Indirect effects of oral tolerance to ovalbumin interfere with the immune responses triggered by Schistosoma mansoni eggs
Braz. j. med. biol. res
;
35(10): 1195-1199, Oct. 2002. ilus, graf
Article
in English
| LILACS
| ID: lil-326245
ABSTRACT
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 æg 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 æm 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 æmý). Active mechanisms triggered by injection of tolerated antigen (ovalbumin) reduce granuloma formation
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Schistosoma mansoni
/
Ovalbumin
/
Lung Diseases, Parasitic
/
Antigens, Helminth
Limits:
Animals
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
2002
Type:
Article
/
Congress and conference
Affiliation country:
Brazil
Institution/Affiliation country:
FIOCRUZ/BR
/
Universidade Federal de Minas Gerais/BR
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