Macrophages induce the inflammatory response in the pulmonary Arthus reaction through G alpha i2 activation that controls C5aR and Fc receptor cooperation

Complement and FcgammaR effector pathways are central triggers of immune inflammation; however, the exact mechanisms for their cooperation with effector cells and their nature remain elusive. In this study we show that in the lung Arthus reaction, the initial contact between immune complexes and alveolar macrophages (AM) results in plasma complement-independent C5a production that causes decreased levels of inhibitory FcgammaRIIB, increased levels of activating FcgammaRIII, and highly induced FcgammaR-mediated TNF-alpha and CXCR2 ligand production. Blockade of C5aR completely reversed such changes. Strikingly, studies of pertussis toxin inhibition show the essential role of G(i)-type G protein signaling in C5aR-mediated control of the regulatory FcgammaR system in vitro, and analysis of the various C5aR-, FcgammaR-, and G(i)-deficient mice verifies the importance of Galpha(i2)-associated C5aR and the FcgammaRIII-FcgammaRIIB receptor pair in lung inflammation in vivo. Moreover, adoptive transfer experiments of C5aR- and FcgammaRIII-positive cells into C5aR- and FcgammaRIII-deficient mice establish AM as responsible effector cells. AM lacking either C5aR or FcgammaRIII do not possess any such inducibility of immune complex disease, whereas reconstitution with FcgammaRIIB-negative AM results in an enhanced pathology. These data suggest that AM function as a cellular link of C5a production and C5aR activation that uses a Galpha(i2)-dependent signal for modulating the two opposing FcgammaR, FcgammaRIIB and FcgammaRIII, in the initiation of the inflammatory cascade in the lung Arthus reaction.     

Hepatitis B virus precore G1896A mutation in chronic liver disease patients with HBeAg negative serology from North India

Hepatitis B with precore stop codon mutation is related with severe liver damage in HBeAg negative patients. It is of utmost importance to screen the G1896A precore mutation. The study was designed to assess the impact of G1986A mutations in patients with different clinical spectra of the liver disease by PCR–LCR. 210 HBV positive patients with HBeAg negative serology of different kind of liver diseases (AVH = 72, FH = 21, CH = 79, Cirrhosis = 20 and HCC = 18) were screened. Patients were screened for the presence or absence of precore G1896A mutation by PCR–LCR. Direct nucleotide sequencing was done to confirm the results of LCR. Precore mutant in HCC was 94.4% (17/18), 85.7% (18/21) in FH, 60% (12/20) in liver cirrhosis, 48.1% (38/79) in chronic hepatitis and 27.7% (20/72) in AVH cases. The serum ALT level was statistically significant between HBeAg negative WT and G1896A mutants in chronic hepatitis cases. ALT level and HBV DNA level was slightly raised in the pre core mutant but and was not significant. Genotype D had a higher prevalence (79.5%) as compared to genotype A (20.5%). The mutations detected by PCR–LCR were in 100% concordance with direct sequencing. The exceptionally high prevalence of G1896A in FH and HCC demonstrates that the precore mutants are strongly associated with the progression of liver diseases in patients with HBeAg negative serology. The findings are also suggestive of screening HBV precore G1896A mutation particularly in HBeAg negative cases. The precore G1896A mutation increases proportionately in severe form of liver diseases. LCR can be a suitable tool for screening of G1896A mutations.     

Siberian plants: untapped repertoire of bioactive endosymbionts

Background

Endosymbionts are microorganisms present in all plant species, and constitute the subject of interest among the scientific community. These symbionts have gained considerable attention in recent years, owing to their emerging biological roles. Global challenges, such as antimicrobial resistance, treatment of infectious diseases such as HIV and tuberculosis, cancer, and many genetic disorders, exist. Endosymbionts can help address these challenges by secreting valueadded bioactive compounds with various activities.

Objective

Herein, we describe the importance of plants inhabiting Siberian niches. These plants are considered to be among the least studied organisms in the plant kingdom worldwide. Barcoding these plants can be of interest for exploring bioactive endosymbionts possessing myriad biological properties.

Methods

A systematic survey of relevant scientific reports was conducted using the PubMed search engine. The reports were analyzed, and compiled to draft this review.

