EXPLORING THE IMMUNOGENICITY POTENTIAL OF PLANT VIRUSES USED AS VACCINE ANTIGEN: TOBACCO PLANT

Tobacco mosaic virus (TMV) was the first virus to be discovered over a century ago and was the first plant virus ever purified and tried to use as a source of therapeutic as well as prophylactic agents. The present study was aimed to investigate the immunogenicity of leaves aqueous extract of non-infected (control) and infected (TMV) tobacco plant. We evaluated the immunogenicity of the aqueous extract on the in vivo immune function of the mouse. Swiss mice were treated subcutaneously on day 0 and 7 with variable doses of aqueous extract of control and TMV plant of tobacco (25 – 300 µg) adsorbed on 0.5 mg of aluminium hydroxide in a final volume of 0.2 ml. On day 15, we analyzed surface markers i.e. CD3/CD4/CD8 population, estimation of Th1 (IFN-gamma, TNF alpha) cytokines from spleen cell culture supernatant and peritoneal macrophages activation were studied. Hepatitis B vaccine used as standard for these immunological studies. The results showed that the leaf aqueous extract of TMV at the dose of 50 and 100 µg adsorbed on 0.5 mg of alum, showed increase in the CD3/CD4/CD8 population, peritoneal macrophages activation and Th1 cytokine levels (IFN-gamma and TNF alpha) from spleen cell culture supernatant as compared to control tobacco plant and hepatitis B vaccine were observed. This suggests that the Tobacco (Nicotiana tabacum) improves the immune system and might be regarded as a biological response modifier.