Evolving our understanding of trained immunity
14 days ago
- #trained-immunity
- #immunology
- #BCG-vaccine
- The BCG vaccine, introduced in 1921, has saved more lives than just by preventing tuberculosis, with its broader protective effects explained by the discovery of trained immunity in 2012.
- Trained immunity refers to the ability of innate immune cells to develop a memory-like response to various threats, a concept that challenges the traditional view that only adaptive immunity has memory.
- The innate immune system, evolutionarily older than the adaptive immune system, can undergo metabolic and epigenetic reprogramming to enhance its antimicrobial and proinflammatory capacities.
- Evidence of trained immunity extends beyond BCG to include agents like β-glucan, LPS, and heme, showing potential in vaccines and cancer therapies.
- Key characteristics of trained immunity include the persistence of epigenetic changes after the initial stimulus and a return to baseline, distinguishing it from priming or differentiation.
- Open questions in the field include the duration of trained immunity, the possibility of re-reprogramming, and its evolutionary origins and links to pathogen adaptation.
- Research in plants and invertebrates has provided insights into innate immune memory, suggesting mechanisms that could be relevant to mammals.
- The distinction between beneficial trained immunity and maladaptive innate immune memory is crucial for developing safe and effective treatments.
- Trained immunity offers therapeutic potential beyond infectious diseases, including cancers, autoimmune diseases, and chronic inflammatory disorders.
- Future research and clinical applications of trained immunity will benefit from emerging technologies and targeted delivery systems.