Archivum Immunologiae et Therapiae Experimentalis

For practitioners at hospitals seeking to use natural (not genetically modified, as appearing in nature) bacteriophages for treatment of antibiotic-resistant bacterial infections (bacteriophage therapy), Europe’s current regulatory framework for medicinal products hinders more than it facilitates. Although many experts consider bacteriophage therapy to be a promising complementary (or alternative) treatment to antibiotic therapy, no bacteriophage-specific framework for documentation exists to date. Decades worth of historical clinical data on bacteriophage therapy (from Eastern Europe, particularly Poland, and the former Soviet republics, particularly Georgia and Russia, as well as from today’s 27 EU member states and the US) have not been taken into account by European regulators because these data have not been validated under current Western regulatory standards. Consequently, applicants carrying out standard clinical trials on bacteriophages in Europe are obliged to initiate clinical work from scratch. This paper argues for a reduced documentation threshold for Phase 1 clinical trials of bacteriophages and maintains that bacteriophages should not be categorized as classical medicinal products for at least two reasons: (1) such a categorization is scientifically inappropriate for this specific therapy and (2) such a categorization limits the marketing authorization process to industry, the only stakeholder with sufficient financial resources to prepare a complete dossier for the competent authorities. This paper reflects on the current regulatory framework for medicines in Europe and assesses possible regulatory pathways for the (re-)introduction of bacteriophage therapy in a way that maintains its effectiveness and safety as well as its inherent characteristics of sustainability and in situ self-amplification and limitation.

Extracellular vesicles (EVs) and particles (EPs) serve as unique carriers of complex molecular information with increasingly recognized roles in health and disease. Individual EVs/EPs collectively contribute to the molecular fingerprint of their producing cell, reflecting its identity, state, function and phenotype. This property is of particular interest in cancer where enormous heterogeneity of cancer cells is compounded by the presence of altered stromal, vascular and immune cell populations, which is further complicated by systemic responses elicited by the disease in individual patients. These diverse and interacting cellular compartments are dynamically represented by myriads of EVs/EPs released into the circulating biofluids (blood) during cancer progression and treatment. Current approaches of liquid biopsy seek to follow specific elements of the EV/EP cargo that may have diagnostic utility (as biomarkers), such as cancer cell-derived mutant oncoproteins or nucleic acids. However, with emerging technologies enabling high-throughput EV/EP analysis at a single particle level, a more holistic approach may be on the horizon. Indeed, each EV/EP carries multidimensional information (molecular “voxel”) that could be integrated across thousands of particles into a larger and unbiased landscape (EV/EP “hologram”) reflecting the true cellular complexity of the disease, along with cellular interactions, systemic responses and effects of treatment. Thus, the longitudinal molecular mapping of EV/EP populations may add a new dimension to crucial aspects of cancer biology, personalized diagnostics, and therapy.

Slime production is a very important factor related to biofilm formation. The objective of the present study was to determine the frequency of slime production by Staphylococcus aureus and Staphylococcus epidermidis strains recovered from 50 patients with diabetic foot ulcers. Slime production was determined using the Congo red agar (CRA) method and compared with immunocytochemistry for the production of polysaccharide intercellular adhesin (PIA). Out of 55 S. aureus strains, 69% produced slime as shown by the CRA method. Of them, 84.2% also produced PIA. Of 17 CRA-negative strains, 70.6% produced PIA. Out of 20 S. epidermidis strains, 75% were CRA positive and 93.3% produced PIA. All CRA-negative S. epidermidis produced PIA. In conclusion, PIA production is a very common trait of S. aureus and S. epidermidis isolates obtained from diabetic foot ulcer patients.

Epstein–Barr virus (EBV) is the major triggering factor for hemophagocytic syndrome or hemophagocytic lymphohistiocytosis (HLH). In patients with EBV-HLH, the EBV-infected T cells or natural killer cells are mostly mono- or oligoclonally proliferating, whereby hypercytokinemia plays a major role and causes hemophagocytosis, cellular damage, and dysfunction of various organs. This report describes the detection and treatment of EBV-associated HLH in the case of a 17-year-old male. Serum samples and skin swabs were tested for the presence of viral DNA using real-time PCR techniques. To confirm the molecular biological tests, electron microscopy was also performed. EBV DNA was detected with real-time PCR in both blood samples and skin swabs. The level of viral DNA constantly decreased during the applied therapy. The presence of the virus in the skin was confirmed by the appearance of herpes virus-like particles detected by electron microscopy in fluid taken from skin ulcerations. The results show that in terms of treatment, special therapeutic measures are required to control the cytokine storm generated by EBV and to suppress proliferating EBV genome-containing cells because the clinical course is often fulminate and results in a poor outcome. Therefore the potential of chemotherapy with a combination of steroids, etoposide, and cyclosporine to control HLH was assessed in the adolescent, who met the stringent diagnostic criteria for this reactive disorder of the mononuclear phagocyte system.

