Pedro Morais’ Post

Incorporation of noncanonical base Z yields modified mRNA with minimal immunogenicity and improved translational capacity in mammalian cells The use of chemically altered mRNAs for #therapeutic purposes in living organisms is highly promising. The base #modification approach is now missing one mode of #mRNA regulation by changing its secondary structure because it mostly respects the classical #Watson-Crick base #pairing. Here, we describe the addition of base Z (2-aminoadenine) to mRNA to produce Z-mRNA, which has significantly lower #immunogenicity and #cytotoxicity than unmodified mRNA in mammalian cells and enhanced translational capacity. Particularly, in mouse embryonic #fibroblast cells, the A-to-Z substitution makes modified mRNAs less immunogenic than the cutting-edge base #alteration N1-methylpseudouridine (m1ψ). We created a Z-mRNA-based vaccination against the SARS-CoV-2 severe acute #respiratory #syndrome #coronavirus as a proof of concept.  In vivo in mice, antigen-encoding Z-mRNA induced significant humoral and cellular #immuneresponse , though less effectively than the most recent m1ψ-mRNA. Z-mRNA broadens the range of possible mRNA base alterations to #noncanonical bases and can provide a useful platform for mRNA-based treatments where a low level of immunogenicity is sought.

#ATP to #ZTP, #mRNA to #Z-mRNA Can this breakthrough lead to innovative #mRNA-based therapies, particularly in cancer treatment? ▪️What is Z? Scientists have been exploring modified mRNA for several decades. In 1977, it was discovered that the S-2L virus, which infects cyanobacteria, uses a different base called 2-amino adenine (abbreviated as Z) instead of adenine in its genome. A brand new paper from researchers at the University of Illinois have achieved a significant milestone by incorporating a base into mRNA that is not naturally present in the human body. ▪️What are the advantages of Modified mRNA? Modified mRNA offers distinct advantages over unmodified mRNA, which contains the standard adenine, uracil, cytosine, and guanine (A, U, C, and G) bases. Z is not naturally found in the human body. The researchers observed that Z forms 3 hydrogen bonds with base U, as opposed to the 2 hydrogen bonds formed between A and U in regular mRNA. ▪️Why is this study important in mRNA Vaccines field? Traditionally, modified bases in mRNA are derived from the human body to closely mimic the body's own mRNA and evade immune surveillance. Surprisingly, the Z-mRNA, when tested in cultured cells, demonstrated ▪️Low #immunogenicity, ▪️Reduced #cytotoxicity, ▪️Enhanced #stability, ▪️Improved #translational capacity Despite altering the standard #Watson–#Crick base pairing, Z-mRNA exhibits favorable properties. This opens the door to the development of alternative mRNA vaccines with fewer side effects. ▪️In Vivo Testing and Future Potential? To evaluate Z-mRNA in vivo, the research team developed a COVID-19 vaccine using this novel mRNA. In mice, the Z-mRNA vaccine triggered a substantial and antigen-specific immune response, although it was not as potent as the modified mRNA vaccines from Moderna and Pfizer, which served as benchmarks. The potency of Z-mRNA vaccines could see a significant boost. The mRNA research story is far from over, reaffirming its potential to reshape the healthcare landscape. What are your thoughts about it? #mRNA #Innovation #NobelPrize

Young mice have a balance between two types of blood stem cells: 1) Antibodies and T-cell producers that are adaptive in immune responses, and 2) those responsible for inflammatory responses. Aging tend to tip the balance towards the pro-inflammatory side. By injecting antibodies produced in young mice, older mice seem to push the balance back and improve responses to various treatments, eg vaccines. Trials in humans are probably three to five years away, but this could open new opportunities for antibodies therapy research. Publication: https://lnkd.in/eWJh_Arw #antibodies #biologics #pluripotent

