Potent anti-inflammatory activity of the lectin-like domain of TNF in joints.

In view of the crucial role of tumor necrosis factor (TNF) in joint destruction, TNF inhibitors, including neutralizing anti-TNF antibodies and soluble TNF receptor constructs, are commonly used therapeutics for the treatment of arthropathies like rheumatoid arthritis (RA). However, not all patients achieve remission; moreover, there is a risk of increased susceptibility to infection with these agents. Spatially distinct from its receptor binding sites, TNF harbors a lectin-like domain, which exerts unique functions that can be mimicked by the 17 residue solnatide peptide. This domain binds to specific oligosaccharides such as N'N'-diacetylchitobiose and directly target the α subunit of the epithelial sodium channel. Solnatide was shown to have anti-inflammatory actions in acute lung injury and glomerulonephritis models. In this study, we evaluated whether the lectin-like domain of TNF can mitigate the development of immune-mediated arthritis in mice. In an antigen-induced arthritis model, solnatide reduced cell influx and release of pro-inflammatory mediators into the joints, associated with reduction in edema and tissue damage, as compared to controls indicating that TNF has anti-inflammatory effects in an acute model of joint inflammation via its lectin-like domain.

Pulmonary macrophages and their different roles in health and disease.

Macrophages are a heterogeneous population of myeloid cells with phenotype and function modulated according to the microenvironment in which they are found. The lung resident macrophages known as Alveolar Macrophages (AM) and Interstitial Macrophages (IM) are localized in two different compartments. During lung homeostasis, macrophages can remove inhaled particulates, cellular debris and contribute to some metabolic processes. Macrophages may assume a pro-inflammatory phenotype after being classically activated (M1) or anti-inflammatory when being alternatively activated (M2). M1 and M2 have different transcription profiles and act by eliminating bacteria, viruses and fungi from the host or repairing the damage triggered by inflammation, respectively. Nevertheless, macrophages also may contribute to lung damage during persistent inflammation or continuous exposure to antigens. In this review, we discuss the origin and function of pulmonary macrophages in the context of homeostasis, infectious and non-infectious lung diseases.

Biological Characterization of Commercial Recombinantly Expressed Immunomodulating Proteins Contaminated with Bacterial Products in the Year 2020: The SAA3 Case.

The serum amyloid A (SAA) gene family is highly conserved and encodes acute phase proteins that are upregulated in response to inflammatory triggers. Over the years, a considerable amount of literature has been published attributing a wide range of biological effects to SAAs such as leukocyte recruitment, cytokine and chemokine expression and induction of matrix metalloproteinases. Furthermore, SAAs have also been linked to protumorigenic, proatherogenic and anti-inflammatory effects. Here, we investigated the biological effects conveyed by murine SAA3 (mu rSAA3) recombinantly expressed in Escherichia coli. We observed the upregulation of a number of chemokines including CCL2, CCL3, CXCL1, CXCL2, CXCL6 or CXCL8 following stimulation of monocytic, fibroblastoid and peritoneal cells with mu rSAA3. Furthermore, this SAA variant displayed potent in vivo recruitment of neutrophils through the activation of TLR4. However, a major problem associated with proteins derived from recombinant expression in bacteria is potential contamination with various bacterial products, such as lipopolysaccharide, lipoproteins and formylated peptides. This is of particular relevance in the case of SAA as there currently exists a discrepancy in biological activity between SAA derived from recombinant expression and that of an endogenous source, i.e. inflammatory plasma. Therefore, we subjected commercial recombinant mu rSAA3 to purification to homogeneity via reversed-phase high-performance liquid chromatography (RP-HPLC) and re-assessed its biological potential. RP-HPLC-purified mu rSAA3 did not induce chemokines and lacked in vivo neutrophil chemotactic activity, but retained the capacity to synergize with CXCL8 in the activation of neutrophils. In conclusion, experimental results obtained when using proteins recombinantly expressed in bacteria should always be interpreted with care.

Serum Amyloid A1 (SAA1) Revisited: Restricted Leukocyte-Activating Properties of Homogeneous SAA1.

