The molecular immune modulator adenosine deaminase-1 enhances HIV specific humoral and cellular responses to a native-like HIV envelope trimer DNA vaccine.

There is currently no prophylactic vaccine available for human immunodeficiency virus (HIV). Research efforts have resulted in improved immunogens that mimic the native envelope (Env) glycoprotein structure. Recently, a novel triple tandem trimer (TTT) platform has been used to generate a plasmid encoding Env immunogen (pBG505-TTT) that expresses only as trimers, making it more suitable for nucleic acid vaccines. We have previously demonstrated that adenosine deaminase-1 (ADA-1) is critical to the T follicular helper (TFH) function and improves vaccine immune responses in vivo. In this study, we demonstrate that co-delivery of plasmid-encoded adenosine deaminase 1 (pADA) with pBG505-TTT enhances the magnitude, durability, isotype switching and functionality of HIV-specific antibodies in a dose-sparing manner. Co-delivery of the molecular immune modulator ADA-1 also enhances HIV-specific T cell polyfunctionality, activation, and degranulation as well as memory B cell responses. These data demonstrate that pADA enhances HIV-specific cellular and humoral immunity, making ADA-1 a promising immune modulator for HIV-targeting vaccines.

IgM N-glycosylation correlates with COVID-19 severity and rate of complement deposition.

The glycosylation of IgG plays a critical role during human severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, activating immune cells and inducing cytokine production. However, the role of IgM N-glycosylation has not been studied during human acute viral infection. The analysis of IgM N-glycosylation from healthy controls and hospitalized coronavirus disease 2019 (COVID-19) patients reveals increased high-mannose and sialylation that correlates with COVID-19 severity. These trends are confirmed within SARS-CoV-2-specific immunoglobulin N-glycan profiles. Moreover, the degree of total IgM mannosylation and sialylation correlate significantly with markers of disease severity. We link the changes of IgM N-glycosylation with the expression of Golgi glycosyltransferases. Lastly, we observe antigen-specific IgM antibody-dependent complement deposition is elevated in severe COVID-19 patients and modulated by exoglycosidase digestion. Taken together, this work links the IgM N-glycosylation with COVID-19 severity and highlights the need to understand IgM glycosylation and downstream immune function during human disease.

Using the power of innate immunoprofiling to understand vaccine design, infection, and immunity.

In the field of immunology, a systems biology approach is crucial to understanding the immune response to infection and vaccination considering the complex interplay between genetic, epigenetic, and environmental factors. Significant progress has been made in understanding the innate immune response, including cell players and critical signaling pathways, but many questions remain unanswered, including how the innate immune response dictates host/pathogen responses and responses to vaccines. To complicate things further, it is becoming increasingly clear that the innate immune response is not a linear pathway but is formed from complex networks and interactions. To further our understanding of the crosstalk and complexities, systems-level analyses and expanded experimental technologies are now needed. In this review, we discuss the most recent immunoprofiling techniques and discuss systems approaches to studying the global innate immune landscape which will inform on the development of personalized medicine and innovative vaccine strategies.

IgM N-glycosylation correlates with COVID-19 severity and rate of complement deposition.

The glycosylation of IgG plays a critical role during human SARS-CoV-2, activating immune cells and inducing cytokine production. However, the role of IgM N-glycosylation has not been studied during acute viral infection in humans. In vitro evidence suggests that the glycosylation of IgM inhibits T cell proliferation and alters complement activation rates. The analysis of IgM N-glycosylation from healthy controls and hospitalized COVID-19 patients reveals that mannosylation and sialyation levels associate with COVID-19 severity. Specifically, we find increased di- and tri-sialylated glycans and altered mannose glycans in total serum IgM in severe COVID-19 patients when compared to moderate COVID-19 patients. This is in direct contrast with the decrease of sialic acid found on the serum IgG from the same cohorts. Moreover, the degree of mannosylation and sialylation correlated significantly with markers of disease severity: D-dimer, BUN, creatinine, potassium, and early anti-COVID-19 amounts of IgG, IgA, and IgM. Further, IL-16 and IL-18 cytokines showed similar trends with the amount of mannose and sialic acid present on IgM, implicating these cytokines' potential to impact glycosyltransferase expression during IgM production. When examining PBMC mRNA transcripts, we observe a decrease in the expression of Golgi mannosidases that correlates with the overall reduction in mannose processing we detect in the IgM N-glycosylation profile. Importantly, we found that IgM contains alpha-2,3 linked sialic acids in addition to the previously reported alpha-2,6 linkage. We also report that antigen-specific IgM antibody-dependent complement deposition is elevated in severe COVID-19 patients. Taken together, this work links the immunoglobulin M N-glycosylation with COVID-19 severity and highlights the need to understand the connection between IgM glycosylation and downstream immune function during human disease.

Lipid nanoparticles (LNP) induce activation and maturation of antigen presenting cells in young and aged individuals.

Herein, we studied the impact of empty LNP (eLNP), component of mRNA-based vaccine, on anti-viral pathways and immune function of cells from young and aged individuals. eLNP induced maturation of monocyte derived dendritic cells (MDDCs). We further show that eLNP upregulated CD40 and induced cytokine production in multiple DC subsets and monocytes. This coincided with phosphorylation of TANK binding kinase 1 (pTBK1) and interferon response factor 7 (pIRF7). In response to eLNP, healthy older adults (>65 yrs) have decreased CD40 expression, and IFN-γ output compared to young adults (<65 yrs). Additionally, cells from older adults have a dysregulated anti-viral signaling response to eLNP stimulation, measured by the defect in type I IFN production, and phagocytosis. Overall, our data show function of eLNP in eliciting DC maturation and innate immune signaling pathways that is impaired in older adults resulting in lower immune responses to SARS-CoV-2 mRNA-based vaccines.

