CD8+ T cells from HLA-A2.1-transgenic mice, but not wild-type mice, immunized with the amino-terminus region (aa 41-152) of dense granule protein 6 (GRA6Nt) of Toxoplasma gondii secreted large amounts of perforin and granzyme B in response to GRA6Nt through antigen presentation by HLA-A2.1 in vitro. When those CD8+ T cells were transferred into chronically infected HLA-A2.1-expressing NSG mice deficient in T cells, cerebral cyst burden of the recipients of HLA-A2.1-transgenic T cells, but not of WT T cells, became significantly less than that of control mice with no cell transfer. Furthermore, the significant reduction of the cyst burden by a transfer of the HLA-A2.1-transgenic CD8+immune T cells required an expression of HLA-A2.1 in the recipient NSG mice. Thus, antigen presentation of GRA6Nt by human HLA-A2.1is able to activate anti-cyst CD8+ T cells that eliminateT. gondii cysts through antigen presentation by human HLA-A2.1.

Periodontal disease, a prevalent oral disease, is an independent risk factor for atherosclerosis. Porphyromonas gingivalis (P.g), a keystone pathogen of periodontal disease, contributes to the pathogenesis of atherosclerosis. However, the exact mechanism remains unclear. An increasing number of studies have proposed the atherogenic influence of perivascular adipose tissue (PVAT) in pathological conditions including hyperlipidemia and diabetes. Nevertheless, the role of PVAT in atherosclerosis promoted by P.g infection has not been explored. In our study, we investigated the association between P.g colonization in PVAT and progression of atherosclerosis through experiments on clinical samples. We further investigated P.g invasion of PVAT, PVAT inflammation, aortic endothelial inflammation, aortic lipid deposition, and systemic inflammation in C57BL/6J mice with or without P.g infection at 20, 24, and 28 weeks of age. PVAT inflammation, characterized by imbalance in Th1/Treg and dysregulated adipokine levels, was associated with P.g invasion, preceding endothelial inflammation that occurred independently of its direct invasion. The phenotype of systemic inflammation coincided with that of PVAT inflammation, but systemic inflammation occurred after endothelial inflammation. Therefore PVAT inflammation in early atherosclerosis could be a primary trigger of aortic endothelial inflammation and lipid deposition in chronic P.g infection, through the dysregulated paracrine secretion of T helper-1-related adipokines.

Although gut dysbiosis contributes to systemic inflammation, the counteractive effect of systemic inflammation on gut microbiota is unknown. Vitamin D may exert anti-inflammatory effects against systemic inflammation, but its regulation of the gut microbiota is poorly understood. In this study, mice were intraperitoneally injected with lipopolysaccharide (LPS) to create a systemic inflammation model and received vitamin D3 treatment orally for 18 continuous days. Then, body weight, morphological changes in the colon epithelium, and gut microbiota (n = 3) were evaluated. We verified that LPS stimulation caused inflammatory changes in the colon epithelium, which could be obviously attenuated by vitamin D3 treatment (10 μg/kg/day) in mice. Then, 16S rRNA gene sequencing of the gut microbiota first revealed that LPS stimulation induced a large number of operational taxonomic units, and vitamin D3 treatment reduced the number. In addition, vitamin D3 had distinctive effects on the community structure of the gut microbiota, which was obviously changed after LPS stimulation. However, neither LPS nor vitamin D3 affected the alpha and beta diversity of the gut microbiota. Furthermore, statistical analysis of differential microorganisms showed that the relative abundance of microorganisms in the phylum Spirochaetes decreased, the family Micrococcaceae increased, the genus [Eubacterium]_brachy_group decreased, the genus Pseudarthrobacter increased, and the species Clostridiales_bacterium_CIEAF_020 decreased under LPS stimulation, but vitamin D3 treatment significantly reversed the LPS-induced changes in the relative abundance of these microorganisms. In conclusion, vitamin D3 treatment affected the gut microbiota and alleviated inflammatory changes in the colon epithelium in the LPS-stimulated systemic inflammation mouse model.

Chronic wounds are difficult to treat due to the presence of biofilm which prevents wound healing. Pseudomonas aeruginosa is one of the most common pathogens found in chronic wounds and conventional treatment strategies have been ineffective in the eradication of its biofilm, without harming the surrounding healthy tissue at the same time. Here, we introduced an innovative approach applying the probiotic product Bio-K+ (containing three lactobacilli) topically as an antimicrobial and antibiofilm agent. We identified lactic acid as the main active component. While antibiotics and antiseptics such as silver-ions only demonstrated limited efficacy, Bio-K+ was able to completely eradicate mature P. aeruginosa biofilms established in an in-vitro and ex-vivo human skin model. Furthermore, it demonstrated biocompatibility in the co-culture with human dermal fibroblasts and accelerated the migration of fibroblasts in a cell migration assay promoting wound healing. To enhance clinical practicability, we introduced Bio-K+ into the hydrocolloid dressing Aquacel, achieving sustained release of lactic acid and biofilm eradication. This new treatment approach applying probiotics could represent a major improvement in the management of chronic wounds and can be extended in treating other biofilm-associated infections.

