Reversing epigenetic T cell exhaustion

This 2019 worldwide discussion among 18 experts concerned T cell exhaustion:

“‘T cell exhaustion’ is a broad term that has been used to describe the response of T cells to chronic antigen stimulation, first in the setting of chronic viral infection but more recently in response to tumours.

Key questions remain about the potential to reverse the epigenetic programme of exhaustion and how this might affect the persistence of T cell populations.”

There were nearly a dozen viewpoints on even “What do we mean by T cell exhaustion and/or dysfunction and how would you define this state?” 🙂

Answers to the question “What are the key controversies and outstanding research questions?” included:

  • “What are the cellular signalling and transcriptional pathways that drive the conversion to an exhausted T cell phenotype, and how can the chromatin and transcriptional changes of exhaustion be reversed in individual exhausted cells?
  • Whether and how we can manipulate signalling pathways to both activate and maintain T cell responses remain open questions, as does the question of whether pharmacological manipulations can reverse the epigenetic changes associated with exhaustion versus expand less-exhausted populations.
  • We need to define better the effects of the microenvironment on the induction of T cell exhaustion, the developmental trajectories of exhaustion and the point at which and extent to which exhaustion can be reversed. Understanding the consequences of unleashing T cells from exhaustion will also be crucial to designing the most effective therapeutic interventions.
  • When and how exhausted T cell populations are formed. The original view that they are terminally differentiated descendants of formerly ‘normal’ effector T cells has been challenged.
  • Whether the predysfunctional T cells themselves, or their more differentiated (and phenotypically dysfunctional) progeny, form the ultimate effector pool for control of human tumours.
  • How do the functions and states (subpopulations) of exhausted T cells change over time? Can the epigenetic state of exhaustion be reversed to form true effector or memory T cells, and is this required for improved cancer immunotherapy?
  • There is no definitive marker for exhausted T cells, although TOX may prove to be useful. Transcriptional profiles are informative, but epigenetic changes are more specific and robust. A major clinical question is whether exhausted T cells can be, or indeed need to be, reprogrammed to achieve therapeutic benefit.” “Defining ‘T cell exhaustion'” (not freely available)


Get outside today

This 2019 Finnish review focused on vitamin D’s immune system effects:

“The epigenome of human monocytes is at multiple levels sensitive to vitamin D. These data served as the basis for the chromatin model of vitamin D signaling, which mechanistically explains the activation of a few hundred primary vitamin D target genes.

Vitamin D and its receptor are able to antagonize the pro-inflammatory actions of the transcription factors nuclear factor activated T cells (NF-AT) and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) in T cells. In this way, vitamin D reduces autoimmunity, such as the onset and progression of multiple sclerosis, as well as chronic inflammation.

Population-wide recommendations do not take inter-individual variations into account, such as a different molecular response to vitamin D, which are expressed by the vitamin D response index. Instead of population-based recommendations for vitamin D3 supplementation there should be personalized recommendations in order to reach a vitamin D status that is optimized for an individual’s health protection.

Trained immunity implies that immune cells memorize challenges, to which they are exposed in their rather short lifespan, in form of changes of their epigenome leading to subtype specification. The stabilization of the epigenomes of the subtypes of monocytes, macrophages and dendritic cells by vitamin D can prevent or delay the onset of common age-related diseases.”

One of the five elements of the clinical trial Reversal of aging and immunosenescent trends was daily 3,000 IU vitamin D3 supplementation for nine months. That study’s monocyte findings included:

“Analysis of CyTOF‐defined immune cell populations revealed the most robust changes to be decreases in total and CD38‐positive monocytes and resulting increases in the lymphocyte‐to‐monocyte ratio (LMR). The changes in mean monocyte populations persisted 6 months after discontinuation of treatment, and the increase in LMR remained highly significant at 18 months as well.” “Vitamin D Signaling in the Context of Innate Immunity: Focus on Human Monocytes”

May you be the hero who solves your own problems

This 2019 Germany/US review subject was the failure of psychotherapy and pharmacotherapy:

“Each mental disorder raises its own host of issues. However, recent evidence across multiple meta-analyses on key mental disorders provides an overarching picture of limited benefits for both psychotherapy and pharmacotherapy.

Some differences for specific disorders are not strong enough to weaken the overall impression that a dead end has been reached in the treatment of mental disorders. For this reason, a paradigm shift seems to be required.”

Investigate the above linked Primal Therapy category to figure out what you could do for yourself. Follow the below review link for reasons to avoid treatments that waste your one precious life. “Toward a paradigm shift in treatment and research of mental disorders”