Critical Role of Lkb1 in the Maintenance of Alveolar Macrophage Self-Renewal and Immune Homeostasis.

Alveolar macrophages (AMs) are pivotal for maintaining lung immune homeostasis. We demonstrated that deletion of liver kinase b1 (Lkb1) in CD11c cells led to greatly reduced AM abundance in the lung due to the impaired self-renewal of AMs but not the impeded pre-AM differentiation. Mice with Lkb1-deficient AMs exhibited deteriorated diseases during airway (.

[Effects of Human Amniotic Mesenchymal Stem Cells on Acute Graft-Versus-Host Disease in Xenotransplantation].

Objective: To investigate the effects of human amniotic mesenchymal stem cell（AMSC） on acute graft-versus-host disease (aGVHD) in xenotransplatation.

Methods: NPG mice were injected with human PBMNC via tail vein to establish a xenografted aGVHD model. The mice in the experimental group were divided into PBMNC infusion group and PBMNC+AMSC co-infusion group, the general condition, survival time and manifestations of aGVHD were observed, the body weight and blood routine indicators were detected, the pathological changes of aGVHD target organs (lung, liver, spleen, small intestine) were observed by HE staining, and the levels of human T cells in peripheral blood, tissues and organs of mice was detected by flow cytometry.

Tsc1 controls the development and function of alveolar macrophages.

Alveolar macrophages (AMs) are pivotal for maintaining the lung homeostasis, but how the development and function of AMs regulated remains largely unknown. In the present study, we demonstrated that the number of AMs was controlled by the Tsc1 protein. Cd11c-specific deletion of Tsc1 caused inefficient transition from pre-AMs to AMs in lung, which led to a great reduction of AM population.