Development and evaluation of indirect enzyme-linked immunosorbent assay for a screening test to detect antibodies against classical swine fever virus.

An indirect enzyme-linked immunosorbent assay (ELISA) was developed for a screening test to detect antibodies against classical swine fever virus (CSFV). Viral glycoproteins, which were purified from swine kidney cells infected with CSFV ALD/A76 strain by the immunoaffinity purification using monoclonal antibody against E2 protein, were adsorbed on a microtiter plate as the antigen for the antibody detection. Each antibody titer of serum sample was expressed as a sample per positive value calculated with optical absorbance of each sample and that of a positive control. The advantage of this ELISA is its higher sensitivity: most sera containing more than 4 neutralization titers were determined to be positive. This ELISA is unable to discriminate between antibodies against CSFV and those against other ruminant pestiviruses, therefore positive sera in this ELISA should be evaluated by a cross-neutralization test using CSFV, bovine viral diarrhea virus, and border disease virus. Taken together, the indirect ELISA developed in this study is useful screening tool to detect antibodies against CSFV for the large-scale monitoring of classical swine fever.

Evaluation of a newly-developed immunochromatography strip test for diagnosing dermatophytosis.

BACKGROUND: Traditionally, dermatophytosis, a common disease affecting millions of people world-wide, has been diagnosed by direct microscopy and fungal culture. The immunochromatography (ICG) strip test was recently developed. METHODS: We compared the performance of the ICG strip test for the detection of dermatophytes in samples from human skin and nails with direct microscopy. The 160 samples, consisting of 88 skin and 72 nail specimens, were subjected to direct microscopy study using a 20% KOH solution and to examination with the ICG strip test. Of 160 samples, 18 were examined by fungal culture using Sabouraud dextrose agar medium. RESULTS: We found that the overall sensitivity and specificity of the ICG test were 83.5% and 66.7%; they were 82.1% and 76.2% for the 88 skin and 85.4% and 58.3% for the 72 nail specimens, respectively. CONCLUSIONS: Our findings indicate that the efficacy of the ICG test is comparable to direct microscopy for the detection of dermatophytes. Performance of the assay was easy, and results were available quickly. We suggest that it is an effective tool for dermatophytosis screening.

Epsilon-polylysine microparticle adjuvant drives cytokine production to Th1 profile.

Epsilon-polylysine micro particles (SGEPL) and polyethyleneimine micro particles (SGPEI) were developed by the addition of a hydrophobic group and the immunological characterization of these micro particles and aluminum hydroxide (ALUM) was investigated. BALB/c mice were injected intraperitoneally with ovalbumin (OVA) as an antigen and SGEPL, SGPEI or ALUM as an adjuvant. The results showed that the mice injected with SGEPL produced a significant portion of anti-OVA antibody subclass IgG2a in the sera and suppressed interleukin (IL)-4 and IL-5, but enhanced IL-12 and interferon-gamma (IFN-gamma) from the spleen cells. Similar results relating to cytokines were also obtained, even without OVA. Direct stimulation with SGEPL to naïve BALB/c mouse spleen cells induced IL-12 and IFN-gamma. Both spleen and purified B cells produced IgG1 and IgE after stimulation with IL-4 and the anti-CD40 monoclonal antibody. With the addition of SGEPL, the IgE production from the cells was suppressed as a result of enhanced IFN-gamma production. Furthermore, IgE production was also suppressed in the purified B cells without the influence of IFN-gamma or IL-12. Thus, we suggest SGEPL drives cytokine production to Th1 profile. It will be a novel promising adjuvant based on this viewpoint.