Human neutrophil elastase inhibitors: Classification, biological-synthetic sources and their relevance in related diseases.

BACKGROUND: Human neutrophil elastase is a multifunctional protease enzyme whose function is to break the bonds of proteins and degrade them to polypeptides or amino acids. In addition, it plays an essential role in the immune mechanism against bacterial infections and represents a key mediator in tissue remodeling and inflammation. However, when the extracellular release of this enzyme is dysregulated in response to low levels of its physiological inhibitors, it ultimately leads to the degradation of proteins, in particular elastin, as well as other components of the extracellular matrix, producing injury to epithelial cells, which can promote sustained inflammation and affect the innate immune system, and, therefore, be the basis for the development of severe inflammatory diseases, especially those associated with the cardiopulmonary system. OBJECTIVE: This review aims to provide an update on the elastase inhibitory properties of several molecules, either synthetic or biological sources, as well as their classification and relevance in related pathologies since a clear understanding of the function of these molecules with the inhibitory capacity of this protease can provide valuable information for the development of pharmacological therapies that manage to modify the prognosis and survival of various inflammatory diseases. METHODS: Collected data from scientific databases, including PubMed, Google Scholar, Science Direct, Nature, Wiley, Scopus, and Scielo. Articles published in any country and language were included. RESULTS: We reviewed and included 132 articles conceptualizing neutrophil elastase activity and known inhibitors. CONCLUSION: Understanding the mechanism of action of elastase inhibitors based on particular aspects such as their kinetic behavior, structure-function relationship, chemical properties, origin, pharmacodynamics, and experimental progress has allowed for a broad classification of HNE inhibitors.

Molecular Bases of Protein Antigenicity and Determinants of Immunogenicity, Anergy, and Mitogenicity.

BACKGROUND: The immune system is able to recognize substances that originate from inside or outside the body and are potentially harmful. Foreign substances that bind to immune system components exhibit antigenicity and are defined as antigens. The antigens exhibiting immunogenicity can induce innate or adaptive immune responses and give rise to humoral or cell-mediated immunity. The antigens exhibiting mitogenicity can cross-link cell membrane receptors on B and T lymphocytes leading to cell proliferation. All antigens vary greatly in physicochemical features such as biochemical nature, structural complexity, molecular size, foreignness, solubility, and so on. OBJECTIVE: Thus, this review aims to describe the molecular bases of protein-antigenicity and those molecular bases that lead to an immune response, lymphocyte proliferation, or unresponsiveness. CONCLUSION: The epitopes of an antigen are located in surface areas; they are about 880-3,300 Da in size. They are protein, carbohydrate, or lipid in nature. Soluble antigens are smaller than 1 nm and are endocytosed less efficiently than particulate antigens. The more the structural complexity of an antigen increases, the more the antigenicity increases due to the number and variety of epitopes. The smallest immunogens are about 4,000-10,000 Da in size. The more phylogenetically distant immunogens are from the immunogen-recipient, the more immunogenicity increases. Antigens that are immunogens can trigger an innate or adaptive immune response. The innate response is induced by antigens that are pathogen-associated molecular patterns. Exogenous antigens, T Dependent or T Independent, induce humoral immunogenicity. TD protein-antigens require two epitopes, one sequential and one conformational to induce antibodies, whereas, TI non-protein-antigens require only one conformational epitope to induce low-affinity antibodies. Endogenous protein antigens require only one sequential epitope to induce cell-mediated immunogenicity.

Immunomodulatory Activity of Diterpenes over Innate Immunity and Cytokine Production in a Human Alveolar Epithelial Cell Line Infected with Mycobacterium tuberculosis.

BACKGROUND: Mexico has the largest number of the genus salvia plant species, whose main chemical compounds of this genus are diterpenes, these chemical compounds have shown important biological activities such as: antimicrobial, anti-inflammatory and immunomodulatory. OBJECTIVE: This study aimed to evaluate the immunomodulatory activity of three diterpenes: 1) icetexone, 2) anastomosine and 3) 7,20-dihydroanastomosine, isolated from Salvia ballotiflora, over innate immunity and cytokine production in a human alveolar epithelial cell line infected with Mycobacterium tuberculosis. METHODS: The immunomodulatory activity of diterpenes over innate immunity included reactive oxygen and nitrogen species (ROS and RNS) induction in response to infection; cytokine production included TNF-α and TGF-ß induction in response to infection. RESULTS: The diterpenes anastomosine and 7,20-dihydroanastomosine showed a statically significant (p < 0.01) increase of RNS after 36 h of infection and treatment of 2.0 µg/mL. Then, the ROS induction in response to infection showed a consistent statically significant (p < 0.01) increase after 12 h of diterpenes treatments. The cell cultures showed an anti-inflammatory effect, in the case of TGF-ß induction, in response to infection when treated with the diterpenes. On the other hand, there was not any significant effect on TNF-α release. CONCLUSION: The diterpenes anastomosine and 7,20-dihydroanastomosine increased the production of RNS after 36 h of infection and treatment. Besides, the three diterpenes increased the production of ROS after 12 h. This RNS and ROS modulation can be considered as an in vitro correlation of innate immunity in response to Mycobacterium tuberculosis infection; and an indicator of the damage of epithelial lung tissue. This study also showed an anti-inflammatory immune response by means of TGF-ß modulation when compared with control group.

