Nicotine promotes Mycobacterium tuberculosis H37Rv growth and overexpression of virulence genes.

Tobacco consumption increases the susceptibility to develop infectious diseases such as tuberculosis (TB). Nicotine (Nc) is the main component of cigarette smoke with immunomodulatory properties, however, its effect on Mycobacterium tuberculosis (Mtb) has been scarcely investigated. The present study evaluated the effect of nicotine on the growth of Mtb and on the induction of virulence-related genes. Mycobacteria were exposed to different concentrations of nicotine then Mtb growth was evaluated. Subsequently, the expression of the virulence-related genes lysX, pirG, fad26, fbpa, ompa, hbhA, esxA, esxB, hspx, katG, lpqh, and caeA was evaluated by RT-qPCR. The effect of nicotine on intracellular Mtb was also evaluated. The results showed that nicotine promotes the growth of Mtb both extracellularly and intracellularly and increases the expression of genes related to virulence. In summary, nicotine promotes the growth of Mtb and the expression of virulence-related genes that could be correlated with the increased the risk of smokers developing TB.

Downregulation of sCD40 and sCTLA4 in Recovered COVID-19 Patients with Comorbidities.

The aim of this study was to analyze molecules associated with regulatory immune response in unvaccinated, recovered COVID-19 patients with and without diabetes mellitus (DM) and hypertension (HTN). We determined anti-SARS-CoV-2 nucleocapsid IgG in plasma by electrochemiluminescence immunoassay. The levels of sCD40, TGF-ß, IL-10, and sCTLA-4 were assessed by ELISA in the serum of the subjects, as well as in healthy donors. We observed that only half of the subjects in the non-comorbid group produced antibodies, whereas all subjects in comorbid groups were IgG-positive for the anti-SARS-CoV-2 nucleocapsid. High levels of sCTL-4 were observed in the non-comorbid group, and the level of IL-10 was observed to increase in seropositive subjects without comorbidities. TGF-ß concentration was similar in all groups studied. Finally, sCD40 decreased in the comorbid group. In conclusion, our results suggest that comorbidities such as DM and HTN alter the production of co-stimulatory inhibitory molecules sCTLA-4 and sCD40 in subjects recovering from mild COVID-19. The alterations observed here were independent of seropositivity, suggesting an effective humoral immune response against COVID-19 separate from the levels of co-stimulatory inhibitory molecules.

Long-term exposure to particulate matter from air pollution alters airway ß-defensin-3 and -4 and cathelicidin host defense peptides production in a murine model.

Epidemiological studies have associated long-term exposure to environmental air pollution particulate matter (PM) with the development of diverse health problems. They include infectious respiratory diseases related to the deregulation of some innate immune response mechanisms, such as the host defense peptides' expression. Herein, we evaluated in BALB/c mice the effect of long-standing exposure (60 days) to urban-PM from the south of Mexico City, with aerodynamic diameters below 2.5 µm (PM2.5) and 10 µm (PM10) on the lung's gene expression and production of three host defense peptides (HDPs); murine beta-defensin-3, -4 (mBD-3, mBD-4) and cathelin-related antimicrobial peptide (CRAMP). We also evaluated mRNA levels of Il1b and Il10, two cytokines related to the expression of host defense peptides. Exposure to PM2.5 and PM10 differentially induced lung inflammation, being PM2.5, which caused higher inflammation levels, probably associated with a differential deposition on the airways, that facilitate the interaction with alveolar macrophages. Inflammation levels were associated with an early upregulation of the three HDPs assessed and an increment in Il1b mRNA levels. Interestingly, after 28 days of exposure, Il10 mRNA upregulation was observed and was associated with the downregulation of HDPs and Il1b mRNA levels. The upregulation of Il10 mRNA and suppression of HDPs might facilitate microbial colonization and the development of diseases associated with long-term exposure to PM.

Retinoic acid induces antimicrobial peptides and cytokines leading to Mycobacterium tuberculosis elimination in airway epithelial cells.

