Viral immunology最新文献

Respiratory syncytial virus (RSV) is one of the most important etiologies of acute respiratory infections that cause bronchiolitis in children under 5 years of age. Treatments are expensive, no vaccine is available, and this is an important cause of hospitalization. Costimulatory molecules have been reported to be good inducers of antiviral type 1 immune response. This study aimed to generate a recombinant vaccine with the RSV F protein fused to 4-1BBL to evaluate the activation of an antiviral response in vitro and the production of neutralizing antibodies in vivo. The codon-optimized F gene was subcloned into an expression vector as follows: streptavidin core, gene F, and costimulatorytumor necrosis factor receptor superfamily member 9 -TNFRS9- ligand (4-1BBL). After the induction of expression in Escherichia coli C43, the recombinant protein (SA-F3x-4-1BBL, denominated SF4) was purified and verified by western blotting. Cultured RAW264.7 macrophages were stimulated with SF4 protein, then tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2), p38, and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) were analyzed by western blot, and mRNA cytokines were analyzed by RT-qPCR. Finally, male C57BL/6 mice were inoculated with SF4, and the generation of anti-RSV neutralizing antibodies and serum cytokines was examined. SF4 had a size of 84.4 kDa with a 5.6% yield. SA-F-4-1BBL upregulated TRAF2, TNF-α, and interferon (IFN)-γ expression levels and activated p38 mitogen-activated protein kinase and NF-κΒ pathways in RAW264.7 cells. Importantly, antibodies capable of neutralizing RSV infection and producing type 1 cytokines were detected in the sera of immunized animals. These results suggest that the fusion protein SF4 activates the 4-1BBL signaling pathway, resulting in an effective antiviral response mediated by neutralizing antibodies and antiviral cytokines.

The increasing use of immune suppressive monoclonal antibodies in the treatment of organ transplant recipients and patients with oncologic, neurological, and autoimmune diseases can lead to serious morbidity and mortality from the reactivation of viral agents that persist in humans. The squirrel monkey polyomaviruses are naturally found in Bolivian squirrel monkeys (SQM) and may be a useful model for the study of polyomavirus-associated pathogenesis and experimental treatment and prevention strategies. Two diverse groups of squirrel monkeys were given, a single dose of an anti-B cell antibody (rituximab) resulting in complete depletion of B cells (CD20+), while an anti-CD8 monoclonal antibody (7 pt-3F9) resulted in a transient depletion of CD8+ lymphocytes compared with control animals (group with no infusion with either of the monoclonal antibodies). The animals remained clinically healthy, with no pathological symptoms suggesting that the intensity and/or duration of immune suppression were inadequate to trigger pathogenic reactivation of the latent polyoma and herpes viruses. We observed a transient reduction in circulating plasma cytokines, IL-2, IFN-γ, and IL-12 reduced JC and BK viral protein-specific proliferative responses in both the CD8 and CD20 depletion groups. This study clearly elucidates the consequences of the use of depletion monoclonal antibodies in immune suppression modalities in the treatment of human malignancies and during transplantation, and SQM acts as a good model in the selection of dosage at which activation of latent viruses is at a minimum, with no pathological consequences.

