HIV P24 [Gold]

Background: High sensitivity for detection of HIV-1 p24 antigen allows for early detection of primary HIV-1 infections. Objectives: To evaluate the detection sensitivity and specificity of the Daina Screen (R) HIV Combo assay using clinical specimens in Japan where the pretest probability (prevalence) is low. Study design: We screened 17,373 preoperative outpatient blood samples using 4th generation lateral flow immunochromatography Daina Screen (R) HIV Combo assay for simultaneously detecting anti-HIV-1/2 and HIV-1 p24 antigen. Results: Of the samples tested, 24 were positive for HIV-1 p24 antigen and 49 for HIV-1/2 antibody. Of the 49 samples, 36 were WB and HIV-1 RNA negative, 10 were WB and HIV-1 RNA positive, and 3 were WB positive, HIV-1 RNA negative, and in-house HIV-1 proviral DNA positive. RT-PCR revealed that of the 24 samples that were p24 antigen positive, one sample was HIV-1 RNA positive, which was reconfirmed using an in-house HIV-1 provirus DNA assay. From the 17,300 HIV-1 p24 antigen and anti-HIV-1/2 negative samples, pools containing 10 negative samples each were tested for HIV-1 by RT-PCR; all results were negative. Conclusion: The Daina Screen (R) HIV Combo assay had a sensitivity and specificity of 100% and 99.7%, respectively, which sufficiently detected HIV infection in the cohort.

Aim: Nanoparticulate design is important for the production of nanotechnological materials and passive immunogens. Using lessons from our hepatitis E vaccine, we herein design protein-based nanoparticles through incorporation of an N-terminal hydrophobic tail (NHT, located on HEV ORF2 aa368-460). Materials & methods: Flu HA1, HIV gp41/gp120/p24, HBsAg and HPV16 L2 were fused with NHT, expressed in Escherichia coli and subjected to self-assembly in vitro. Nanosized particles were characterized by size-exclusion chromatography and negative electron microscopy. Immunogenicity was assessed in mice. Results: All the NHT-fused proteins spontaneously formed nanoparticulates and presented with immunogenicity approximately 2-log over their nonassembling forms. Conclusion: Protein self-assembly provides an attractive means to create nanosized particles that bear specific antigens. Our strategy outlines a novel and shared method for the design of immunogenic nanoparticles.