GPR41 and GPR43 regulate CD8 T cell priming during herpes simplex virus type 1 infection.

Naïve CD8 T cells need to undergo a complex and coordinated differentiation program to gain the capacity to control virus infections. This not only involves the acquisition of effector functions, but also regulates the development of a subset of effector CD8 T cells into long-lived and protective memory cells. Microbiota-derived metabolites have recently gained interest for their influence on T cells, but much remains unclear about their role in CD8 T cell differentiation.

CD4 T cell immunity against cutaneous melanoma encompasses multifaceted MHC II-dependent responses.

Whereas CD4 T cells conventionally mediate antitumor immunity by providing help to CD8 T cells, recent clinical studies have implied an important role for cytotoxic CD4 T cells in cancer immunity. Using an orthotopic melanoma model, we provide a detailed account of antitumoral CD4 T cell responses and their regulation by major histocompatibility complex class II (MHC II) in the skin. Intravital imaging revealed prominent interactions of CD4 T cells with tumor debris-laden MHC II host antigen-presenting cells that accumulated around tumor cell nests, although direct recognition of MHC II melanoma cells alone could also promote CD4 T cell control.

CRISPR-Cas9 screening identifies an IRF1-SOCS1-mediated negative feedback loop that limits CXCL9 expression and antitumor immunity.

CXCL9 expression is a strong predictor of response to immune checkpoint blockade therapy. Accordingly, we sought to develop therapeutic strategies to enhance the expression of CXCL9 and augment antitumor immunity. To perform whole-genome CRISPR-Cas9 screening for regulators of CXCL9 expression, a CXCL9-GFP reporter line is generated using a CRISPR knockin strategy.

Functional flexibility and plasticity in immune control of systemic Salmonella infection.

Immunity to systemic Salmonella infection depends on multiple effector mechanisms. Lymphocyte-derived interferon gamma (IFN-γ) enhances cell-intrinsic bactericidal capabilities to antagonize the hijacking of phagocytes as replicative niches for Salmonella. Programmed cell death (PCD) provides another means through which phagocytes fight against intracellular Salmonella.

CD4+ T cell immunity to Salmonella is transient in the circulation.

While Salmonella enterica is seen as an archetypal facultative intracellular bacterial pathogen where protection is mediated by CD4+ T cells, identifying circulating protective cells has proved very difficult, inhibiting steps to identify key antigen specificities. Exploiting a mouse model of vaccination, we show that the spleens of C57BL/6 mice vaccinated with live-attenuated Salmonella serovar Typhimurium (S. Typhimurium) strains carried a pool of IFN-γ+ CD4+ T cells that could adoptively transfer protection, but only transiently.

Flexible Usage and Interconnectivity of Diverse Cell Death Pathways Protect against Intracellular Infection.

Programmed cell death contributes to host defense against pathogens. To investigate the relative importance of pyroptosis, necroptosis, and apoptosis during Salmonella infection, we infected mice and macrophages deficient for diverse combinations of caspases-1, -11, -12, and -8 and receptor interacting serine/threonine kinase 3 (RIPK3). Loss of pyroptosis, caspase-8-driven apoptosis, or necroptosis had minor impact on Salmonella control.

MiR-21 is required for efficient kidney regeneration in fish.

Background: Acute kidney injury in mammals, which is caused by cardiovascular diseases or the administration of antibiotics with nephrotoxic side-effects is a life-threatening disease, since loss of nephrons is irreversible in mammals. In contrast, fish are able to generate new nephrons even in adulthood and thus provide a good model to study renal tubular regeneration.

Results: Here, we investigated the early response after gentamicin-induced renal injury, using the short-lived killifish Nothobranchius furzeri.