Tuberculosis (TB) is the leading cause of death by a single infectious agent, Mycobacterium tuberculosis (Mtb). Alveolar macrophages and respiratory epithelial cells are the first cells exposed to Mtb during the primary infection, once these cells are activated, secrete cytokines and antimicrobial peptides that are associated with the Mtb contention and elimination. Vitamins are micronutrients that function as boosters on the innate immune system, however, is unclear whether they have any protective activity during Mtb infection. Thus, we investigated the role of vitamin A (retinoic acid), vitamin C (ascorbic acid), vitamin D (calcitriol), and vitamin E (alfa-tocopherol) as inductors of molecules related to mycobacterial infection in macrophages and epithelial cells. Our results showed that retinoic acid promotes the expression of pro- and anti-inflammatory molecules such as Thymic stromal lymphopoietin (TSLP), ß-defensin-2, IL-1ß, CCL20, ß-defensin-3, Cathelicidin LL-37, TGF-ß, and RNase 7, whereas calcitriol, ascorbic acid, and α-tocopherol lead to an anti-inflammatory response. Treatment of Mtb-infected epithelial cells and macrophage-like cells with the vitamins showed a differential response, where calcitriol reduced Mtb in macrophages, while retinoic acid reduced infection in epithelial cells. Thereby, we propose that a combination of calcitriol and retinoic acid supplementation can drive the immune response, and promotes the Mtb elimination by increasing the expression of antimicrobial peptides and cytokines, while simultaneously modulating inflammation.

Lactococcus lactis NZ9000 Prevents Asthmatic Airway Inflammation and Remodelling in Rats through the Improvement of Intestinal Barrier Function and Systemic TGF-ß Production.

INTRODUCTION: The use of probiotics has been broadly popularized due to positive effects in the attenuation of aberrant immune responses such as asthma. Allergic asthma is a chronic respiratory disease characterized by airway inflammation and remodelling. OBJECTIVE: This study was aimed to evaluate the effect of oral administration of Lactococcus lactis NZ9000 on asthmatic airway inflammation and lung tissue remodelling in rats and its relation to the maintenance of an adequate intestinal barrier. METHODS: Wistar rats were ovalbumin (OVA) sensitized and challenged and orally treated with L. lactis. Lung inflammatory infiltrates and cytokines were measured, and remodelling was evaluated. Serum OVA-specific immunoglobulin (Ig) E levels were assessed. We also evaluated changes on intestinal environment and on systemic immune response. RESULTS: L. lactis diminished the infiltration of proinflammatory leucocytes, mainly eosinophils, in the bronchoalveolar compartment, decreased lung IL-4 and IL-5 expression, and reduced the level of serum allergen-specific IgE. Furthermore, L. lactis prevented eosinophil influx, collagen deposition, and goblet cell hyperplasia in lung tissue. In the intestine, L. lactis-treated asthmatic rats increased Peyer's patch and goblet cell quantity and mRNA expression of IgA, MUC-2, and claudin. Additionally, intestinal morphological alterations were normalized by L. lactis administration. Splenocyte proliferative response to OVA was abolished, and serum levels of transforming growth factor (TGF)-ß were increased by L. lactis treatment. CONCLUSIONS: These findings suggest that L. lactis is a potential candidate for asthma prevention, and the effect is mediated by the improvement of intestinal barrier function and systemic TGF-ß production.

Host Defense Peptide RNase 7 Is Down-regulated in the Skin of Diabetic Patients with or without Chronic Ulcers, and its Expression is Altered with Metformin.

