How persistent pathogens could accelerate the aging process | Amy Proal | TEDxBoston

Key Concepts

• Healthspan Extension: The goal of increasing the period of life spent in good health, free from chronic disease and disability.
• Persistent Pathogens: Infectious organisms (viruses, bacteria, parasites) that remain in the body long-term, often without overt symptoms, and can influence aging processes.
• Hallmarks of Aging: Key biological processes that contribute to aging, such as mitochondrial dysfunction, microbiome dysbiosis, cellular senescence, and inflammaging.
• Obligate Intracellular Parasites: Organisms, like viruses, that cannot reproduce or carry out metabolic processes independently and must infect host cells to survive and replicate.
• Telomere Attrition: The shortening of protective caps on chromosomes, which is associated with cellular aging.
• Cellular Senescence: A state where cells stop dividing and can contribute to aging-related inflammation and tissue dysfunction.
• Pathogen-Driven Age Distortion: The concept that persistent pathogens can actively contribute to and accelerate the aging process by interfering with host cellular functions and genetic signaling.
• Reconceptualization of Aging: The idea that aging models need to expand beyond solely focusing on host genetics to include the influence of other genetic entities, such as viruses.
• Antipathogen Therapies: Treatments aimed at eliminating or controlling persistent infections.
• Diagnostic Platforms: Advanced testing methods for identifying chronic infections that may be missed by standard diagnostics.

The Failure to Extend Healthspans Due to Unaccounted Pathogens

The speaker posits that most individuals will fail to extend their healthspans because current aging models overlook a significant root cause: persistent viral, bacterial, parasitic, and other pathogens. These organisms can infect and remain in human tissues throughout life, often acquired from birth and through various exposures.

Key Points:

• Ubiquitous and Persistent Infections: Many infections, even those that initially cause mild or transient symptoms (like food poisoning, colds, flu, or insect bites), can leave persistent organisms in tissues, nerves, or the gut.
• Examples of Persistent Pathogens:
  • Herpesviruses: At least 95% of individuals harbor one or more strains (e.g., Epstein-Barr virus, Human Herpesvirus 6, Cytomegalovirus), which persist in cells and nerves for life.
  • Toxoplasma gondii: A parasite that infects up to 87% of people in some global regions, capable of persisting in the brain.
  • SARS-CoV-2: Research has detected the COVID-19 virus in tissue samples from individuals with and without chronic symptoms, months or years after initial infection, indicating persistence. The image shown depicts persistent SARS-CoV-2 in gut tissue of a long COVID patient nearly two years post-infection.

Pathogens as "Hackers" of the Human Body and Drivers of Aging

Persistent pathogens are described as "hackers" that distort human cellular signaling and drive aging processes.

Key Points:

• Mechanism of Action: Pathogens create proteins and products that interfere with the signaling of host genes.
• Impact on Hallmarks of Aging: Pathogens can drive all recognized hallmarks of aging, including:
  • Mitochondrial Dysfunction: Pathogens hijack host cell metabolism, draining cellular energy production to support their own replication. As obligate intracellular parasites, viruses steal raw materials from host mitochondria, disrupting cellular metabolism.
  • Telomere Attrition: Human Herpesvirus 6 has been shown to integrate into telomeres, leading to shorter and more unstable telomeres, which is detrimental to longevity.
  • Cellular Senescence: Viral proteins can distort signaling pathways that regulate cellular senescence, impacting the cell's ability to repair and divide.
  • Other Hallmarks: Pathogens can also contribute to microbiome dysbiosis, T-cell exhaustion, epigenetic alterations, inflammaging, and cognitive decline.

Supporting Evidence/Argument:

• A study found that viral proteins can directly interact with and distort human aging pathways, leading to the conclusion that aging models need a "reconceptualization of the locus of aging," expanding beyond host genetics to include interacting viral entities.

Addressing Pathogen-Driven Age Distortion

The speaker advocates for a shift in focus towards addressing persistent pathogens as a crucial step in healthspan extension.

Key Arguments/Perspectives:

• Prioritization of Antipathogen Strategies: Interventions like cellular reprogramming or CRISPR gene editing may be less effective if persistent pathogens are actively undermining cellular function. The analogy used is trying to extinguish a forest fire while someone continues to add fuel.
• Logical First Step: Curbing pathogen activity should precede extensive gene editing of human genes.
• Existing and Future Solutions:
  • Existing Therapies: Numerous antiviral and antiparasitic medications and compounds can be integrated into healthspan protocols.
  • New Therapies: Development of novel antipathogen compounds and immune-activating therapies is encouraged.

Real-World Application/Example:

• A population-level data analysis indicated that individuals with herpes simplex virus who regularly took affordable, generic anti-herpes medications had a 10-fold lower risk of developing dementia later in life.

Improving Diagnostics for Persistent Pathogens

The current diagnostic capabilities for identifying persistent pathogens are often inaccurate and outdated, hindering effective treatment.

Key Points:

• Limitations of Current Tests: Standard medical tests often fail to detect chronic infections.
• Need for Advanced Diagnostics: Investment in new diagnostic platforms is essential.
• Emerging Technologies: Some groups are developing methods to detect pathogens or their proteins in small vesicles within blood samples, which are missed by current standard testing.

Call to Action:

• These new diagnostic platforms should be integrated into biological age tracking to enable better diagnosis, tracking, and control of pathogen activity.

Conclusion/Synthesis

The central takeaway is that successful healthspan extension requires a fundamental shift in our understanding and approach to aging. Current models are incomplete because they fail to account for the pervasive and detrimental influence of persistent pathogens. By acknowledging these "pathogen hackers," developing more accurate diagnostic tools, and integrating antipathogen therapies into healthspan protocols, we can unlock the true potential for extending healthy life. The speaker concludes with a call to action to incorporate pathogen activity into aging models for more effective healthspan interventions.