REVIEW | doi:10.20944/preprints202301.0084.v1
Subject: Life Sciences, Immunology Keywords: microbial evolution; immune evasion; first-line immunity; non-structural protein; interferon; lymphocytes; metabolism; ageing
Online: 4 January 2023 (12:43:27 CET)
Microbial immune escape represents the primary cause of induced pathogenesis in humans, and it represents a pivotal method used by viral agents to increase their load and suppress key mechanisms of the innate and adaptive immune system. This phenomenon represents the primary factor that led to the onset of the 1918-1920 A(H1N1) Influenza and 2020-2022 COVID-19 pandemics, and it possibly played a major role in the onset of the AIDS pandemic as well. Moreover, repeated incidents of immune evasion could be associated with higher rates of cellular aging (Jackson et al., 2017), most likely due to the consequent increased demands of energy consumption. Highly developed viral immune evasion ultimately indicates the high inner intelligence of human immunity due to reflective and imitative characteristics of reactions that are produced against initial actions. Ribonucleic acid-based viral genomes contain open reading frames, which consist of genes producing sixteen non-structural proteins. Such proteins play a considerable role in desensitizing first-line immunity during cellular infection, and non-structural proteins 1, 10 and 16 have the strongest effects against a healthy expression rate of Type I and Type III Interferon-encoding genes. Type I Interferons consist of IFN-alpha, -beta, -delta, -epsilon, -omega, -tau and -zeta, whilst Type III Interferons consist of IFN-lambda1, -lambda2 and -lambda3, and they act as stimulators of intracellular signalling cascades that in turn lead to the activation and expression of interferon-stimulated genes (Brown et al., 2022). The earlier the interferon-stimulated genes are activated, the lower the extent of pro-inflammatory mediation and overall, the more effective the antiviral immune response will be, given the exponential nature of the viral load increase. Non-structural protein 16 methylates the 5’ cap of the virus, making the pathogen-associated molecular patterns less recognisable by pattern-recognition receptors, and it requires activation by bonding with non-structural protein 10. It is preserved in the S-Adenosyl-L-Methionine pocket of the SARS-CoV-2 genome. Non-structural protein 1 (NS1) directly cleaves the host cell mRNA producing Type I and possibly Type III Interferons, thereby preventing a translation process of the immune proteins. NS1 has recently been found to often be packaged into exosomes once secreted by the viral genome in the cytosol, meaning that exocytosis and paracrine signalling to neighbouring cells before their actual infection is possible. As a result, NS1 is highly capable of silencing the first-line immune responses of uninfected neighbouring cells as well, thereby highlighting the need to adjust the focus of therapeutics and vaccinology toward first-line immunity and further indicating its foundational importance in the support for the development of precise and balanced defenses against microbial agents of concern (EL SAFADI et al., 2022).
REVIEW | doi:10.20944/preprints202212.0155.v4
Subject: Life Sciences, Virology Keywords: covid-19; pandemic; immune evasion; first-line immunity; viral evolution; interferon; dendritic cells; cytokines; chemokines; innate immunity; adaptive immunity; vaccinology
Online: 21 February 2023 (02:38:38 CET)
The SARS–CoV-2 infection has caused both acute and chronic COVID–19 disease during the recent pandemic with emerging more transmissible SARS–CoV–2 Omicron variants (BQ1 and XBB1) that have increased demands for more effective immunogens and therapeutic approaches to protect the lives of numerous SARS–CoV-2 affected individuals and reduce overall disease burden that could be affected by concurrent other pathogens causing diseases. Following a worldwide campaign of mass vaccination, there is still a significant demand to quell the harmful effects of novel SARS–CoV–2 infections due to higher mutation rates within specific areas of the SARS–CoV-2 domain, leading to enhanced viral entry, especially within individuals with one or more significant comorbidities, and there is still a dilemma of how prevention of future pandemics will occur as within host animal mutations and cross species transfer naturally occurs. Concerns intersect at a specific point; a gained evolutionary ability of several viruses over the previous centuries to remain undetected during the first stages of infection by means of capping the 5' end of their DNA and RNA genes respectively. This may occur by reducing the rate of host Type I and Type III Interferons (IFN) cellular synthesis, that would usually occur and affect both apoptotic pathways, that facilitate viral replication and clearance, as well as immune cells, that process and present pathogenic antigen epitopes. Furthermore, although methods of vaccination exist, other methods in clinical development remain that could evoke an immune response in different cellular, serum or mucosal compartments being cellular, serum and mucosal that evoke differential antibody responses. Antibodies are classed as natural and synthetic. Natural antibodies are further classified into neutralizing and non-neutralizing, whilst synthetic antibodies are also further classified into monoclonal and polyclonal. As a result of single cell study transcriptome research, viruses do utilize an array of protein receptors for receptor-mediated cellular entry. This, therefore suggests that potential differential production of antibody immunoglobulins (Ig) within serum and mucosal areas remains affected by cytokines, adhesion molecules and chemokines that can be upregulated or downregulated upon host viral infection. Serum plasma antibodies can be multimeric that may not efficiently cross the nasal epithelium cell layer, therefore offering less protection against mucosal inflammation due to mucin proteins. On the other hand, antibodies produced by mucosal plasma cells at epithelial surfaces are known to provide effective immune responses in some viral infections. The existence of developments that stimulate mucosal immune responses has so far only been seen with influenza nasal immunogens. Nevertheless, scientists developed ways of immunization and early treatment worldwide that generally showed good success rates and fewer risks of adverse events, and the still early present stages of COVID-19 research should