BACKGROUND: Diabetic foot ulcers (DFUs) are one of the main complications in patients with type 2 diabetes mellitus (DM2), previous studies have reported that DM2 patients have lower production of host defense peptides (HDP). AIM OF THE STUDY: To investigate the expression of RNase 7, cathelicidin, HBD-2, and psoriasin in biopsies obtained from DM2 patients with or without DFU. METHODS: Biopsies from DFU patients grade 3 according to Wagner's classification, from diabetic patients without ulcer and from healthy donors were obtained. qPCR, immunohistochemistry and cell line cultures were performed. To assess whether L-isoleucine, calcitriol, phenyl butyrate, metformin, glyburide or insulin induced RNase 7, keratinocytes were stimulated, and RNase 7 expression was evaluated. RESULTS: Our data showed that RNase 7 levels were decreased in both diabetic groups when were compared with skin from healthy donors. Since most of the DM2 patients are treated with drugs to reduce glycemia, we investigated whether glyburide, metformin or insulin were able to induce any change regarding RNase 7 production. Results showed that metformin reduces the expression of RNase 7 in in vitro treated keratinocytes, suggesting that the chronic use of metformin should be evaluated in DFU patients, whereas calcitriol, phenyl butyrate and L-isoleucine did not increase the RNase 7 production. CONCLUSIONS: Due RNase 7 has antimicrobial activity, its downregulation can make prone to DM2 patients to develop infections and impaired wound healing.

Lipid Metabolism Alterations in a Rat Model of Chronic and Intergenerational Exposure to Arsenic.

Chronic exposure to arsenic (As), whether directly through the consumption of contaminated drinking water or indirectly through the daily intake of As-contaminated food, is a health threat for more than 150 million people worldwide. Epidemiological studies found an association between chronic consumption of As and several pathologies, the most common being cancer-related disorders. However, As consumption has also been associated with metabolic disorders that could lead to diverse pathologies, such as type 2 diabetes mellitus, nonalcoholic fatty liver disease, and obesity. Here, we used ultra-performance liquid chromatography (UPLC) coupled to electrospray ionization/quadrupole time-of-flight mass spectrometry (ESI-QToF) to assess the effect of chronic intergenerational As exposure on the lipid metabolism profiles of serum from 4-month-old Wistar rats exposed to As prenatally and also during early life in drinking water (3 ppm). Significant differences in the levels of certain identified lysophospholipids, phosphatidylcholines, and triglycerides were found between the exposed rats and the control groups, as well as between the sexes. Significantly increased lipid oxidation determined by the malondialdehyde (MDA) method was found in exposed rats compared with controls. Chronic intergenerational As exposure alters the rat lipidome, increases lipid oxidation, and dysregulates metabolic pathways, the factors associated with the chronic inflammation present in different diseases associated with chronic exposure to As (i.e., keratosis, Bowen's disease, and kidney, liver, bladder, and lung cancer).

Cervical cancer stem cells and other leading factors associated with cervical cancer development.

Cervical cancer (CC) is one of the leading causes of cancer-associated mortalities in women from developing countries. Similar to other types of cancer, CC is considered to be a multifactorial disease, involving socioeconomic, cultural, immunological and epigenetic factors, as well as persistent human papilloma virus (HPV) infection. It has been well established that cancer stem cells (CSCs) play an important role in defining tumor size, the speed of development and the level of regression following treatment; therefore, CSCs are associated with a poor prognosis. CSCs have been detected in many types of cancer, including leukemia, pancreatic, colon, esophagus, liver, prostate, breast, gastric and lung cancer. In cervical cancer, CSCs have been associated with resistance to normally used drugs such as cisplatin. The present review summarizes the strategies that high-risk HPV viruses (HPV-16 and HPV-18) have developed to transform normal epithelial cells into cancer cells, as well as the cellular pathways and studies associated with the identification of cervical cancer stem cell biomarkers. In this sense, the present review provides state of the art information regarding CC development.

Season and size of urban particulate matter differentially affect cytotoxicity and human immune responses to Mycobacterium tuberculosis.

