Abnormal Immune Function of Hemopoietic Cells from Alymphoplasia (aly) Mice, a Natural Strain with Mutant NF-κB-Inducing Kinase

Abstract

Alymphoplasia (aly) mice, a natural strain with a mutant NF-κB-inducing kinase (NIK) gene, manifest a unique phenotype; they lack lymph nodes and Peyer’s patches, have a disturbed spleen architecture, and exhibit defects in both Ab and cellular immune responses. Although a stromal defect caused by impaired lymphotoxin-β receptor signaling accounts for their abnormal lymphoid organogenesis, the exact mechanisms underlying the development of immunodeficiency in aly mice are poorly understood. We therefore investigated the contribution of hemopoietic cells with the aly NIK mutation to the development of immunodeficiency. Transfer of aly/aly bone marrow cells into aly/+ mice resulted in poorly developed B cell follicles and lack of support for the development of germinal centers and isotype switching, indicating that the hemopoietic cells of aly mice contain an autonomous defect. However, follicular dendritic cell clusters were maintained in the spleens of these bone marrow chimeras, suggesting that the lack of follicular dendritic cell clusters in aly mice is probably due to the stromal defect. The aly mice lacked marginal zone B cells in their spleens, and aly/aly B cells showed an impaired proliferative response after in vitro stimulation. IL-2 production by activated T cells was also impaired. By contrast, the dendritic cells of aly mice exhibited grossly normal development and function. Supporting the concept of an autonomous cell defect, Rel protein expression was altered in aly/aly spleens. Thus, the aly NIK mutation affects hemopoietic cell function in an intrinsic fashion and, together with the stromal defect, may contribute to the development of immunodeficiency in aly mice.

NIK promotes tissue destruction independently of the alternative NF-κB pathway through TNFR1/RIP1-induced apoptosis

“…Such biological functions of NIK independent of the processing of p100 have been also described in other settings and highlight a role for NIK beyond the activation of the alternative NF-κB pathway. [59][60][61] We also found that NIK pro-death function has a role in a model of viral infection associated with TNFα-induced hepatocytes apoptosis. Indeed, we have observed that adenovirus-infected NIK-deficient hepatocytes were resistant to TNFα-mediated cell death.…”

NF-κB-Inducing Kinase Establishes Self-Tolerance in a Thymic Stroma-Dependent Manner

“…The alymphoplasia (aly) strain of mice carries a natural mutation of the NIK gene (5,6) in which a G855R substitution in the C terminus of the protein results in inability to bind to IKK-␣ (7). NIK aly/aly mice have provided a unique model for the abnormal development of lymphoid organs; NIK aly/aly mice lack all lymph nodes and Peyer's patches, and spleen architecture such as development of germinal centers and follicular dendritic cell clusters is disturbed (5,6,8). We and others have demonstrated that this is due to defective NF-B activation through the lymphotoxin (LT)-␤ receptor (LT␤R) (6,7,9), a receptor essential for the development of lymphoid organs (10).…”

“…Immunohistochemical analysis of the thymus was performed as previously described (8,9). Briefly, frozen tissue sections were fixed in cold acetone, and stained by first incubating with peanut agglutinin (PNA)-biotin and Ulex europaeus agglutinin 1 (UEA-1)-biotin (Vector Laboratories, Burlingame, CA).…”

“…BM transfer was performed as described previously (8). In brief, BM cells were suspended in R10 medium containing anti-CD90 (Thy1.2) mAb (clone 5a-8; Cedarlane Laboratories, Ontario, Canada) plus low toxicity rabbit C (Cedarlane Laboratories).…”

“…Anti-CD3 mAb (clone 145-2C11) (Cedarlane Laboratories) at a final concentration of 10 g/ml was added to the culture for stimulation, and [ 3 H] incorporation during the last 6 h of the culture was measured. For inoculation into thymus-grafted BALB/c nu/nu mice, CD4 ϩ T cells were isolated from spleen and lymph node of BALB/c nu/ϩ mice by using MACS CD4 MicroBeads (Miltenyi Biotec, Bergisch Gladbach, Germany), as described previously (8). CD4 ϩ CD25 Ϫ cells were prepared by the depletion of CD25 ϩ cells with anti-CD25 Ab plus low toxicity rabbit C.…”