also be taken into consideration. For example, the administration of human interferons I and III into the nasal mucosa cellular layer, as key mediators of anti–viral activity, can stimulate cellular activity to train the innate and adaptive immune system cells to develop and appropriately stimulate an adequate immune response through B and T cells. Recently, it was discovered that specific plants secrete proteins that also stimulate the production of Type I Interferons. It might be that focusing on directly offering the immune system the information about the genetics and protein structure of the pathogen, rather than training its first-line mechanisms to develop faster, excessively increases its specificity, making it reach a level that brings the virus the opportunity to evolve and escape previously-developed host immune mechanisms. Naturally-selected polymorphic viruses through genetic recombination pose challenges to traditional concepts of cellular and molecular immune system neutralization of these viruses during the first stages of cellular infection. It is until the scientific community realizes this potentially crucial aspect that we will probably continue to face serious epidemics and pandemics of respiratory diseases over the coming several decades, evidenced with dengue fever and more recently monkeypox. Type I IFNs tend to be produced faster than Type III IFNs, and the first induce slightly more abundant pro-inflammatory signals than the latter, meaning that type III IFNs, if produced early, may further decrease the extent of excessive proinflammatory signals. Hence, we believe that nasal sprays containing a low dosage of Type I and Type III IFNs not only represent a relevant COVID-19 therapeutic, but also a potential unknown modulatory therapy of the future. Of note, it has been indicated that IFN I and / or III display significant immunizing and early therapeutic effects for other viral evoked diseases like Influenza (Influenza (A)H1N1), rabies (Rabies lyssavirus), measles (Measles virus), rubella (Rubivirus rubellae), Hepatitis B, HIV-induced AIDS, Ebola, Marburg, as well as bacterial diseases, such as lower respiratory tract infectious diseases induced by Haemophilus influenzae, Streptococcus pneumoniae and Staphylococcus aureus, and a number of oncological diseases, like hepatic melanoma.
REVIEW | doi:10.20944/preprints202212.0190.v1
Subject: Life Sciences, Immunology Keywords: maternal infection; fetal neurodevelopmental delays; neuroimmunology; innate immunity; adap-tive immunity; interferon; natural lymphocyte; adaptive lymphocyte; neuroprotection; neurogen-esis
Online: 12 December 2022 (04:04:15 CET)
Maternal infectious disease may pose considerable challenges to the fetal health due to the distribution of important elements of the sanguine and lymphatic system from the mother via the umbilical cord. The mother and the fetus have a degree of interdependence that is similar to the one between the eukaryotic cell and the mitochondrion, particularly during the first half term of the pregnancy, which explains the increased appetite of the expecting mother during the first stages of the fetal development. There is a solid bridge between the adaptive immune system and the encephalon that was only discovered a few decades ago. As a result, scientists may still be in the introductory stages of research, and there might be a significant and profound degree of association between the immune system and a healthy neurological development. There is a significant link between the onset of significant maternal infectious disease and the onset of neurodevelopmental disease in the fetus, and virtually all immune cells play major roles in the promotion and inhibition of neurogenesis alike. Likewise, there is a probability that maternal infectious diseases during pregnancy represent a risk factor of fetal neurodevelopmental disease, as a pressurised development of the adaptive immune memory could result in a pressurised or inhibited neurological development, which both can result in a delayed development of certain sub-regions of the brain. For example, the fetus may display poorer social abilities and sharp analytical skills later in life, which is an important sign of neurodevelopmental disease. A pressurised development of the adaptive immune memory could not require the development of a significant form of disease, but rather just a sharp rate of immune preparation against several important pathogenic agents during the introductory stages of life, when the encephalon experiences the sharpest increase rate in development. The problem per se is not the process of immunisation, but a much sharper process of immunisation over the first stages of life in case of an exposure to one dangerous pathogen or more numerous kinds of pathogens and antigens that normally cause moderate disease morbidity. The more dangerous the microbe is, the sharper the development of the adaptive immune memory will be, and the same happens in the case of an increased number of infectious microbes and antigens that infected the cells of the mothers and the fetuses in cause, and this may, in the majority of the situations, still be the case even if the pathogens are already significantly weakened or lifeless, given that the gain of adaptive immune memory alone constitutes an important factor of neurogenesis and an increased rate of neurological development, and that the infant will become almost or fully protected against the pathogens in cause, despite not having had experienced the disease beforehand. In this case, neurodevelopmental delays are possibly not caused by an impaired neurogenesis, but by an excessive one, whilst maternal infection-associated neurodevelopmental delays may be caused by an impaired neurogenesis. Nevertheless, the aetiology of immunity-related neurodevelopmental delays may be more complex in nature and implicate a chronological and spatial sequence of induced excedentary and deficitary rates of neurogenesis, hence reflecting the incredibly complex nature and various forms of neurodevelopmental disease. It is important to mention that a single dose of infant immunisation brings significantly lower risks of adverse neurological events than the onset of a significant maternal infectious disease during pregnancy. The objective of paediatric neuro-immunological studies may be to improve the understanding of the association between a healthy immune developmental rate and a balanced ratio of the developmental rates of important brain regions and sub-regions.