Exposure to air pollution particulate matter (PM) and tuberculosis (TB) are two of the leading global public health challenges affecting low and middle income countries. An estimated 4.26 million premature deaths are attributable to household air pollution and an additional 4.1 million to outdoor air pollution annually. Mycobacterium tuberculosis (M.tb) infects a large proportion of the world's population with the risk for TB development increasing during immunosuppressing conditions. There is strong evidence that such immunosuppressive conditions develop during household air pollution exposure, which increases rates of TB development. Exposure to urban air pollution has been shown to alter the outcome of TB therapy. Here we examined whether in vitro exposure to urban air pollution PM alters human immune responses to M.tb. PM2.5 and PM10 (aerodynamic diameters <2.5µm, <10µm) were collected monthly from rainy, cold-dry and warm-dry seasons in Iztapalapa, a highly populated TB-endemic municipality of Mexico City with elevated outdoor air pollution levels. We evaluated the effects of seasonality and size of PM on cytotoxicity and antimycobacterial host immunity in human peripheral blood mononuclear cells (PBMC) from interferon gamma (IFN-γ) release assay (IGRA)+ and IGRA- healthy study subjects. PM10 from cold-dry and warm-dry seasons induced the highest cytotoxicity in PBMC. With the exception of PM2.5 from the cold-dry season, pre-exposure to all seasonal PM reduced M.tb phagocytosis by PBMC. Furthermore, M.tb-induced IFN-γ production was suppressed in PM2.5 and PM10-pre-exposed PBMC from IGRA+ subjects. This observation coincides with the reduced expression of M.tb-induced T-bet, a transcription factor regulating IFN-γ expression in T cells. Pre-exposure to PM10 compared to PM2.5 led to greater loss of M.tb growth control. Exposure to PM2.5 and PM10 collected in different seasons differentially impairs M.tb-induced human host immunity, suggesting biological mechanisms underlying altered M.tb infection and TB treatment outcomes during air pollution exposures.

La contaminación del aire atmosférico en la respuesta inmune innata antimicobacteriana / Atmospheric air pollution and innate antimycobacterial immunity

Indoor and outdoor air pollution has been considered a serious public health problem worldwide, and is associated annually with around 7 million deaths (4.8 million associated with outdoor air and 2.2 million indoor air). The main reasons for these deaths include: chronic obstructive pulmonary diseases, pneumonia, ischemic cardiopathy and lung cancer. In addition, epidemiological studies have associated exposure to this type of pollutants with a greater susceptibility to the development of infectious and non-infectious diseases. One of the most important infectious diseases is tuberculosis, which over the years has worsened with the emergence of resistant multi-drug strains, as well as with association with other diseases such as diabetes mellitus type 2 and the acquired immune deficiency syndrome (AIDS). In fact, despite efforts made by the World Health Organization to stop the epidemic, a large number of deaths (about 1.7 million worldwide) are still caused by this disease. In this review, a brief summary will be made of the effects of exposure to indoor and outdoor air pollution on the innate immune response against tuberculosis, and how these alterations could be linked to the development of pulmonary tuberculosis.

La contaminación del aire de interiores y de exteriores ha sido considerada un serio problema de salud pública a nivel mundial, el cual se asocia anualmente con alrededor de 7 millones de muertes (4.8 millones asociadas con el aire de exteriores y 2.2 millones con el aire de interiores). Entre las principales razones ligadas a estas muertes se encuentran: enfermedad pulmonar obstructiva crónica, neumonía, cardiopatía isquémica y cáncer de pulmón. Además, estudios epidemiológicos han asociado la exposición a este tipo de contaminantes con mayor susceptibilidad para la aparición de enfermedades infecciosas y no infecciosas. Entre las enfermedades infecciosas, una de las más importantes es la tuberculosis, la cual, durante el transcurso de los años, ha empeorado con el surgimiento de cepas resistentes a múltiples fármacos, así como por la asociación con otras afecciones como la diabetes mellitus tipo 2 y el síndrome de inmunodeficiencia adquirida (sida). A pesar del esfuerzo realizado por la Organización Mundial de la Salud (OMS) por detener esta epidemia, aún existen anualmente un gran número de muertes causadas por esta enfermedad: alrededor de 1.7 millones a nivel mundial. En esta revisión se hará un breve resumen de los efectos que tiene la exposición a la contaminación del aire de interiores y de exteriores en la respuesta inmune innata en contra de la tuberculosis, y cómo estas alteraciones pueden estar ligadas a la aparición de tuberculosis pulmonar.

