Plasmids encoding the mucosal chemokines CCL27 and CCL28 are effective adjuvants in eliciting antigen-specific immunity in vivo.

A hurdle facing DNA vaccine development is the ability to generate strong immune responses systemically and at local immune sites. We report a novel systemically administered DNA vaccination strategy using intramuscular codelivery of CCL27 or CCL28, which elicited elevated peripheral IFN-gamma and antigen-specific IgG while driving antigen-specific T-cell secretion of cytokine and antibody production in the gut-associated lymphoid tissue and lung. This strategy resulted in induction of long-lived antibody responses that neutralized influenza A/PR8/34 and protected mice from morbidity and mortality associated with a lethal intranasal viral challenge. This is the first example of the use of CCL27 and CCL28 chemokines as adjuvants to influence a DNA vaccine strategy, suggesting further examination of this approach for manipulation of vaccine-induced immunity impacting both quality and phenotype of responses.

The interpretation of ELISA results by means of the standard deviation ratio.

An improved sensitivity to low levels of hepatitis B surface antigen (HBsAg) was demonstrated when ELISA results were interpreted by a statistical method. The absorbance of each test well was compared with the mean absorbance of all low-colour test samples. Those wells with an absorbance of more than two standard deviations above the mean were referred for confirmatory tests. Samples containing 1.0 ng/ml of HBsAg were reliably detected by a rapid assay technique (1.5 h). Predictive value analysis showed greater sensitivity than was possible from a direct comparison of test samples with controls.