#Oligonucleotides, #Immunotherapy Oligo means 'small,' because ASOs are made up of relatively few (usually fewer than 25) nucleotides. An ASO is a small string of DNA or RNA letters that can stick to the mRNA. While they act on genetic diseases, ASOs are not considered 'gene therapy' as they only make contact with RNA, not DNA.                 Advantages of #Oligonucleotides in #Immunotherapy: Precision Targeting: can be designed to specifically target certain genes, messenger RNAs (mRNAs), or non-coding RNAs. This enables precise modulation of gene expression, allowing for the selective manipulation of immune-related pathways. Versatility: Oligonucleotides can be tailored for various immunotherapeutic applications, including immune activation, immune suppression, and immune checkpoint modulation. Reduced Off-Target Effects: can minimize off-target effects by specifically binding to their intended targets, reducing the risk of unwanted immune responses. Modulation of Immune Responses: can be used to influence immune responses boosting immune cell activation, or inhibiting immune-suppressive pathways. Personalized Medicine: can be customized to match the genetic profiles of individual patients, enabling personalized treatment strategies that maximize therapeutic benefits while minimizing adverse effects. Combination Therapy: can be combined with other immunotherapies, such as immune checkpoint inhibitors or cell therapies, to enhance their efficacy and broaden the scope of treatment options.                 Challenges of Oligonucleotides in Immunotherapy: Delivery Challenges: Developing efficient and targeted delivery systems that ensure oligonucleotide uptake while minimizing toxicity is a major challenge. Stability and Degradation: Oligonucleotides are susceptible to degradation by nucleases, limiting their stability and effectiveness in vivo. Immunogenicity: Depending on the sequence and modifications used, oligonucleotides can trigger immune responses, potentially leading to reduced therapeutic efficacy or unwanted side effects. Off-Target Effects: Despite efforts to design specific sequences, there's a risk of off-target effects, where oligonucleotides inadvertently bind to unintended targets, potentially causing adverse effects. Regulatory and Manufacturing Challenges: Developing and manufacturing oligonucleotides for clinical use involves complex processes and stringent regulatory requirements. Ensuring consistent and reproducible production is crucial. Limited Clinical Data: While oligonucleotides hold promise, their full potential in immunotherapy is still being explored, and long-term safety and efficacy data in larger patient populations are necessary. Cost: Developing, manufacturing, and delivering oligonucleotide-based therapies can be expensive, impacting their accessibility and affordability for patients.

Innovation using mRNA technology is moving fast! The emergency approval of COVID vaccines (Pfizer and Moderna) was a huge breakthrough for mRNA therapies. But mRNA technology goes beyond just COVID vaccines. One area rejuvenation and aging. Companies like Rejuvenation Technologies are using synthetic mRNA to bring back telomeres, which get shorter as we age. By making cells produce telomerase, the therapy aims to reverse telomere shortening and maybe even make us live longer. This could help with age-related diseases and totally change how we treat and prevent cancer, heart disease, and brain conditions. More on this here: https://lnkd.in/dNcdEePz mRNA tech also opens up lots of possibilities in other areas. Think personalized medicine, vaccines for different diseases, and spotting diseases early. It could also help with growing tougher crops and to make sustainable biofuels. Lots of mRNA news coming soon! #mRNA #healthspan

#Immunotherapy | #Glycobiology | Inhibiting #Macrophage N-Glycan Processing Enhances #Antibody-Dependent Cellular #Phagocytosis | Jesus Aguilar Diaz de leon et al Hit the Sweet Spot in Breaking Study | Factors regulating macrophage effector function represent potential targets to optimize the efficacy of antibody-mediated therapies. Macrophages are myeloid cells capable of engulfing and destroying diseased or damaged target cells. Antibodies binding to the target cell surface can engage macrophage Fc gamma receptors (FcγRs) to elicit antibody-dependent cellular phagocytosis (ADCP), a process that contributes to treatments mediated by anti-tumor antibodies. Conversely, macrophage ADCP of apoptotic T cells is also linked to tolerance in the tumor environment. Here* researchers evaluated the role of asparagine(N)-linked glycans in the function of macrophages derived from primary human monocytes. Macrophages treated with kifunensine, an inhibitor of N-glycan processing, exhibited greater target binding and ADCP of antibody-coated target cells. Kifunensine treatment increased ADCP of both rituximab-coated Raji B cells and trastuzumab-coated SKBR3 cells. ADCP required FcγRs; inhibiting CD64 / FcγRI led to the greatest reduction, followed by CD32 / FcγRII and then CD16 / FcγRIII in most donors. Kifunensine treatment also increased the antibody-binding affinity of CD16. Differences in the abundance of phosphorylated immune receptors, including Siglec-9, CD32a, and LAIR-1 correlated with the increased ADCP. These results demonstrate that N-glycan processing regulates macrophage effector function. *https://lnkd.in/eu3mqQ65 Professor Nicholas Barnes PhD, FBPhS Omar Qureshi Catherine Brady Celentyx Ltd #immunooncology www.celentyx.com FIGURE | Macrophage N-glycan processing is inhibited with kifunensine | A. Monocytes isolated from individual donors were then differentiated into macrophages in vitro. Kifunensine was added to inhibit N-glycan processing during differentiation. FcγRs – antibody-binding Fc γ receptors | B. Mammalian N-glycan processing. Kifunensine increases the abundance of Man9 N-glycans.

