The Redox-Metabolic Couple of T Lymphocytes: Potential Consequences for Hypertension

Determinants of health as predictors for differential antibody responses following SARS-CoV-2 primary and booster vaccination in an at-risk, longitudinal cohort

Post vaccine immunity following COVID-19 mRNA vaccination may be driven by extrinsic, or controllable and intrinsic, or inherent health factors. Thus, we investigated the effects of extrinsic and intrinsic on the peak antibody response following COVID-19 primary vaccination and on the trajectory of peak antibody magnitude and durability over time. Participants in a longitudinal cohort attended visits every 3 months for up to 2 years following enrollment. At baseline, participants provided information on their demographics, recreational behaviors, and comorbid health conditions which guided our model selection process. Blood samples were collected for serum processing and spike antibody testing at each visit. Cross-sectional and longitudinal models (linear-mixed effects models) were generated to assess the relationship between selected intrinsic and extrinsic health factors on peak antibody following vaccination and to determine the influence of these predictors on antibody over time. Following cross-sectional analysis, we observed higher peak antibody titers after primary vaccination in females, those who reported recreational drug use, younger age, and prior COVID-19 history. Following booster vaccination, females and Hispanics had higher peak titers after the 3rd and 4th doses, respectively. Longitudinal models demonstrated that Moderna mRNA-1273 recipients, females, and those previously vaccinated had increased peak titers over time. Moreover, drug users and half-dose Moderna mRNA-1273 recipients had higher peak antibody titers over time following the first booster, while no predictive factors significantly affected post-second booster antibody responses. Overall, both intrinsic and extrinsic health factors play a significant role in shaping humoral immunogenicity after initial vaccination and the first booster. The absence of predictive factors for second booster immunogenicity suggests a more robust and consistent immune response after the second booster vaccine administration.

Immunogenicity and safety of inactivated SARS-CoV-2 vaccine in haemodialysis patients: a prospective cohort study

End-stage renal disease patients on haemodialysis (HD) have been largely excluded from SARS-CoV-2 vaccine trials due to safety reasons and shown to mount lower responses to vaccination. This study aims to evaluate the immunogenicity and safety of inactivated COVID-19 vaccine among HD patients compared to healthy controls. All subjects who received the primary inactivated COVID-19 vaccination had their blood samples tested 21 days after the second dose. We report the immunogenicity based on anti-RBD IgG titre (IU/mL), the inhibition rate of neutralizing antibodies (NAbs) (%) to RBD, and seroconversion rates. Adverse events were assessed within 30 min and on the 7th day after each dose. Among 75 HD patients and 71 healthy controls, we observed no significant difference in all immunogenicity measures: anti-RBD IgG GMT (277.91 ± 7.13 IU/mL vs. 315.50 ± 3.50 IU/mL, p = 0.645), NAbs inhibition rate (82% [53-96] vs. 84% [39-98], p = 0.654), and seroconversion rates (anti-RBD IgG: 86.7% vs. 85.9%, p = 0.895; NAbs: 45.3% vs. 60.6%, p = 0.065). The number of adverse events is not significantly different between the two groups. The primary inactivated SARS-CoV-2 vaccination elicits an adequate antibody response and can be safely administered in haemodialysis patients.

Immunosenescence in Aging-Related Vascular Dysfunction

The immunosenescence-related disproportion in T lymphocytes may have important consequences for endothelial dysfunction, which is a key event in vascular aging. The study was designed to assess the prognostic values of the inflammatory-immune profile to better predict and prevent vascular diseases associated with old age. Eighty individuals aged 70.9 ± 5.3 years were allocated to a low- (LGI) or high-grade inflammation (HGI) group based on CRP (<3 or ≥3 mg/L) as a conventional risk marker of cardiovascular diseases. Significant changes in inflammatory and endothelium-specific variables IL-1β, IL-6, TNFα, oxLDL, H2O2, NO, 3-nitrotyrosine, and endothelial progenitor cells (OR 7.61, 95% CI 2.56−29.05, p < 0.0001), confirmed their interplay in vascular inflammation. The flow-cytometry analysis demonstrated a high disproportion in T lymphocytes CD4+ and CD8+ between LGI and HGI groups. CRP was <3 mg/mL for the CD4/CD8 ratio within the reference values ≥ 1 or ≤2.5, unlike for the CD4/CD8 ratio < 1 and >2.5. The odds ratios for the distribution of CD4+ (OR 5.98, 95% CI 0.001−0.008, p < 0.001), CD8+ (OR 0.23, 95% CI 0.08−0.59, p < 0.01), and CD8CD45RO+ T naïve cells (OR 0.27, 95% CI 0.097−0.695, p < 0.01) and CD4/CD8 (OR 5.69, 95% CI 2.07−17.32, p < 0.001) indicated a potential diagnostic value of T lymphocytes for clinical prognosis in aging-related vascular dysfunction.

