Histological Study on the Effect of Transfer of Sensitized Rat Spleen Cells on the Late Asthmatic Response

Introduction: Antigen inhalation challenge produces acute airway obstruction which is followed by cellular infiltration into the airways (late asthmatic response). Aim of the Work: This work is carried out to demonstrate the effect of transfer of sensitized rat spleen cells on the late asthmatic response after its suppression by the myelotoxic immune-suppressive drug cyclophosphamide (CY). Materials and Methods: Twenty-five male adult albino rats weighing 150-200 gm were divided into four groups: Group I(control group), Group II (Asthmatic group) that were sensitized on days 1, 14 by 2 intra-peritoneal (i.p.) injections of 10 mg ovalbumin (OVA) complexed with 100 mg aluminum hydroxide and were challenged with intranasal instillation of 100 μl of 0.1% OVA in physiological saline in each nostril on days 21, 28 of the experiment. Group III (CY group): was treated as the asthmatic group but given 100 mg/Kg of CY i.p. on day 25 of the experiment. Group IV (transfer group): Was treated as the CY group but i.p. injected with freshly prepared sensitized rat spleen cells (4X10(^)(6)) on day 26 of the experiment. Results: Histological examination of lung and trachea of the asthmatic group revealed thickened alveolar septa, peribronchial and perivascular cellular infiltration. Statistically there was a significant increase in total cell count, eosinophil and lymphocyte counts in bronchoalveolar lavage fluid (BALF). These effects were suppressed by CY administration (CY group) and restored after spleen cell transfer (transfer group). Conclusion: spleen cell transfer restored the late asthmatic response after its suppression by cyclophosphamide.