Inhibition of high-mobility group box 1 protein (HMGB1) enhances bacterial clearance and protects against Pseudomonas Aeruginosa pneumonia in cystic fibrosis

Pulmonary infection with Pseudomonas aeruginosa and neutrophilic lung inflammation significantly contribute to morbidity and mortality in cystic fibrosis (CF). High-mobility group box 1 protein (HMGB1), a ubiquitous DNA binding protein that promotes inflammatory tissue injury, is significantly elevated in CF sputum. However, its mechanistic and potential therapeutic implications in CF were previously unknown. We found that HMGB1 levels were significantly elevated in bronchoalveolar lavage fluids (BALs) of CF patients and cystic fibrosis transmembrane conductance regulator (CFTR )(-/-) mice. Neutralizing anti-HMGB1 monoclonal antibody (mAb) conferred significant protection against P. aeruginosa-induced neutrophil recruitment, lung injury and bacterial infection in both CFTR(-/-) and wild-type mice. Alveolar macrophages isolated from mice treated with anti-HMGB1 mAb had improved phagocytic activity, which was suppressed by direct exposure to HMGB1. In addition, BAL from CF patients significantly impaired macrophage phagocytotic function, and this impairment was attenuated by HMGB1-neutralizing antibodies. The HMGB1-mediated suppression of bacterial phagocytosis was attenuated in macrophages lacking toll-like receptor (TLR)-4, suggesting a critical role for TLR4 in signaling HMGB1-mediated macrophage dysfunction. These studies demonstrate that the elevated levels of HMGB1 in CF airways are critical for neutrophil recruitment and persistent presence of P. aeruginosa in the lung. Thus, HMGB1 may provide a therapeutic target for reducing bacterial infection and lung inflammation in CF.

Synthesis, spectral characterization, thermal and photoluminescence properties of Zn(II) and Cd(II)-azido/thiocyanato complexes with thiazolylazo dye and 1,2-bis(diphenylphoshino)ethane

A series of complexes of the type [M(L)(dppe)X2]; where M=Zn(II) or Cd(II); L=4-(2'-thiazolylazo)chlorobenzene (L1), 4-(2'-thiazolylazo)bromobenzene (L2) and 4-(2'-thiazolylazo) iodobenzene (L3); dppe=1,2-bis(diphenylphosphino)ethane; X=N3- or NCS- have been prepared and characterized on the basis of their microanalysis, molar conductance, thermal, IR, UV-vis and 1H NMR spectral studies. IR spectra show that the ligand L is coordinated to the metal atom in bidentate manner via azo nitrogen and thiazole nitrogen. An octahedral structure is proposed for all the complexes. The thermal behavior of the complexes revealed that the thiocyanato complexes are thermally more stable than the azido complexes. All the complexes exhibit blue-green emission with high quantum yield as the result of the fluorescence from the intraligand emission excited state.

Synthesis, structural characterization, thermal and electrochemical studies of mixed ligand Cu(II) complexes containing 2-phenyl-3-(benzylamino)-1,2-dihydroquinazoline-4-(3H)-one and bidentate N-donor ligands

Some mixed ligand Cu(II) complexes of the type [Cu(L)(en)X(2)] (1a-3a), [Cu(L)(en)](ClO(4))(2) (4a), [Cu(L)(phen)X(2)] (1b-3b) and [Cu(L)(phen)](ClO(4))(2) (4b) [where L = 2-phenyl-3-(benzylamino)-1,2-dihydroquinazoline-4-(3H)-one; en = ethylenediamine; phen = 1,10-phenanthroline; X = Cl(-), N(3)(-) and NCS(-)] have been prepared. The complexes were characterized on the basis of elemental analysis, molar conductance, magnetic moment, IR, UV-vis, mass, ESR and thermal studies. On the basis of electronic spectral data and magnetic susceptibility measurement octahedral geometry has been proposed for 1a-3a and 1b-3b and square-planer geometry for 4a and 4b. The ESR spectral data of complexes provided information about their structure on the basis of Hamiltonian parameters and degree of covalency. The electrochemical behaviour of mixed ligand Cu(II) complexes was studied which showed that complexes of phen appear at more positive potential as compared to those for corresponding en complexes.

