The T cell factor, pangolin, from Litopenaeus vannamei play a positive role in the immune responses against white spot syndrome virus infection

As a downstream interactor of β-catenin, Pangolin which is the homologous protein of the T cell factor/lymphoid enhancer factor (TCF/LEF) in vertebrates is less understood in the research field of immunity. In this study, two isoforms of Litopenaeus vannamei Pangolin (LvPangolin1 and LvPangolin2) were identified. Phylogenetic tree analysis revealed that all of the Pangolin proteins from invertebrates were represented the same lineage. The mRNA expression profiles of the LvPangolin1 and LvPangolin2 genes differed across different tissues. The expression of LvPangolin1 and the amount of LvPangolin1and LvPangolin2 combined (LvPangolinComb) were significantly increased in the haemocyte, intestine and gill but reduced in the hepatopancreas after white spot syndrome virus (WSSV) challenge. The inhibition of LvPangolin1 but not LvPangolinComb significantly reduced the survival rates of L. vannamei after WSSV infection, while significantly higher WSSV viral loads in both LvPangolin1-inhibited and LvPangolinComb-inhibited L. vannamei were observed. Knockdown of LvPangolin by RNAi could distinctly decrease the expression of antimicrobial peptide (AMP) genes and their related transcription factors. All of these results indicate that LvPangolin plays a positive role in the response to WSSV infection and that this may be mediated through regulating the immune signalling pathways which control the expression of AMPs with antiviral abilities.

Common variants in the TCF7L2 gene help to differentiate autoimmune from non-autoimmune diabetes in young (15-34 years) but not in middle-aged (40-59 years) diabetic patients

AIMS/HYPOTHESIS

Type 1 diabetes in children is characterised by autoimmune destruction of pancreatic beta cells and the presence of certain risk genotypes. In adults the same situation is often referred to as latent autoimmune diabetes in adults (LADA). We tested whether genetic markers associated with type 1 or type 2 diabetes could help to discriminate between autoimmune and non-autoimmune diabetes in young (15-34 years) and middle-aged (40-59 years) diabetic patients.

METHODS

In 1,642 young and 1,619 middle-aged patients we determined: (1) HLA-DQB1 genotypes; (2) PTPN22 and INS variable-number tandem repeat (VNTR) polymorphisms; (3) two single nucleotide polymorphisms (rs7903146 and rs10885406) in the TCF7L2 gene; (4) glutamic acid decarboxylase (GAD) and IA-2-protein tyrosine phosphatase-like protein (IA-2) antibodies; and (5) fasting plasma C-peptide.

RESULTS

Frequency of risk genotypes HLA-DQB1 (60% vs 25%, p = 9.4 x 10(-34); 45% vs 18%, p = 1.4 x 10(-16)), PTPN22 CT/TT (34% vs 26%, p = 0.0023; 31% vs 23%, p = 0.034), INS VNTR class I/I (69% vs 53%, p = 1.3 x 10(-8); 69% vs 51%, p = 8.5 x 10(-5)) and INS VNTR class IIIA/IIIA (75% vs 63%, p = 4.3 x 10(-6); 73% vs 60%, p = 0.008) was increased in young and middle-aged GAD antibodies (GADA)-positive compared with GADA-negative patients. The type 2 diabetes-associated genotypes of TCF7L2 CT/TT of rs7903146 were significantly more common in young GADA-negative than in GADA-positive patients (53% vs 43%; p = 0.0004). No such difference was seen in middle-aged patients, in whom the frequency of the CT/TT genotypes of TCF7L2 was similarly increased in GADA-negative and GADA-positive groups (55% vs 56%).

CONCLUSIONS/INTERPRETATION

Common variants in the TCF7L2 gene help to differentiate young but not middle-aged GADA-positive and GADA-negative diabetic patients, suggesting that young GADA-negative patients have type 2 diabetes and that middle-aged GADA-positive patients are different from their young GADA-positive counterparts and share genetic features with type 2 diabetes.

Frizzled 9 knock-out mice have abnormal B-cell development

The binding of frizzled (Fzd) receptors by their Wnt ligands results in the inhibition of beta-catenin degradation and subsequent transcription of beta-catenin/LEF-inducible genes. The beta-catenin pathway is known to be involved in development, tumorigenesis, and stem cell self-renewal. In humans, the FZD9 gene lies in the region of chromosome 7q11.23 deleted in the neurodevelopmental disorder, Williams-Beuren syndrome (WBS). Fzd9-/- mice show no obvious features of WBS, but reveal a role for Fzd9 in lymphoid development and maturation. Fzd9-/- mice show pronounced splenomegaly, thymic atrophy, and lymphadenopathy with age, with accumulation of plasma cells in lymph nodes. There is a depletion of developing B cells in the bone marrow (BM), particularly in the pre-B stage where immunoglobulin heavy chains are expressed and the cells are undergoing clonal expansion prior to light chain rearrangement. The pre-B defect is partially intrinsic to the hematopoietic system; as in competitive BM reconstitution studies, Fzd9-/- -derived BM exhibits defective B-cell development when implanted into a wild-type host. Mature B cells are present in normal numbers in lymph node and spleen. These findings suggest a role for Fzd9 signaling in lymphoid development, particularly at points where B cells undergo self-renewal prior to further differentiation.