No Evidence of Neutrophil Response Modulation in Goats after Immunization against Paratuberculosis with a Heat-Inactivated Vaccine.

Neutrophils are believed to play a role in the initial stages of paratuberculosis, and it has recently been demonstrated that vaccination can modulate their function via priming or through epigenetic and metabolic reprogramming (training). Modulation of the neutrophil response against Mycobacterium avium subspecies paratuberculosis (Map) through vaccination has been demonstrated in a rabbit model but not in ruminants. Therefore, in the present work, the effect of vaccination on the response of caprine neutrophils against Map was studied. Neutrophils were isolated from non-vaccinated (n = 7) and Gudair®-vaccinated goat kids (n = 7), before vaccination and 30 days post-vaccination. Then, several neutrophil functions were quantified ex vivo: cell-free and anchored neutrophil extracellular trap (NET) release, phagocytosis, and the differential expression of several cytokines and TLR2. The induction of cell-free NETosis and TLR2 expression by Map is reported for the first time. However, vaccination showed no significant effect on any of the functions studied. This suggests that the protection conferred by Gudair® vaccination is based on mechanisms that are independent of the neutrophil function modulation. Further research into the impact of alternative vaccination strategies or the paratuberculosis infection stage on ruminant neutrophil function could provide valuable insights into its role in paratuberculosis.

A standardized combination of Terminalia chebula and Withania somnifera extracts enhances immune function in adults: a pilot randomized, double-blind, placebo-controlled clinical study.

Background: The use of botanical medicine has been demonstrated as a potential strategy to manage or treat a variety of health issues. Terminalia chebula (Retz) fruit and Withania somnifera (L.) Dunal roots are important medicinal herbs described in Ayurveda and traditional therapy for diverse health benefits. Objective: This pilot study aimed to evaluate the immune function-enhancing potential of a unique blend of T. chebula fruit and W. somnifera root extracts, LN20189, in healthy men and women. Methods: Forty healthy volunteers (age: 35-60 years) were randomized into two groups receiving either LN20189 (500 mg per day) or a matched placebo over 28 consecutive days. The total T-cell population was the primary efficacy measure in this study. The secondary efficacy measures included counts of CD4, CD8, natural killer (NK) cells, serum levels of interleukin-2 (IL-2), interferon-gamma (IFN-γ), total immunoglobulin-G (IgG), and Immune Function Questionnaire (IFQ) scores. Safety parameter assessments were also conducted. Results: Post-trial, in LN20189-supplemented subjects, T cells, CD4, NK cells count, and the CD4:CD8 ratio were increased by 9.32, 10.10, 19.91, and 17.43%, respectively, as compared to baseline. LN20189 supplementation increased serum IFN-γ and IgG levels by 14.57 and 27.09% from baseline and by 13.98 and 21.99%, compared to placebo, respectively. Also, the IFQ scores in the LN20189 group were 84.68% (vs. baseline) and 69.44% (vs. placebo) lower at the end of the trial. LN20189 improved the study volunteers' cellular and humoral immune functions. Conclusion: In summary, LN20189 supplementation was found tolerable and improved the key cellular and humoral factors of the immune system and helped improve immune function of the trial volunteers.

Kinetics of pro- and anti-inflammatory spike-specific cellular immune responses in long-term care facility residents after COVID-19 mRNA primary and booster vaccination: a prospective longitudinal study in Japan.

