The families of tetraspanins and galectins are essential for the organization of molecules on the surface of lymphocytes, and deficiencies in specific family members can lead to impaired immunity, tumour development and autoimmunity. This Review investigates the molecular mechanisms of membrane organization by tetraspanins and galectins, specifically their role in B cell and T cell proliferation, survival and migration, as well as in antibody production and T cell polarization, and discusses potential therapeutic opportunities.

This Review discusses how the study of novel mouse models of human ADAR1 deficiency has led to the identification of the innate immune receptors recognizing endogenous immunostimulatory double-stranded RNA and their respective downstream signalling pathways that induce autoinflammatory pathology.

This Review covers the biology of anti-cytokine autoantibodies and their varied roles in causing, preventing and treating diseases. Recent reports of anti-type I interferon autoantibodies in critical COVID-19 have led to renewed interest in this topic, which offers fascinating insights into the reversibility of immune tolerance and the origins of autoimmunity in otherwise healthy individuals.

Cryptosporidium are protozoan parasites that infect intestinal epithelial cells and can cause severe diarrhoeal disease, particularly in malnourished children. This Review summarizes the immune mechanisms that protect against this parasitic infection, highlighting the innate mechanisms that detect Cryptosporidium at the intestinal epithelium and the adaptive immune mechanisms that mediate resistance.