Nontuberculous Mycobacteria, Mucociliary Clearance, and Bronchiectasis.

Nontuberculous mycobacteria (NTM) are environmental and ubiquitous, but only a few species are associated with disease, often presented as nodular/bronchiectatic or cavitary pulmonary forms. Bronchiectasis, airways dilatations characterized by chronic productive cough, is the main presentation of NTM pulmonary disease. The current Cole's vicious circle model for bronchiectasis proposes that it progresses from a damaging insult, such as pneumonia, that affects the respiratory epithelium and compromises mucociliary clearance mechanisms, allowing microorganisms to colonize the airways.

Formation of colonies in cellular culture in an infection model.

is one of the most important nontuberculous mycobacteria that cause lung diseases. infection models developed to analyze the immune response are frequently based on the addition of mycobacteria to mononuclear cells or neutrophils from peripheral blood. An important requirement of these assays is that most cells phagocytose mycobacteria, only accomplished by using large multiplicities of infection (1 or more bacteria per cell) which may not adequately reflect the inhalation of a few mycobacteria by the host.

Increased serum concentrations of estrogen-induced growth factors Midkine and FGF2 in NF1 patients with plexiform neurofibroma.

Neurofibromatosis type 1 (NF1) predisposes to the development of dermal and plexiform neurofibromas and serum of NF1 patients stimulates neurofibroma proliferation in vitro. This study aimed to determine whether, in NF1 patients, serum levels of midkine (MK) and fibroblast growth factor 2 (FGF2) were associated with the number and/or type of neurofibromas. In addition, their concentrations were correlated with serum levels of dehydroepiandrosterone sulfate (DHEAS), a neurosteroid secreted by the peripheral nervous system.

A rapid proteomic system (MALDI-TOF) for nontuberculous-mycobacteria identification.

Proteomic techniques relaying upon mass spectrometry (MALDI_TOF) applied to nontuberculous mycobacteria (NTM) identification, constitute a difficult goal. Cell wall structure features complicates the protein extraction procedure. A total of 106 isolates belonging to a variety of MNTs species isolated from clinical samples taken at the Complejo Asistencial Universitario de León for a two years period (2019-20) were identified following a simplified method (MALDI-TOF Biotyper Bruker®) developped in our laboratory.

Mycobacterium avium complex infected cells promote growth of the pathogen Pseudomonas aeruginosa.

Bronchiectasis is considered a consequence of the neutrophilic inflammatory response to infection. Mycobacterial infections, mainly from the Mycobacterium avium complex and M. abscessus, have been inextricably linked to bronchiectasis development.

Oral Consumption of Bread from an RNAi Wheat Line with Strongly Silenced Gliadins Elicits No Immunogenic Response in a Pilot Study with Celiac Disease Patients.

Celiac disease (CD) is a genetically predisposed, T cell-mediated and autoimmune-like disorder caused by dietary exposure to the storage proteins of wheat and related cereals. A gluten-free diet (GFD) is the only treatment available for CD. The celiac immune response mediated by CD4+ T-cells can be assessed with a short-term oral gluten challenge.

A rapid proteomic system (MALDI-TOF) for nontuberculous-mycobacteria identification.

Proteomic techniques relaying upon mass spectrometry (MALDI_TOF) applied to nontuberculous mycobacteria (NTM) identification, constitute a difficult goal. Cell wall structure features complicates the protein extraction procedure. A total of 106 isolates belonging to a variety of MNTs species isolated from clinical samples taken at the Complejo Asistencial Universitario de León for a two years period (2019-20) were identified following a simplified method (MALDI-TOF Biotyper Bruker®) developped in our laboratory.

A strategy based on Amplified Fragment Length Polymorphism (AFLP) for routine genotyping of nontuberculous mycobacteria at the clinical laboratory.

The increasing worldwide incidence of mycobacteriosis and the need to achieve improved clinical management makes nontuberculous mycobacteria (NTM) genotyping a useful tool. However, because of technical difficulties, medium size microbiology laboratories do not attempt to compare the genetic patterns that each of their isolates present. We have aimed to optimize a genotyping method with a reduced hands-on experimental time and that requires few technical resources.

The unexplained increase of nontuberculous mycobacteriosis.

Epidemiological data show a worldwide increase in nontuberculous mycobacteriosis. Although it has been partially attributed to the improvement of microbiological methodologies that has allowed a better recovery and identification of nontuberculous mycobacteria (NTM), it is generally accepted that there is a genuine incidence augmentation. The reasons of the increase are likely multifactorial, depending on the nature of the pathogen, the host, and their interaction.

Blood antimicrobial activity varies against different Mycobacterium spp.

