Department of Physics, Chemistry and Biology (IFM)

Figure 4 a, b, c and d shows the antibody mediated responses obtained when TWEAK and GITRL were used separately as adjuvant at 7.5µg and 10µg concentrations respectively. Fig 4 e, f, g and h shows the responses obtained from the co vaccinated groups when TWEAK and GITRL were used at various concentrations in combination as adjuvant.

One week following each immunization, the mice was bled and the sera were collected. ELISA was performed using HIV-1 Clade C Recombinant protein (purchased from NIH, USA) as the antigen. The plates were developed and the absorbance was measured. It can be observed from the graphs that the different concentrations of TWEAK and GITRL have driven the antibody mediated response to various extents.
In all the graphs shown, Y axis denotes the Optical density (OD) values measured at 450 nm, and X axis represents the various reciprocal titer to which the OD corresponds to. OD is the measure of the level of humoral response; higher the OD is, higher is the level of humoral response and thereby higher is the circulating level of serum IgG.

It is clear from the graphs that the groups that were co vaccinated with 10µg GITRL (Figure 4d) and (3.75µg GITRL + 3.75µg TWEAK) (Figure 4h) respectively has produced a higher response when compared to that of the response produced by the HIV-1 DNA alone vaccinated group.
However, the antibody mediated response driven when 10 µg GITRL was used as adjuvant was remarkable higher than that of the response obtained from the DNA-alone vaccinated group.
A statistical analysis performed using a student’s paired t-test revealed a statistical significance with a ‘p’ value of 0.022 (p<0.05).