Preventive and therapeutic applications of neutralizing antibodies to Human Immunodeficiency Virus Type 1 (HIV-1)

Shear-reversible clusters of HIV-1 in solution: stabilized by antibodies, dispersed by mucin

IMPORTANCE

The phenomenon of reversible clustering is expected to further nuance HIV immune stealth because virus surfaces can escape interaction with antibodies (Abs) by hiding temporarily within clusters. It is well known that mucin reduces HIV virulence, and the current perspective is that mucin aggregates HIV-1 to reduce infections. Our findings, however, suggest that mucin is dispersing HIV clusters. The study proposes a new paradigm for how HIV-1 may broadly evade Ab recognition with reversible clustering and why mucin effectively neutralizes HIV-1.

New insights on circular RNAs and their potential applications as biomarkers, therapeutic agents, and preventive vaccines in viral infections: with a glance at SARS-CoV-2

The occurrence of viral infections and approaches to handling them are very challenging and require prompt diagnosis and timely treatment. Recently, genomic medicine approaches have come up with the discovery of the competing endogenous RNA (ceRNA) network, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) on the basis of gene silencing. CircRNAs, as a group of non-encoded RNAs, make a loop-like structure by back-splicing through 3' and 5' ends. They are stable, abundant, specific, and highly conserved and can be quickly generated at large scales in vitro. CircRNAs have the potential to contribute in several cellular processes in a way that some serve as microRNA sponges, cellular transporters, protein-binding RNAs, transcriptional regulators, and immune system modulators. CircRNAs can even play an important role in modulating antiviral immune responses. In the present review, circRNAs' biogenesis, function, and biomarker and therapeutic potential as well as their prospective applications as vaccines against viral infections such as SARS-CoV-2 are explained. By considering their unique properties, their potential to be used as novel vaccines, biomarkers, and a therapeutic approach appears possible.

Mapping the intellectual structure of the coronavirus field (2000-2020): a co-word analysis

Over the two last decades, coronaviruses have affected human life in different ways, especially in terms of health and economy. Due to the profound effects of novel coronaviruses, growing tides of research are emerging in various research fields. This paper employs a co-word analysis approach to map the intellectual structure of the coronavirus literature for a better understanding of how coronavirus research and the disease itself have developed during the target timeframe. A strategic diagram has been drawn to depict the coronavirus domain's structure and development. A detailed picture of coronavirus literature has been extracted from a huge number of papers to provide a quick overview of the coronavirus literature. The main themes of past coronavirus-related publications are (a) "Antibody-Virus Interactions," (b) "Emerging Infectious Diseases," (c) "Protein Structure-based Drug Design and Antiviral Drug Discovery," (d) "Coronavirus Detection Methods," (e) "Viral Pathogenesis and Immunity," and (f) "Animal Coronaviruses." The emerging infectious diseases are mostly related to fatal diseases (such as Middle East respiratory syndrome, severe acute respiratory syndrome, and COVID-19) and animal coronaviruses (including porcine, turkey, feline, canine, equine, and bovine coronaviruses and infectious bronchitis virus), which are capable of placing animal-dependent industries such as the swine and poultry industries under strong economic pressure. Although considerable research into coronavirus has been done, this unique field has not yet matured sufficiently. Therefore, "Antibody-virus Interactions," "Emerging Infectious Diseases," and "Coronavirus Detection Methods" hold interesting, promising research gaps to be both explored and filled in the future.

Ebola virus antibody decay-stimulation in a high proportion of survivors

Neutralizing antibody function provides a foundation for the efficacy of vaccines and therapies^1–3. Here, using a robust in vitro Ebola virus (EBOV) pseudo-particle infection assay and a well-defined set of solid-phase assays, we describe a wide spectrum of antibody responses in a cohort of healthy survivors of the Sierra Leone EBOV outbreak of 2013–2016. Pseudo-particle virus-neutralizing antibodies correlated with total anti-EBOV reactivity and neutralizing antibodies against live EBOV. Variant EBOV glycoproteins (1995 and 2014 strains) were similarly neutralized. During longitudinal follow-up, antibody responses fluctuated in a ‘decay–stimulation–decay’ pattern that suggests de novo restimulation by EBOV antigens after recovery. A pharmacodynamic model of antibody reactivity identified a decay half-life of 77–100 days and a doubling time of 46–86 days in a high proportion of survivors. The highest antibody reactivity was observed around 200 days after an individual had recovered. The model suggests that EBOV antibody reactivity declines over 0.5–2 years after recovery. In a high proportion of healthy survivors, antibody responses undergo rapid restimulation. Vigilant follow-up of survivors and possible elective de novo antigenic stimulation by vaccine immunization should be considered in order to prevent EBOV viral recrudescence in recovering individuals and thereby to mitigate the potential risk of reseeding an outbreak.

In many survivors of Ebola virus infection, antibody responses show long-term patterns of decline followed by restimulation, possibly owing to recrudescence of persisting virus.

Broadly neutralizing antibodies in HIV-1 treatment and prevention

Antibodies that naturally develop in some individuals infected with human immunodeficiency virus 1 (HIV-1) and are capable of broadly neutralizing diverse strains of HIV-1 are useful for two applications: they can inform the rational design of vaccine immunogens, and they may be capable of preventing and treating HIV-1 infection when administered passively. A phase IIb study has been initiated with the experimental broadly neutralizing antibody (bnAb) VRC01, which has considerable breadth and potency (also referred to as a phase IIb HVTN 703/HPTN 081 and HVTN 704/HPTN 085 AMP efficacy trials) to evaluate its protective efficacy in individuals at risk of HIV acquisition. bnAbs prevent HIV-1 infection by selectively targeting vulnerable sites on the viral envelope (Env) protein that facilitates the entry of HIV. Although in very early stages, bnAbs capable of neutralizing a broad range of inter- and intraclade HIV-1 isolates have been demonstrated to have potential in treating patients either alone or in combination with antiretroviral drug therapy (cART); however, they are proposed to be advantageous over the latter as far as durability and side effects are concerned. Recent studies have indicated that combination therapy of potent bnAbs along with latency-reversing agents (LRAs) might also target latent reservoirs of HIV and kill them by recruiting effector cells, such as natural killer cells, thus confirming clinical progression. Possession of such qualities makes these new-generation potent bnAbs extremely valuable in effectively complementing the shortcomings of current ART drugs and improving the quality of life of infected individuals.