Irradiated β-glucan enhances immune response to bacterial infection through CD4 and CD8 T-lymphocytes

&beta-glucans are glucose polymers with a variety of stimulatory effects on the immune system. The objective of this study was to evaluate the immune-enhancing activities of low molecular weight gamma irradiated &beta-glucan (I&beta-g) extracted from Pleurotus ostreatus in response to Pseudomonas aeruginosa infection in rats.
&beta-glucan (&beta-g) powder was exposed to 50 kGy of gamma radiation. For experimental study, healthy male rats were divided in six groups. Group I: did not receive any treatment. Group 2: infected group was injected once with P. aeruginosa. Group 3: were orally administrated with &beta-g for 15 days at a dose of 65 mg/Kg body weight/day. Group 4: were orally administrated with I&beta-g for 15 days at a dose of 65 mg/Kg body weight/day. Group 5: rats were treated with &beta-g and injected once with P. aeruginosa. Group 6: rats were treated with I&beta-g and injected once with P. aeruginosa. Rats were sacrificed 24 h post bacterial infection.
&beta-g and I&beta-g were characterized using FTIR spectra and SEM, showed breakdown of the glycosidic bonds with deformation and splitting of &beta-g molecule. Oral ingestion of &beta-g markedly enhanced the production of lymphocytes and leucocytes and CD8 compared to that of I&beta-g, although I&beta-g was more effective in stimulating CD4 count compared to that of &beta-g and ameliorated CD4/CD8 ratio. I&beta-g enhanced GPx and CAT activity, elevated zinc concentration in the blood compared to that of &beta-g, although both I&beta-g and &beta-g elevated GSH and caused no effect on MDA level in post infected groups.
In conclusion I&beta-g improves antioxidant state and enhances immune system in particular CD4 count against bacterial infections which is an important marker of immune system.