BACKGROUND: The magnitude and durability of cell-mediated immunity in older and severely frail individuals following coronavirus disease 2019 (COVID-19) vaccination remain unclear. A controlled immune response could be the key to preventing severe COVID-19; however, it is uncertain whether vaccination induces an anti-inflammatory cellular immune response. To address these issues, a 48-week-long prospective longitudinal study was conducted. A total of 106 infection-naive participants (57 long-term care facility [LTCF] residents [median age; 89.0 years], 28 outpatients [median age; 72.0 years], and 21 healthcare workers [median age; 51.0 years]) provided peripheral blood mononuclear cell (PBMC) samples for the assessment of spike-specific PBMC responses before primary vaccination, 24 weeks after primary vaccination, and three months after booster vaccination. Cellular immune responses to severe acute respiratory syndrome coronavirus 2 spike protein were examined by measuring interferon (IFN)-γ, tumor necrosis factor (TNF), interleukin (IL)-2, IL-4, IL-6, and IL-10 levels secreted from the spike protein peptide-stimulated PBMCs of participants. RESULTS: LTCF residents exhibited significantly lower IFN-γ, TNF, IL-2, and IL-6 levels than healthcare workers after the primary vaccination. Booster vaccination increased IL-2 and IL-6 levels in LTCF residents comparable to those in healthcare workers, whereas IFN-γ and TNF levels in LTCF residents remained significantly lower than those in healthcare workers. IL-10 levels were not significantly different from the initial values after primary vaccination but increased significantly after booster vaccination in all subgroups. Multivariate analysis showed that age was negatively associated with IFN-γ, TNF, IL-2, and IL-6 levels but not with IL-10 levels. The levels of pro-inflammatory cytokines, including IFN-γ, TNF, IL-2, and IL-6, were positively correlated with humoral immune responses, whereas IL-10 levels were not. CONCLUSIONS: Older and severely frail individuals may exhibit diminished spike-specific PBMC responses following COVID-19 vaccination compared to the general population. A single booster vaccination may not adequately enhance cell-mediated immunity in older and severely frail individuals to a level comparable to that in the general population. Furthermore, booster vaccination may induce not only a pro-inflammatory cellular immune response but also an anti-inflammatory cellular immune response, potentially mitigating detrimental hyperinflammation.

Lipid Nanoparticles Outperform Electroporation in Delivering Therapeutic HPV DNA Vaccines.

Therapeutic HPV vaccines that induce potent HPV-specific cellular immunity and eliminate pre-existing infections remain elusive. Among various candidates under development, those based on DNA constructs are considered promising because of their safety profile, stability, and efficacy. However, the use of electroporation (EP) as a main delivery method for such vaccines is notorious for adverse effects like pain and potentially irreversible muscle damage. Moreover, the requirement for specialized equipment adds to the complexity and cost of clinical applications. As an alternative to EP, lipid nanoparticles (LNPs) that are already commercially available for delivering mRNA and siRNA vaccines are likely to be feasible. Here, we have compared three intramuscular delivery systems in a preclinical setting. In terms of HPV-specific cellular immune responses, mice receiving therapeutic HPV DNA vaccines encapsulated with LNP demonstrated superior outcomes when compared to EP administration, while the naked plasmid vaccine showed negligible responses, as expected. In addition, SM-102 LNP M exhibited the most promising results in delivering candidate DNA vaccines. Thus, LNP proves to be a feasible delivery method in vivo, offering improved immunogenicity over traditional approaches.

Poxvirus Immune Evasion.

Poxviruses have evolved a wide array of mechanisms to evade the immune response, and we provide an overview of the different immunomodulatory strategies. Poxviruses prevent the recognition of viral DNA that triggers the immune responses and inhibit signaling pathways within the infected cell. A unique feature of poxviruses is the production of secreted proteins that mimic cytokines and cytokine receptors, acting as decoy receptors to neutralize the activity of cytokines and chemokines. The capacity of these proteins to evade cellular immune responses by inhibiting cytokine activation is complemented by poxviruses' strategies to block natural killer cells and cytotoxic T cells, often through interfering with antigen presentation pathways. Mechanisms that target complement activation are also encoded by poxviruses. Virus-encoded proteins that target immune molecules and pathways play a major role in immune modulation, and their contribution to viral pathogenesis, facilitating virus replication or preventing immunopathology, is discussed.

Case Report: Approaches for managing resistant cytomegalovirus in pediatric allogeneic hematopoietic cell transplantation recipients.

The instructional case is a pediatric haploidentical TCRαß+/CD19+ depleted allogeneic hematopoietic cell transplantation recipient who developed early onset CMV infection, which was complicated by resistant CMV (both UL97 and UL54) and successfully managed with maribavir and haploidentical CMV-specific T lymphocytes. Novel approaches to resistant CMV infection are reviewed and effective utilization of recent advances in diagnosis and management of resistant CMV in pediatric HCT are highlighted.