Comprehending the morphological disparities between SARS-CoV-2 and SARS-CoV viruses can shed light on the underlying mechanisms of infection and facilitate the development of effective diagnostic tools and treatments. Hence, this study aimed to conduct a comprehensive analysis and comparative assessment of the morphology of SARS-CoV-2 and SARS-CoV using transmission electron microscopy (TEM) images. The dataset encompassed 519 isolated SARS-CoV-2 images obtained from patients in Italy (INMI) and 248 isolated SARS-CoV images from patients in Germany (Frankfurt). In this paper, we employed TEM images to scrutinize morphological features, and the outcomes were contrasted with those of SARS-CoV viruses. The findings reveal disparities in the characteristics of SARS-CoV-2 and SARS-CoV, such as envelope protein (E) 98.6 and 102.2 nm, length of spike protein (S) 10.11 and 9.50 nm, roundness 0.86 and 0.88, circularity 0.78 and 0.76, and area sizes 25145.54 and 38591.35 pixels, respectively. In conclusion, these results will augment the identification of virus subtypes, aid in the study of antiviral medications, and enhance our understanding of disease progression and the virus life cycle. Moreover, these findings have the potential to assist in the development of more accurate epidemiological prediction models for COVID-19, leading to better outbreak management and saving lives.

The role of HEV infection in AP remains unclear. 1000 patients with AP and 1000 HCs were enrolled, and pancreatitis was evaluated in HEV-infected rhesus macaques. The positive rates of anti-HEV IgG, IgM, and HEV RNA in the AP patients were significantly higher than HCs. With the increase in the severity of AP, the percentage of HEV infection increased. AP patients were divided into AP- and AP+AHE groups. The percentage of severe AP in the AP+AHE group was significantly higher than in the AP- group. HEV infection was one of the main independent risk factors and had high predictive power for AP outcomes. A high level of HEV titer would prolong the recovery time and increase the risk of recurrent AP. Moreover, AP+AHE patients receiving conservative treatment showed a better prognosis. Furthermore, HEV can replicate in the pancreas of rhesus macaques. The pancreatic islet structure was damaged, the tissue was loose after 272 dpi, and a large amount of hyperemia appeared after 770 dpi. HEV infection also caused a large number of inflammatory cells in the pancreas. The pancreas and liver had a comparable viral load. HEV infection affects AP's occurrence, development, and prognosis.

Osteomyelitis in children due to Q fever is a rare occurrence. In this study, we review 25 pediatric cases of this disease entity. The mean age of these 25 patients was 3.7years (range, 2-7 years). The risk factor for infection was history of contact with animals, such as cattle and sheep (23/25, 92.0%). The most common sites of infection were foot and ankle (12/25, 48.0%). The diagnosis of Q fever was confirmed by serologic testing in 25 children. On PCR, Coxiella burnetii was detected in 17 cases and it was not detected in the remaining five cases. A total of 22 children were treated with antibiotics, of which 15 received surgical treatment. The composition and duration of treatment varied greatly. Only 18 patients achieved significant recovery of joint mobility after drug and/or surgical treatment. Our current literature review show that the clinical manifestations of Q fever osteomyelitis in children are atypical. In the absence of serological test results, mNGS identification may be a good option. Compared with the guidelines that recommend doxycycline combined with hydroxychloroquine, we recommend that ciprofloxacin-based treatment combined with rifampicin or sulfamethoxazole/trimethoprim should be preferred in children under the age of 8 years, and the need for performing combined surgical debridement and determining the treatment duration should be evaluated according to their actual clinical situation.

The COVID-19 pandemic has affected people worldwide with varying clinical presentations ranging from mild to severe or fatal, and studies have found that age, gender, and some comorbidities can influence the severity of the disease. It would be valuable to have genetic markers that might help predict the likely outcome of infection. For this objective, genes encoding VEGFR-2 (rs1870377), CCR5Δ32 (rs333), and TLR3 (rs5743313) were analyzed for polymorphisms in the peripheral blood of 160 COVID-19 patients before COVID-19 vaccine was available in Türkiye. We observed that possession of the VEGFR-2 rs1870377 mutant allele increased the risk of severe/moderate disease in females and subjects ≥65 years of age, but was protective in males <65 years of age. Other significant results were that the CCR5Δ32 allele was protective against severe disease in subjects ≥65 years of age, while TLR3 rs5743313 polymorphism was found to be protective against severe/moderate illness in males <65 years of age. The VEGFR-2 rs1870377 mutant allele was a risk factor for severe/moderate disease, particularly in females over the age of 65. These findings suggest that genetic polymorphisms have an age- and sex-dependent influence on the severity of COVID-19, and the VEGFR-2 rs1870377 mutant allele could be a potential predictor of disease severity.