In vitro analysis of mycobacterial pathogenicity or host susceptibility has traditionally relied on the infection of macrophages, the target cell of mycobacteria, despite difficulties reproducing their antimycobacterial activity. We have employed alternative models, namely whole blood and leukocytes in plasma, from QuantiFERON negative individuals, and performed infections with the pathogenic M. tuberculosis, the less pathogenic M.

In vitro infection with Mycobacterium tuberculosis induces a distinct immunological pattern in blood from healthy relatives of tuberculosis patients.

Part of the susceptibility to tuberculosis has a genetic basis, which is clear in primary immunodeficiencies, but is less evident in apparently immunocompetent subjects. Immune responses were analysed in blood samples from tuberculosis patients and their healthy first-degree relatives who were infected in vitro with mycobacteria (either Mycobacterium tuberculosis or M. bovis BCG).

Immunological response to Mycobacterium tuberculosis infection in blood from type 2 diabetes patients.

The convergence of tuberculosis and diabetes represents a co-epidemic that threatens progress against tuberculosis. We have investigated type 2 diabetes as a risk factor for tuberculosis susceptibility, and have used as experimental model whole blood infected in vitro with Mycobacterium tuberculosis. Blood samples from diabetic patients were found to have a higher absolute neutrophil count that non-diabetic controls, but their immune functionality seemed impaired because they displayed a lower capacity to phagocytose M.

In vitro infection of human cells with Mycobacterium tuberculosis.

It has been estimated that approximately 50% of individuals exposed to Mycobacterium tuberculosis never become tuberculin skin test positive, which may indicate that successful human immunological responses are able not only to inhibit mycobacterial growth, but also to kill the bacteria. Nevertheless, it has been extremely difficult to reproduce this effect in vitro and the ability of human phagocytes to eliminate the bacteria is controversial. This is one of the reasons why we do not fully understand either tuberculosis resistance or susceptibility.

Macrophages from elders are more permissive to intracellular multiplication of Mycobacterium tuberculosis.

The elderly account for a disproportionate share of all tuberculosis cases, and the population ageing may not fully explain this phenomenon. We have performed in vitro infection experiments to investigate whether there is an immunological basis for the apparent susceptibility of elders to tuberculosis. In our infection model, Mycobacterium tuberculosis induces a higher production of interleukin (IL)-6 and reactive oxygen species in macrophages from elders than from younger adults.

Non-chemotactic influence of CXCL7 on human phagocytes. Modulation of antimicrobial activity against L. pneumophila.

We have investigated the role of CXCL7 in the immune response of human phagocytes against the intracellular bacteria Mycobacterium tuberculosis and Legionella pneumophila. We have observed that polymorphonuclear neutrophil (PMN) chemotaxis induced by the supernatants of infected monocyte derived macrophages (MDM) may be attributed to CXCL8 rather than CXCL7, although both chemokines are present in large quantities. We have also found that CXCL7 is present not only in the supernatants of MDM, but also in the supernatants of PMN of some, but not all, individuals.

Apoptosis and oxidative burst in neutrophils infected with Mycobacterium spp.

Two of the better characterized antimicrobial mechanisms displayed by human neutrophils are the reactive oxygen species (ROS) production and the induction of apoptosis. Their importance in mycobacterial infections is, however, controversial and we aimed to analyze them simultaneously in neutrophils infected with either Mycobacterium tuberculosis or the non-pathogenic M. gordonae.

Cytokines as immunomodulators in tuberculosis therapy.

The use of cytokines for therapeutic purposes is limited by their high cost and toxicity. Nevertheless, the emergence of extensively drug-resistant tuberculosis (XDR TB), for which chemotherapy is ineffective, has again made cytokine-based therapy attractive as one of the last available options. The results of clinical trials treating pulmonary tuberculosis with cytokines have not been encouraging, making it clear that therapeutic strategies utilizing a single cytokine are inadequate.

Detection of inhibition of antimicrobial activity by mycobacterial lysates in human monocytes infected with Legionella pneumophila.

Antimicrobial activity in human monocytes infected with Mycobacterium tuberculosis has been difficult to demonstrate in vitro, and the molecular mechanisms allowing the bacteria to survive intracellularly are unknown. As a means to test the influence of bacterial products in the microbicidal activity of monocytes we have developed an infection model with Legionella pneumophila, which is killed by interferon gamma activated cells. We demonstrate that this model is useful because M.

Human phagocytes lack the ability to kill Mycobacterium gordonae, a non-pathogenic mycobacteria.

Non-pathogenic mycobacteria, like Mycobacterium gordonae, are rarely associated to disease. The analysis of the mechanisms which are successful against them in the human host may provide useful information to understand why they fail against the pathogenic M. tuberculosis.