This study aims to evaluate the antiviral role of nucleic acid-based agonists for the activation of toll-like receptor (TLR) signaling pathways, and its protective role in respiratory influenza A virus infections. TLR-3 is expressed on myeloid dendritic cells, respiratory epithelium, and macrophages, and appears to play a central role in mediating both the antiviral and inflammatory responses of the innate immunity in combating viral infections. Influenza viruses can effectively inhibit the host's ability to produce interferons, and thereby suppress the immune system's antiviral defence mechanisms. Poly ICLC is a synthetic double stranded RNA comprising of polyriboinosinic-poly ribocytidylic acid (Poly IC) stabilized with l-lysine (L) and carboxymethylcellulose (C). Poly ICLC and liposome-encapsulated Poly ICLC (LE Poly ICLC) are TLR-3 agonists and are potent inducer of interferons and natural killer cells. Intranasal pre-treatment of mice with Poly ICLC and LE Poly ICLC provided high level of protection against lethal challenge with a highly lethal avian H5N1 influenza (HPAI) strain (A/H5N1/chicken/Henan clade 2), and against lethal seasonal influenza A/PR/8/34 [H1N1] and A/Aichi/2 [H3N2] virus strains. The duration of protective antiviral immunity to multiple lethal doses of influenza virus A/PR/8/34 virus had been previously found to persist for up to 3 weeks in mice for LE Poly ICLC and 2 weeks for Poly ICLC. Similarly, pre-treatment of mice with CpG oligonucleotides (TLR-9 agonist) was also found to provide complete protection against influenza A/PR/8/34 infection in mice. RT-PCR analysis of lung tissues of mice treated with Poly ICLC and LE Poly ICLC revealed upregulation of TLR-3 mRNAs gene expression. Taken together, these results do support the potential role of TLR-3 and TLR-9 agonists such as Poly ICLC and LE Poly ICLC in protection against lethal seasonal and HPAI virus infection.

Although both Bcl-2/Bax ratio and Mcl-1 have been identified to be of clinical relevance in B-cell chronic lymphocytic leukemia (CLL), there is controversy regarding their role; further, their relative importance is not well delineated. Expression of Bcl-2, Bax, the Bcl-2/Bax ratio, and Mcl-1 in 51 consecutive previously untreated CLL patients and 16 controls was determined by Western blotting. Only 37 patients were treated, all with chlorambucil and prednisone initially. Six patients achieved complete response (CR), 14 were non-responders (NR), and 17 had a partial response (PR), as defined by NCI criteria. There was considerable inter-patient variability in protein expression and overlap with healthy volunteers (P > 0.05). All patients with CR had low Mcl-1 levels compared to the PR + NR group (0.07 ± 0.02 vs. 0.14 ± 0.07, P = 0.043). Higher Mcl-1 expression as determined by dichotomizing the data was associated with a failure to achieve CR (P = 0.021). The Bcl-2/Bax ratio was significantly associated with treatment response only when CR and PR were considered together (0.89 ± 0.53 [CR + PR] vs. 3.38 ± 4.47 [NR], P = 0.0118). There was no association with Rai stage. Low Mcl-1 appears to be a requirement for CR, while low Bcl-2/Bax ratio is indicative of some response to conventional treatment. Am.

We studied the immunogenicity of an anti-SARS subunit vaccine comprised of the fragment of the SARS coronavirus (SARS-CoV) spike protein amino acids 318-510 (S318-510) containing the receptor-binding domain. The S protein fragment was purified from the culture supernatant of stably transformed HEK293T cells secreting a tagged version of the protein. The vaccine was given subcutaneously to 129S6/SvEv mice in saline, with alum adjuvant or with alum plus CpG oligodeoxynucleotides (ODN). Mice immunized with the adjuvanted antigen elicited strong antibody and cellular immune responses; furthermore, adding the CpG ODN to the alum resulted in increased IgG2a antibody titers and a higher number of INF-gamma-secreting murine splenocytes. Mice vaccinated with S318-510 deglycosylated by PNGase F (dgS318-510) showed a lower neutralizing antibody response but had similar numbers of INF-gamma-producing cells in the spleen. This finding suggests that carbohydrate is important for the immunogenicity of the S318-510 protein fragment and provide useful information for designing an effective and safe SARS subunit vaccine.

No abstract