Lipid nanoparticles (LNP) induce activation and maturation of antigen presenting cells in young and aged individuals.

Despite the overwhelming success of mRNA-based vaccine in protecting against SARS-CoV-2 infection and reducing disease severity and hospitalization, little is known about the role lipid nanoparticles (LNP) play in initiating immune response. In this report we studied the adjuvantive impact of empty LNP with no mRNA cargo (eLNP) on anti-viral pathways and immune function of cells from young and aged individuals. We found that eLNP induced maturation of monocyte derived dendritic cells by measuring the expression of CD40, CD80, HLA-DR and production of cytokines including IFN-α,IL-6, IFN-γ, IL-12, and IL-21. Flow cytometry analysis of specific dendritic cell subsets showed that eLNP can induce CD40 expression and cytokine production in cDC1, cDC2 and monocytes. Empty LNP (eLNP) effects on dendritic cells and monocytes coincided with induction pIRF7 and pTBK1, which are both important in mitigating innate immune signaling. Interestingly our data show that in response to eLNP stimulus at 6 and 24 hrs, aged individuals have decreased CD40 expression and reduced IFN- γ output compared to young adults. Furthermore, we show that cDC1, cDC2, and CD14 dim CD16 + monocytes from healthy aged individuals have dysregulated anti-viral signaling response to eLNP stimulation as measured by the defect in type I IFN production, phosphorylation of IRF7, TBK-1, and immune function like phagocytosis. These data showed a novel function of eLNP in eliciting DC maturation and innate immune signaling pathways and that some of these functions are impaired in older individuals providing some suggestion of why older individuals (> 65 yrs of age) respond display lower immune responses and adverse events to SARS-CoV-2 mRNA-based vaccines.

Aging alters antiviral signaling pathways resulting in functional impairment in innate immunity in response to pattern recognition receptor agonists.

The progressive impairment of immunity to pathogens and vaccines with aging is a significant public health problem as the world population shifts to an increased percentage of older adults (> 65). We have previously demonstrated that cells obtained from older volunteers have delayed and defective induction of type I interferons and T cell and B cell helper cytokines in response to TLR ligands when compared to those from adult subjects. However, the underlying intracellular mechanisms are not well described. Herein, we studied two critical pathways important in the production of type I interferon (IFN), the interferon response factor 7 (pIRF7), and TANK-binding kinase (pTBK-1). We show a decrease in pIRF7 and pTBK-1 in cross-priming dendritic cells (cDC1s), CD4+ T cell priming DCs (cDC2s), and CD14dimCD16+ vascular patrolling monocytes from older adults (n = 11) following stimulation with pathway-specific agonists in comparison with young individuals (n = 11). The decrease in these key antiviral pathway proteins correlates with decreased phagocytosis, suggesting impaired function in Overall, our findings describe molecular mechanisms which explain the innate functional impairment in older adults and thus could inform us of novel approaches to restore these defects.

Improved Durability to SARS-CoV-2 Vaccine Immunity following Coimmunization with Molecular Adjuvant Adenosine Deaminase-1.

Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have demonstrated strong immunogenicity and protection against severe disease, concerns about the duration and breadth of these responses remain. In this study, we show that codelivery of plasmid-encoded adenosine deaminase-1 (pADA) with SARS-CoV-2 spike glycoprotein DNA enhances immune memory and durability in vivo. Coimmunized mice displayed increased spike-specific IgG of higher affinity and neutralizing capacity as compared with plasmid-encoded spike-only-immunized animals. Importantly, pADA significantly improved the longevity of these enhanced responses in vivo. This coincided with durable increases in frequencies of plasmablasts, receptor-binding domain-specific memory B cells, and SARS-CoV-2-specific T follicular helper cells. Increased spike-specific T cell polyfunctionality was also observed. Notably, animals coimmunized with pADA had significantly reduced viral loads compared with their nonadjuvanted counterparts in a SARS-CoV-2 infection model. These data suggest that pADA enhances immune memory and durability and supports further translational studies.

The 2020 Pandemic: Current SARS-CoV-2 Vaccine Development.

Coronaviruses are enveloped viruses with a positive-sense single-stranded RNA genome infecting animals and humans. Coronaviruses have been described more than 70 years ago and contain many species. Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) are lethal species caused by human coronaviruses (HCoVs). Currently, a novel strain of HCoVs, named Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (Covid-19). SARS-CoV-2 was first identified in December 2019 in Wuhan, the capital city of the Hubei province of China, and has since spread worldwide causing an outbreak in more than 200 countries. The SARS-CoV-2 outbreak was declared a pandemic on March 11th, 2020 and a public health emergency of international concern (PHEIC) in late January 2020 by the World Health Organization (WHO). SARS-CoV-2 infects the respiratory tract causing flu-like symptoms and, in some, may cause severe illness like pneumonia and multi-organ failure leading to death. Today, Covid-19 cases almost reaching 9 million, with more than 450 thousand deaths. There is an urgent demand for developing a vaccine since no effective therapies or vaccines have been approved to this day to prevent or minimize the spread of the infection. In this review, we summarized the furthest vaccines in the clinical pipeline.