Metabolomics applied to the discovery of tuberculosis and diabetes mellitus biomarkers.

Tuberculosis (TB) and diabetes mellitus Type 2 (DM2) are two diseases as ancient as they are harmful to human health. The outcome for both diseases in part depends on immune and metabolic individual responses. DM2 is increasing yearly, mainly due to environmental, genetic and lifestyle habits. There are multiple evidence that DM2 is one of the most important risk factor of becoming infected with TB or reactivating latent TB. Mass spectrometry-based metabolomics is an important tool for elucidating the metabolites and metabolic pathways that influence the immune responses to M. tuberculosis infection during diabetes. We provide an up-to-date review highlighting the importance and benefit of metabolomics for identifying biomarkers as candidate molecules for diagnosis, disease activity or prognosis.

RNase 7 but not psoriasin nor sPLA2-IIA associates with Mycobacterium tuberculosis during airway epithelial cell infection.

Tuberculosis is a disease caused by Mycobacterium tuberculosis (Mtb). Innate immunity is the first line of defense against Mtb and malfunctions in any of its components are associated with the susceptibility to the disease. Epithelial products such as host defense peptides (HDPs) are the first molecules produced to counteract the infection. Although a wide variety of HDPs are produced by epithelial cells only a few of them have been studied during Mtb infection. Here, we assessed the expression and production of the HDPs psoriasin, secreted phospholipases A2 (sPLA2-IIA) and Ribonuclease (RNase) 7 in airway epithelial cells (NCI-H292), type II pneumocytes (A549 cells) and monocyte-derived macrophages from human peripheral blood mononuclear cells and from the human cell line THP1 after Mtb in vitro infection. Results show that psoriasin and sPLA2-IIA were not induced by Mtb in any of the evaluated cells, while RNase 7 was overexpressed in infected airway epithelial cells. Intracellular analysis by flow cytometry demonstrated that the highest levels of RNase 7 were observed 6 h post-infection and the induction was dependent on direct interaction between airway epithelial cells and Mtb. In addition, analysis by electron microscopy showed that RNase 7 was capable of attaching to the cell wall of intracellular mycobacteria. Our studies suggest that the induction of RNase 7 in response to Mtb could have a role in anti-mycobacterial immunity, which needs to be studied as an innate immune mechanism.

Vitamin D and L-Isoleucine Promote Antimicrobial Peptide hBD-2 Production in Peripheral Blood Mononuclear Cells from Elderly Individuals.

Elderly individuals are susceptible to develop infectious diseases; promoting innate immunity to prevent infections is a key issue. Human ß-defensin-2 (hBD-2) is an antimicrobial peptide with antimicrobial and immunomodulatory properties. L-isoleucine and vitamin D are important molecules that induce hBD-2. The Aim of this study was to determine the use L-isoleucine and Vitamin D to induce hBD-2 in cells from healthy elderly individuals and elderly individuals with recurrent infections. We explored three groups: young adults (n = 20) used as control group, elderly adults (n = 18) and elderly with recurrent infections (n = 11). PBMCs (peripheral blood mononuclear cells) were isolated from the different groups and then were treated with L-isoleucine or vitamin D3. hBD-2 concentration was assessed with a sandwich enzyme Immunosorbent assay by triplicate. Using the vehicle as a mock control. Our results showed that a percentage of the individuals responded to the treatments producing hBD-2 (p < 0.05). These results showed that both molecules induced hBD-2 in elderly individuals and can be potentially used as prophylactic therapy to decrease infection diseases rates in this vulnerable group.

Modulation of Human Macrophage Responses to Mycobacterium tuberculosis by Silver Nanoparticles of Different Size and Surface Modification.

