Identification of an IL-4-Inducible Gene Expressed in Differentiating Lymphocytes and Male Germ Cells

Interleukin 4 (IL-4) is a cytokine that is involved in the differentiation of B and T lymphocytes. In this report, we describe the identification of a novel gene, N.52, which was cloned from the murine pre-B cell line R8205 grown in the presence of IL-4 for 48 hr. Although N.52 expression is detectable at low levels in unstimulated R8205 cells, the level of N.52 dramatically increases after only .4 hr exposure to IL-4 and remains at a high .level up to 48 hr. Although N.52 expression is low or absent in normal spleen B and T cells, its expression can be induced by the differentiation signals delivered by LPS in B cells and by Con A in T-cell hybrids. While N.52 mRNA is absent in all highly differentiated organs, it is detectable in stem cell harboring lymphoid tissues such as bone marrow, fetal liver, and thymus. Furthermore, N.52 mRNA is expressed at strikingly high levels in the testis, specifically in differentiating male germ cells. It is induced by differentiation signals triggered by the combination of cyclic AMP and retinoic acid in teratocarcinoma F9 cells. Taken together, these data suggest that N.52 is a developmentally regulated gene whose expression in cells of the immune and reproductive systems may be controlled by stimuli that induce differentiation

Effects of murine natural killer cells on Cryptoccus neoformans /

NK cells have Fc receptors on their surfaces, and are capable of antibody-dependent cell-mediated cytotoxicity (ADCC) against IgG-coated target cells. We examined the effects of the IgG fraction of rabbit anti-cryptococcal antibody on the NK cell-mediated growth inhibition of C. neoformans. In the presence of rabbit anti-cryptococcal antibody the growth inhibitory activity of the NK cells against C. neoformans was significantly augmented. The antibody-dependent cryptococcal growth inhibitory activity of the various effector cells was parallel to their levels of NK activity against YAC-1 targets and their spontaneous growth inhibitory activity against C. neoformans. Enrichment for NK cells by Percoll fractionation was concomitant with enhancement of both antibody-dependent and spontaneous anti-cryptococcal activities. The data indicate that the effector cells involved in antibody-dependent growth inhibition of cryptococci are either NK cells or copurify and coexist in the same population with NK cells. (Abstract shortened with permission of author.)Previous data generated by Murphy and McDaniel indicate that normal murine nylon wool nonadherent splenic cells, with the characteristics of natural killer (NK) cells, effectively inhibit the in vitro growth of Cryptococcus neoformans, a yeast-like pathogen. Nylon wood nonadherent cells from spleens of 7-8 week old mice were further fractionated on discontinuous Percoll gradients. The enrichment of NK cells in Percoll fractions 1 and 2 was confirmed by morphological examination, immunofluorescent staining, and by assessing the cytolytic activity of each Percoll cell fraction against YAC-1 targets in the 4 h ('51)Cr release assay. Cells isolated from each Percoll fraction were tested for growth inhibitory activity against C. neoformans, using an in vitro 18 h growth inhibition assay. The results showed that NK cell enrichment was concomitant with the enrichment of anti-cryptococcal activity in the Percoll fractions 1 and 2. Cells from NK-rich fractions formed conjugates with the mycotic targets similar to those reported in the NK-tumor system. In addition, the percentage of effector cell-Cryptococcus conjugates was directly proportional to the level of C. neoformans growth inhibitory activity of the effector cells employed. Scanning electron microscopy of the effector cell-Cryptococcus conjugates showed a direct contact between the effector cells and cryptococcal targets. An immunolabeling method combined with scanning electron microscopy was used to demonstrate that the effector cells attached to C. neoformans were asialo GM(, 1) positive and, therefore, had NK cell characteristics

Genetic diversity of Helicobacter pylori type IV secretion system cagI and cagN genes and their association with clinical diseases

