Peripheral NK cell phenotypic alteration and dysfunctional state post hepatitis B subviral particles stimulation in CHB patients: evading immune surveillance.

Background: The relationship between chronic hepatitis B (CHB) infection and natural killer (NK) cell dysfunction is well-established, but the specific role of HBV viral antigens in driving NK cell impairment in patients with CHB remains unclear. This study investigates the modulatory effects of hepatitis B virus subviral particles (HBVsvp, a representative model for HBsAg) on the phenotypic regulation (activating and inhibitory receptors), cytokine production and cytotoxic potential of peripheral blood mononuclear cell-derived natural killer cells (PBMCs-derived NK cell), which contributes to NK cell dysfunction in CHB infection, potentially serving as an effective HBV immune evasion strategy by the virus. Methods: NK cells were isolated from peripheral blood of patients with CHB (n=5) and healthy individuals (n=5), stimulated with HBVsvp. Subsequent flow cytometric characterization involved assessing changes in activating (NKp46 and NKG2D) and inhibitory (CD94) receptors expression, quantifying TNF-α and IFN- γ cytokine secretion, and evaluating the cytotoxic response against HepG2.2.15 cells with subsequent HBVsvp quantification. Results: In CHB patients, in vitro exposure of PBMCs-derived NK cell with HBVsvp (represent HBsAg model) significantly reduced NK cell-activating receptors expression (P = 0.022), increased expression of CD94 + NK cells (p = 0.029), accompanied with a reduced TNF-α - IFN-γ cytokine levels, and impaired cytotoxic capacity (evidenced by increased cell proliferation and elevated HBVsvp levels in co-cultures with HepG2.2.15 cells in a time-dependent), relative to healthy donors. Conclusion: These findings suggest that HBVsvp may induce dysfunctional NK cell responses characterized by phenotypic imbalance with subsequent reduction in cytokine and cytotoxic levels, indicating HBVsvp immunosuppressive effect that compromises antiviral defense in CHB patients. These data enhance our understanding of NK cell interactions with HBsAg and highlight the potential for targeting CD94 inhibitory receptors to restore NK cell function as an immunotherapeutic approach. Further clinical research is needed to validate these observations and establish their utility as reliable biomarkers.

Photobiological modulation of hepatoma cell lines and hepatitis B subviral particles secretion in response to 650 nm low level laser treatment.

BACKGROUND: Chronic hepatitis B virus (HBV) infection is a serious global health concern, with an increased incidence and risk of developing cirrhosis and hepatocellular carcinoma (HCC). Patients chronically infected with HBV are likely to experience chronic oxidative stress, leading to mitochondrial dysfunction. Photobiomodulation is induced by the absorption of low-level laser therapy (LLLT) with a red or infrared laser by cytochrome C oxidase enzyme, resulting in mitochondrial photoactivation. Although it is widely used in clinical practice, the use of LLL as adjuvant therapy for persistent HBV infection is uncommon. This study aimed to investigate the effect of LLLT dosage from 2 J/cm2 to 10 J/cm2 of red diode laser (650 nm) on both hepatoma cell lines (HepG2.2.15 [integrated HBV genome stable cell model] and non-integrated HepG2), with a subsequent impact on HBVsvp production. METHODS: The present study evaluated the effects of different fluences of low-level laser therapy (LLLT) irradiation on various aspects of hepatoma cell behavior, including morphology, viability, ultrastructure, and its impact on HBVsvp synthesis. RESULTS: In response to LLLT irradiation, we observed a considerable reduction in viability, proliferation, and HBVsvp production in both hepatoma cell lines HepG2.2.15 and HepG2. Ultrastructural modification of mitochondria and nuclear membranes: This effect was dose, cell type, and time-dependent. CONCLUSIONS: The use of LLLT may be a promising therapy for HCC and HBV patients by reducing cell proliferation, HBVsvp production, and altering mitochondrial and nuclear structure involved in cellular death inducers. Further research is required to explore its clinical application.

HBVsvp-Pulsed Dendritic Cell Immunotherapy Induces Th1 Polarization and Hepatitis B Virus-Specific Cytotoxic T Lymphocytes Production.