Tannic Acid, as a Structural Moiety Coupled to a Protein Antigen, Exhibiting a Molecular-structure Adjuvant Activity for Antibody Specificity Enhancement.

BACKGROUND: An antigen is a small foreign substance, such as a microorganism structural protein, that may trigger an immune response once inside the body. Antigens are preferentially used rather than completely attenuated microorganisms to develop safe vaccines. Unfortunately, not all antigens are able to induce an immune response. Thus, new adjuvants to enhance the antigen's ability to stimulate immunity must be developed. OBJECTIVES: Therefore, this work aimed to evaluate the molecular-structure adjuvant activity of tannic acid (TA) coupled to a protein antigen in Balb/c mice. METHODS: Bovine serum albumin (BSA) was used as an antigen. The coupling of BSA and TA was mediated by carbodiimide crosslinking, and verified by SDS-PAGE. Forty-two Balb/c mice were divided into seven groups, including two controls without antigen, an antigen control, an adjuvant control, and two treatment groups. An additional group was used for macrophages isolation. A 30-day scheme was used to immunize the mice. The analysis of humoral immunity included immunoglobulin quantification, isotyping and antigen-antibody precipitation. The analysis of cell-mediated immunity included the quantification of nitric oxide from peritoneal macrophages and splenocytes' proliferation assay after treatment stimulation. RESULTS: No differences were found in the antibodies' concentration or isotypes induced with the conjugate or the pure BSA. However, an immunogenicity improvement (p < 0.05) was observed through the specific anti-BSA antibody titers in mice immunized with the conjugate. Besides, macrophage activation (p < 0.05) was detected when stimulated with the treatments containing TA. CONCLUSION: Tannic acid exhibited macrophages' activation properties. Moreover, when TA was incorporated into the structure of a protein antigen, such as BSA, an antibody specificity enhancement was observed. This was a consequence of antigen processing by activated antigen-presenting cells. These results showed the use of tannic acid as a novel candidate for vaccine molecular-structure adjuvant.

Tannic Acid Exhibits Adjuvant Activity by Enhancing Humoral and Cell-Mediated Immunity Against BSA as a Protein Antigen.

BACKGROUND: Immunization or vaccination is the process of inducing artificial immunity against an antigen taking advantage of the mechanisms of immunological memory. Current vaccines include substances known as adjuvants, which tend to improve the immunogenicity of the antigen, reduce the antigen quantity employed, and boost the immune response in weak responders. Unfortunately, only a few vaccine adjuvants are approved for human use. OBJECTIVE: Thus, the objective of this study was to investigate the effect of Tannic acid on humoral and cell-mediated immunity against bovine serum albumin (BSA) as a protein antigen in Wistar rats. METHODS: In order to establish the Tannic acid concentration to test it as an adjuvant, the lethal dose 50 and maximum non-toxic dose were calculated through cytotoxicity and hemolytic assays with J774 A.1 cell line and rat erythrocytes by resazurin reduction method and UV/vis spectrophotometry. Thirty Wistar rats were divided into 5 groups that included two controls without antigen and three treatment groups of adjuvants plus BSA as a protein antigen. The rats were immunized in a 30-day scheme. Blood samples were collected for humoral immunity analysis by means of immunoglobulin quantification, isotyping and antigen-antibody precipitation inhibition analysis. Rat peritoneal macrophages and splenocytes were isolated for cell-mediated immunity analysis by means of nitric oxide quantification from adjuvant stimulated peritoneal macrophages and lymphocytes proliferation assay. RESULTS: Tannic acid was capable of increasing the immunogenicity of the antigen; besides, it was able to stimulate cell-mediated immunity by means of increased lymphocyte proliferation. Moreover, Tannic acid improved the humoral response by means of increased specific antibodies titers. These activities may be attributed to pattern recognition receptors stimulation. CONCLUSION: Tannic acid was considered biocompatible when tested in vivo because the concentration tested did not show cytotoxicity or hemolytic effect, and there was no detrimental effect observed on the animals' health. These results show Tannic acid as a promising candidate for vaccine adjuvant.

Leptin G-2548A and Leptin Receptor Q223R Gene Polymorphisms are Differently Associated with Oxidative Process in Mexican Mestizo and Indigenous with Obesity.

