Indirect effects of oral tolerance to ovalbumin interfere with the immune responses triggered by Schistosoma mansoni eggs
| Autor: | C.R. Carvalho, H.L. Lenzi, R. Correa-Oliveira, N.M. Vaz |
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| Jazyk: | angličtina |
| Rok vydání: | 2002 |
| Předmět: | |
| Zdroj: | Brazilian Journal of Medical and Biological Research, Vol 35, Iss 10, Pp 1195-1199 (2002) |
| Druh dokumentu: | article |
| ISSN: | 0100-879X 1414-431X |
| DOI: | 10.1590/S0100-879X2002001000012 |
| Popis: | The objective of the present study was to investigate whether the injection of a tolerated protein (indirect effects) affects the formation of granulomas around Schistosoma mansoni eggs trapped in the lungs after intravenous (iv) injection into normal (noninfected) C57BL/6 mice (6 animals per group). To induce oral tolerance to chicken egg ovalbumin a 1/5 dilution of egg white in water was offered ad libitum in a drinking bottle for 3 days. Control mice received water. After 7 days, control and experimental animals were injected iv with 2,000 S. mansoni eggs through a tail vein. In some mice of both groups the iv injection of eggs was immediately followed by intraperitoneal (ip) immunization with 10 µg of dinitrophenylated conjugates of ovalbumin (DNP-Ova) emulsified in complete Freund's adjuvant (CFA) or only CFA; 18 days later, mice were bled and killed by ether inhalation. The lungs were fixed in formalin and embedded in paraffin. Serial sections of 5 µm were stained with Giemsa, Gomori's silver reticulin and Sirius red (pH 10.2). Granuloma diameters were measured in histological sections previously stained with Gomori's reticulin. Anti-DNP and anti-soluble egg antigen (SEA) antibodies were analyzed by ELISA. In mice orally tolerant to ovalbumin the concomitant ip injection of DNP-Ova resulted in significantly lower anti-SEA antibodies (ELISA*: 1395 ± 352 in non-tolerant and 462 ± 146 in tolerant mice) and affected granuloma formation around eggs, significantly decreasing granuloma size (area: 22,260 ± 2478 to 12,993 ± 3242 µm²). Active mechanisms triggered by injection of tolerated antigen (ovalbumin) reduce granuloma formation. |
| Databáze: | Directory of Open Access Journals |
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