Effects of Anthropogenic Disturbance and Seasonal Variation on Aerobiota in Highly Visited Show Caves in Slovenia.

Aerosols in caves are natural tracers and, together with climatic parameters, provide a detailed insight into atmospheric conditions, responses to climatic changes and anthropogenic influences in caves. Microbiological air monitoring in show caves is becoming increasingly useful to understand changes in cave ecosystems and to implement and review measures for sustainable cave use and tourism development. In 2017 and 2018, air along tourist trails in caves Postojnska jama and Skocjanske jame (Slovenia) was sampled before and after tourist visits. Samples were analysed using culture-dependent methods, flow cytometry, detection of ß-D-glucan and lipopolysaccharide and compared with CO2 and temperature data to measure anthropogenic influences and seasonality on aerobiota. While the presence of tourists significantly increased concentrations of airborne microorganisms (p < 0.05), ß-D-glucan and CO2 did not show such a trend and were more dependent on seasonal changes. Locally, concentrations of cultivable microorganisms above 1000 CFU/m3 were detected, which could have negative effects on the autochthonous microbiota and possibly on human health. A mixture of bacteria typically associated with humans was found in the air and identified with MALDI-TOF MS. Using MALDI-TOF MS, we achieved a 69.6% success rate in identification. Micrococcus luteus, Streptococcus mitis, Staphylococcus epidermidis and Moraxella spp. were recognized as good indicators of cave anthropisation.

Long-Term Monitoring of Bioaerosols in an Environment without UV and Desiccation Stress, an Example from the Cave Postojnska Jama, Slovenia.

A natural cave environment subject to regular human visitation was selected for aerobiological study to minimize the effects of severe temperature fluctuations, UV radiation, and desiccation stress on the aerobiome. The longer sampling period of bioaerosols, up to 22 months, was generally not associated with a proportionally incremental and cumulative increase of microbial biomass. The culture-independent biomass indicator ATP enabled quick and reliable determination of the total microbial biomass. Total airborne microbial biomass was influenced by human visitation to the cave, as confirmed by significantly higher concentrations being observed along tourist footpaths (p < 0.05). Airborne beta-glucans (BG) and lipopolysaccharide (LPS) are present in cave air, but their impact on the cave remains to be evaluated. Staphylococcus spp., as an indicator of human presence, was detected at all sites studied. Their long-term survival decrease is likely due to high relative humidity, low temperature, the material to which they adhere, and potentially natural elevated radon concentration. The most commonly recorded species were: S. saprophyticus, which was identified in 52% of the studied sites, S. equorum in 29%, and S. warneri in 24% of the studied sites. Only a few isolates were assigned to Risk group 2: S. aureus, S. epidermidis, S. haemolyticus, S. pasteuri, and S. saprophyticus.

Engineered and wild-type L. lactis promote anti-inflammatory cytokine signalling in inflammatory bowel disease patient's mucosa.

Dysbiosis of intestinal microbiota and aberrant inflammatory responses in gastrointestinal mucosa plays important roles in the development of inflammatory bowel disease (IBD). The purpose of this study was to demonstrate the probiotic activity of Lactococcus lactis and the ability of TNF-α-binding by recombinant L. lactis bearing TNF-α-binding affibodies. Various concentrations of recombinant L. lactis were exposed to TNF-α and its binding measured by ELISA. Mucosal biopsies of patients with active IBD were incubated with various L. lactis strains or E. coli DH5α strain and concentrations of TNF-α, IL-23, and IL-10 in the supernatants determined by ELISA. Recombinant L. lactis, at 1 × 109 and 1 × 108 CFU/mL, bound 22.6% and 18.4%, respectively of TNF-α (p < 0.05). When IBD-mucosa was incubated with any L. lactis strain at 1 × 109 CFU/mL, levels of TNF-α and IL-23 were significantly decreased and that of IL-10 increased relative to that for the sterile culture. Opposite trends were observed with E. coli cultures. Recombinant L. lactis at 1 × 108 CFU/mL bound as much as 62.8% (p = 0.026) of TNF-α in IBD-mucosa supernatants compared with the control strain. L. lactis strains are reported, for the first time, to induce an ex vivo anti-inflammatory cytokine profile in IBD inflamed mucosa. L. lactis could therefore constitute a promising alternative approach for treating IBD.