Since the realization that the lungs are not sterile but are normally inhabited by various bacterial species, studies have been conducted to define healthy lung microbiota and to investigate whether it changes during lung diseases, infections, and inflammation. Using next-generation sequencing, we investigated bacterial microbiota from whole lungs in two rat strains (previously shown to differ in gut microbiota composition) in a healthy state and during pulmonary infection caused by the opportunistic fungus Aspergillus fumigatus. No differences in alpha diversity indices and microbial composition between DA and AO rats before infection were noted. Fungal infection caused dysbiosis in both rat strains, characterized by increased alpha diversity indices and unchanged beta diversity. The relative abundance of genera and species was increased in DA but decreased in AO rats during infection. Changes in lung microbiota coincided with inflammation (in both rat strains) and oxidative stress (in DA rats). Disparate response of lung microbiota in DA and AO rats to pulmonary fungal infection might render these two rat strains differentially susceptible to a subsequent inflammatory insult.

Mycobacterium chimaera causes pulmonary disease, but little is known of gradations in isolate virulence. Previously, 17 M. chimaera isolates were screened for survival in THP1 macrophages. "M. chimaera 1" was categorized as "more virulent" because it showed the greatest survival in macrophages, whereas "M. chimaera 2" was categorized as "less virulent" with reduced survival. Herein, we infected C3HeB/FeJ mice to compare the in vivo immune responses to M. chimaera 1 and 2. Unlike macrophages, significantly lower M. chimaera 1 counts were recovered from mouse lung tissue and BAL cells with less lung histopathologic changes compared to M. chimaera 2. Compared to M. chimaera 2, significantly more IL-1β, IL-6, and TNFα was produced early after M. chimaera 1 infection. LC-MS metabolomics analyses of BAL fluid revealed divergence in sphingolipid, phospholipid metabolism between M. chimaera 1 versus M. chimaera 2 mice. From pan-GWAS analyses, virulence and organizing DNA/molecular structure genes were associated with more virulent M. chimaera isolates. Vigorous lung-specific immune responses to M. chimaera 1 may influence effective bacterial control, but for a different isolate M. chimaera 2, subvert immune control. Continued studies of the gradations in virulence among the same NTM species will advance our understanding of NTM pathogenesis.

OBJECTIVE: Metagenomic Next-Generation Sequencing (mNGS) has been validated to have an important role in the diagnosis of mycobacterium infection. The study aimed to further explore the mycobacteria identification ability of mNGS on formalin-fixed paraffin-embedded（FFPE）tissues from postoperative specimens. METHODS: Patients who underwent surgical biopsy or resection for clarifying the diagnosis and whose initial postoperative pathology indicated granulomatous lesions were included. Fresh tissues were sent for mycobacterium culture and Xpert MTB/RIF (Xpert) to establish the diagnosis. FFPE specimens were sent for mNGS and molecular pathology，the diagnostic values were compared between the two methods. RESULTS: A total of 65 cases with definite diagnoses were finally included in the study. 31 cases were confirmed as mycobacterium granuloma using the fresh specimen etiology as diagnostic criteria. The overall sensitivity and specificity of mNGS on FFPE specimens in the diagnosis of mycobacterium granuloma were 100% and 88.24%, respectively. In 19 cases diagnosed as tuberculous granulomas, the sensitivity (100%vs 47.37%) and negative predictive value (NPV,100%vs 82.14%) of mNGS were both significantly higher than that of molecular pathology on the FFPE section（both p 0.00）while the positive predictive value (PPV) and specificity were not significantly different. In 12 cases diagnosed as Non-tuberculous mycobacterium (NTM）granuloma, the sensitivity of mNGS was also significantly higher than that of molecular pathology on FFPE section (100% vs 66.67%, p 0.00) while the specificity, PPV and NPV were all not significantly different. CONCLUSIONS: The mNGS could be used for one-time detection of pathogens on FFPE sections with high sensitivity. It could be recommended as a supplementary method for the identification of pathogenic bacteria in the diagnosis of postoperative granuloma lesions.

The immunogenicity and protective ability of recombinant PA (rPA) with two innate immune system modulators, i.e., monophosphoryl lipid A (MPLA), a TLR4 agonist, and recombinant flagellin C (FliC), a TLR5 agonist, were studied in the mouse model. BALB/c mice were inoculated with three doses of rPA+alum (Alum group), rPA+FliC+alum (FliC group), rPA+MPLA+alum (MPLA group), or only alum adjuvant (Alum alone group). Significant increases in anti-PA IgG titers were observed in the Alum, FliC and MPLA groups when compared to control Alum alone group. Similarly, a significant enhancement of proinflammatory (TNF-α, IL-1β), Th1 (IFN-γ, IL-12(p70), IL-2) and Th2 (IL-10, IL-4) cytokines were also noticed in Alum, FliC and MPLA groups compared to Alum alone group. The rPA-specific IgG and cytokine responses in MPLA and FliC groups were significantly higher than the Alum group, suggesting enhancement of immune response by these TLR agonists. MPLA was also found to skew the IgG1:IgG2a ratio towards IgG2a. At a challenge dose of 25 LD50, complete protection was observed in mice of MPLA group whereas lesser protection was observed in FliC (80%) and Alum (50%) groups. Therefore, we suggest the use of MPLA in further development of rPA based anthrax vaccines.