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Apolipophorin-III (ApoLp-III) acts in lipid transport, lipoprotein metabolism, and innate immunity in insects. In this study, an ApoLp-III gene of Antheraea pernyi pupae (Ap-ApoLp-III) was isolated and characterized. The full-length cDNA of Ap-ApoLp-III is 687 bp, including a 5'-untranslated region (UTR) of 40 bp, 3'-UTR of 86 bp and an open reading frame of 561 bp encoding a polypeptide of 186 amino acids that contains an Apolipophorin-III precursor domain (PF07464). The deduced Ap-apoLp-III protein sequence has 68, 59, and 23% identity with its orthologs of Manduca sexta, Bombyx mori, and Aedes aegypti, respectively. Phylogenetic analysis showed that the Ap-apoLp-III was close to that of Bombycoidea. qPCR analysis revealed that Ap-ApoLp-III expressed during the four developmental stages and in integument, fat body, and ovaries. After six types of microorganism infections, expression levels of the Ap-ApoLp-III gene were upregulated significantly at different time points compared with control. RNA interference (RNAi) of Ap-ApoLp-III showed that the expression of Ap-ApoLp-III was significantly downregulated using qPCR after injection of E. coli. We infer that the Ap-ApoLp-III gene acts in the innate immunity of A. pernyi., (© 2014 Wiley Periodicals, Inc.)

Proteins stored in insect hemolymph may serve as a source of amino acids and energy for metabolism and development. The expression of the main storage proteins was assessed in bacterial-challenged honey bees using real-time (RT)-PCR and Western blot. After ensuring that the immune system had been activated by measuring the ensuing expression of the innate immune response genes, defensin-1 (def-1) and prophenoloxidase (proPO), we verified the expression of four genes encoding storage proteins. The levels of vitellogenin (vg) mRNA and of the respective protein were significantly lowered in bees injected with bacteria or water only (injury). An equivalent response was observed in orally-infected bees. The levels of apolipophorin II/I (apoLp-II/I) and hexamerin (hex 70a) mRNAs did not significantly change, but levels of Hex 70a protein subunit showed a substantial decay after bacterial challenge or injury. Infection also caused a strong reduction in the levels of apoLp-III transcripts. Our findings are consistent with a down-regulation of the expression and accumulation of storage proteins as a consequence of activation of the immune system, suggesting that this phenomenon represents a strategy to redirect resources to combat injury or infection., ((c) 2009 Wiley Periodicals, Inc.)

Trypanosoma brucei brucei infects a wide range of mammals, but is unable to infect humans because this subspecies is lysed by normal human serum (NHS). The phenotype of cellular lysis is debated. For some authors the lysosome undergoes osmotic swelling due to massive influx of chloride ions from the cytoplasmic compartment, but others describe multiple small cytoplasmic vacuoles and general swelling of the cellular body. Using population-level imaging of live immobilized trypanosomes throughout the lysis process, we report that specific swelling of the lysosome is a genuine and major characteristic of NHS-mediated lysis and that this phenotype is independent of the strain of trypanosomes and of NHS aging or damaging. Thus, irrespective of experimental conditions NHS reproducibly induced the swelling of the parasite lysosome.

Trypanosoma brucei brucei is the causative agent of Nagana in cattle and can infect a wide range of mammals but is unable to infect humans because it is susceptible to the innate cytotoxic activity of normal human serum. A minor subfraction of human high-density lipoprotein (HDL), containing apolipoprotein A-I (APOA1), apolipoprotein L-I (APOL1) and haptoglobin-related protein (HPR) provides this innate protection against T. b. brucei infection. Both HPR and APOL1 are cytotoxic to T. b. brucei but their specific activities for killing increase several hundred-fold when assembled in the same HDL. This HDL is called trypanosome lytic factor (TLF) and kills T. b. brucei following receptor binding, endocytosis, and lysosomal localization. Trypanosome lytic factor is activated in the acidic lysosome and facilitates lysosomal membrane disruption. Lysosomal localization is necessary for T. b. brucei killing by TLF. Trypanosoma brucei rhodesiense, which is indistinguishable from T. b. brucei, is resistant to TLF killing and causes human African sleeping sickness. Human infectivity by T. b. rhodesiense correlates with the evolution of a human serum resistance associated protein (SRA) that is able to ablate TLF killing. When T. b. brucei is transfected with the SRA gene it becomes highly resistant to TLF and human serum. In the SRA transfected cells, intracellular trafficking of TLF is altered and TLF mainly localizes to a subset of SRA containing cytoplasmic vesicles but not to the lysosome. These findings indicate that the cellular distribution of TLF is influenced by SRA expression and may directly determine susceptibility.