Functional Complement Analysis Can Predict Genetic Testing Results and Long-Term Outcome in Patients With Complement Deficiencies.

Background: Prevalence of complement deficiencies (CDs) is markedly higher in Slovenian primary immunodeficiency (PID) registry in comparison to other national and international PID registries. Objective: The purposes of our study were to confirm CD and define complete and partial CD in registered patients in Slovenia, to evaluate frequency of clinical manifestations, and to assess the risk for characteristic infections separately for subjects with complete and partial CD. Methods: CD was confirmed with genetic analyses in patients with C2 deficiency, C8 deficiency, and hereditary angioedema or with repeated functional complement studies and measurement of complement components in other CD. Results of genetic studies (homozygous subjects vs. heterozygous carriers) and complement functional studies were analyzed to define complete (complement below the level of heterozygous carriers) and partial CD (complement above the level of homozygous patients). Presence of characteristic infections was assessed separately for complete and partial CD. Results: Genetic analyses confirmed markedly higher prevalence of CD in Slovenian PID registry (26% of all PID) than in other national and international PID registries (0.5-6% of all PID). Complement functional studies and complement component concentrations reliably distinguished between homozygous and heterozygous CD carriers. Subjects with partial CD had higher risk for characteristic infections than previously reported. Conclusion: Results of our study imply under-recognition of CD worldwide. Complement functional studies and complement component concentrations reliably predicted risk for characteristic infections in patients with complete or partial CD. Vaccination against encapsulated bacteria should be advocated also for subjects with partial CD and not limited to complete CD.

Identification of rare genetic variation of NLRP1 gene in familial multiple sclerosis.

The genetic etiology and the contribution of rare genetic variation in multiple sclerosis (MS) has not yet been elucidated. Although familial forms of MS have been described, no convincing rare and penetrant variants have been reported to date. We aimed to characterize the contribution of rare genetic variation in familial and sporadic MS and have identified a family with two sibs affected by concomitant MS and malignant melanoma (MM). We performed whole exome sequencing in this primary family and 38 multiplex MS families and 44 sporadic MS cases and performed transcriptional and immunologic assessment of the identified variants. We identified a potentially causative homozygous missense variant in NLRP1 gene (Gly587Ser) in the primary family. Further possibly pathogenic NLRP1 variants were identified in the expanded cohort of patients. Stimulation of peripheral blood mononuclear cells from MS patients with putatively pathogenic NLRP1 variants showed an increase in IL-1B gene expression and active cytokine IL-1ß production, as well as global activation of NLRP1-driven immunologic pathways. We report a novel familial association of MS and MM, and propose a possible underlying genetic basis in NLRP1 gene. Furthermore, we provide initial evidence of the broader implications of NLRP1-related pathway dysfunction in MS.

Fungal cell wall agents and bacterial lipopolysaccharide in organic dust as possible risk factors for pulmonary sarcoidosis.