A specific natural killer cells phenotypic signature associated to long term elite control of HIV infection.

Elite controllers (ECs) are an exceptional group of people living with HIV (PLWH) that control HIV replication without therapy. Among the mechanisms involved in this ability, natural killer (NK)-cells have recently gained much attention. We performed an in-deep phenotypic analysis of NK-cells to search for surrogate markers associated with the long term spontaneous control of HIV. Forty-seven PLWH (22 long-term EC [PLWH-long-term elite controllers (LTECs)], 15 noncontrollers receiving antiretroviral treatment [ART] [PLWH-onART], and 10 noncontrollers cART-naïve [PLWH-offART]), and 20 uninfected controls were included. NK-cells homeostasis was analyzed by spectral flow cytometry using a panel of 15 different markers. Data were analyzed using FCSExpress and R software for unsupervised multidimensional analysis. Six different subsets of NK-cells were defined on the basis of CD16 and CD56 expression, and the multidimensional analysis revealed the existence of 68 different NK-cells clusters based on the expression levels of the 15 different markers. PLWH-offART presented the highest disturbance of NK-cells homeostasis and this was not completely restored by long-term ART. Interestingly, long term spontaneous control of HIV (PLWH-LTEC group) was associated with a specific profile of NK-cells homeostasis disturbance, characterized by an increase of CD16dimCD56dim subset when compared to uninfected controls (UC) group and also to offART and onART groups (p < 0.0001 for the global comparison), an increase of clusters C16 and C26 when compared to UC and onART groups (adjusted p-value < 0.05 for both comparisons), and a decrease of clusters C10 and C20 when compared to all the other groups (adjusted p-value < 0.05 for all comparisons). These findings may provide clues to elucidate markers of innate immunity with a relevant role in the long-term control of HIV.

Complications of Brentuximab Therapy in Patients with Hodgkin's Lymphoma and Concurrent Autoimmune Pathology-A Case Series.

Background: Brentuximab Vedotin (BV) has revolutionized the treatment landscape for Hodgkin's lymphoma, yet its effects on pre-existing autoimmune disorders remain elusive. Methods: Here, we present four cases of patients with concurrent autoimmune conditions-Crohn's disease, vitiligo, type I diabetes, and minimal change disease-undergoing BV therapy for Hodgkin's lymphoma. The patients were treated with A-AVD instead of ABVD due to advanced-stage disease with high IPI scores. Results: Our findings reveal the surprising and complex interplay between BV exposure and autoimmune manifestations, highlighting the need for multidisciplinary collaboration in patient management. Notably, the exacerbation of autoimmune symptoms was observed in the first three cases where T-cell-mediated autoimmunity predominated. Additionally, BV exposure precipitated autoimmune thrombocytopenia in the vitiligo patient, underscoring the profound disruptions in immune regulation. Conversely, in the minimal change disease case, a disease characterized by a blend of B- and T-cell-mediated immunity, the outcome was favorable. Conclusions: This paper underscores the critical importance of vigilance toward autoimmune flare-ups induced by BV in patients with concurrent autoimmune conditions, offering insights for tailored patient care.

Immunogenicity of Recombinant Zoster Vaccine: A Systematic Review, Meta-Analysis, and Meta-Regression.

BACKGROUND: The adjuvanted recombinant zoster vaccine (RZV), consisting of varicella-zoster virus glycoprotein E (gE) and the AS01B adjuvant system, effectively prevents herpes zoster (HZ). In the absence of a well-defined correlate of protection, it is important to monitor the RZV immune response, as a proxy of clinical effectiveness. METHODS: This systematic review examined post-vaccination parameters: humoral and cell-mediated immunity, avidity index, geometric mean concentration of antibody (GMC), and immunity persistence. The meta-analysis used a random-effects model, and subgroup and meta-regression analyses were conducted. RESULTS: Among 37 included articles, after one month from RZV-dose 2, the pooled response rate for anti-gE humoral immunity was 95.2% (95%CI 91.9-97.2), dropping to 77.6% (95%CI 64.7-86.8) during immunosuppression. The anti-gE cell-mediated immunity-specific response reached 84.6% (95%CI 75.2-90.9). Varying factors, such as age, sex, coadministration with other vaccines, prior HZ, or live-attenuated zoster vaccine, did not significantly affect response rates. RZV induced a substantial increase in gE avidity. Immunity persistence was confirmed, with more rapid waning in the very elderly. CONCLUSIONS: This systematic review indicates that RZV elicits robust immunogenicity and overcomes immunocompromising conditions. The findings underscore the need for further research, particularly on long-term immunity, and have the potential to support HZ vaccination policies and programs.