Characterization and electrochemical studies of Mn(II), Co(II), Ni(II) and Cu(II) complexes with 2-mercapto-3-substituted-quinazolin-4-one and 1,10-phenanthroline or ethylenediamine as ligands

Some mixed ligand complexes of the type [M(L(1) or L(2))(phen or en)(H(2)O)Cl], where M=Mn(II), Co(II), Ni(II) and Cu(II); HL(1)=2-mercapto-quinazolin-4-one; HL(2)=2-mercapto-3-phenyl-quinazolin-4-one; phen=1,10-phenanthroline; en=ethylenediamine have been prepared. All complexes were characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility measurements, IR, UV-vis, ESR and powder X-ray diffraction studies. IR spectra of these complexes reveal that the complex formation occurred through both nitrogen and sulphur atoms. On the basis of electronic spectral data and magnetic susceptibility measurement octahedral geometry has been proposed for the complexes. The ESR spectral data of the Cu(II) complexes showed that the metal-ligand bonds have considerable covalent character. X-ray diffraction studies of Cu(II) complexes are used to elucidate the crystal structure. The electrochemical behaviour of mixed ligand Ni(II) complexes was studied which showed that complexes of phen appear at more positive potential as compared to those for corresponding en complexes.

IL-4-Induced Gene-1 Is a Leukocyte l-Amino Acid Oxidase with an Unusual Acidic pH Preference and Lysosomal Localization

IL-4-induced gene-1 (Il4i1 or Fig1) initially isolated as a gene of unknown function from mouse B lymphocytes, is limited in expression to primarily immune tissues and genetically maps to a region of susceptibility to autoimmune disease. The predicted Il4i1 protein (IL4I1) sequence is most similar to apoptosis-inducing protein and Apoxin I, both l-amino acid oxidases (LAAO; Enzyme Commission 1.4.3.2). We demonstrate that IL4I1 has unique LAAO properties. IL4I1 has preference for aromatic amino acid substrates, having highest specific activity with phenylalanine. In support of this selectivity, IL4I1 is inhibited by aromatic competitors (benzoic acid and para-aminobenzoic acid), but not by nonaromatic LAAO inhibitors. Il4i1 protein and enzyme activity is found in the insoluble fraction of transient transfections, implying an association with cell membrane and possibly intracellular organelles. Indeed, IL4I1 has the unique property of being most active at acidic pH (pH 4), suggesting it may reside preferentially in lysosomes. IL4I1 is N-linked glycosylated, a requirement for lysosomal localization. Confocal microscopy of cells expressing IL4I1 translationally fused to red fluorescent protein demonstrated that IL4I1 colocalized with GFP targeted to lysosomes and with acriflavine, a green fluorescent dye that is taken up into lysosomes. Thus, IL4I1 is a unique mammalian LAAO targeted to lysosomes, an important subcellular compartment involved in Ag processing.

Characterization of the human homolog of the IL-4 induced gene-1 (Fig1)

Mouse interleukin-four induced gene-1 (mFig1) maps to a region of susceptibility for systemic lupus erythematosus (SLE) that includes the Sle3 locus. To begin examining this relationship in humans, we have isolated and characterized the human homolog of mFig1. Human Fig1 (hFig1) has the same eight exon genomic structure as mFig1. The predicted 63-kDa protein, like mFig1, contains a signal peptide, a large internal sequence that is most similar (43% identical over 484 amino acids) to L-amino acid oxidase (LAAO), and a carboxy terminal domain with no similarity to known genes. When compared to the LAAO crystal structure, hFig1 conserves key residues thought to be involved in catalysis and binding of the flavin adenine dinucleotide cofactor. Surprisingly, the carboxy terminal domains of hFig1 and mFig1 have little similarity (<11% identity), different lengths and amino acid composition. Like mFig1, hFig1 RNA is induced by interleukin-4 (IL-4) in B lymphocytes, and is primarily found in immune tissues. Finally, hFig1 maps to the predicted mFig1 syntenic region on human chromosome 19q13.3-19q13.4, a hot spot for susceptibility to several autoimmune diseases, including SLE.

