Evidence for light perception in a bioluminescent organ.

Here we show that bioluminescent organs of the squid Euprymna scolopes possess the molecular, biochemical, and physiological capability for light detection. Transcriptome analyses revealed expression of genes encoding key visual transduction proteins in light-organ tissues, including the same isoform of opsin that occurs in the retina. Electroretinograms demonstrated that the organ responds physiologically to light, and immunocytochemistry experiments localized multiple proteins of visual transduction cascades to tissues housing light-producing bacterial symbionts. These data provide evidence that the light-organ tissues harboring the symbionts serve as extraocular photoreceptors, with the potential to perceive directly the bioluminescence produced by their bacterial partners.

A chimeric multi-epitope DNA vaccine elicited specific antibody response against severe acute respiratory syndrome-associated coronavirus which attenuated the virulence of SARS-CoV in vitro.

Epitope-based vaccines designed to induce antibody responses specific for severe acute respiratory syndrome-associated coronavirus (SARS-CoV) are being developed as a means for increasing vaccine potency. In this study, we identified four B cell epitopes from the spike (S) and membrane (M) protein through bioinformatics analysis and constructed a multi-epitope DNA vaccine. Intramuscular immunization of mice with this vaccine was sufficient to induce specific prime as well as a long-term memory humoral immune response to at least two candidate epitopes, S(437-459) and M(1-20). A DNA prime-protein boost strategy greatly enhanced the antibody generation and the immune sera not only reacted with the lysates of SARS-CoV-infected Vero cells but also neutralized the cytopathic effect of SARS by 75% at 1:160 dilution. The novel immunogenic S protein peptide revealed in this study provides new target for SARS vaccine design; and our work indicated multi-epitope DNA vaccine as an effective means for eliciting polyvalent humoral immune response against SARS-CoV.

An annotated cDNA library of juvenile Euprymna scolopes with and without colonization by the symbiont Vibrio fischeri.

BACKGROUND: Biologists are becoming increasingly aware that the interaction of animals, including humans, with their coevolved bacterial partners is essential for health. This growing awareness has been a driving force for the development of models for the study of beneficial animal-bacterial interactions. In the squid-vibrio model, symbiotic Vibrio fischeri induce dramatic developmental changes in the light organ of host Euprymna scolopes over the first hours to days of their partnership. We report here the creation of a juvenile light-organ specific EST database. RESULTS: We generated eleven cDNA libraries from the light organ of E. scolopes at developmentally significant time points with and without colonization by V. fischeri. Single pass 3' sequencing efforts generated 42,564 expressed sequence tags (ESTs) of which 35,421 passed our quality criteria and were then clustered via the UIcluster program into 13,962 nonredundant sequences. The cDNA clones representing these nonredundant sequences were sequenced from the 5' end of the vector and 58% of these resulting sequences overlapped significantly with the associated 3' sequence to generate 8,067 contigs with an average sequence length of 1,065 bp. All sequences were annotated with BLASTX (E-value < -03) and Gene Ontology (GO). CONCLUSION: Both the number of ESTs generated from each library and GO categorizations are reflective of the activity state of the light organ during these early stages of symbiosis. Future analyses of the sequences identified in these libraries promise to provide valuable information not only about pathways involved in colonization and early development of the squid light organ, but also about pathways conserved in response to bacterial colonization across the animal kingdom.

Hepatitis B virus infection and coronary atherosclerosis: results from a population with relatively high prevalence of hepatitis B virus.

AIM: To investigate the possible association between hepatitis B virus (HBV) infection and angiographically proven coronary artery disease (CAD) in a population with relatively high prevalence of HBV. METHODS: Sera from 434 patients who underwent coronary angiography were tested for HBV antigens (HBsAg, HBeAg) and antibodies (Anti-HBs, Anti-HBc and Anti-HBe) by ELISA. RESULTS: Seventy-seven percent (224/291) of the patients with CAD and 73.4% (105/143) of the patients without angiographic evidence of atherosclerosis were seropositive for HBV (P > 0.05). However, C-reactive protein (CRP) levels were significantly higher in patients with CAD (P = 0.008), while lower in HBV seropositive population (P = 0.043 and P = 0.021 after adjustment for conventional risk factors). CONCLUSION: Our results suggested HBV infection negatively correlates with CRP levels, but seems not to be associated with coronary atherosclerosis.