Combining SARS-CoV-2 interferon-gamma release assay with humoral response assessment to define immune memory profiles.

OBJECTIVES: In the post-SARS-CoV-2 pandemic era, "breakthrough infections" are still documented, due to variants of concerns (VoCs) emergence and waning humoral immunity. Despite widespread utilization, the definition of the anti-Spike (S) immunoglobulin-G (IgG) threshold to define protection has unveiled several limitations. Here, we explore the advantages of incorporating T-cell response assessment to enhance the definition of immune memory profile. METHODS: SARS-CoV-2 interferon-gamma release assay test (IGRA) was performed on samples collected longitudinally from immunocompetent healthcare workers throughout their immunization by infection and/or vaccination, anti-receptor-binding domain IgG levels were assessed in parallel. The risk of symptomatic infection according to cellular/humoral immune capacities during Omicron BA.1 wave was then estimated. RESULTS: Close to 40% of our samples were exclusively IGRA-positive, largely due to time elapsed since their last immunization. This suggests that individuals have sustained long-lasting cellular immunity, while they would have been classified as lacking protective immunity based solely on IgG threshold. Moreover, the Cox regression model highlighted that Omicron BA.1 circulation raises the risk of symptomatic infection while increased anti-receptor-binding domain IgG and IGRA levels tended to reduce it. CONCLUSION: The discrepancy between humoral and cellular responses highlights the significance of assessing the overall adaptive immune response. This integrated approach allows the identification of vulnerable subjects and can be of interest to guide antiviral prophylaxis at an individual level.

High-dimensional mass cytometry identified circulating natural killer T-cell subsets associated with protection from cytomegalovirus infection in kidney transplant recipients.

Cytomegalovirus (CMV) infection is associated with poor kidney transplant outcomes. While innate and adaptive immune cells have been implicated in its prevention, an in-depth characterization of the in vivo kinetics of multiple cell subsets and their role in protecting against CMV infection has not been achieved. Here, we performed high-dimensional immune phenotyping by mass cytometry, and functional assays, on 112 serially collected samples from CMV seropositive kidney transplant recipients. Advanced unsupervised deep learning analysis was used to assess immune cell populations that significantly correlated with prevention against CMV infection and anti-viral immune function. Prior to infection, kidney transplant recipients who developed CMV infection showed significantly lower CMV-specific cell-mediated immune (CMI) frequencies than those that did not. A broad diversity of circulating cell subsets within innate and adaptive immune compartments were associated with CMV infection or protective CMV-specific CMI. While percentages of CMV (tetramer-stained)-specific T cells associated with high CMI responses and clinical protection, circulating CD3+CD8midCD56+ NK-T cells overall strongly associated with low CMI and subsequent infection. However, three NK-T cell subsets sharing the CD11b surface marker associated with CMV protection and correlated with strong anti-viral CMI frequencies in vitro. These data were validated in two external independent cohorts of kidney transplant recipients. Thus, we newly describe the kinetics of a novel NK-T cell subset that may have a protective role in post-transplantation CMV infection. Our findings pave the way to more mechanistic studies aimed at understanding the function of these cells in protection against CMV infection.

Immunogenicity and protective efficacy of a multivalent herpesvirus vectored vaccine against H9N2 low pathogenic avian influenza in chicken.

