Current strategies for HIV-1 cure have not been successful in eliminating the latent reservoir. This Review highlights potential therapeutic strategies that engage the immunology of dendritic cells and natural killer cells in efforts to achieve HIV-1 cure.

Studying ageing at the single-cell level has provided insight into the changes that occur systemically and in tissues as we age. For example, we now have a greater appreciation of the heterogeneity and dynamic nature of immune cell ageing and of the impact of age-associated tissue remodelling on the immune system, together contributing to increased vulnerability to some diseases.

This study links the complement-mediated retraction of T helper 1 cell responses to vitamin D receptor signalling, an autoregulatory loop that might be impaired in patients with COVID-19.

A preprint by Sanin et al. establishes a transcriptional framework to define common macrophage activation states across tissues and biological conditions.

B cell-derived GABA can inhibit T cell and macrophage activation and limit anti-tumour T immune responses.

A preprint by Kersten et al. describes a positive-feedback loop promoting the mutual formation of tumour-associated macrophages and exhausted T cells as they move towards the tumour core.

Transient skin inflammation in early life leads to the development of T helper 2 cell–fibroblast niches that alter wound repair responses and may drive fibrotic pathology later in life.

In this Review, Manabe and Heneka examine how the systemic inflammation associated with sepsis can lead to acute cerebral dysfunction known as sepsis-associated encephalopathy (SAE). Moreover, they suggest that some of the mechanisms involved in SAE may be relevant for understanding the cognitive impairments that develop in some patients with COVID-19.