Results

The literature survey on Siberian plants regarding endosymbionts included a few reports, since extremely few exploratory studies have been conducted on the plants in these regions. Studies on the endosymbionts of these plants are highly valuable, as they report potent endosymbionts possessing numerous biological properties. Based on these considerations, this review aims to create awareness among the global scientific community working on related areas.

Conclusion

This review could provide the basis for barcoding novel endosymbionts of Siberian plants and their ecological importance, which can be exploited in various sectors. The main purpose of this review is to create awareness of Siberian plants, which are among the least studied organisms in the plant kingdom, with respect to endosymbionts, among the scientific community.

     

Developmental and environmental factors that enhance binding of Bordetella pertussis to human epithelial cells in relation to sudden infant death syndrome (SIDS)

Abstract Asymptomatic infection due to Bordetella pertussis has been suggested to be one cause of sudden infant death syndrome (SIDS). We examined developmental and environmental factors previously found to affect binding of another toxigenic species, Staphylococcus aureus , to human epithelial cells: expression of the Lewis^a antigen; infection with respiratory syncytial virus (RSV); exposure to cigarette smoke; and the inhibitory effect of breast milk on bacterial binding. Binding of two strains of B. pertussis (8002 and 250825) to buccal epithelial cells was significantly reduced by treating the cells with monoclonal antibodies to Lewis^a ( P < 0.05) and Lewis^x ( P < 0.01) antigens. Both strains bound in significantly greater numbers to cells from smokers compared with cells from non-smokers ( P < 0.05). HEp-2 cells infected with RSV subtypes A or B had higher binding indices for both 8002 ( P < 0.001) and 250825 ( P < 0.01). On RSV-infected cells, there was significantly enhanced binding of monoclonal antibodies to Lewis^x ( P < 0.05), CD14 ( P < 0.001) and CD18 ( P < 0.01); and pre-treatment of cells with anti-CD14 or CD18 also significantly reduced binding of both strains of B. pertussis . Pre-treatment of the bacteria with human milk significantly reduced their binding to epithelial cells. The results are discussed in relation to our three-year survey of bacterial carriage among 253 healthy infants, their mothers and local SIDS cases between 1993–1995 and in relation to the change to an earlier immunisation schedule for infants and the recent decline in SIDS in Britain.     

A second enzyme protecting mineralocorticoid receptors from glucocorticoid occupancy

We have confirmed that A6 cells (derived fromkidney of Xenopus laevis), whichcontain both mineralocorticoid and glucocorticoid receptors, do notnormally possess 11-hydroxysteroid dehydroxgenase (11-HSD1 or11-HSD2) enzymatic activity and so are without apparent "protective" enzymes. A6 cells do not convert the glucocorticoid corticosterone to 11-dehydrocorticosterone but do, however, possess steroid 6-hydroxylase that transforms corticosterone to6-hydroxycorticosterone. This hydroxylase is cytochromeP-450 3A (CYP3A). We have nowdetermined the effects of 3,5-tetrahydroprogesterone andchenodeoxycholic acid (both inhibitors of 11-HSD1) and11-dehydrocorticosterone and11-hydroxy-3,5-tetrahydroprogesterone (inhibitors of11-HSD2) and carbenoxalone, which inhibits both 11-HSD1 and11-HSD2, on the actions and metabolism of corticosterone and activeNa⁺ transport [short-circuitcurrent(I_sc)] inA6 cells. All of these 11-HSD inhibitory substances induced asignificant increment in corticosterone-inducedI_sc, which wasdetectable within 2 h. However, none of these agents caused an increasein I_sc whenincubated by themselves with A6 cells. In all cases, the additionalI_sc was inhibitedby the mineralocorticoid receptor (MR) antagonist, RU-28318, whereasthe original I_scelicited by corticosterone alone was inhibited by the glucocorticoidreceptor antagonist, RU-38486. In separate experiments, each agent wasshown to significantly inhibit metabolism of corticosterone to6-hydroxycorticosterone in A6 cells, and a linear relationshipexisted between 6-hydroxylase inhibition and the MR-mediatedincrease in I_scin the one inhibitor tested. Troleandomycin, a selective inhibitor ofCYP3A, inhibited 6-hydroxylase and also significantly enhancedcorticosterone-induced I_sc at 2 h. Theseexperiments indicate that the enhanced MR-mediated I_sc in A6 cellsmay be related to inhibition of 6-hydroxylase activity in thesecells and that this 6-hydroxylase (CYP3A) may be protecting theexpression of corticosterone-induced active Na⁺ transport in A6 cells byMR-mediated mechanism(s).