The application of recombinant herpesvirus of turkey, expressing the H9 hemagglutinin gene from low pathogenic avian influenza virus (LPAIV) H9N2 and the avian orthoavulavirus-1 (AOAV-1) (commonly known as Newcastle Disease virus (NDV)) fusion protein (F) as an rHVT-H9-F vaccine, is an alternative to currently used classical vaccines. This study investigated H9- and ND-specific humoral and mucosal responses, H9-specific cell-mediated immunity, and protection conferred by the rHVT-H9-F vaccine in specific pathogen-free (SPF) chickens. Vaccination elicited systemic NDV F- and AIV H9-specific antibody response but also local antibodies in eye wash fluid and oropharyngeal swabs. The ex vivo H9-specific stimulation of splenic and pulmonary T cells in the vaccinated group demonstrated the ability of vaccination to induce systemic and local cellular responses. The clinical protection against a challenge using a LPAIV H9N2 strain of the G1 lineage isolated in Morocco in 2016 was associated with a shorter duration of shedding along with reduced viral genome load in the upper respiratory tract and reduced cloacal shedding compared to unvaccinated controls.

In vitro analysis on the adhesion potential of Lactiplantibacillus plantarum from infant faeces and its gastrointestinal localization, growth promotion, and immunomodulation in Wistar rats: a preliminary study.

Lactic acid bacteria, found in heterogenous niches, are known for their health-endorsing properties and are in demand as prospective probiotics. Hence, the scientific community around the globe is in continuous search for novel and new potential strains with extensive applicability and minimum risk. In this context, the present study evaluated the efficiency of Lactiplantibacillus plantarum (P2F2) of human origin, a highly autoaggregating and coaggregating (with pathogens) strain, for its colonization, growth promotion, and immunomodulation. Results indicated moderate hydrophobicity on adhesion to xylene and n-hexadecane and weak electron-donating properties with chloroform. The biofilm of P2F2 formed on polystyrene was strong and highly correlated to exopolysaccharide production. The autoaggregation was moderately correlated with hydrophobicity and biofilm production. It was noted that the P2F2 strain modulated the gut microbiota and increased intestinal villi length in Wistar rats. The lipid and glucose profiles remained intact. P2F2 treatment increased the activity of reactive oxygen species-generating cells in the peritoneal cavity, besides augmenting the mitogen-induced splenocyte proliferation and maintained the immunoglobulins at the normal level. Results from this study conclusively suggest that the strain P2F2 adheres to the intestine and modulates the gut ecosystem besides enhancing cell-mediated immunity without altering the serological parameters tested.

Changes in the Adaptive Cellular Repertoire after Infection with Different SARS-CoV-2 VOCs in a Cohort of Vaccinated Healthcare Workers.

BACKGROUND: Currently approved vaccines are highly effective in protecting against hospitalization and severe COVID-19 infections. How pre-existing immunity responds to new variants with mutated antigens is crucial information for elucidating the functional interplay between antibodies and B and T cell responses during infection with new SARS-CoV-2 variants. METHODS: In this study, we monitored the dynamics and persistence of the immune response versus different SARS-CoV-2 variants of concern that emerged during the pandemic period (2021-2022) in a cohort of vaccinated healthcare workers, who experienced breakthrough infection in the Pre-Delta, Delta, and Omicron waves. We evaluated both the humoral and cell-mediated responses after infection. We also evaluated the anti-SARS-CoV-2 antibodies levels produced by infection in comparison with those produced after vaccination. RESULTS: Our results highlighted that the immune response against the Delta VOC mainly involved an adaptive humoral and switched memory B cells component, even 3 months after the last vaccine dose, conversely showing a high percentage of depleted adaptive T cells. Omicron infections triggered a consistent production of non-vaccine-associated anti-N antibodies, probably to balance the spike epitope immune escape mechanisms. CONCLUSION: Our results suggest a direct dependence between the VOC and different humoral and B and T cell balances in the post-infection period, despite the administration of a different number of vaccine doses and the elapsed time since the last vaccination.

Differential Immune Response Patterns Induced by Anionic and Cationic Lipid Adjuvants in Intranasal Anti-Influenza Immunization.

