial to edema establishment and progression. Additionally, CeEI appears to be a useful tool for studying the physiology of pulmonary edema and provides a template for molecular engineering and drug design for ALI therapy.

Detección de anticuerpos contra los antígenos de diferenciación tumoral proteinasa 3 (PR3) y mieloperoxidasa (MPO) en la leucemia promielocítica / Detection of antibodies to antigens of proteinase 3 (PR3) tumor differentiations and myeloperoxidase (MPO) in cases of promyelocytic leukemia

La leucemia promielocítica (LPM) subtipo M3 representa del 5-15 por ciento en la clasificación FAB de las leucemias mieloides agudas (LMA). Está asociada con características genéticas únicas que incluyen la translocación recíproca t(15;17)(q22;q12). El mecanismo por el que ocurre la t(15;17) no se conoce. Las leucemias de estirpe mieloide expresan diversos antígenos de diferenciación tumoral como son la proteinasa 3 (PR 3) y la mieloperoxidasa (MPO) que se encuentran sobreexpresados en el promielocito. Se plantea que participan en la maduración y en la regulación de la división celular. Existe poca información acerca de la respuesta inmune de pacientes con LPM dirigida contra las células tumorales. En nuestro trabajo se detectó la presencia de anticuerpos contra los antígenos de diferenciación tumoral PR3 y MPO en diferentes fases del tratamiento de la enfermedad, mediante inmunofluorescencia indirecta. Los anticuerpos anti PR3 y anti MPO se detectaron en aquellos pacientes sin tratar y en fase de inducción, no así en la consolidación y mantenimiento, de ahí su posible utilidad como marcadores de diferenciación celular(AU)

ABSTRACT Promyelocytic leukemia (PML) subtype M3 represents the 5-15 percent in the FAB classification of acute myeloid leukemias (AML). It is associated with the unique genetic features including the reciprocal t-translocation (15;17) (q22;q12). The mechanism of t is unknown. The myeloid leukemias express different tumoral differentiation antigens such as the proteinase 3 (PR 3) and myeloperoxidase (MPO) which are over-expressed in promyelocyte. It is involved in maturation and regulation of cell division. There is scarce information on the immune response of patients with PLM against tumor cells. In our paper we detected presence of antibodies to RP3 and MPO tumor differentiation antigens in different phases of disease treatment by indirect immunofluorescence. Anti-MPO and anti-PR3 antibodies were detected in those patients without treatment and in induction phase but not in the consolidation and maintenance, thus its potential usefulness as cellular differentiation markers(AU)

Detección de anticuerpos contra los antígenos de diferenciación tumoral proteinasa 3 (PR3) y mieloperoxidasa (MPO) en la leucemia promielocítica / Detection of antibodies to antigens of proteinase 3 (PR3) tumor differentiations and myeloperoxidase (MPO) in cases of promyelocytic leukemia

La leucemia promielocítica (LPM) subtipo M3 representa del 5-15 por ciento en la clasificación FAB de las leucemias mieloides agudas (LMA). Está asociada con características genéticas únicas que incluyen la translocación recíproca t(15;17)(q22;q12). El mecanismo por el que ocurre la t(15;17) no se conoce. Las leucemias de estirpe mieloide expresan diversos antígenos de diferenciación tumoral como son la proteinasa 3 (PR 3) y la mieloperoxidasa (MPO) que se encuentran sobreexpresados en el promielocito. Se plantea que participan en la maduración y en la regulación de la división celular. Existe poca información acerca de la respuesta inmune de pacientes con LPM dirigida contra las células tumorales. En nuestro trabajo se detectó la presencia de anticuerpos contra los antígenos de diferenciación tumoral PR3 y MPO en diferentes fases del tratamiento de la enfermedad, mediante inmunofluorescencia indirecta. Los anticuerpos anti PR3 y anti MPO se detectaron en aquellos pacientes sin tratar y en fase de inducción, no así en la consolidación y mantenimiento, de ahí su posible utilidad como marcadores de diferenciación celular.

ABSTRACT Promyelocytic leukemia (PML) subtype M3 represents the 5-15 percent in the FAB classification of acute myeloid leukemias (AML). It is associated with the unique genetic features including the reciprocal t-translocation (15;17) (q22;q12). The mechanism of t is unknown. The myeloid leukemias express different tumoral differentiation antigens such as the proteinase 3 (PR 3) and myeloperoxidase (MPO) which are over-expressed in promyelocyte. It is involved in maturation and regulation of cell division. There is scarce information on the immune response of patients with PLM against tumor cells. In our paper we detected presence of antibodies to RP3 and MPO tumor differentiation antigens in different phases of disease treatment by indirect immunofluorescence. Anti-MPO and anti-PR3 antibodies were detected in those patients without treatment and in induction phase but not in the consolidation and maintenance, thus its potential usefulness as cellular differentiation markers.