Hypertension is associated with antibody response and breakthrough infection in health care workers following vaccination with inactivated SARS-CoV-2

Several types of vaccines have been developed to prevent the coronavirus disease 2019 (COVID-19). It is important to understand whether demographic and clinical variables affect the effectiveness of various types of vaccines. This study analysed the association between demographic/clinical factors, antibody response and vaccine effectiveness in healthcare workers vaccinated with inactivated virus.

We enrolled 101 healthcare workers who received two doses of inactivated viral vaccine (CoronaVac). Blood samples were analysed at 1, 3, and 5 months after the second dose of vaccination. Data regarding demographic characteristics, medical histories, and clinical parameters were collected by interview and medical examination. In a separate retrospective study, we analysed the incidence of vaccine breakthrough infection on 2714 healthcare workers who received two doses of inactivated viral vaccine. Medical histories and demographic data were collected using a structured self-reported questionnaire.

We found that antibody titres markedly increased at 1 month after vaccination but gradually decreased at 3–5 months post-vaccination. We observed a significant association between age (≥40 years) and antibody level, whereas sex and body mass index (BMI) exhibited no effect on antibody titres. Amongst clinical variables analysed, high blood pressure and history of hypertension were significantly correlated with lower antibody titres. Consistently, we found a significant association in the retrospective study between hypertension and the incidence of breakthrough infection.

In conclusion, our results showed that hypertension is associated with lower antibody titres and breakthrough infection following COVID-19 vaccination. Thus, blood pressure control might be important to improve the efficacy of inactivated virus vaccine.

T Cell Immunometabolism and Redox Signaling in Hypertension

PURPOSE OF REVIEW

In this article, we summarize the current literature supporting metabolic and redox signaling pathways as important mechanisms underlying T cell activation in the context of hypertension.

RECENT FINDINGS

T cell immunometabolism undergoes dramatic remodeling in order to meet the demands of T cell activation, differentiation, and proliferation. Recent evidence demonstrates that the T cell oxidation-reduction (redox) system also undergoes significant changes upon activation, which can itself modulate metabolic processes and T cell function. Dysregulation of these signaling pathways can lead to aberrant T cell activation and inappropriate ROS production, both of which are linked to pathological conditions like hypertension. While the contribution of T cells to the progression of hypertension has been thoroughly investigated, how T cell metabolism and redox signaling changes, both separately and together, is an area of study that remains largely untouched. This review presents evidence from our own laboratory as well as others to highlight the importance of these two mechanisms in the study of hypertension.

Splenic denervation attenuates repeated social defeat stress-induced T-lymphocyte inflammation

Background

Post-traumatic stress disorder (PTSD) is a devastating psychological disorder. Patients with PTSD canonically demonstrate an increased risk for inflammatory diseases, as well as increased sympathetic tone and norepinephrine (NE) outflow. Yet, the exact etiology and causal nature of these physiologic changes remain unclear. Previously, we demonstrated that exogenous NE alters mitochondrial superoxide in T-lymphocytes to produce a pro-inflammatory T-helper 17 (TH17) phenotype, and observed similar TH17 polarization in a preclinical model of PTSD. Therefore, we hypothesized sympathetic-driven neuroimmune interactions could mediate psychological trauma-induced T-lymphocyte inflammation.

Methods

Repeated social defeat stress (RSDS) is a preclinical murine model that recapitulates the behavioral, autonomic, and inflammatory aspects of PTSD. Targeted splenic denervation (Dnx) was performed to deduce the contribution of splenic sympathetic nerves to RSDS-induced inflammation. Eighty-five C57BL/6J mice underwent Dnx or sham-operation, followed by RSDS or control paradigms. Animals were assessed for behavioral, autonomic, inflammatory, and redox profiles.

Results

Dnx did not alter the antisocial or anxiety-like behavior induced by RSDS. In circulation, RSDS Dnx animals exhibited diminished levels of T-lymphocyte-specific cytokines (IL-2, IL-17A, and IL-22) compared to intact animals, whereas other non-specific inflammatory cytokines (e.g., IL-6, TNF-α, and IL-10) were unaffected by Dnx. Importantly, Dnx specifically ameliorated the increases in RSDS-induced T-lymphocyte mitochondrial superoxide, TH17 polarization, and pro-inflammatory gene expression with minimal impact to non-T-lymphocyte immune populations.

Conclusions

Overall, our data suggest that sympathetic nerves regulate RSDS-induced splenic T-lymphocyte inflammation, but play less of a role in the behavioral and non-T-lymphocyte inflammatory phenotypes induced by this psychological trauma paradigm.