Evaluation of Peritoneal Macrophages Migration Inhibition and Lymphocytes Mitotic Index in Shigella Dysenteriae Type1 Immunized Guinea Pigs

Abstract

Background and objective : To determine the performance and functional activity of macrophage and lymphocytes after immunization with phenol killed Shigella dysenteriae type 1 Materials and Methods: phenol killed Shigella dysenteriae type 1 (16 103bacteria /ml ) was injected subcutaneously(S/C) in 10 guinea pigs at a dose of 0.5 ml .At the 3rd week animals given a 1st booster dose of (1 ml) of killed bacteria. At 5th week, a 2nd booster dose (1ml) was given (S/C) . Five animals were used as control group and injected with phosphate buffer saline . After isolation of peritoneal macrophage and Blood Lymphocytes, macrophage migration inhibition (MMIT) and lymphocytes, transformation (LTT) tests have been applied. Results: The level of inhibition of migration decreased gradually, while reducing the concentration of the PHA antigen. Migration inhibition coefficient was (0.477 0.268) when PHA antigen (400 g / ml) , (0.610 0.181) when PHA (40 g / ml), (0.641 0.145) when PHA antigen (4 g / ml). No significant difference in migration inhibition coefficient was detected between immunized groups (p value =0.118245) at different concentration of PHA antigen. The control group did not show any migration inhibition for macrophages at different concentrations of PHA antigen. Significant difference was detected between control groups (p value =0.033035) at different concentration of PHA antigen. Significant difference (p value =0.00759 ) , (p value =0.017049) , (p value =0.000278) was detected between immunized and control groups at 4 g / ml, 40 g / ml, 400 g / ml, concentration of PHA antigen respectively . Lymphocyte transformation test showed a clear response of the lymphocytes toward PHA. The mitotic index (Ml) of the lymphocytes exposed to the (0.1mg/ml) PHA antigen was(11.56 3.22 )and for (5mg/ml) PHA was (41.49 26.298 )and for control was (1.18 0.516). Significant difference in mitotic index was detected between groups (p value =0.003554) according to the dose of PHA antigen. Conclusions: MMIT and LTT can be used effectively to evaluate and monitoring of immunological responsiveness to shigella dysenteriae type 1 antigen and both MMIT and LTT proportionally associated with pre sensitization dose and duration of exposure to antigen.