Summary The thymus has a high capacity to support the differentiation of ILCs, especially when E protein transcription factors are ablated. Whether it contributes to the homeostasis of ILC pools in tissues is not clear. Single-cell RNA sequencing analysis shows a substantial amount of ILC precursors in wild type but not athymic nude blood. The precursors express CD3 intracellularly (ic) but not on the surface. The abundance of Lin − CD127 + CD62L + icCD3ε + precursors varies with age, peaking at 2–3 months. These cells can differentiate into various ILC subsets on OP9-DL1 stroma in vitro . In the lung, small intestine, and epidermis, icCD3ε + cells differentiate into diverse ILC subsets in different tissue environments in steady state. Helminth infection promotes their differentiation toward functional ILC2s. Thus, the thymus appears to play a role in replenishing ILC pools in different peripheral tissues. Because thymic activity is age-dependent, this finding may help explain age-related differences in immune responses.

Accumulating data suggest an important role of growth factors in autoimmune diseases and parasitic nematode infections. Nematodes are used in clinical studies of autoimmune diseases and parasite-derived molecules are widely studied for their therapeutic potential in various types of disorders. However, the effect of nematode infection on growth factors in autoimmune disorders has not been studied. The objective of this study was to evaluate the influence of infection with the intestinal nematode Heligmosomoides polygyrus in murine autoimmune models on the production of growth factors. Here, the level of a variety of growth factors related mainly to angiogenesis was evaluated by protein array in the intestinal mucosa of C57BL/6 dextran sodium sulfate-induced colitic mice and in cerebral spinal fluid of experimental autoimmune encephalomyelitis (EAE) mice infected with nematodes. In addition, vessel formation was evaluated in the brains of EAE mice infected with H. polygyrus. A significant influence of nematode infection on the level of angiogenic factors was observed. Parasitic infection of colitic mice resulted in upregulation of mucosal AREG, EGF, FGF-2, and IGFBP-3 in the intestine of the host and better adaptation (infectivity). In EAE mice, infection increased the level of FGF-2 and FGF-7 in CSF. In addition, remodeling of brain vessels was observed, with a higher density of long vessels. Nematode-derived factors are promising tools to fight autoimmune diseases and to study angiogenesis.

Altered regulatory T cell (Treg) function could contribute to MS. The expression of activating and inhibitory receptors influences the activity of Tregs. Our aim was to investigate T cell phenotypes in relapsing–remitting MS (RRMS) patients at an early phase of the disease. We examined the influence of demographic parameters on the distribution of CD4+ and CD8+ T cell subclasses by generalized linear modeling. We also studied the expression of the following markers—CTLA-4, GITR, PD-1, FoxP3, Helios, CD28, CD62L, CD103—on T cell subsets from peripheral blood with a 14-color flow cytometry panel. We used an antibody array to define the profiles of 34 Th1/Th2/Th17 cytokines in the serum. Expression of PD-1 and GITR on CD4+ and CD8+ Tregs was decreased in RRMS patients. The proinflammatory factors IFN-γ, IL-17, IL-17F, TGFβ-1, TGFβ-3, IL-1SRII, IL-12 p40, sgp130, IL-6sR were significantly increased in RRMS patients. Therefore, a deficiency of PD-1 and GITR immune checkpoints on CD4+ and CD8+ Tregs is a feature of RRMS and might underlie impaired T cell control.