BACKGROUND: In chronic hepatitis B virus (CHB) patients, both dendritic cells (DCs) and T cells are functionally impaired and consequently the HBV-specific cellular immune responses are downregulated. The present study aims to investigate whether monocyte-derived DC (MoDCs)-pulsed-HBV subviral particles (HBVsvp) can polarize Th1 cells to induce HBV-specific cytotoxic T-lymphocytes (CTL) responses in CHB patients. METHODS AND MATERIALS: To this end, the human hepatoma HepG2.2.15 cell line was used to produce HBVsvp as a culturing system, and HBVsvp were concentrated for highly virus titer using the polyethylene glycol protocol. Peripheral blood mononuclear cells (PBMCs), collected from CHB patients and healthy donors, were differentiated into MoDCs and T cells. PBMCs-derived MoDCs were first pulsed with HBVsvp and then cultured with PBMCs-derived T cells. MoDCs and/or T subsets cells were identified for phenotypic activation by FACS analysis. The cytokine secretion of IL-4, IL-12, and IFN-γ in the culture supernatants was detected. RESULTS: The MoDCs were restored for their activation upon pulsing with HBVsvp in vitro, as identified by significantly overexpression of both CD86 and HLA-DR, and overproduction of IL-4 and IL-12. Furthermore, MoDCs-pulsed-HBVsvp induced Th1 frequencies and activated HBV-specific CTL to produce significantly highest amount of IFN-γ. Enhanced HBV-specific CTL led to strong cytolytic capacity against HepG2.2.15. CONCLUSION: Overall, our data suggest that in vitro activation of MoDCs with HBVsvp overcomes the functionally impaired DCs and T cells in CHB patients offering a promising tool for therapeutic or vaccine-based approaches against HBV.

Crosstalk between aldehyde dehydrogenase-1 and chemoresistance in breast cancer: Insights into the role of vitamin D3.

AIMS: Aldehyde dehydrogenase-1 (ALDH-1) is considered a signature of breast cancer stem cells and is linked to poor outcomes in breast cancer patients. This study aimed at investigating the effect of vitamin D3 on enhancing the tumor responsiveness to different conventional chemotherapeutic agents, viz., cisplatin, methotrexate, and doxorubicin. MAIN METHODS: In vitro and in vivo experiments were performed using combinations of vitamin D3 and chemotherapeutic agents. Cell cycle analysis and apoptosis assays were performed. Moreover, ALDH-1 expression levels were estimated in cancer cell lines and solid tumors. For solid tumors, tumor volume and histopathological necrotic indices were estimated. Leukocyte presence was also evaluated in tumors using leukocyte common antigen (LCA). KEY FINDINGS: Results showed a synergistic interaction between vitamin D3 and each of the chemotherapeutic agents on breast cancer cell lines as well as cell cycle arrest at G2/M phase. A decrease in ALDH-1 levels was reported in both breast cancer cells and in tumor tissues. Reductions in tumor volume were also observed in the groups which received the combination therapy. An influence on necrosis rather than apoptosis was also reported, as evidenced by necrotic indices and Bcl-2 expression in tumor sections, respectively. Increased local leukocytes in tumors was also evident, as indicated by increased expression of leukocyte common antigen (LCA). SIGNIFICANCE: Overall, the present study shows that vitamin D3 has an impact on resistance to different chemotherapeutic agents which could be due to the inhibition of ALDH-1, suggesting its use as an adjuvant therapy in cancer patients receiving chemotherapy.

Cloning, expression and nanodiscs assemble of recombinant HIV-1 gp41.