This study aims to evaluate the estimate of causal relationship between Epstein-Barr virus (EBV) antibody levels and autoimmune diseases (AIDs), such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), through bidirectional two-sample Mendelian randomization (MR) analysis. Despite 50 years of research into the link between EBV infection and AIDs, inconsistent results persist due to the complex mechanisms of EBV within the body. We utilized large-scale genome-wide association studies (GWAS) data from the Integrative Epidemiology Unit (IEU) Open GWAS Project database to conduct rigorous MR analysis, incorporating various sensitivity analyses to assess potential impacts and ensure robustness. EBV antibodies (including VCA-IgG, ZEBRA-IgG, EBNA-1-IgG, and EA-D-IgG) were used as exposure variables, whereas RA and SLE served as outcome variables. In the reverse analysis, RA and SLE were treated as exposure variables and EBV antibodies as outcome variables. When EBV antibodies are designated as the exposure variables, the random-effects inverse-variance weighted (IVW) analysis indicated a significant negative genetic causal relationship between EBV EA-D antibody levels and RA (p = 0.007, odds ratio [OR] = 0.700, 95% confidence interval [CI] = [0.539-0.907]). No significant genetic causal relationship was found between SLE and EBV antibody levels. When RA and SLE are designated as the exposure variables, the random-effects IVW analysis revealed significant positive genetic causal relationships between SLE and EBV ZEBRA antibody levels (p = 0.009, OR = 1.028, 95% CI = [1.007-1.050]) and EBV EA-D antibody levels (p = 0.005, OR = 1.032, 95% CI = [1.009-1.054]). No significant genetic causal relationship was observed between RA and EBV antibody levels. This study offers compelling evidence of a causal relationship between EBV antibody levels and AIDs through MR analysis. Our findings lay a new foundation and perspective for future research directions, clinical prognosis, and treatment.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and first identified in Wuhan, China, in December 2019, has led to global efforts in vaccination to mitigate rising morbidity and mortality, with vaccines proving crucial in controlling the pandemic. This study evaluated the humoral responses to the inactivated virus vaccine Sinopharm or Koxing Kerlafor, the protein subunit vaccine ZF001, and the adenoviral vector vaccine Convidecia after 18 months of inactivated virus vaccination by heterologous and homologous booster vaccination in patients with previous SARS-CoV-2 infection and healthy individuals. We discovered that patients who had recovered from the infection and then received a third vaccine dose (booster) exhibited durable immunity. Furthermore, the heterologous booster vaccine induced higher neutralizing antibody responses compared with the homologous booster. These findings offer valuable insights into the efficacy of different COVID-19 vaccine strategies following booster immunization.

Field evidence indicates differences in the rate and severity of COVID-19 infection among Afghans and Iranians, potentially influenced by individual genomic variances. Therefore, investigating the potential causes of these disparities holds significant clinical importance. This study aims to explore and compare variations in the genes encoding angiotensin-converting enzyme 1 (ACE1) and angiotensin-converting enzyme 2 (ACE2), along with total ACE activity levels in the blood of Afghans and Iranians with COVID-19, to assess any potential correlation with disease severity. In this case-control study, 124 Afghans and 124 Iranians with COVID-19 residing in Rafsanjan city, Iran, were examined. Blood samples were collected from all subjects, and serum was isolated for measuring total ACE activity using the kinetic method. DNA extraction was performed using the salting-out method, and gene polymorphisms of ACE1 and ACE2 were determined through polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism techniques. The DD genotype and D allele, as well as the GG genotype and G allele, were more prevalent among individuals with severe COVID-19 cases compared with those with mild symptoms, indicating an increased risk of severe infection. Although the Iranian group exhibited higher levels of these genetic components, along with longer hospital stays, intensive care unit admissions, and mortality rates than the Afghan group, the differences were not statistically significant. Furthermore, individuals with the DD genotype displayed double the total ACE activity levels compared with those with the II genotype, with the ID genotype falling in between. The presence of the DD genotype and D allele, as well as the GG genotype and G allele, likely serves as a significant risk factor for COVID-19 susceptibility, potentially heightening the risk of severe infection among Iranians compared with Afghans.

This study investigates the demographic, clinical characteristics, virological profiles, and immunological responses of patients with viral encephalitis (VE) compared with a control group. The VE group displayed a wide range of neurological symptoms. Virological analysis revealed the predominance of Herpesviridae family viruses. Immune responses in cerebrospinal fluid (CSF) from patients with VE were examined, highlighting an immunological shift toward T helper 1 (Th1) cells dominance, altered T helper 17 cells/regulatory T cells (Th17/Tregs) balance, and high interleukin-6 expression. These findings provide insights into the complex immunological landscape of VE, highlighting the role of specific cytokines and T cell subsets in its pathogenesis and potentially guiding targeted therapeutic strategies.