Exposure to silver nanoparticles (AgNP) used in consumer products carries potential health risks including increased susceptibility to infectious pathogens. Systematic assessments of antimicrobial macrophage immune responses in the context of AgNP exposure are important because uptake of AgNP by macrophages may lead to alterations of innate immune cell functions. In this study we examined the effects of exposure to AgNP with different particle sizes (20 and 110 nm diameters) and surface chemistry (citrate or polyvinlypyrrolidone capping) on cellular toxicity and innate immune responses against Mycobacterium tuberculosis (M.tb) by human monocyte-derived macrophages (MDM). Exposures of MDM to AgNP significantly reduced cellular viability, increased IL8 and decreased IL10 mRNA expression. Exposure of M.tb-infected MDM to AgNP suppressed M.tb-induced expression of IL1B, IL10, and TNFA mRNA. Furthermore, M.tb-induced IL-1ß, a cytokine critical for host resistance to M.tb, was inhibited by AgNP but not by carbon black particles indicating that the observed immunosuppressive effects of AgNP are particle specific. Suppressive effects of AgNP on the M.tb-induced host immune responses were in part due to AgNP-mediated interferences with the TLR signaling pathways that culminate in the activation of the transcription factor NF-κB. AgNP exposure suppressed M.tb-induced expression of a subset of NF-κB mediated genes (CSF2, CSF3, IFNG, IL1A, IL1B, IL6, IL10, TNFA, NFKB1A). In addition, AgNP exposure increased the expression of HSPA1A mRNA and the corresponding stress-induced Hsp72 protein. Up-regulation of Hsp72 by AgNP can suppress M.tb-induced NF-κB activation and host immune responses. The observed ability of AgNP to modulate infectious pathogen-induced immune responses has important public health implications.

Air pollution particulate matter alters antimycobacterial respiratory epithelium innate immunity.

Inhalation exposure to indoor air pollutants and cigarette smoke increases the risk of developing tuberculosis (TB). Whether exposure to ambient air pollution particulate matter (PM) alters protective human host immune responses against Mycobacterium tuberculosis has been little studied. Here, we examined the effect of PM from Iztapalapa, a municipality of Mexico City, with aerodynamic diameters below 2.5 µm (PM2.5) and 10 µm (PM10) on innate antimycobacterial immune responses in human alveolar type II epithelial cells of the A549 cell line. Exposure to PM2.5 or PM10 deregulated the ability of the A549 cells to express the antimicrobial peptides human ß-defensin 2 (HBD-2) and HBD-3 upon infection with M. tuberculosis and increased intracellular M. tuberculosis growth (as measured by CFU count). The observed modulation of antibacterial responsiveness by PM exposure was associated with the induction of senescence in PM-exposed A549 cells and was unrelated to PM-mediated loss of cell viability. Thus, the induction of senescence and downregulation of HBD-2 and HBD-3 expression in respiratory PM-exposed epithelial cells leading to enhanced M. tuberculosis growth represent mechanisms by which exposure to air pollution PM may increase the risk of M. tuberculosis infection and the development of TB.

Prophylactic potential of defensins and L-isoleucine in tuberculosis household contacts: an experimental model.

AIM: Patients with pulmonary tuberculosis (TB) are the most important source for TB infection, being the risk of infection determined by the source case infectiousness and the contact closeness. Currently, the administration of isoniazid is used to prevent the infection to some extent in household contacts. At experimental level, defensins are efficient molecules for the treatment of TB and other infectious diseases. MATERIALS & METHODS: In this work, we used a model of Mycobacterium tuberculosis transmission by long cohabitation of infected and noninfected mice, and treated the latter group with antimicrobial peptides in order to determine the potential capacity of defensins to prevent the infection. RESULTS: Our results showed that the intratracheal administration of human neutrophil peptide-1, human ß-defensin-2 alone or in combination and the use of L-isoleucine significantly prevents bacterial transmission, diminishing pulmonary lesions and bacterial loads. CONCLUSION: Data suggest the potential use of L-isoleucine as prophylactic for TB household contacts.

Tuberculin skin test and interferon-gamma release assay values are associated with antimicrobial peptides expression in polymorphonuclear cells during latent tuberculous infection.

