Long-Residence Pneumonia Vaccine Developed Using PEG-Grafted Hybrid Nanovesicles from Cell Membrane Fusion of Mycoplasma and IFN-γ-Primed Macrophages

Long non-coding RNA MMTP mediates necroptosis in alveolar macrophages during Mycoplasma hyopneumoniae infection by enhancing TNF-α transcription

Mycoplasma hyopneumoniae (M. hyo), a major respiratory pathogen in swine, causes chronic respiratory diseases characterized by severe lung inflammation. Alveolar macrophages, which serve as the first line of defense in the respiratory immune system, undergo necroptosis in response to M. hyo infection. This form of programmed cell death amplifies pulmonary inflammation and leads to impaired lung function, yet the precise molecular mechanisms remain poorly understood. Long non-coding RNAs (lncRNAs), known for their regulatory roles in transcriptional and epigenetic processes, have been linked to various inflammatory and infectious diseases. In this study, we identified a novel lncRNA, lncRNA-MMTP, as a critical regulator of necroptosis during M. hyo infection. Mechanistically, lncRNA-MMTP interacts with the transcription factor TFII-I to enhance c-Fos promoter activity, leading to increased transcription of TNF-α and activation of the RIPK1/RIPK3/MLKL necroptotic pathway. Importantly, knockdown of lncRNA-MMTP or inhibition of TFII-I significantly reduced TNF-α levels and necroptosis in alveolar macrophages. These findings not only elucidate a new molecular pathway underlying M. hyo-induced lung inflammation but also suggest potential therapeutic targets for managing pathogen-induced inflammatory responses in the respiratory system.

Hybrid Cell Membrane-Based Nanoplatforms for Enhanced Immunotherapy against Cancer and Infectious Diseases

Immunotherapy based on nanoplatforms is a promising approach to treat cancer and infectious diseases, and it has achieved considerable progress in clinical practices. Cell membrane-based nanoplatforms endow nanoparticles with versatile characteristics, such as half-life extension, targeting ability, and immune-system regulation. However, monotypic cell membrane usually fails to provoke strong immune response for immunotherapy while maintaining good biosafety. The integration of different cell-membrane types provides a promising approach to construct multifunctional nanoplatforms for improved immunotherapeutic efficacy by enhancing immunogenicity or targeting function, evading immune clearance, or combining with other therapeutic modalities. In this review, the design principles, preparation strategies, and applications of hybrid cell membrane-based nanoplatforms for cancer and infection immunotherapy are first discussed. Furthermore, the challenges and prospects for the potential clinical translation of hybrid cell membrane-based nanoplatforms are discussed.

Recent Advances of Engineered Cell Membrane-Based Nanotherapeutics to Combat Inflammatory Diseases

An immune reaction known as inflammation serves as a shield from external danger signals, but an overactive immune system may additionally lead to tissue damage and even a variety of inflammatory disorders. By inheriting biological functionalities and serving as both a therapeutic medication and a drug carrier, cell membrane-based nanotherapeutics offer the potential to treat inflammatory disorders. To further strengthen the anti-inflammatory benefits of natural cell membranes, researchers alter and optimize the membranes using engineering methods. This review focuses on engineered cell membrane-based nanotherapeutics (ECMNs) and their application in treating inflammation-related diseases. Specifically, this article discusses the methods of engineering cell membranes for inflammatory diseases and examines the progress of ECMNs in inflammation-targeted therapy, inflammation-neutralizing therapy, and inflammation-immunomodulatory therapy. Additionally, the article looks into the perspectives and challenges of ECMNs in inflammatory treatment and offers suggestions as well as guidance to encourage further investigations and implementations in this area.

A comparative study of general and severe mycoplasma pneumoniae pneumonia in children

OBJECTIVES

The increasing prevalence of severe Mycoplasma pneumoniae pneumonia (SMPP) poses a significant threat to the health of children. This study aimed to characterise and assess the outcomes in children with SMPP.

METHODS

We retrospectively analysed children hospitalised for M. pneumoniae pneumonia (MPP) between January and December 2022. Retrospectively, demographic, clinical, underlying diseases, laboratory and radiological findings, and treatment outcomes were collected and analysed. Disease severity was defined as severe or general according to the Guideline for diagnosis and treatment of community-acquired pneumonia in children (2019 version).

RESULTS

Over a 12-month observation period, 417 children with MPP were enrolled, 50.6% (211/417) of whom had SMPP, with the peak incidence observed in winter. Of the 211 children with SMPP, 210 were treated and discharged with improvement, while one child with congenital heart disease died of cardioembolic stroke. A significantly higher proportion of patients with SMPP had underlying diseases, extrapulmonary complications (myocardial and digestive system involvement), and bacterial co-infection. A total of 25 (12%) children with SMPP received mechanical ventilation. The median duration of mechanical ventilation was 3 days. All children were treated with macrolide antibiotic. A significantly higher proportion of patients with SMPP received antibiotic other than macrolides, methylprednisolone sodium succinate, intravenous immunoglobulin and anticoagulation, compared with patients with general MPP (GMPP). Children with SMPP had significantly higher levels of white blood cells, neutrophil percentage, C-reactive protein, procalcitonin, interferon-γ, interleukin (IL)-2, IL-5, IL-6, IL-8, IL-10 and significantly lower percentages of lymphocytes, monocytes, and natural killer cells, compared with GMPP group.

CONCLUSION

Our findings suggest that severely ill children have more pronounced inflammatory reaction and extrapulmonary complications. For effective management of children with SMPP, hormonal, prophylactic, anticoagulant therapy, as well as the use of antibiotics other than macrolides for bacterial co-infections, could be incorporated into treatment regimens.

Cell-in-Cell Phenomena in Wall-Less Bacteria: Is It Possible?

This work describes curious structures formed by the mainly phytopathogenic mycoplasma Acholeplasma laidlawii, as well as the human pathogen Ureaplasma parvum cells which resemble cell-in-cell structures of higher eukaryotes and protists. The probable significance of such structures for the mycoplasma cell is discussed. The possibility of their formation in nature and their potential role in the transformation of genetic material, for example, by maintaining (on the one hand) the stability of the genome in the line of generations during asexual reproduction or (on the other hand) the genome plasticity, are substantiated. It should be especially noted that all the arguments presented are based only on morphological data. However, closer attention to unusual structures, the existence of which was shown by electron microscopy images in this case, may prompt researchers to analyze their data more carefully and find something rare and non-trivial among seemingly trivial things. If it is proven by additional methods that cell-in-cell structures can indeed be formed by prokaryotes without a cell wall, this phenomenon may acquire general biological significance.

Promoting Cell Fusion by Polyvalent DNA Ligands

Artificially induced in vitro cell fusion is one essential technique that has been extensively used for biological studies. Nevertheless, there is a lack of robust and efficient method to produce fused cells efficiently. Herein, we proposed to use cell-membrane-anchored polyvalent DNA ligands (PDL) to bring cells into close proximity by forming clusters to enhance PEG-induced cell fusion. PDL of complementary sequences are separately anchored onto different population of cells through cholesterol-induced hydrophobic insertion into lipid membrane. Cells are clustered via mixing cells of complementary PDL prior to cell fusion. PDL exhibited strong stability on cell membrane, induced efficient cell clustering, and eventually achieved cell fusion efficiently in combination with PEG induction. We demonstrated homogeneous and heterogeneous cell fusion of high yield on various cell types. This report presented a programmable yet robust technique for achieving efficient cell fusion that hold great application potentials.