Currently, vaccine development against different respiratory diseases is at its peak. It is of utmost importance to find suitajble adjuvants that can increase the potency of the vaccine candidates. This study aimed to determine the systemic and splenic immune mechanisms in mice models induced by anionic and cationic lipid adjuvants in the presence of the vaccine-candidate influenza antigen hemagglutinin (HA). In the presence of the HA antigen, the cationic adjuvant (N3) increased conventional dendritic cell 1 (cDC1) abundance with enhanced MHCI and CD80-CD86 costimulatory marker expression, and significantly higher CD8T and Th17 populations with enhanced interferon-gamma (IFNγ) expression in CD8T and CD4T populations. Conversely, the anionic adjuvant (L3) increased the cDC2 population percentage with significantly higher MHCII and DEC205 expression, along with an increase in the CD4T and regulatory T cell populations. The L3-treated group also exhibited higher percentages of activated B and plasma cell populations with significantly higher antigen-specific IgG and IgA titer and virus neutralization potential. While the anionic adjuvant induced significantly higher humoral responses than the cationic adjuvant, the latter influenced a significantly higher Th1/Th17 response. For customized vaccine development, it is beneficial to have alternative adjuvants that can generate differential immune responses with the same vaccine candidate antigen. This study will aid the selection of adjuvants based on their charges to improve specific immune response arms in the future development of vaccine formulation.

Baculovirus Vector-Based Varicella-Zoster Virus Vaccine as a Promising Alternative with Enhanced Safety and Therapeutic Functions.

Varicella-zoster virus (VZV) poses lifelong risks, causing varicella and herpes zoster (HZ, shingles). Currently, varicella and HZ vaccines are predominantly live attenuated vaccines or adjuvanted subunit vaccines utilizing VZV glycoprotein E (gE). Here, we propose our vaccine candidates involving a comparative analysis between recombinant baculoviral vector vaccines (AcHERV) and a live attenuated vaccine strain, vOka. AcHERV vaccine candidates were categorized into groups encoding gE only, VZV glycoprotein B (gB) only, or both gE and gB (gE-gB) as AcHERV-gE, AcHERV-gB, and AcHERV-gE-gB, respectively. Humoral immune responses were evaluated by analyzing total IgG, IgG1, IgG2a, and neutralizing antibodies. Cell-mediated immunity (CMI) responses were evaluated by enzyme-linked immunospot (ELISPOT) assay and Th1/Th2/Th17 cytokine profiling. In the mouse model, AcHERV-gE-gB elicited similar or higher total IgG, IgG2a, and neutralizing antibody levels than vOka and showed robust VZV-specific CMI responses. From the perspective of antigens encoded in vaccines and their relationship with CMI response, both AcHERV-gB and AcHERV-gE-gB demonstrated results equal to or superior to AcHERV-gE, encoding only gE. Taken together, these results suggest that AcHERV-gE-gB can be a novel candidate for alleviating risks of live attenuated vaccine-induced latency and effectively preventing varicella during early stages of life while providing strong CMI for effective resistance against HZ and therapeutic potential in later stages of life.

The Nucleocapsid Protein of SARS-CoV-2, Combined with ODN-39M, Is a Potential Component for an Intranasal Bivalent Vaccine with Broader Functionality.

Despite the rapid development of vaccines against COVID-19, they have important limitations, such as safety issues, the scope of their efficacy, and the induction of mucosal immunity. The present study proposes a potential component for a new generation of vaccines. The recombinant nucleocapsid (N) protein from the SARS-CoV-2 Delta variant was combined with the ODN-39M, a synthetic 39 mer unmethylated cytosine-phosphate-guanine oligodeoxynucleotide (CpG ODN), used as an adjuvant. The evaluation of its immunogenicity in Balb/C mice revealed that only administration by intranasal route induced a systemic cross-reactive, cell-mediated immunity (CMI). In turn, this combination was able to induce anti-N IgA in the lungs, which, along with the specific IgG in sera and CMI in the spleen, was cross-reactive against the nucleocapsid protein of SARS-CoV-1. Furthermore, the nasal administration of the N + ODN-39M preparation, combined with RBD Delta protein, enhanced the local and systemic immune response against RBD, with a neutralizing capacity. Results make the N + ODN-39M preparation a suitable component for a future intranasal vaccine with broader functionality against Sarbecoviruses.

The Role of Glutathione in the Management of Cell-Mediated Immune Responses in Individuals with HIV.