It has been reported that patients with progressive tuberculosis (TB) express abundant amounts of the antimicrobial peptides (AMPs) cathelicidin (LL-37) and human neutrophil peptide-1 (HNP-1) in circulating cells, whereas latent TB infected donors showed no differences when compared with purified protein derivative (PPD) and QuantiFERON®-TB Gold (QFT)-healthy individuals. The aim of this study was to determine whether LL-37 and HNP-1 production correlates with higher tuberculin skin test (TST) and QFT values in TB household contacts. Twenty-six TB household contact individuals between 26-58 years old TST and QFT positive with at last two years of latent TB infection were recruited. AMPs production by polymorphonuclear cells was determined by flow cytometry and correlation between TST and QFT values was analysed. Our results showed that there is a positive correlation between levels of HNP-1 and LL-37 production with reactivity to TST and/or QFT levels. This preliminary study suggests the potential use of the expression levels of these peptides as biomarkers for progression in latent infected individuals.

Tuberculin skin test and interferon-gamma release assay values are associated with antimicrobial peptides expression in polymorphonuclear cells during latent tuberculous infection

It has been reported that patients with progressive tuberculosis (TB) express abundant amounts of the antimicrobial peptides (AMPs) cathelicidin (LL-37) and human neutrophil peptide-1 (HNP-1) in circulating cells, whereas latent TB infected donors showed no differences when compared with purified protein derivative (PPD) and QuantiFERON®-TB Gold (QFT)-healthy individuals. The aim of this study was to determine whether LL-37 and HNP-1 production correlates with higher tuberculin skin test (TST) and QFT values in TB household contacts. Twenty-six TB household contact individuals between 26-58 years old TST and QFT positive with at last two years of latent TB infection were recruited. AMPs production by polymorphonuclear cells was determined by flow cytometry and correlation between TST and QFT values was analysed. Our results showed that there is a positive correlation between levels of HNP-1 and LL-37 production with reactivity to TST and/or QFT levels. This preliminary study suggests the potential use of the expression levels of these peptides as biomarkers for progression in latent infected individuals.

Immunotherapy for pulmonary TB: antimicrobial peptides and their inducers.

TB is an infectious disease that still has an enormous impact on public health worldwide. With the continuous increasing epidemic of multidrug-resistant TB, new drugs and vaccines are urgently needed. In the last decade there has been a broad advance in the knowledge of innate immunity in TB. Together with the growing research regarding immunomodulators, new promising insights have been developed that can contribute in the control of TB. This is the case of antimicrobial peptides, which can be potential therapeutic or adjuvant agents. The current high cost of antimicrobial peptide synthesis may be a current deterrent for treatment; antimicrobial peptide-inducers can be an alternative for low-cost treatment and/or adjuvants.

Ability of innate defence regulator peptides IDR-1002, IDR-HH2 and IDR-1018 to protect against Mycobacterium tuberculosis infections in animal models.

Tuberculosis is an ongoing threat to global health, especially with the emergence of multi drug-resistant (MDR) and extremely drug-resistant strains that are motivating the search for new treatment strategies. One potential strategy is immunotherapy using Innate Defence Regulator (IDR) peptides that selectively modulate innate immunity, enhancing chemokine induction and cell recruitment while suppressing potentially harmful inflammatory responses. IDR peptides possess only modest antimicrobial activity but have profound immunomodulatory functions that appear to be influential in resolving animal model infections. The IDR peptides HH2, 1018 and 1002 were tested for their activity against two M. tuberculosis strains, one drug-sensitive and the other MDR in both in vitro and in vivo models. All peptides showed no cytotoxic activity and only modest direct antimicrobial activity versus M. tuberculosis (MIC of 15-30 µg/ml). Nevertheless peptides HH2 and 1018 reduced bacillary loads in animal models with both the virulent drug susceptible H37Rv strain and an MDR isolate and, especially 1018 led to a considerable reduction in lung inflammation as revealed by decreased pneumonia. These results indicate that IDR peptides have potential as a novel immunotherapy against TB.