Responses to multiple injections with alum alone compared to injections with alum adsorbed to proteins in mice.

New effects and mechanisms of alum on innate immunity have emerged in recent years. A number of cellular and molecular mechanisms induced by aluminum adjuvant have been reported, while the role of NALP3 and inflammasome in the cellular pathway induced by alum is still controversial. The effect of injection of alum alone without vaccine antigen into human has not been reported so far. Recently, in a phase IIIa double-blinded placebo controlled clinical trial testing the therapeutic HBsAg-anti-HBs vaccine formulated with alum against chronic viral hepatitis B patients, the placebo group receiving alum only showed substantial therapeutic effects. To explore possible underlying therapeutic mechanisms, mice were treated either with multiple injections of alum alone or with alum adsorbed to proteins (HBsAg-anti-HBs). After 4 injections Gr1(+)/CD11b(+) cells in the spleen were increased in both alum alone and alum adsorbed in proteins groups. Increased Gr1(+)/CD11b(+) cells in spleens remained consistently high in the alum alone treated group, while Gr1(+)/CD11b(+)cells decreased in the alum adsorbed to proteins group after 6 injections. Both treatments triggered increased levels of TNF-alpha measured in the plasma, but only the alum alone treated mice showed increased levels of IL-10. Histology of the liver tissues revealed a higher number of spotty necrotic foci in the alum alone immunized group. Taken together, potent inflammatory responses were induced in the alum alone immunized mice, which suggests that the substantial therapeutic effects observed in chronic hepatitis B patients immunized with alum alone might be attributed to inflammatory responses.

Establishing a Th17 based mouse model for preclinical assessment of the toxicity of candidate microbicides.

BACKGROUND: To effectively block the invasion of human immunodeficiency virus (HIV)-1 on mucosal surface, vaginal anti-HIV-1 microbicides should avoid inflammatory responses and disruption of mucosa integrity because these will facilitate transepithelial viral penetration and replication. However, existing models fail to predict and evaluate vaginal mucosal toxicity induced by microbicides, and most importantly, they are unable to identify subtle or subclinical inflammatory reactions. This study was designed to develop a cost-effective in vivo model to evaluate microbicide safety in a preclinical study which can recapitulate the mucosal topical reaction. METHODS: A murine model was employed with nonoxynol-9 (N-9) as the topical stimulant within the vagina. Different concentrations of N-9 (1%, 3%, and 4%) were topically applied to the vagina for five consecutive days. A panel of inflammatory cytokines including interleukine-2 (IL-2), IL-4, IL-6, IL-17A, interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and immuno-regulatory IL-10 were assayed in vaginal lavage. Cytokines were quantified by using cytometric bead array (CBA) and reverse transcript (RT) real-time PCR. Histopathological evaluation of vaginal tissues was conducted on hematoxylin-eosin stained slides and scored with a semi-quantitative system according to the severity of epithelial disruption, leucocyte infiltration, edema, and vascular injection. The association between the cytokines and histopathological scores was assessed by linear regression analysis. RESULTS: All three concentrations of N-9 induced inflammatory cytokine production. The 4% N-9 application resulted in a consistent production of cytokines in a time-dependent manner. The cytokines reached peak expression on day three with the exception of IL-4 which reached its peak on day one. Histopathological examination of 4% N-9 treated cervicovaginal tissues on day three showed intensive damage in four mice (sores: 10 - 13) and moderate damage in one mouse (score: 8), which were significantly associated with both inflammatory cytokines IL-17A and IL-6 and anti-inflammatory cytokines IL-4 and IL-10. Interestingly, IL-17A showed significant positive association with inflammatory cytokine TNF-α (r = 0.739; P < 0.05), anti-inflammatory cytokines IL-10 (r = 0.804; P < 0.01) and IL-4 (r = 0.668; P < 0.05). CONCLUSIONS: Our data demonstrate that a panel of cytokines (IL-17A, IL-6, IL-4 and IL-10) could be used as surrogate biomarkers to predict the histopathological damage. Th17 may play a central role in orchestrating inflammatory cytokine responses. This Th17 based mouse model is cost-effective and suitable to assess the toxicity of candidate microbicides in preclinical studies.

[Capacity of HIV enzyme immunoassay diagnostic kits to detect antibodies against different genotypes of HIV].

OBJECTIVE: To investigate the capacity of commercial HIV enzyme immunoassay (EIA) diagnostic kits to detect antibodies against different genotypes of HIV. METHODS: HIV RNA was detected with RT-PCR from samples positive for HIV antibody. The purified PCR products were sequenced directly and the genotypes of HIV from samples were analyzed. The samples for each genotype of HIV were diluted and the diluted samples were detected with different HIV EIA diagnostic kits. RESULTS: All 20 samples positive for HIV antibody were also positive for HIV RNA; 9 of 20 isolates were genotype B, 9 of them were genotype C or CRF BC, 2 of them were CRF AE. The sensitivity of different HIV EIA diagnostic kits to detect antibodies against different genotypes of HIV was not significantly different. CONCLUSION: The capacity of commercial HIV diagnostic kits to detect antibodies against different HIV genotypes may not be significantly different.