Analysis by one-dimensional (1-D) SDS-PAGE/Western blotting of whole mite extract (larval and adult stages) with sheep sera taken 0-84 days after infection with the sheep scab mite, Psoroptes ovis revealed a progressive IgE antibody response, with a dominant high molecular weight allergen (MW 180 kDa) detected early during infection. Further analysis by two-dimensional (2-D) SDS-PAGE/Western blotting with post-infection sera, revealed a more complex picture with numerous (> 20) IgE reactive spots. Trypsin digest and Maldi-ToF analyses of these spots identified two house dust mite allergen homologues, namely tropomyosin (Der p 10) and paramyosin (Der p 11), and analysis of a third spot indicated an apolipoprotein-like IgE reactive protein (Der p 14). Further 1-D and 2-D SDS/Western blotting, with specific antibodies to the house dust mite allergens Der p 10, 11, and to the IgE reactive peptide of the high molecular weight house dust mite allergen, Der p 14 (vitellogenin/apolipophorin), provided firm evidence for the presence of these three allergens in extracts of the Psoroptes mite. These studies show for the first time that homologues of the house dust mite 10, 11 and 14 group allergens are represented as immunodominant allergens of the sheep scab mite, and may represent important vaccine candidates.

Background: We investigated the possible role of antiphospholipid (APA) and anti-human 2-glycoprotein I (beta2-GPI) antibodies (Ab) in thrombosis and atherosclerosis in human immunodeficiency (HIV)-positive patients, in whom they seem to be more frequent., Methods: We measured APA and anti-beta2-GPI Ab in 58 HIV-positive patients together with markers of disease progression, circulating beta2-GPI, plasma lipids, biological markers of endothelial activation and integrity (plasma thrombomodulin, von Willebrand factor, vascular cell adhesion molecule 1) and with antimalonic dialdehyde antibodies (anti-MDA Ab)., Results: We found a 41% frequency of IgG APA in the HIV-positive patients. APA IgMs were rarely positive (7%), and anti-beta2-GPI IgGs were positive in 3-4% patients. There was no correlation between APA or anti-beta2-GPI Ab and the presence of opportunistic infections. Although plasma thrombomodulin, von Willebrand factor and vascular cell adhesion molecule 1 were significantly increased in the HIV-positive patients, APA was correlated only with vascular cell adhesion molecule 1, suggesting that APAs are correlated with endothelial activation but not with vascular endothelial lesions. A correlation between APA and anti-MDA IgG was demonstrated using multivariate analysis (r=0.542, P < 0.0001), suggesting a relationship between the targets of these antibodies. Finally, IgG APAs are frequent in HIV infection but are not correlated with biological markers of endothelial injury., Conclusion: Our results do not support a role for APA or anti-beta2-GPI in HIV-associated silent vascular endothelial damage. However, the role of these autoantibodies in clinically relevant thrombotic events should be investigated in HIV-positive patients.

Lipid particles of the yeast, Saccharomyces cerevisiae, were isolated to high purity and their components were analysed. The hydrophobic core of this organelle consists of triacylglycerols and steryl esters, which are almost exclusively located to that compartment. Lipid particles are stabilized by a surface membrane consisting of phospholipids and proteins. Electron microscopy confirmed the purity of the preparations and the proposed structure deduced from biochemical experiments. Major proteins of lipid particles have molecular weights of 72, 52, 43 and 34 kDa, respectively. The 43 kDa protein reacts with an antiserum against human apolipoprotein AII. In lipid particles of the yeast mutant strain S. cerevisiae erg6, which is deficient in sterol delta 24-methyltransferase, this protein is missing thereby identifying the protein and confirming our previous finding (Zinser et al., 1993) that sterol delta 24-methylation is associated with lipid particles. A possible involvement of surface proteins of lipid particles in the interaction with other organelles is discussed with respect to sterol translocation in yeast.

Eighty-nine primary lung carcinomas and 23 metastatic lung tumors were immunohistochemically studied for the expression of pulmonary surfactant apoproteins, by using monoclonal (PE-10) and polyclonal antibodies. Surfactant apoprotein was demonstrated in the cytoplasm and/or nuclear inclusion bodies of only primary lung adenocarcinomas (36 of 75 cases), not in any other histologic type of primary lung carcinoma or in metastatic lung tumors. In primary lung adenocarcinoma, although typical type II pneumocyte type adenocarcinoma was not included in the current series, the majority of surfactant apoprotein-positive single cell type tumors were of the Clara cell type, with a single bronchial surface epithelial cell type, according to the light microscopic subclassification of adenocarcinoma cells. The Clara cell type adenocarcinomas could at times be distinguished only with difficulty from adenocarcinoma of type II pneumocyte type. Normal and hyperplastic type II pneumocytes were of course positive for surfactant apoprotein in the cytoplasm. However, none of the positive cells could definitely be identified as Clara cells in non-neoplastic lungs. The findings obtained in this study indicate that surfactant apoprotein is a good marker to distinguish adenocarcinoma of the lung from other histologic types of lung cancer and from neoplasms metastatic to the lung, and that type II pneumocytes and Clara cells, non-neoplastic and neoplastic, are morphologically and functionally closely related and might belong to the same cell lineage.