In the article, Chinese experts present the current scientific knowledge on how circadian rhythms regulate the immune system at the molecular, cellular and physiological levels, thereby contributing to homeostasis and disease resistance.

Poor functioning of circadian rhythms increases the risk of various immune-related diseases

The authors of the study say that disrupted circadian rhythms due to improper light exposure can lead to immune system dysfunction, increasing the risk of health problems such as the development of tumours, aggravated inflammatory reactions and autoimmune diseases. Disruption of circadian rhythms in the immune system can impair the body’s ability to recognise and respond to pathogens and tumours. This negatively affects the timing and severity of disease symptoms. For example, mice infected with encephalitis virus at the end of their active phase show a significantly reduced survival rate.

Research has also shown that disruption of key circadian genes such as BMAL1 leads to amplified inflammatory responses and increased risk of autoimmune diseases. For example, dendritic cells that lack BMAL1 are unable to properly control the antigen presentation and T-cell activation rhythms, thereby promoting tumour growth in mice. Furthermore, the disruption of circadian rhythms as a result of affecting the entry, quantity and flow of lymphocytes into the lymph nodes leads to diseases of adaptive immunity.