Metastasis is the direst face of cancer, and it is not a feature solely dependent on cancer cells; however, a complex interaction between cancer cells and host causes this process. Investigating the mechanisms of metastasis can lead to its control. Myeloid-derived suppressor cells (MDSCs) are key components of tumor microenvironment that favor cancer progression. These cells result from altered myelopoiesis in response to the presence of tumor. The most recognized function of MDSCs is suppressing anti-tumor immune responses. Strikingly, these cells are among important players in cancer dissemination and metastasis. They can exert their effect on metastatic process by affecting anti-cancer immunity, epithelial–mesenchymal transition, cancer stem cell formation, angiogenesis, establishing premetastatic niche, and supporting cancer cell survival and growth in metastatic sites. In this article, we review and discuss the mechanisms by which MDSCs contribute to cancer metastasis.

The objective of this study was to determine the expression levels of metallothionein (MT) and p53 protein, recognized neoplastic transformation markers, in pancreatic serous cystadenomas (SCA) and adenomocarcinomas. Neoplastic pancreatic tissue was taken from 20 patients with diagnosed benign (SCA: 5 cases) or malignant tumors (adenomocarcinomas: 15 cases) and control pancreatic tissue from healthy persons who had died in car accidents. Sections were stained with hematoxylin-eosin. Immunohistochemical localization of MT and p53 protein was carried out by LSAB2-HRP using specific antibodies against MT and p53. Metallothionein expression was observed only in the epithelial cells of the neoplastic tissue of SCAs. MT expression in the cystadenomas was weaker than in the healthy pancreatic tissue. No tissue was found with p53 protein expression. In the adenomocarcinomas, positive staining for MT was observed in 67% and p53 was positive in the carcinoma cells. The weak MT expression and lack of p53 protein expression in pancreatic SCAs confirms the lack of local invasive potential of the neoplastic lesion. Increased expressions of MT and p53 were observed in the less differentiated tumors. Thus the expression of MT may be a potential prognostic marker for tumors.

Parasympathomimetics, immunosuppression and plasmapheresis have considerably improved management and prognosis of myasthenia gravis. Side effects of these measures, however, may complicate the course of the disease. In a 66-year-old male with myasthenia gravis and lower back pain, blood cultures, echocardiography and magnetic resonance imaging led to the diagnosis of endocarditis and spondylodiscitis. Enterococcus faecalis grew in the blood cultures as well as on the aortic and tricuspid valve vegetations which were resected during cardiac surgery. Possible sources of the infection might be E. faecalis infections of catheter tips during a 46-day stay in the intensive care unit 11 months earlier where he had undergone plasmapheresis, hemodiafiltration and mechanical ventilation, or recurrent diarrheas since 18 months. Infection was favored by immunosuppression with glucocorticoids and azathioprine which received the patient because of myasthenia gravis and hypothyroidism. Patients with myasthenia gravis require close follow up, including infection parameters, especially when they receive immunosuppressive therapy and when microorganisms known to cause endocarditis, are identified.

Infection with human papillomaviruses (HPVs) often causes cutaneous benign lesions, cervical cancer, and a number of other tumors. The mechanisms of host immune system to prevent and control HPV infection still remain poorly understood. Toll-like receptors (TLRs) are specific pattern recognition molecules that bind to microbial components to trigger innate immunity and direct adaptive immunity in the face of immunological danger. TLRs have been established to play an essential role in sensing and initiating antiviral immune responses. Recent accumulating evidence demonstrated that HPVs modulate TLR expression and interfere with TLR signaling pathways, leading to persistent viral infection and carcinogenesis. This review summarizes current knowledge on the roles of TLR during HPV infection, focusing on TLR recognition, modulation of TLR expression and signaling, regulatory receptors involved in TLR signaling, and cross-talk of TLRs with antimicrobial peptides. Immunotherapeutic strategies based on TLR agonists have emerged to be one of the novel promising avenues in treatment of HPV-associated diseases in the future.