RESUMEN
Objectives: SARS-CoV-2 infection causes a spectrum of clinical disease presentation, ranging from asymptomatic to fatal. While neutralising antibody (NAb) responses correlate with protection against symptomatic and severe infection, the contribution of the T-cell response to disease resolution or progression is still unclear. As newly emerging variants of concern have the capacity to partially escape NAb responses, defining the contribution of individual T-cell subsets to disease outcome is imperative to inform the development of next-generation COVID-19 vaccines. Methods: Immunophenotyping of T-cell responses in unvaccinated individuals was performed, representing the full spectrum of COVID-19 clinical presentation. Computational and manual analyses were used to identify T-cell populations associated with distinct disease states. Results: Critical SARS-CoV-2 infection was characterised by an increase in activated and cytotoxic CD4+ lymphocytes (CTL). These CD4+ CTLs were largely absent in asymptomatic to severe disease states. In contrast, non-critical COVID-19 was associated with high frequencies of naïve T cells and lack of activation marker expression. Conclusion: Highly activated and cytotoxic CD4+ T-cell responses may contribute to cell-mediated host tissue damage and progression of COVID-19. Induction of these potentially detrimental T-cell responses should be considered when developing and implementing effective COVID-19 control strategies.
RESUMEN
Global control of COVID-19 requires broadly accessible vaccines that are effective against SARS-CoV-2 variants. In this report, we exploit the immunostimulatory properties of bacille Calmette-Guérin (BCG), the existing tuberculosis vaccine, to deliver a vaccination regimen with potent SARS-CoV-2-specific protective immunity. Combination of BCG with a stabilised, trimeric form of SARS-CoV-2 spike antigen promoted rapid development of virus-specific IgG antibodies in the blood of vaccinated mice, that was further augmented by the addition of alum. This vaccine formulation, BCG:CoVac, induced high-titre SARS-CoV-2 neutralising antibodies (NAbs) and Th1-biased cytokine release by vaccine-specific T cells, which correlated with the early emergence of T follicular helper cells in local lymph nodes and heightened levels of antigen-specific plasma B cells after vaccination. Vaccination of K18-hACE2 mice with a single dose of BCG:CoVac almost completely abrogated disease after SARS-CoV-2 challenge, with minimal inflammation and no detectable virus in the lungs of infected animals. Boosting BCG:CoVac-primed mice with a heterologous vaccine further increased SARS-CoV-2-specific antibody responses, which effectively neutralised B.1.1.7 and B.1.351 SARS-CoV-2 variants of concern. These findings demonstrate the potential for BCG-based vaccination to protect against major SARS-CoV-2 variants circulating globally.
Asunto(s)
Enfermedades Genéticas Ligadas al Cromosoma X , Enfermedades Autoinflamatorias Hereditarias , Linfohistiocitosis Hemofagocítica , Enzimas Activadoras de Ubiquitina/genética , Anciano , Citocinas/inmunología , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Enfermedades Genéticas Ligadas al Cromosoma X/inmunología , Enfermedades Autoinflamatorias Hereditarias/genética , Enfermedades Autoinflamatorias Hereditarias/inmunología , Humanos , Linfohistiocitosis Hemofagocítica/genética , Linfohistiocitosis Hemofagocítica/inmunología , Masculino , SíndromeAsunto(s)
Subgrupos de Linfocitos B/clasificación , Inmunodeficiencia Variable Común/clasificación , Informe de Investigación/normas , Australasia , Subgrupos de Linfocitos B/patología , Inmunodeficiencia Variable Común/diagnóstico , Inmunodeficiencia Variable Común/inmunología , Inmunodeficiencia Variable Común/patología , Citometría de Flujo , Humanos , Laboratorios/normas , Pronóstico , Valores de ReferenciaRESUMEN
Dupilumab is a fully human monoclonal IgG4 antibody that blocks IL-4 and IL-13 signaling. Its efficacy has been assessed across a range of atopic diseases, due to its ability to inhibit T helper cell 2 (Th2) mediated inflammation. It has already been approved in the USA and Europe for the treatment of atopic dermatitis. Recently, it also gained approval in the USA as add-on treatment for moderate-to-severe asthma in adolescents and adults. Phase II and III randomized controlled trials have demonstrated improvements in asthma exacerbation rates, FEV1, oral glucocorticoid use and a range of patient-reported outcomes, with a favorable safety profile. This article will review the available clinical trial data relating to the efficacy and safety of dupilumab in the management of asthma and related atopic respiratory conditions.