Introduction RSV infection remains a serious threat to newborns and the elderly. Currently, there is no vaccine available to prevent RSV infection. A mucosal RSV vaccine would be attractive as it could induce mucosal as well as systemic antibodies, capable of protecting both the upper and lower respiratory tract. Previously, we reported on a virosomal RSV vaccine for intramuscular injection with intrinsic adjuvant properties mediated by an incorporated lipophilic Toll-like receptor 2 (TLR2) ligand. However, it has not been investigated whether this virosomal RSV vaccine candidate would be suitable for use in mucosal immunization strategies and if additional incorporation of other innate receptor ligands, like NOD2-ligand, could further enhance the immunogenicity and protective efficacy of the vaccine. Objective To explore if intranasal (IN) immunization with a virosomal RSV vaccine, supplemented with TLR2 and/or NOD2-ligands, is an effective strategy to induce RSV-specific immunity. Methods We produced RSV-virosomes carrying TLR2 (Pam 3 CSK 4 ) and/or NOD2 (L18-MDP) ligands. We tested the immunopotentiating properties of these virosomes in vitro , using TLR2- and/or NOD2-ligand-responsive murine and human cell lines, and in vivo by assessing induction of protective antibody and cellular responses upon IN immunization of BALB/c mice. Results Incorporation of Pam 3 CSK 4 and/or L18-MDP potentiates the capacity of virosomes to activate (antigen-presenting) cells in vitro , as demonstrated by NF-κB induction. In vivo , incorporation of Pam 3 CSK 4 in virosomes boosted serum IgG antibody responses and mucosal antibody responses after IN immunization. While L18-MDP alone was ineffective, incorporation of L18-MDP in Pam 3 CSK 4 -carrying virosomes further boosted mucosal antibody responses. Finally, IN immunization with adjuvanted virosomes, particularly Pam 3 CSK 4 /L18-MDP-adjuvanted-virosomes, protected mice against infection with RSV, without priming for enhanced disease. Conclusion Mucosal immunization with RSV-virosomes, supplemented with incorporated TLR2- and/or NOD2-ligands, represents a promising approach to induce effective and safe RSV-specific immunity.
OBJECTIVE: To see the prevalence of Hepatitis C virus (HCV) and its genotypes in general population of the locality and to evaluate the importance of reverse transcriptase-polymerase chain reaction (RT-PCR) test over HCV antibody test in early diagnosis of HCV infection. METHODS: The study took place at the National Institute for Biotechnology and Genetic Engineering (NIBGE) and we collected the samples from HCV screening camps organized by Allah Rakhi Trust Hospital Faisalabad and from blood donors visiting to Allied Hospital Faisalabad. Blood samples from 300 subjects (77% males and 23% females) with a mean average age of 32 ± 20 years were randomly collected, and analyzed after separating the plasma by serological testing as well as molecular methods during the period from January 2004 to December 2004. Genotyping of HCV positive samples were performed by restriction fragment length polymorphism (RFLP) analysis of the PCR products. RESULTS: The results indicated that 48 (16%) cases were positive for anti-HCV antibody and 14 (4.7%) were on the borderline. Alanine aminotransferase (ALT) level indicated a wide range of activity from 5.0U/L to 128U/L. On the average, 79.4U/L activity was found. By nested PCR, 84 (28%) samples were positive for HCV-RNA. The results of genotyping have indicated that 8 (9.5%) samples were of genotype-1 while only 2 (2.4%) samples were of HCV genotype-2. Hepatitis C virus genotype-3 was found to be major prevalent genotype as it was present in 68 (81%) samples. Six (7.1%) samples could not be identified by this method thus remained un-typed. CONCLUSION: Hepatitis C virus-RNA detection by molecular method was found to be more sensitive for early diagnosis of HCV infection and relatively higher incidence of HCV infection with genotype-3 was found in general population of the area.