BAFF Expression is Modulated by Female Hormones in Human Immune Cells.

Among several autoimmune diseases, one of the main risk factors is the female gender, and much consideration has been given to the involvement of female hormones in their etiology. B-cell activating factor (BAFF) is a key factor in survival and maturation of B cells and is overexpressed in several autoimmune patients although the mechanism behind this feature is unclear. In murine models, BAFF expression could be upregulated by exogenous estrogen treatment in splenocytes; however, no evidence of this relationship was available in humans. Here, leukocytes from healthy male and female individuals were collected and cultivated in the presence or absence of estrogen or progesterone. BAFF gene expression was accessed by quantitative PCR and compared between treated and untreated group of cells. In the presence of estrogen, BAFF expression was upregulated by more than 5 times in both genders. When exposed to progesterone, the female-originated cells showed increased expression, while the cells of male origin a significant downregulation of BAFF. Our results suggest that female hormones can modulate the expression of BAFF, a key cytokine in autoimmune pathways, in human immune cells. These data might contribute to the understanding of the etiology as well as the gender bias featured by several autoimmune disorders.

A 3'-untranslated region variant is associated with impaired expression of CD226 in T and natural killer T cells and is associated with susceptibility to systemic lupus erythematosus.

OBJECTIVE: Costimulatory receptor CD226 plays an important role in T cell activation, differentiation, and cytotoxicity. This study was undertaken to investigate the genetic association of CD226 with susceptibility to systemic lupus erythematosus (SLE) and to assess the functional implications of this association. METHODS: Twelve tag single-nucleotide polymorphisms (SNPs) in CD226 were typed in 1,163 SLE patients and 1,482 healthy control subjects from Europe or of European ancestry. Analyses of association were performed by single-marker Cochran-Mantel-Haenszel meta-analysis, followed by haplotype analysis. Gene expression was analyzed by quantitative real-time polymerase chain reaction analyses of RNA from peripheral blood mononuclear cells, and by fluorescence-activated cell sorter analysis. To study the functional impact of the associated variants, luciferase reporter constructs containing different portions of the 3'-untranslated region (3'-UTR) of the gene were prepared and used in transfection experiments. RESULTS: A 3-variant haplotype, rs763361;rs34794968;rs727088 (ATC), in the last exon of CD226 was associated with SLE (P = 1.3 × 10(-4) , odds ratio 1.24, 95% confidence interval 1.11-1.38). This risk haplotype correlated with low CD226 transcript expression and low CD226 protein levels on the surface of CD4+ and CD8+ T cells and natural killer T (NKT) cells. NK cells expressed high levels of CD226, but this expression was independent of the haplotype. Reporter assays with deletion constructs indicated that only the presence of rs727088 could account for the differences in the levels of luciferase transcripts. CONCLUSION: This study identified an association of CD226 with SLE in individuals of European ancestry. These data support the importance of the 3'-UTR SNP rs727088 in the regulation of CD226 transcription both in T cells and in NKT cells.

Promoter insertion/deletion in the IRF5 gene is highly associated with susceptibility to systemic lupus erythematosus in distinct populations, but exerts a modest effect on gene expression in peripheral blood mononuclear cells.

OBJECTIVE: We examined the genetic association of the promoter insertion/deletion (indel) in IRF5 gene with systemic lupus erythematosus (SLE) in distinct populations and assessed its role in gene expression. METHODS: Four IRF5 polymorphisms were genotyped in 1488 SLE patients and 1466 controls. Gene expression was analyzed by quantitative real-time PCR using RNA from peripheral blood mononuclear cells (PBMC). RESULTS: The promoter indel and rs2070197 had independent genetic effects, which accounted for the association of rs2004640 and rs10954213. Gene expression analysis revealed that rs10954213 exerted the greatest influence on IRF5 transcript levels. CONCLUSION: We corroborated the association of the promoter indel with SLE in 5 different populations and revealed that rs10954213 is the main single-nucleotide polymorphism responsible for altered IRF5 expression in PBMC.

Characterization and partial purification of a lectin from the hemolymph of the white shrimp Litopenaeus schmitti.

The agglutinating activity of the hemolymph of Litopenaeus schmitti is insensitive to calcium and specific for acetylated sugars, particularly sialic acid (Neu5Ac) and O-sialoglycoconjugates (bovine submaxillary mucin) and has varying specificity for different LPS, which may suggest a putative role in microorganism recognition. Affinity chromatography on fetuin-agarose of the agglutinin resulted in a 220 kDa band (lectin), and a 82.5 kDa band, which probably is hemocyanin. The 220 kDa protein consists of 31 and 34 kDa subunits, suggesting that this lectin is multimeric. The lectin molecular mass was estimated by gel filtration to be 153+/-10 kDa. The hemolymph of L. schmitti comprises at least another soluble lectin, with distinct chemical and carbohydrate specificity than the 220 kDa lectin.