Infection, sterile injury, and chronic inflammation trigger the acute phase response in order to re-establish homeostasis. This response includes production of positive acute phase proteins in the liver, such as members of the serum amyloid A (SAA) family. In humans the major acute phase SAAs comprise a group of closely related variants of SAA1 and SAA2. SAA1 was proven to be chemotactic for several leukocyte subtypes through activation of the G protein-coupled receptor FPRL1/FPR2. Several other biological activities of SAA1, such as cytokine induction, reported to be mediated via TLRs, have been debated recently. Especially commercial SAA1, recombinantly produced in Escherichia coli, was found to be contaminated with bacterial products confounding biological assays performed with this rSAA1. We purified rSAA1 by RP-HPLC to homogeneity, removing contaminants such as lipopolysaccharides, lipoproteins and formylated peptides, and re-assessed several biological activities attributed to SAA1 (chemotaxis, cytokine induction, MMP-9 release, ROS generation, and macrophage differentiation). The homogeneous rSAA1 (hrSAA1) lacked most cell-activating properties, but its leukocyte-recruiting capacity in vivo and it's in vitro synergy with other leukocyte attractants remained preserved. Furthermore, hrSAA1 maintained the ability to promote monocyte survival. This indicates that pure hrSAA1 retains its potential to activate FPR2, whereas TLR-mediated effects seem to be related to traces of bacterial TLR ligands in the E. coli-produced human rSAA1.

Avaliação da qualidade de saneantes clandestinos comercializados em Belo Horizonte, Minas Gerais / Assessment of the quality of unlicensed home-made sanitizing products sold in Belo Horizonte, Minas Gerais

Os saneantes representam uma variedade de agentes de limpeza, incluindo os desinfetantes. Os saneantes clandestinos não passam por nenhum tipo de avaliação quanto à eficácia e possíveis contaminações, portanto o consumidor não tem segurança ao utilizá-lo. Este trabalho teve por objetivo analisar amostras de saneantes clandestinos comercializadas quanto aos parâmetros de rotulagem, qualidade microbiológica e físico-química e a avaliação da eficácia. A contagem de micro-organismos e a pesquisa de patógenos foram determinadas conforme indicado na Farmacopéia Brasileira. A avaliação da eficácia das amostras foi realizada pela determinação da atividade antimicrobiana de produtos desinfetantes por meio da redução da carga microbiana frente a micro-organismos patogênicos. 91% das amostras apresentaram rótulos em desacordo com a Legislação. O teste de Capacidade Inibitória indicou que, para inibir possíveis contaminações, os saneantes clandestinos possuem maior quantidade de princípio ativo do que o indicado nos rótulos e do que o determinado pela Legislação. Além disso, nove amostras apresentaram como princípio ativo o formaldeído, conservante banido das formulações de desinfetantes. Nove amostras apresentaram contaminação por bactérias e/ou fungos. O teste de eficácia indicou que aproximadamente 50% das amostras não foram eficazes contra micro-organismos testados e que não houve redução da carga microbiana nos tempos testados. As amostras analisadas podem oferecer riscos aos consumidores e fabricantes, uma vez que os resultados indicaram que o processo de produção não segue as Boas Práticas de Fabricação, além de serem importantes para reafirmar as ações preventivas, na conscientização dos fabricantes e consumidores pela busca de produtos de qualidade.

The term sanitizer includes a variety of cleaning agents, including disinfectants. Unlicensed home-made sanitizing products do not undergo any kind of quality control to attest to their effectiveness and lack of contamination, so do not ensure consumer safety. Therefore, the aim of this study was to analyze samples of clandestine home-made sanitizers sold in the local market, to check microbiological and physicochemical quality and labeling and assess their effectiveness. Total viable counts of microorganisms and pathogens were determined as indicated in the Brazilian Pharmacopoeia. Effectiveness was assessed by challenging the product with pathogenic microorganisms and antimicrobialactivity was determined by the reduction of the bacterial load. Results showed that 91% of the samples had labels violating current legislation. The analysis indicated that, to guarantee inhibitory capacity, home-made sanitizers had a higher level of active ingredient than indicated on their labels and than allowed by legislation. In addition, nine samples had formaldehyde as the active ingredient, a preservative banned as a component of disinfectants. Nine samples were contaminated by bacteria and/or fungi. The antimicrobial challenge test showed that approximately 50% of the samples were ineffective against the microorganisms tested, with no reduction in the microbial load. The present study points to home-made sanitizers as risks to consumers and manufacturers. Results indicate that the production process does not follow Good Manufacturing Practice, hence they are very significant in reaffirming preventive practices and making manufacturers and consumers aware of the need to seek products of certified quality.