Rhinosporidiosis--a clinicopathological study of 34 cases

Rhinosporidiosis was the commonest (68%) fungal lesion encountered during the period of 11 1/2 years from January 1987 to July 1998. Men in 2nd, 3rd, 4th decade were commonly affected. Nose and nasopharynx were the commonest (85%) sites involved followed by ocular tissue (9%). One patient had involvement of bone (tibia). Generally a lymphoplasmacytic response was observed in all cases. Polymorphonuclear leukocytic response mostly observed at the site of rupture of sporangia. Epithelioid cell granulomatous and giant cell response observed in 47% of cases. Transepithelial migration of sporangia observed in 76% of cases. Rhinosporidium seeberi could be easily identified in haematoxylin and eosin stained sections. The walls of young trophic forms are delineated well with the PAS stain and verhoeff van Gieson stain.

Clinical profile of non-O1 strain-O139 of Vibrio cholerae in the region of Ambajogai, Maharashtra

OBJECTIVES

To study clinical profile of the newly emerged novel strain non-O1, O139 of Vibrio cholerae, in the region of Ambajogai, District Beed of Maharashtra.

METHODS

Out of 208 patients of acute gastroenteritis, 41 revealed to be positive for Vibrio cholerae by recommended method of stool examination. All the strains were sent to National Institute of Cholera and Infectious Diseases, Calcutta for confirmation.

RESULTS

Out of 41 cases, 12 were of Vibrio cholerae O1, 29 Non-O1, of which nine found to be O139 strain. All patients were from 2-80 years of age with low-socioeconomic status and maximum incidence was in August (64.70%), presented with severe rice watery loose motions. Vomiting was observed in 26 (63.41%), more so in patients of O139 infection (88.88%) than four (33.33%) of O1 infection. Sweating was observed in three patients (33.33%) of O139 infection, cramps in gastrocnemis muscles in three patients (33.33%) of O139 infection and two (16.66%) of O1 infection. Signs of dehydration were mild to moderate in four patients (33.33%) of O1 infection; severe dehydration in six (66.66%), moderate in two (22.22%) and mild in one patient (11.11%) of O139 infection. While dehydration was severe in four (20%), moderate in one (5%) and mild in three patients (15%) of Non-O1 infection (excluding O139 cases). Clinical features were more severe in patients of serotype O139 than the patients of O1 and Non-O1 (excluding O139 cases). However all patients responded to intravenous fluids, oral rehydration and antibiotics (tetracycline) within 24-48 hours without any mortality.

CONCLUSIONS

This study reflects the first emergence of Non-O1, strain O139 during the year 1997 with severe and critical clinical features in Ambajogai region causing high morbidity in the form of severe dehydration and peripheral circulatory collapse which requires early and correct diagnosis and prompt treatment.

Frequency analysis of proliferating and cytotoxic T cells in livers and peripheral blood of patients with chronic hepatitis B

Frequencies of proliferating and cytotoxic lymphocytes from liver biopsy samples and peripheral blood of chronic hepatitis B (CHB) patients and control subjects were monitored by limiting dilution analysis. Precursor frequencies of proliferating T lymphocytes were not significantly different in the liver and peripheral blood compartments of patients and controls. Moreover, similar frequencies of natural killer cells and cytotoxic T lymphocytes were observed in the peripheral blood of patients and controls. A higher frequency of cytotoxic T cells (1 of 22) compared to NK cells (1 of 306) was observed in liver tissues of CHB patients. Dual colour flow cytometric analysis revealed the presence of both CD4+ HLA-DR+ and CD8+ HLA-DR+ T cells in the liver tissues. These results suggest that in livers of CHB patients not only activated CD8+ T cells but also activated CD4+ T cells may play a significant role in the pathogenesis of chronic hepatitis B.