Effect of HTLV-1 Infection on the Clinical Course of Patients with Rheumatoid Arthritis

Association Between Herpes Simplex Virus II Infection and Rheumatoid Arthritis in US Adults: A Population-Based Propensity Score-Matching Study

BACKGROUND/OBJECTIVE

The potential correlation between herpes simplex virus (HSV) and human papillomavirus (HPV) infections and rheumatoid arthritis (RA) has not been definitively established. Further research is needed to determine the relationship between the development of RA and the presence of these viral infections.

METHODS

A case-control study was conducted with data from the National Health and Nutrition Examination Survey between 2009 and 2014. Our analysis examined the association between HSV I, HSV II, HPV oral polymerase chain reaction (PCR), HPV vaginal PCR, and RA. We identified adults aged 20 to 49 years with a primary diagnosis of RA using the National Health and Nutrition Examination Survey database codes (MCQ191 = 1 [years 2009-2010]; MCQ195 = 2 [years 2011-2014]) and excluded patients with incomplete data on key variables and primary outcomes.

RESULTS

The study included 8620 patients, with 150 patients diagnosed with RA and 1500 patients without RA. Patients with RA had a significantly higher prevalence of HSV II infection compared with those without RA (36.34% vs. 24.72%, p = 0.015) after propensity score matching. No significant differences were observed for HSV I, HPV oral PCR, and HPV vaginal PCR between the 2 groups. Patients with RA were older; were more likely to be female, obese, and non-Hispanic White; and had a higher prevalence of comorbidities than those without RA.

CONCLUSIONS

This population-based propensity score-matching study provides evidence of an association between HSV II infection and RA in US adults. Further research is needed to fully elucidate the relationship between viral infections and RA, with the aim of developing effective risk reduction strategies and innovative treatments for RA.

An immunoinformatics and extended molecular dynamics approach for designing a polyvalent vaccine against multiple strains of Human T-lymphotropic virus (HTLV)

Human T-lymphotropic virus (HTLV), a group of retroviruses belonging to the oncovirus family, has long been associated with various inflammatory and immunosuppressive disorders. At present, there is no approved vaccine capable of effectively combating all the highly pathogenic strains of HTLV that makes this group of viruses a potential threat to human health. To combat the devastating impact of any potential future outbreak caused by this virus group, our study employed a reverse vaccinology approach to design a novel polyvalent vaccine targeting the highly virulent subtypes of HTLV. Moreover, we comprehensively analyzed the molecular interactions between the designed vaccine and corresponding Toll-like receptors (TLRs), providing valuable insights for future research on preventing and managing HTLV-related diseases and any possible outbreaks. The vaccine was designed by focusing on the envelope glycoprotein gp62, a crucial protein involved in the infectious process and immune mechanisms of HTLV inside the human body. Epitope mapping identified T cell and B cell epitopes with low binding energies, ensuring their immunogenicity and safety. Linkers and adjuvants were incorporated to enhance the vaccine's stability, antigenicity, and immunogenicity. Initially, two vaccine constructs were formulated, and among them, vaccine construct-2 exhibited superior solubility and structural stability. Molecular docking analyses also revealed strong binding affinity between the vaccine construct-2 and both targeted TLR2 and TLR4. Molecular dynamics simulations demonstrated enhanced stability, compactness, and consistent hydrogen bonding within TLR-vaccine complexes, suggesting a strong binding affinity. The stability of the complexes was further corroborated by contact, free energy, structure, and MM-PBSA analyses. Consequently, our research proposes a vaccine targeting multiple HTLV subtypes, offering valuable insights into the molecular interactions between the vaccine and TLRs. These findings should contribute to developing effective preventive and treatment approaches against HTLV-related diseases and preventing possible outbreaks. However, future research should focus on in-depth validation through experimental studies to confirm the interactions identified in silico and to evaluate the vaccine's efficacy in relevant animal models and, eventually, in clinical trials.

HAM/TSP Pathogenesis: The Transmigration Activity of HTLV-1-Infected T Cells into Tissues

Slowly progressive spastic paraparesis with bladder dysfunction, the main clinical feature of human T-cell leukemia virus-1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), is induced by chronic inflammation in the spinal cord, mainly the lower thoracic cord. A long-standing bystander mechanism, such as the destruction of surrounding tissues by inflammatory cytokines, etc., induced under the interaction between infiltrated HTLV-1-infected CD4⁺ T cells and HTLV-1-specific CD8⁺ cytotoxic T cells, has been considered implicated for the induction of chronic inflammation. As this bystander mechanism is triggered conceivably by the transmigration of HTLV-1-infected CD4⁺ T cells to the spinal cord, heightened transmigrating activity of HTLV-1-infected CD4⁺ T cells to the spinal cord might play a crucial role as the first responder in the development of HAM/TSP. This review evaluated the functions of HTLV-1-infected CD4⁺ T cells in HAM/TSP patients as the prerequisite for the acquisition of the activity such as adhesion molecule expression changes, small GTPases activation, and expression of mediators involved in basement membrane disruption. The findings suggest that HTLV-1-infected CD4⁺ T cells in HAM/TSP patients have enough potential to facilitate transmigration into the tissues. Future HAM/TSP research should clarify the molecular mechanisms leading to the establishment of HTLV-1-infected CD4⁺ T cells as the first responder in HAM/TSP patients. In addition, a regimen with an inhibitory activity against the transmigration of HTLV-1-infected CD4⁺ T cells into the spinal cord might be recommended as one of the therapeutic strategies against HAM/TSP patients.

Special Issue 'Viral Infection and Autoimmune Diseases'

Viral infection, which is one of the environmental factors, and human autoimmune diseases are often associated with each other [...].