Structural studies of membrane proteins have been hurdled by their difficulty for expression in heterogeneous expression systems due to their intrinsically strong hydrophobicity and requirements for association with other cellular membranes. This study aims to design a construct for expression of membrane proteins. Because of its outstanding interest in HIV-1 vaccine design, transmembrane gp41 amino acid residue 662-723 was chosen as a representative membrane protein. Therefore, we constructed expression vectors for expression of gp41(662-723) alone (pET28a-gp41(662-723)) or coupled with a fusion partner: GB1 (pET30a-GB1-gp41(662-723)) and Trx (pET32a-Trx-gp41(662-723)). For enhancing protein expression, the expression plasmids were transformed into E. coli BL-21 (DE3), E. coli T7 Express lysY/Iq and E. coli Lemo21 (DE3). Interestingly, HIV-1 gp41(662-723) was expressed as a C-terminus fusion to the fusion partner Trx (Trx-gp41(662-723)) with an apparent molecular mass of 21.8 kDa. Trx-gp41(662-723) was overexpressed into E. coli T7 Express lysY/Iq by early induction as OD600 ~0.5 followed by incubation at 20 °C/overnight. Our data demonstrated that almost all recombinant Trx-gp41(662-723) was incorporated into lipid nanodiscs by slowing down the nanodiscs assembly process. Negative-stained electron micrographs revealed homogenous 10 nm Trx-gp41(662-723)-nanodiscs. While the neutralizing epitopes in the purified Trx-gp41(662-723) were accessible and recognizable by anti-MPER bNAbs, these epitopes became less accessibly exposed, particularly in the C-terminal region of MPER, after incorporation of Trx-gp41(662-723) into nanodiscs.

Phenotypic screening and molecular characterization of carbapenemase-producing Gram-negative bacilli recovered from febrile neutropenic pediatric cancer patients in Egypt.

AIM: Infections with carbapenem-resistant Gram-negative bacteria (GNB) are among the most frequent complications in the immunocompromised cancer patients because of their considerable morbidity and mortality. Therefore, the aim of the current study was to characterize the prevalence of carbapenemase-producing GNB recovered from febrile neutropenic pediatric cancer patients in Egypt. METHODS: Standard methods were used for identification, sensitivity testing (Kirby-Bauer and broth microdilution method according to CLSI guidelines). Standard methods were applied for both phenotypic and genotypic detection of the carbapenemase-producing GNB. RESULTS: A total of 185 GNB were recovered from different clinical specimens, Escherichia (E.) coli (86; 46.48%), followed by Klebsiella spp. (71; 38.37%), Acinetobacter (A.) baumannii (7; 3.78%) and others including Pseudomonas spp., Enterobacter (Ent.) cloacae and Proteus spp. (21; 11.35%). It is a matter of concern that 116 out of 171 enterobacterial isolates (94.15%) showed resistance to three or more antimicrobial classes and were considered multidrug resistant. Additionally, the rate of carbapenem-resistance displayed a worrisome trend as 113 out of 171 enterobacterial isolates (66.08%) and 12 out of 14 non fermenting bacilli (85.71%) showed resistance pattern to at least one of the tested carbapenems. After performing a series of phenotypic tests for initial screening of potential carbapenemase producers, molecular characterization to the 29 extracted plasmids were subjected to PCR (using 5 common carbapenemase primers). The results revealed that blaOXA-48 was the most prevalent 17 (58.62%), followed by blaNDM 8(27.58%), then blaVIM 3 (10.3%) and blaKPC 2 (6.89%). CONCLUSION: These results are an alarming threat to public health that calls for urgent application of antimicrobial stewardship programs along with routine surveillance for controlling outbreaks.

Wharton's jelly-derived mesenchymal stem cells combined with praziquantel as a potential therapy for Schistosoma mansoni-induced liver fibrosis.

Liver fibrosis is one of the most serious consequences of S. mansoni infection. The aim of the present study was to investigate the potential anti-fibrotic effect of human Wharton's jelly-derived mesenchymal stem cells (WJMSCs) combined with praziquantel (PZQ) in S. mansoni-infected mice. S. mansoni-infected mice received early (8(th) week post infection) and late (16(th) week post infection) treatment with WJMSCs, alone and combined with oral PZQ. At the 10(th) month post infection, livers were collected for subsequent flow cytometric, histopathological, morphometric, immunohistochemical, gene expression, and gelatin zymographic studies. After transplantation, WJMSCs differentiated into functioning liver-like cells as evidenced by their ability to express human hepatocyte-specific markers. Regression of S. mansoni-induced liver fibrosis was also observed in transplanted groups, as evidenced by histopathological, morphometric, and gelatin zymographic results besides decreased expression of three essential contributors to liver fibrosis in this particular model; alpha smooth muscle actin, collagen-I, and interleukin-13. PZQ additionally enhanced the beneficial effects observed in WJMSCs-treated groups. Our results suggest that combining WJMSCs to PZQ caused better enhancement in S. mansoni-induced liver fibrosis, compared to using each alone.