Abstract A number of cagPAI genes in the Helicobacter pylori genome are considered the most evolved genes under a diversifying selection and evolutionary pressure. Among them, cagI and cagN are described as a part of the two different-operon of cagPAI that are involved in the T4SS machinery, but the definite association of these factors with clinical manifestations is still unclear. A total of 70 H. pylori isolates were obtained from different gastroduodenal patients. All isolates were examined for the presence of primary H. pylori virulence genes by PCR analysis. Direct DNA sequence analysis was performed for the cagI and cagN genes. The results were compared with the reference strain. The cagI, cagN, cagA, cagL, vacA s1m1, vacA s1m2, vacA s2m2, babA2, sabA, and dupA genotypes were detected in 80, 91.4, 84, 91.4, 32.8, 42.8, 24.4, 97.1, 84.3, and 84.3% of the total isolates, respectively. The most variable codon usage in cagI was observed at residues 20–25, 55–60, 94, 181–199, 213–221, 241–268, and 319–320, while the most variable codon usage in CagN hypervariable motif (CagNHM) was observed at residues 53 to 63. Sequencing data analysis of cagN revealed a hypothetical hexapeptide motif (EAKDEN/K) in residues of 278–283 among six H. pylori isolates, which needs further studies to evaluate its putative function. The present study demonstrated a high prevalence of cagI and cagN genes among Iranian H. pylori isolates with gastroduodenal diseases. Furthermore, no significant correlation between cagI and cagN variants and clinical diseases was observed in the present study. However, all patients had a high prevalence of cagPAI genes including cagI, cagN, cagA, and cagL, which indicates more potential role of these genes in disease outcome

Polymorphisms Of genes encoding interleukin-4 and its receptor are associated with chronic idiopathic urticaria

<b>RATIONALE</b>\ud \ud - Interleukin-4 (IL-4) has pivotal role in promotion of T\ud helper2 responses. ll-4 is also an important regulator of adaptive immune responses. This study is aimed at investigating of association of polymorphisms\ud in IL-4 and IL-4-receptor genes with susceptibility to CIU.\ud \ud <b>METHODS</b>\ud \ud - A matched case-control study was conducted on 89 patients\ud with CIU and 138 healthy controls. Autologous serum skin test (ASST) was performed according to international standards. Total IgE levels, thyroid peroxidase antibodies (TPO) and anti thyroglobulin antibodies (ATG) were investigated using spectrophotometry and enzyme-linked\ud immunosorbant-assay, respectively. Single nucleotide polymorphisms at following positions were genotyped using polymerase chain reaction: IL-4-1098T>G (rs243248), -590C>T (rs2243250), -33C>T (rs2070874), and IL-4-receptor+1902A>G (rs1801275). Estimated frequencies were compared between patients and controls.\ud \ud <b>RESULTS</b>\ud \ud - ASSTwas positive in 39 (43.8%) and abnormal TPO and ATG\ud were found in 12 (13.4%) and 6 (6.7%) of patients which were significantly higher than controls (p<0.05). Mean serum level of IgE was 140.57 (IU/ml) in CIU patients which fell in normal range similar to controls. patients and controls. Among polymorphic sites in IL-4gene, only C allele\ud at -33C>T (OR 2.39, 95%CI (1.41 to 4.05), p<0.001) was significantly higher in patients compared to controls. CC genotype at -590C>T (OR 4.5, 95%CI (1.9 to 10.82)) and -33C>T (OR 3.46, 95%CI (1.88 to 6.43)), were significantly higher in CIU patients (p<0.0001).\ud \ud <b>CONCLUSIONS</b>\ud \ud - Polymorphisms in promoter region of IL-4 but not IL-\ud 4-receptor gene confer susceptibility to CIU and may predispose patients to immune dysregulation

Polymorphisms Of genes encoding interleukin-4 and its receptor are associated with chronic idiopathic urticaria

RATIONALE - Interleukin-4 (IL-4) has pivotal role in promotion of T helper2 responses. ll-4 is also an important regulator of adaptive immune responses. This study is aimed at investigating of association of polymorphisms in IL-4 and IL-4-receptor genes with susceptibility to CIU. METHODS - A matched case-control study was conducted on 89 patients with CIU and 138 healthy controls. Autologous serum skin test (ASST) was performed according to international standards. Total IgE levels, thyroid peroxidase antibodies (TPO) and anti thyroglobulin antibodies (ATG) were investigated using spectrophotometry and enzyme-linked immunosorbant-assay, respectively. Single nucleotide polymorphisms at following positions were genotyped using polymerase chain reaction: IL-4-1098T>G (rs243248), -590C>T (rs2243250), -33C>T (rs2070874), and IL-4-receptor+1902A>G (rs1801275). Estimated frequencies were compared between patients and controls. RESULTS - ASSTwas positive in 39 (43.8%) and abnormal TPO and ATG were found in 12 (13.4%) and 6 (6.7%) of patients which were significantly higher than controls (pT (OR 2.39, 95%CI (1.41 to 4.05), pT (OR 4.5, 95%CI (1.9 to 10.82)) and -33C>T (OR 3.46, 95%CI (1.88 to 6.43)), were significantly higher in CIU patients (pCONCLUSIONS - Polymorphisms in promoter region of IL-4 but not IL- 4-receptor gene confer susceptibility to CIU and may predispose patients to immune dysregulation