CISH attenuates homeostatic cytokine signaling to promote lung-specific macrophage programming and function

A single-cell atlas of lung homeostasis reveals dynamic changes during development and aging

Aging is a global challenge, marked in the lungs by function decline and structural disorders, which affects the health of the elderly population. To explore anti-aging strategies, we develop a dynamic atlas covering 45 cell types in human lungs, spanning from embryonic development to aging. We aim to apply the discoveries of lung's development to address aging-related issues. We observe that both epithelial and immune cells undergo a process of acquisition and loss of essential function as they transition from development to aging. During aging, we identify cellular phenotypic alternations that result in reduced pulmonary compliance and compromised immune homeostasis. Furthermore, we find a distinctive expression pattern of the ferritin light chain (FTL) gene, which increases during development but decreases in various types of lung cells during the aging process.

Role of the pioneer transcription factor GATA2 in health and disease

The transcription factor GATA2 is involved in human diseases ranging from hematopoietic disorders, to cancer, to infectious diseases. GATA2 is one of six GATA-family transcription factors that act as pioneering transcription factors which facilitate the opening of heterochromatin and the subsequent binding of other transcription factors to induce gene expression from previously inaccessible regions of the genome. Although GATA2 is essential for hematopoiesis and lymphangiogenesis, it is also expressed in other tissues such as the lung, prostate gland, gastrointestinal tract, central nervous system, placenta, fetal liver, and fetal heart. Gene or transcriptional abnormalities of GATA2 causes or predisposes patients to several diseases including the hematological cancers acute myeloid leukemia and acute lymphoblastic leukemia, the primary immunodeficiency MonoMAC syndrome, and to cancers of the lung, prostate, uterus, kidney, breast, gastric tract, and ovaries. Recent data has also linked GATA2 expression and mutations to responses to infectious diseases including SARS-CoV-2 and Pneumocystis carinii pneumonia, and to inflammatory disorders such as atherosclerosis. In this article we review the role of GATA2 in the etiology and progression of these various diseases.

Intestinal Epithelial Cell-specific Deletion of Cytokine-inducible SH2-containing Protein Alleviates Experimental Colitis in Ageing Mice

BACKGROUND AND AIMS

The incidence of inflammatory bowel disease [IBD] in the elderly has increased in recent years. However, the mechanisms underlying the ageing-related IBD susceptibility remain elusive. Cytokine-inducible SH2-containing protein [CISH] is involved in regulating metabolism, the expansion of intestinal tuft cells and type-2 innate lymphoid cells, and ageing-related airway inflammation. Here, we investigated the role of CISH in ageing-related colitis susceptibility.

METHODS

CISH and phosphorylated signal transducer and activator of transcription-3 [p-STAT3] levels were evaluated in the colons of ageing mice and older ulcerative colitis [UC] patients. Mice with intestinal epithelial cell-specific knockout of Cish [CishΔIEC] and Cish-floxed mice were administered dextran sodium sulphate [DSS] or trinitrobenzene sulphonic acid [TNBS] to induce colitis. Colonic tissues were analysed in quantitative real-time polymerase chain reaction, immunoblotting, immunohistochemical, and histological staining experiments. Differentially expressed genes from colonic epithelia were analysed by RNA sequencing.

RESULTS

Ageing increased the severity of DSS-induced colitis and the expression of colonic epithelial CISH in mice. CishΔIEC prevented DSS- or TNBS-induced colitis in middle-aged mice but not in young mice. RNA-sequencing analysis revealed that CishΔIEC significantly suppressed DSS-induced oxidative stress and proinflammatory responses. During ageing in the CCD841 cell model, knockdown of CISH decreased ageing-induced oxidative stress and proinflammatory responses, whereas these effects were compromised by knocking down or inhibiting STAT3. The increase in CISH expression was higher in the colonic mucosa of older patients with UC than in that of healthy controls.

CONCLUSIONS

CISH might be a proinflammatory regulator in ageing; therefore, targeted therapy against CISH may provide a novel strategy for treating ageing-related IBD.

CIS and TGF-β regulatory pathways influence immunity to bacterial infection

Immunotherapy has revolutionized cancer therapy by reactivating tumor-resident cytotoxic lymphocytes. More recently, immunotherapy has emerged to restore immunity against infectious agents, including bacterial infections. Immunotherapy primarily targets inhibitory pathways in T cells, however interest in other effector populations, such as natural killer (NK) cells, is growing. We have previously discovered that NK cell metabolism, proliferation, and activation can be neutralized through the transforming growth factor (TGF)-β immunosuppressive pathway by inducing plasticity of NK cells and differentiation into innate lymphoid cell (ILC)1-like subsets. NK cells are also regulated through cytokine-inducible SH2-containing protein (CIS), which is induced by interleukin (IL)-15 and is a potent intracellular checkpoint suppressing NK cell survival and function. Targeting these two distinct pathways to restore NK cell function has shown promise in cancer models, but their application in bacterial infection remains unknown. Here, we investigate whether enhancement of NK cell function can improve anti-bacterial immunity, using Salmonella Typhimurium as a model. We identified conversion of NK cells to ILC1-like for the first time in the context of bacterial infection, where TGF-β signaling contributed to this plasticity. Future work should focus on identifying further drivers of ILC1 plasticity and its functional implication in bacterial infection models. We further describe that CIS-deficient mice displayed enhanced pro-inflammatory function and dramatically enhanced anti-bacterial immunity. Inhibition of CIS may present as a viable therapeutic option to enhance immunity towards bacterial infection.