A forward genetic screen reveals roles for Nfkbid , Zeb1 , and Ruvbl2 in humoral immunity

Abstract

Using chemical germ-line mutagenesis, we screened mice for defects in the humoral immune response to a type II T-independent immunogen and an experimental alphavirus vector. A total of 26 mutations that impair humoral immunity were recovered, and 19 of these mutations have been positionally cloned. Among the phenovariants were bumble , cellophane , and Worker ascribed to mutations in Nfkbid , Zeb1 , and Ruvbl2 , respectively. We show that IκBNS, the nuclear IκB-like protein encoded by Nfkbid , is required for the development of marginal zone and peritoneal B-1 B cells and additionally required for extrafollicular antibody responses to T-independent and -dependent immunogens. Zeb1 is also required for marginal zone and peritoneal B-1 B-cell development as well as T-cell development, germinal center formation, and memory B-cell responses. Finally, Ruvbl2 is required for T-cell development and maximal T-dependent antibody responses. Collectively, the mutations that we identified give us insight into the points at which disruption of an antibody response can occur. All of the mutations identified to date directly affect lymphocyte development or function; none have an exclusive effect on cells of the innate immune system.

Inhibition of ZEB1 by miR-200 characterizes Helicobacter pylori-positive gastric diffuse large B-cell lymphoma with a less aggressive behavior

“…6,7 Although studies on ZEB1 focus mostly on its roles in epithelial-mesenchymal transition and metastasis, it is becoming evident that ZEB1 is also critical in the development of hematopoietic cells, including both B cells and T cells. For the B-lineage, ZEB1 may inhibit BCL6, the master transcription factor for the formation of germinal center B cells, 8 and is required for the normal development of marginal zone B cells and the production of immunoglobulin M. 9,10 Consistent with these data, overexpression of ZEB1 induces a more aggressive behavior of diffuse large B-cell lymphoma of the lymph nodes. 11 For the T-lineage, ZEB1 regulates T-cell development.…”

B-1a transitional cells are phenotypically distinct and are lacking in mice deficient in IκBNS

“…Mice with ablated IκBNS expression (bumble) were previously found to display normal development of pro/pre-, immature, and mature follicular B cells, whereas peritoneal B-1a cells were completely absent and the frequencies of B-1b cells were severely reduced (21,22). There could be several possible reasons for the lack of peritoneal B-1 cells in bumble, including impaired B-1 development or maintenance, unsupportive microenvironment, and/or migrational defects.…”

“…In contrast, compound deficiencies in NF-κB1/NF-κB2 or c-Rel/RelA impair development of all mature B-cell subsets (18,19). Also, the more recently identified atypical IκB proteins are involved in B-cell development (20)(21)(22). The atypical IκBs interact with NF-κB transcription factors in the nucleus rather than in the cytoplasm and, in contrast to traditional IκBs, are not only inhibitory but may either augment or repress transcriptional activity of target genes, depending on the cell type and conditions of activation that are studied (23).…”

“…We previously identified a mouse strain with a nonsense mutation in the nfkbid gene encoding the atypical IκB protein, IκBNS, among a number of hits in a forward genetic N-ethyl-N-nitrosourea (ENU) mutagenesis screen for mice displaying B-cell response defects. The strain, which was named bumble, had reduced antibody responses to TI antigens and displayed reduced frequencies of peritoneal B-1 cells and spleen MZB cells (22).…”

IgD class switching is initiated by microbiota and limited to mucosa-associated lymphoid tissue in mice

“…B-cell receptor transgenic mice (WT;Igh B1-8 or Trp53bp1 −/− ; Igh B1-8 ) were immunized i.p. with NP-LPS (50 μg; Biosearch Technologies) on day 0 as described previously (25). At 14 d after immunization, blood was collected in MiniCollect Tubes (Mercedes Medical) and centrifuged at 1,500 × g to separate the serum.…”