Figure 4. In vitro proliferations of lymphocytes from vaccinated chickens in response to recall HA antigen.

PBMCs from vaccinated chickens were restimulated with HA antigen (10 μg/ml) for 72 hours and lymphocyte proliferation was determined by MTT assay. Results are expressed as stimulation indices, defined as proliferation in response to recall antigen relative to the mock stimulated cells. Each data points represent mean ± SD of five chickens per group.*p < 0.05. ns, non-significant.