Leptin levels and oxidative stress are implicated in obesity risk. Reports of association of leptin gene (LEP) and leptin receptor gene (LEPR) polymorphisms with leptin elevation are contradictory in a diverse population. Only a few studies report the linkage of obesity with biochemical markers and genetic factors. OBJECTIVE: The aim of this study was to examine whether plasma lipid peroxidation, antioxidant capability, leptin levels are associate selected LEP -2548 A/G and LEPR Q223R polymorphisms in mestizo and indigenous obesity Mexican population. METHODS: We identified and characterized 50 overweight or obese subjects and 50 healthy, normal- weight volunteers with indigenous Tepehuana or Mexican mestizo ethnicity from Durango, Mexico. LEP -2548 A/G and LEPR Q223R polymorphisms were determined by genotyping. Concentrations of leptin, antioxidant capacity (CA) and lipoperoxidation (LIPX) were determined in fast conditions on plasma with Enzyme-Linked ImmunoSorbent Assay (ELISA) in all participants. RESULTS: The highest genotype frequency was the heterozygous LEPR, which was associated with lipid peroxidation levels in normal-weight Tepehuan populations. A positive correlation was observed (r = 0.5; p <0.01) between LEP polymorphism and lipoperoxidation in normal weight Tepehuan subjects. On the other hand, the LEPR polymorphism was associated with the level of lipoperoxidation (r = 0.13; P <0.05) in mestizo populations of normal weight. CONCLUSION: It is probable that there is a synergistic effect for obesity, where the presence of oxidative stress and single nucleotide polymorphisms (SNP) of leptin and its receptor contributes to the generation of pathological subcutaneous fat of obesity, together with the environmental conditions of the populations.

Insights from Pharmaceutical Biotechnology into Phenolic Biopharmaceuticals against COVID-19.

BACKGROUND: The COVID-19 pandemic had infected more than 3.5M people around the world and more than 250K people died in 187 countries by May 2020. The causal agent of this disease is a coronavirus whose onset of symptoms to death range from 6 to 41 days with a median of 14 days. This period is dependent on several factors such as the presence of comorbidities, age and the efficiency of the innate or adaptive immune responses. METHODS: The effector mechanisms of both types of immune responses depend on the pathogen involved. In the case of a viral infection, the innate immune response may approach the harmful virus through pattern recognition receptors inducing an antiviral state. RESULTS: On the other hand, the adaptive immune response activates antibody production to neutralize or eliminate the virus. Phenolics are plant secondary metabolites with many biological activities for plants and humans against infection. Chemical modification of proteins may enhance their biological properties; thus, a protein of medical interest, for instance, a viral protein can be used as a scaffold to build a biopharmaceutical conjugated or complexated with phenolics exhibiting structural complexity or biological activities to achieve effective phenolic-protein-based therapeutics like vaccine adjuvant complexes, immunogen conjugates, and antiviral conjugates. CONCLUSION: Pharmaceutical biotechnology applies the principles of biotechnology to develop biopharmaceuticals for protein-based therapeutics; such as adjuvants, recombinant proteins, monoclonal antibodies, and antivirals. As neither a vaccine nor a treatment for COVID-19 is currently available, this manuscript focuses on insights from pharmaceutical biotechnology into phenolic biopharmaceuticals against COVID-19.

[The role of alexithymia as a psychosomatic factor in psoriasis]. / El papel de la alexitimia como factor psicosomático en la psoriasis.

BACKGROUND: Alexithymia is the lack of mental representations of emotions leading to limited ability to understand and regulate these and can contribute to the development or maintenance of a psychosomatic illness. The aim of the study was to demonstrate that alexithymia is a feature that occurs more frequently in patients with psoriasis and that the coexistence of alexitimia-psoriasis is associated with high levels of trait anxiety. METHODS: We applied the Toronto Alexithymia Scale -20 (TAS-20), Inventory of state-trait anxiety (STAI) to 16 outpatients with psoriasis of Dermatology Service of Hospital de Especialidades (Centro Médico Nacional Siglo XXI) and the results were compared with 25 control subjects. RESULTS: 25 % of patients with psoriasis presented alexitimia, while in the control group was 8 % (p = 0.002). Correlation between the scores of the TSA-20 and STAI-trait (r = 0.6957, p < 0.0001) was observed. CONCLUSIONS: The alexitimia occurs more frequently in individuals with psoriasis than in the general population, and levels of trait anxiety in individuals with psoriasis are similar regardless of the presence of alexithymia.

Introducción: la alexitimia consiste en la carencia de representaciones mentales de las emociones que conduce a una capacidad limitada para comprender y regular estas, y que puede contribuir en el desarrollo o mantenimiento de una enfermedad psicosomática. El objetivo de este estudio fue demostrar que la alexitimia es una característica que se presenta más frecuentemente en pacientes con psoriasis y que la coexistencia de alexitimia-psoriasis se asocia, como rasgo, a niveles altos de ansiedad. Métodos: la escala de alexitimia de Toronto-20 (TAS- 20) y el inventario de ansiedad estado-rasgo (IDARE) se aplicaron a 16 pacientes con psoriasis de la consulta externa de Dermatología del Hospital de Especialidades del Centro Médico Nacional Siglo XXI y se compararon con 25 individuos control. Resultados: de los pacientes con psoriasis, 25 % presentaron alexitimia, mientras que en el grupo control fue un 8 % (p = 0.002). Se observó correlación entre las puntuaciones de la TSA-20 y del IDARE-rasgo (r = 0.6957, p < 0.0001). Conclusiones: la alexitimia se presenta con mayor frecuencia en individuos con psoriasis que en la población en general y los niveles de ansiedad como rasgo en individuos con psoriasis son similares, independientemente de la presencia de alexitimia.