ELISA for detection of dengue virus-induced cytokine and its antibody.

ELISA technique has been standardized for detection of a dengue type 2 virus (DV)-induced cytokine, the cytotoxic factor (CF) and CF-specific antibodies. The performed ELISA was found to be sensitive (90.9%), specific (92.5%), accurate (91%) and reproducible and was able to detect a minimum of 7 ng/ml CF in the test samples. The technique was used to detect CF in DV inoculated mouse sera and DV-infected mouse spleen cell culture fluids. Significant utility of the test was detection of a CF-like cytokine in the sera of human cases of dengue haemorrhagic fever.

Flow cytometric analysis of T4:T8 splenic cell during dengue virus infection of mice.

The present study was undertaken to investigate the effect of dengue type 2 virus (DV) and DV-induced cytokines (CF and CF2) on T lymphocyte subpopulations of spleen by flow cytometry. Following DV-ic inoculation in mice the percent number of CD4+ and CD8+ lymphocytes in the spleen was reduced, the peak reduction in both was observed on the 6th day post-inoculation (p.i.). Intravenous inoculation of CF or CF2 in mice also decreased the percent number of CD4+ as well as CD8+ T lymphocytes subpopulation in the spleen, the maximum reduction being observed at 1 and 2 hr, respectively. The reduction in T lymphocyte subpopulation by CF and CF2 was found to be dose dependent. Thus, the alterations of T lymphocyte subpopulations during DV infection are mediated via cytokines.