This study aims to explore the mechanism underlying the role of ubiquitin-specific protease 14 (USP14) in regulating P53 expression and influencing the development of hepatitis B. The animal and cell models of hepatitis B were constructed. The mRNA and protein expression of USP14, mouse double minute 2 (MDM2), and P53 were detected by western blot and qPCR. The USP14 overexpression vector was constructed. The pathological changes of liver tissue were detected by HE and Masson staining. Protein immunoprecipitation was used to detect the interaction between MDM2 and P53, as well as between MDM2 and USP14. The ubiquitination levels of P53 after USP14 overexpression were detected. qPCR and western blot were used to detect the expression of MDM2, Bcl-2, P53, Bax, and Caspase-1 in vivo and in vitro. Compared with the control group, the model group showed increased cell proliferation, increased expression of MDM2 and Bcl-2 in cells and liver tissue, and decreased expression of P53, Bax, and Caspase-1. Compared with the model group, overexpression of USP14 resulted in a decrease in MDM2 expression and an increase in P53 expression. After transfection with the USP14 overexpression plasmid, cell proliferation was inhibited, and the expression of MDM2 and Bcl-2 was decreased in cells and liver tissue, while the expression of P53, Bax, and Caspase-1 was increased. In the model of hepatitis B, USP14 upregulation downregulated MDM2 and promoted P53 deubiquitination to delay the invasion of hepatitis B virus and the development of hepatitis.

Following viral infection, antigen-restricted T lymphocytes are activated and recognize infected cells to eliminate them. A subset of T cells differentiates into memory lymphocytes able to counteract viral rechallenge in a faster and enhanced way. SARS-CoV-2 can escape immune responses leading to a poor clinical outcome. Immune escape can be associated with the failure of the development of T cell memory compartments. The aim of this study is to characterize the T memory subsets and to test the immune response against class I- and II-restricted immunodominant epitopes shared by ancestral and SARS-CoV-2 variants strains. T memory subsets and recognition of SARS-CoV-2S Spike-specific epitopes were analyzed by flow cytometry on 14 fully vaccinated healthy donors (HDV) and 18 COVID-19 recovered patients (CD). The results obtained showed that CD8+ T naïve subset numbers decreased in association with a significant increase of the effector memory T cell subset whereas there was a small increase in the percentage of SARS-CoV-2 antigen-restricted T clones in both CD4⁺ and CD8+ subset in the CD compared to HDV sample. Collectively, these features may reflect a broader cytotoxic T cell repertoire stimulated by the virus during the natural infection compared to the spike-restricted response activated during vaccination.

Viral infections are one of the principal causes of global primary health crises, with increased rate of infection and mortality demonstrated by the newer progeny of viruses. Viral invasion of the host involves utilization of various cellular machinery. Ubiquitination is one of a few central regulatory systems used by viruses for establishment of the infections in the host. Members of the ubiquitination system are involved in carrying out proteasomal degradation or functional modification of proteins in numerous cellular processes. E3 ubiquitin ligases play a major role in this system through recognition and recruitment of protein substrates and catalyzing the transfer of ubiquitin to these substrates. The versatility of ubiquitin ligases frequently makes them useful tools for the viruses, for either utilizing or degrading other cellular machineries, for carrying out their multiplication or inactivating the defensive strategies of the host. Therefore, these ligases are important targets for aiming at major pathways causing viral protein degradation or functional modification of the infection process. In this review, we have discussed the role and mechanism of different types of ubiquitin ligases in the context of infections of mainly human viruses, highlighting the viral proteins directly interacting with the ligases. Knowledge about these direct interactions is central in understanding the ubiquitin-dependent processes. This comprehensive account may also be beneficial for pharmaceutical exploration of E3 ligase-based broad-spectrum antiviral treatment.

Human T-cell lymphotropic virus type-I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), the main neurological manifestation of HTLV-I, is a chronic inflammatory disease. Viral-host interaction and host genetics are two important contributors to the development of the HAM/TSP. This study was conducted to measure the serum level of tumor necrosis factor-alpha-like weak inducer of apoptosis (TWEAK) by ELISA method in three groups of participants including 34 HAM/TSP patients (HAM/TSP), 35 asymptomatic HTLV-1 carriers (ACs), and 20 healthy controls (HCs). Also, the titer of the proviral load in two groups of HAM/TSP and ACs was assessed by the real-time polymerase chain reaction (PCR). The statistical results showed that, there is no significant difference between the three groups in TWEAK cytokine level (p = 0.667). Also, there was no significant difference in proviral load titer between groups of HAM/TSP and ACs (p = 0.08). Furthermore, no significant difference was observed between proviral load and TWEAK cytokine concentration between groups of HAM/TSP and ACs. Our findings showed that despite the inflammatory nature of HAM/TSP disease, the expression level of TWEAK in HAM/TSP patients is not significantly different from the groups of ACs and HCs. Therefore, the involvement of other factors in causing HAM/TSP is not unexpected.