     

In situ end labelling of DNA to detect apoptotic cell death in a variety of human tumours

The present studies illustrate clinical applications of in situ end labelling (ISEL) of DNA to detect apoptosis in a variety of human malignancies including myelodysplastic syndromes (MDS, n=10), non-Hodgkin's lymphoma (NHL, n=10), head and neck cancer (n = 3), breast cancer (n = 1) and cervical cancer (n = 1). These studies also describe a new in situ double labelling technique to detect apoptosis and proliferation (S-phase cells) simultaneously in the same section of plastic embedded tissue. In vivo intravenous infusions of thymidine analogues (i.e. bromodeoxyuridine (BrdU) and/or iododeoxyuridine (IUdR)) followed by their detection with a specific monoclonal antibody in a plastic embedded biopsy, combined with ISEL in the same section, facilitated simultaneous estimations of apoptosis and proliferation. The most salient finding of these studies was excessive apoptosis in MDS including the cells in S-phase as indicated by uniquely double labelled cells in their bone marrow biopsies. On the other hand, a very low degree of apoptosis was observed in NHL and other solid tumours. Moreover, the solid tumours exhibited definite compartments of apoptosis and proliferation. Further experiments are underway to confirm these findings in a larger study in order to design appropriate therapeutic modalities for these disorders.     

Relationship of Apical Dominance to the Nutrient Accumulation Pattern in Pisum sativum var. Alaska

Decapitation of the pea plant resulted in the growth of all the lateral shoots. The initial growth of all lateral buds was somewhat similar. The differential growth rates developed later on. The pattern of growth of lateral shoots varied with the age of the plant when decapitation was performed. The basal shoots dominated when the plants were decapitated at the 2-leaf stage. At 3-leaf stage decapitation resulted in the dominance of shoot 5. Decapitation at 4-or-more-leaf stage resulted in the eventual dominance of the suhterminal lateral shoot. As a rule P-32 moved to the most actively growing part of the plant, i.e. apex in intact vegetative plant, the growing lateral shoots in a decapitated plant, the elongating subapical parts of the stem and the roots. The various metabolic sinks seemed to compete actively for this nutrient, therefore P-32 accumulation in any particular growing region of the plant was taken as an indicator of nutrient utilization potential of that part. The stem apex of an intact plant seemed to loose its dominance with the increasing age of the plant. The loss of apical dominance was almost complete during the reproductive phase of the plant, during which the upper lateral shoots initiated growth. Their growth, however, was inhibited soon because of competition with the other developing sinks, viz., the flower and the fruit. The amount of soluble carbohydrates in various parts of the pea plant followed essentially the same pattern as did P-32 accumulation. These distribution patterns were apparently correlated with the growth of the plant.     

Purification and characterization of 2S albumin from Nelumbo nucifera

The 2S albumins are a group of seed storage proteins that have recently attracted considerable attention in the field of allergen science due to their allergenic potential. A new 2S albumin from seeds of Nelumbo nucifera (Nn-2S alb) was purified to electrophoretic homogeneity by the combination of ammonium sulfate fractionation, gel filtration, and ion exchange chromatography. The protein has a molecular mass of about 12 kDa estimated by SDS–PAGE, in good agreement with 12.5 ± 0.01 kDa determined by ESI–MS. Circular dichroism data showed that protein contained about 66% α-helices as estimated by K2D3, indicating that the protein was predominantly helical. The sedimentation coefficient (s°_20,w) of the predicted model was 1.72 ± 0.21 S. The predicted 3-dimensional structure of the Nn-2S alb revealed that the protein has a region of 12 amino acids which largely corresponds to the conserved immuno-dominant epitope of 2S allergens.