In addition to NKG2D, NKp46/NCR1 play an important role in inhibition of liver fibrosis. This suggests that fibrosis can be better controlled through the manipulation of NKp46 activity.

No abstract

It is still unclear how glucocorticoids (GCs) induce apoptosis of thymocytes and T lymphoma cells. Emergence of GC-resistant lymphoma cells is a major obstacle in GC therapy, emphasizing the need for novel strategies that maintain the sensitivity of lymphoma cells to the proapoptotic effects of GC. We have undertaken a kinome study to elucidate the signal transduction pathways involved in mediating GC-induced apoptosis. Our study shows that glycogen synthase kinase (GSK3) plays a central role in promoting GC-induced apoptosis. In the absence of a ligand, GSK3alpha, but not GSK3beta, is sequestered to the glucocorticoid receptor (GR). Exposure to GCs leads to dissociation of GSK3alpha from GR and subsequent interaction of GSK3alpha and GSK3beta with the proapoptotic Bim protein, an essential mediator of GC-induced apoptosis. Chemical inhibition of GSK3 by SB216763, BIO-Acetoxime, or LiCl and GSK3 inhibition using a dominant-negative mutant of GSK3 impede this cell death process, indicating that GSK3 is involved in transmitting the apoptotic signal. GC resistance in lymphoma cells can be relieved by inhibiting the phosphatidylinositol-3 kinase-Akt survival pathway, which inactivates GSK3. Notch1, a transcription factor frequently activated in T acute lymphoblastic leukemia cells, confers GC resistance through activation of Akt. Altogether, this study illuminates the link connecting upstream GR signals to the downstream mediators of GC-induced apoptosis. Our data suggest that targeting protein kinases involved in GSK3 inactivation should improve the outcome of GC therapy.

No abstract

The nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (NF-κB1) is a master regulator of immune and inflammatory responses.1,2 NF-κB1 belongs to the NF-κB/Rel family of transcription factors that consists of five members in humans: NF-κB1 (p105/p50), NF-κB2 (p100/p52), RelA, c-Rel, and RelB. The p105 and p100 precursors are proteolytically processed by the proteasome to generate the shorter p50 and p52 isoforms. Homo-and heterodimers are formed by p50, p52 and the Rel proteins. Unstimulated, these dimeric complexes are sequestered in the cytoplasm by inhibitory IκB proteins in an inactive state. Upon stimulation, the phosphorylation and subsequent degradation of IκB proteins is rapidly triggered, releasing the NF-κB/Rel complexes to enter the nucleus where they bind to DNA at κB sites and activate or repress the expression of their target genes. 3 Recently, heterozygous mutations affecting the NFKB1 gene were identified in three human families. Haploinsufficiency of NF-κB1 was causative for combined variable immunodeficiency (CVID) characterized by recurrent infections due to immunoglobulin deficiency (pan-IgG, IgA and/or IgM). 4 We report here on two pediatric patients from unrelated families with two novel NFKB1 gene mutations identified by whole-exome sequencing ( Figure 1A,B). Both patients had early onset of disease during their teenage years and presented in addition to hypogammaglobulinemia or selective IgA deficiency with a striking lack of specific antibodies (clinical characteristics are summarized in Table 1 and Online Supplementary Table S1).Patient 1 is a now 26-year old female who first presented with recurrent autoimmune hemolytic anemia at the age of 14. Hypogammaglobulinemia (IgG2 subclass deficiency), deficient production of specific antibodies, decreased class-switched and memory B cells, naïve CD4-positive and regulatory T cells, increased activated and double-negative T cells (DNT cells, CD4 -CD8 -TCRα/β + ), autoimmune phenomena (hemolytic anemia, thrombocytopenia and leukopenia), lymphadenopathy, and hepatosplenomegaly were observed. She developed chronic lung disease with bronchiectasis, frequent respiratory tract infections and pneumonia. Infections with viral, bacterial and fungal pathogens were frequent. She suffered from intractable abdominal pain and bloody diarrhea without evidence of infection. After a liver biopsy she developed pancolitis with subsequent sepsis and multi-organ failure and was successfully resuscitated. The patient is being treated with intravenous immunoglobulin. Steroids were intermittently given to reduce pulmonary infiltrates with partial response. Mycophenolate mofetil stabilized blood counts, but pulmonary symptoms and infections remained.To identify the genetic cause of disease whole exome sequencing was performed for the patient and her family (Online Supplementary Methods, Online Supplementary Table S2). A heterozygous de novo NFKB1 frameshift mutation was detected ( Figure 1A). The NFKB1 gene encodes two proteins: p50 and its precursor ...