Human immunodeficiency virus (HIV) is a major cause of death worldwide. Without appropriate antiretroviral therapy, the infection can develop into acquired immunodeficiency syndrome (AIDS). AIDS leads to the dysregulation of cell-mediated immunity resulting in increased susceptibility to opportunistic infections and excessive amounts of inflammatory cytokines. HIV-positive individuals also demonstrate diminished glutathione (GSH) levels which allows for increased viral replication and increased pro-inflammatory cytokine release, further contributing to the high rates of mortality seen in patients with HIV. Adequate GSH supplementation has reduced inflammation and slowed the decline of CD4+ T cell counts in HIV-positive individuals. We aim to review the current literature regarding the role of GSH in cell-mediated immune responses in individuals with HIV- and AIDS-defining illnesses.

Neutralizing antibody titers against D8 genotype and persistence of measles humoral and cell-mediated immunity eight years after the first dose of measles, mumps, and rubella vaccine in Brazilian children.

OBJECTIVE: Assess the level of measles vaccine-induced neutralizing antibodies against the D8 genotype and the persistence of humoral and cell-mediated immunity in children who received their first dose of the measles, mumps, and rubella vaccine eight years previously. METHODS: Measles-specific IgG and neutralizing antibodies were determined in serum using ELISA and plaque reduction neutralization test, respectively. Cellular response was evaluated from peripheral blood mononuclear cells (PBMC). IFN-γ-secreting cells, memory B and T cells, and immunological mediators were assayed by ELISpot, flow cytometry, and multiplex liquid microarray assay, respectively. RESULTS: Antibody concentrations declined over time; however, the vaccine-induced neutralizing antibodies' effect against D8 and vaccinal genotypes persisted. PBMC stimulated with the vaccine virus exhibited specific IFN- γ-measles-secreting responses in most participants. Participants with high levels of neutralizing antibodies showed a higher proportion of activated B cells compared to participants with low levels of neutralizing antibodies, while proportions of memory CD4+ and CD8+ T cells were similar between these groups. PBMC supernatant cytokine levels showed a significant difference between stimulated and non-stimulated conditions for IL-2, TNF-α, IL-10, and CXCL10. CONCLUSION: Despite the decline in antibody concentrations over time, the participants still demonstrated neutralizing capacity against the measles D8 genotype five to eight years after the second dose of the measles, mumps, and rubella vaccine. Additionally, most of the enrolled children exhibited cell-mediated immunity responses to measles virus stimulation.

QuantiFERON-CMV assay by chemiluminescence immunoassay: Is it more suitable for real-live monitoring of transplant patients?

BACKGROUND: The QuantiFERONCMV (QF-CMV) assay is an interferon-gamma release assay (IGRA) used to monitor CMV-specific cell-mediated immunity (CMV-CMI) by ELISA in transplant patients. However, a chemiluminescent immunoassay (CLIA) has been developed to quantify IFNG in the QuantiFERON-Tuberculosis (TB) to detect latent TB infection. OBJECTIVES: The aim of this work is to compare the results of QF-CMV by ELISA with those obtained by CLIA in an automated Liaison XL analyzer using the QuantiFERON-TB Gold Plus reagents. STUDY DESIGN: The QF-CMV assay had been performed by ELISA in kidney and lung transplant patients between July 2019-April 2023 at the IMIBIC/Reina Sofía Hospital (Cordoba, Spain). The remaining QF-CMV supernatants had been preserved at -80 ºC from then. Now, the IFNG levels in the same samples were determined by CLIA. RESULTS: One hundred and three QF-CMV supernatants from kidney (n = 50) and lung (n = 53) transplant patients were selected. An agreement of 87.4 % (kappa coefficient 0.788) between CLIA and ELISA was observed. Thirteen (12.6 %) discrepant results were detected. Some Indeterminate results by ELISA converted to Non-reactive by CLIA (0.53-0.92 IU/mL for Mitogen-Nil values). Likewise, borderline Non-reactive results by ELISA were above the 0.2 IU/mL cut-off by CLIA and then were Reactive (0.21-0.31 for CMV-Nil values). CONCLUSION: CLIA shows substantial concordance with ELISA and acceptable discrepancies. The possible higher sensitivity of CLIA returns a higher number of Reactive results, which entails potential clinical consequences. Therefore, a new threshold to confer protection against CMV infection after transplantation needs to be defined.