Congratulations to Katalin Karikó and Drew Weissman, who were awarded this year’s Nobel Prize in Physiology/Medicine for their contribution to the field of mRNA vaccines. Their pioneering research into nucleoside base modifications led to the development of effective mRNA vaccines against COVID-19 and underscores the increasingly popular field of RNA research. https://lnkd.in/dUFuYQW7 This prestigious recognition highlights the transformative potential of RNA biology – which Optimer technology is supporting in multiple ways.   Optimer binders are being explored as reagents to support mRNA vaccine manufacture, as well as targeting RNA therapies, vaccine adjuvants and gene switches. As an antibody alternative Optimer offer ethically compliant reagents with new targeting abilities that can offer greater insights into and new mechanisms to treat disease.  

The discovery by 2023 medicine laureates Katalin Karikó and Drew Weissman was critical for making the mRNA vaccine platform suitable for clinical use at a time when it was most needed. RNA contains four bases, abbreviated A, U, G, and C, corresponding to A, T, G, and C in DNA, the letters of the genetic code. Karikó and Weissman knew that nucleoside bases in RNA from mammalian cells are frequently chemically modified, while in vitro transcribed mRNA is not. They wondered if the absence of altered bases in the in vitro transcribed RNA could explain unwanted inflammatory reactions. To investigate this, they produced different variants of mRNA, each with unique chemical alterations in their bases, which they delivered to dendritic cells. The results were striking: the inflammatory response was almost abolished when base modifications were included in the mRNA. This was a paradigm change in our understanding of how cells recognise and respond to different forms of mRNA. Karikó and Weissman immediately understood that their discovery had profound significance for using mRNA as therapy. These seminal results were published in 2005, fifteen years before the COVID-19 pandemic. The results published by Karikó and Weissman in their seminal 2005 paper received little attention at the time but laid the foundation for critically important developments that have served humanity during the COVID-19 pandemic. The approval of two effective and safe COVID-19 mRNA-vaccines in late 2020 propelled the mRNA vaccine field into a new era. The discovery that the use of modified bases in in vitro-transcribed mRNA circumvents undesired inflammatory responses and increases protein production following in vivo delivery demonstrates the value of basic research. The 2023 Nobel Prize in Physiology or Medicine has been awarded to Katalin Karikó and Drew Weissman for their discoveries concerning nucleoside base modifications that enabled the development of effective mRNA vaccines against COVID-19. Learn more Press release: https://bit.ly/3LyuMgU Advanced information: https://bit.ly/454TWdZ

This report demonstrates a novel class of innate immune cells designated “variable immunoreceptor–expressing myeloids” (VIREMs). Using single-cell transcriptomics and genome-wide epigenetic profiling, we establish that VIREMs are myeloid cells unrelated to lymphocytes. We visualize the phenotype of B-VIREMs that are capable of genetically recombining and expressing antibody genes, the exclusive hallmark function of B lymphocytes. These cells, designated B-VIREMs, display monoclonal antibody cell surface signatures and regularly circulate in the blood of healthy individuals. Single-cell data reveal clonal expansion of circulating B-VIREMs as a dynamic response to disease stimuli. Live-cell imaging models suggest that B-VIREMs load their own Fc receptors with endogenous antibodies during vesicle transport to the cell surface. A first cloned B-VIREM–derived antibody (Vab1) specifically binds stomatin, a ubiquitous scaffold protein that is strictly expressed intracellularly, allowing Vab1-bearing macrophages to phagocytose cell debris without requiring prior opsonization. Our results suggest important antigen-specific tissue maintenance functionalities in these innate immune cells. #covid #science #health #hospitalization #vaccine #pandemic #longcovid