BACKGROUND: Composition of organic dust is very complex, involving particles of microbial, animal and plant origin. Several environmental exposure studies associate microbial cell wall agents in organic dust with various respiratory symptoms and diseases. The aim of the present study was to investigate the in vitro effects of the co-exposure of fungal cell wall agents (FCWAs) and bacterial lipopolysaccharide (LPS) on inflammatory immune responses of peripheral blood mononuclear cells (PBMCs) from patients with pulmonary sarcoidosis. METHODS: PBMCs from 22 patients with pulmonary sarcoidosis and 20 healthy subjects were isolated and stimulated in vitro with FCWAs (soluble and particulate (1 → 3)-ß-D-glucan, zymosan and chitosan) and/or LPS. Subsequently, cytokines were measured by ELISA and the mRNA expression of dectin-1, toll-like receptor 2 (TLR2), TLR4 and mannose receptor (MR) was analysed by real-time RT-PCR. RESULTS: Patients with sarcoidosis had a significantly higher secretion of inflammatory cytokines tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), IL-10 and IL-12 (1.7-fold, 2.0-fold, 2.2-fold, and 2.8-fold, respectively; all p < 0.05) after in vitro co-stimulation of PBMCs with FCWAs and LPS. We showed that PBMCs from patients with sarcoidosis had a higher baseline mRNA expression of dectin-1, TLR2, TLR4 and MR (6-fold, 11-fold, 18-fold, and 4-fold, respectively). Furthermore, we found a reduced expression of dectin-1, TLR2 and TLR4 after stimulation with FCWAs and/or LPS, although the reduction was significantly weaker in patients than in healthy subjects. CONCLUSIONS: In conclusion, co-stimulation with FCWAs and LPS of PBMC from patients with sarcoidosis caused a weaker reduction of dectin-1, TLR2, TLR4 receptors expression, which could increase the sensitivity of PBMCs, leading to excessive inflammatory cytokine responses and result in the development or progression of pulmonary sarcoidosis.

Fungal exposure and low levels of IL-10 in patients with sarcoidosis.

BACKGROUND AND OBJECTIVES: Sarcoidosis is an inflammatory disease with increased levels of inflammatory cytokines. Previous studies have shown a relation between the degree of granuloma infiltration and serum cytokine levels, except for interleukin- (IL-) 10. The aim of the study was to further investigate the serum levels of IL-10 in patients with sarcoidosis and relate them to fungal exposure in terms of the amount of fungi in the air of their homes and ß-glucan in bronchoalveolar lavage (BAL) fluid. METHODS: Patients with sarcoidosis (n = 71) and healthy controls (n = 27) were enrolled. IL-10 was determined in serum. BAL was performed and the amount of ß-glucan was measured. Domestic exposure to fungi was determined by measuring airborne ß-N-acetylhexosaminidase (NAHA) in the bedrooms. RESULTS: At high levels of fungal exposure (domestic fungal exposure and ß-glucan in BAL), serum IL-10 values were lower than at low and intermediate exposure levels. CONCLUSION: The low serum IL-10 values at high fungal exposure suggest that fungal cell wall agents play a role in granuloma formation in sarcoidosis by inhibiting the secretion of the anti-inflammatory cytokine IL-10.

Fungal cell wall agents suppress the innate inflammatory cytokine responses of human peripheral blood mononuclear cells challenged with lipopolysaccharide in vitro.

Exposure to high levels of fungi might lead to diseases, such as airway inflammation, hypersensitivity pneumonitis and allergy. To comprehend the mechanisms behind the exposure to fungi and a disease, we examined the in vitro innate inflammatory cytokine response of human peripheral blood mononuclear cells (PBMC) challenged by fungal cell wall agents (FCWAs), i.e., soluble and particulate (1→3)-ß-D-glucan-curdlan (BGS and BGP), zymosan (ZYM) and chitosan (CHT) in the absence or presence of lipopolysaccharide (LPS). We also studied FCWA effects on the mRNA expression of dectin-1, TLR2, TLR4 and mannose receptor (MR) by real-time RT-PCR. Our results demonstrated that BGP strongly induced the secretion of TNF-α, IL-6, IL-10 and IL-12; BGS, ZYM and CHT were weaker, but still significant cytokine inducers. We showed that BGS significantly augmented the LPS-induced in vitro secretion of TNF-α. On the other hand, BGP, ZYM and CHT suppressed the LPS-induced production of all cytokines. At the mRNA level, the dectin-1, TLR2 and TLR4 expressions were significantly reduced by all FCWAs in the absence of LPS and even more in the presence of LPS. While we demonstrated that the innate inflammatory cytokine response of PBMC induced by CHT was mediated by MR, the MR mRNA expression was significantly reduced by CHT. On the contrary, BGS significantly enhanced the MR mRNA expression. In conclusion, a long-term and massive exposure to LPS and FCWA (e.g., organic dust) may cause an important disruption of normal immune response and allow development and/or persistence of various immunopathological events.