Submitted to: Parasitology Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/1/2006
Publication Date: 2/1/2007
Citation: Uston, P.I., Urban Jr, J.F., Ashraf, M., Ampy, F.R. 2007. L3l4es antigen and secretagogues induce histamine release from porcine peripheral blood basophils after ascaris suum infection. Parasitology Research. 100(3):603-611. Interpretive Summary: Ascaris suum remains as a parasitic infection of swine that causes considerable loss to the industry because of poor efficiency and secondary microbial disease. There is recent information that also indicates affects on the vaccination efficacy against microbial pathogens. Worm infections generally skew the immune system to control the worm infection at the expense of mechanisms that target microbial pathogens. This study shows that the blood circulating basophil is increased during worm infection of pigs and that the level of histamine contained in these cells also increases. This suggests that the systemic circulation of cells that can release relatively large amounts of histamine when confronted with worm parasites can affect the normal health status of the pig, and could negatively affect growth and production parameters. This information would benefit research to optimize the health and performance of food animals since it would reduce the expression of disease.
Technical Abstract: The aim of this paper was to investigate the role of porcine basophils in protective immunity. Experimental pigs were infected with 1,000 Ascaris suum eggs daily for 21 days. Control pigs were maintained helminth-free. Circulating porcine basophils were isolated from the anti-coagulated whole blood of A. suum-infected and non-infected pigs by dextran (4.5%) sedimentation of erythrocytes or by the centrifugation of dextran-isolated leukocytes through discontinuous Percoll gradients. Results showed that 2.2% of the isolated leukocytes, stained with May-Grunwald Giemsa, were basophils. Each basophil from infected pigs contained 1.30×10-2 to 1.20×10-1 pg of histamine. Peripheral blood basophils (PBBs) from infected swine released 49% specific histamine when induced with A. suum-derived antigen (L3L4ES), 55% with anti-immunoglobulin G, and 62% with calcium ionophore A23l87. During A. suum infection, the number of isolated basophils and histamine levels peaked at 14 to 21 days post-infection and then showed a significant decrease. Percent-specific histamine released from PBBs by infected swine was significantly greater than that released by control pigs. The L3L4ES antigen and secretagogues effectively induced specific/nonspecific histamine release from PBBs and should facilitate future investigations of porcine basophils.