P system epithopes in Ascaris lumbricoides


Rosario, March 19, 2002

P SYSTEM EPITHOPES IN Ascaris lumbricoides

Dear Editor,

The blood group P substances of tissue cells mediate the adhesion of a series of pathogenic bacterias (Escherichia coli, Streptococcus suis, Pseudomona aeruginosa, and de Shiga toxin of Shigella dysenteriae). Further, P (globoside) has been shown to be the cellular receptor for parvovirus B19.

The antigens of the P system have also been detected in various animal species, where the characters occur not only on erythrocytes and tissue cells but also on water-soluble glycoproteins of secretions and body fluids10.

Strong P1 (+ Pk) activity has been found in the ovomucoid of turtledove eggs3. Another excellent source for P1 (+ Pk) active material is the fluid in hydatic cysts taken from sheep liver containing live protoscolices of the tapeworm Echinococcus granulosus1. Further, P1 specific substances were found in the extracts of earthworm Lumbricus terrestris7 and the roundworm Ascaris suum8.

Mimicry, antigenic modulation and natural selection have been proposed to explain hosts tolerance for a parasite9.

We worked with 27 Ascaris lumbricoides extracts [ AE ].

In order to perform our experiments [ AE ] were prepared. Adult specimens were washed in physiological solution supplemented with 200 mg /ml of streptomycin and 200 mg /ml of penicillin. After that a refrigerated mechanical rupture was performed for 5 days. The supernatants were collected and kept at –20ºC with a final concentration of timerozal 1:10002,5.

Inhibition agglutination tests were made facing the [ AE ] against anti P and anti P1 monoclonal antibodies in optimal concentrations (lot No. 2-87 / lot No. 2-88 Monoclonal Antibodies against Blood Group Antigens. IV Workshop. Paris. July 2001). Suspensions of fresh red cells (P and P1) were used as a revealing system4.

Results have shown that out of the 27 [ AE ] studied, 15 presented P and P1 epithopes and only one [ AE ] P1 epithope.

Previous studies have shown the presence of A and B antigens in the [ AE ] 6. Owing to the similarity between ABO system and P system, we conclude that membrane glycolipids would be involved in the escape mechanism of the immune response for Ascaris lumbricoides.

Bioq. Patricia PONCE DE LEÓN


Departamento de Microbiología

Laboratorio de Inmunohematología

Facultad de Cs. Bioq. y Farm.

Suipacha 531

2000 Rosario, Argentina.

Email: tefu1958@hotmail.com


1. CAMERON, G.L. & STAVELEY, J.M. - Blood group P subtance in hydatic cyst fluid. Nature (Lond.), 179: 147-148, 1957.

2. CAPRON, A.; BIGUET, J.; VERNES, A. & AFCHAIN, D. - Structure antigénique des helminthes. Aspects immunologiques des relations hôte-parasite. Path. Biol., 16: 121-138, 1968.

3. FRANÇOIS GERARD, C.; BROCTEUR, J. & ANDRE, A. - Turtledove: a new source of P1 like material cross-reacting with the human erythrocyte antigen. Vox Sang (Basel), 39: 141-148, 1980.

4. MARCELLI, A.; FINE, J.M. & RIBAT, I. - Techniques in Immunohematologie. Paris, Flammarion, 1981.

5. MONROY OSTRIA, A.; GOMEZ GUTIERREZ, L.J.; RAMIREZ RAMIREZ, A. & CARRILLO LANDIN,G. - Reconocimiento por inmunotransferencia de antígenos de Taenia solium y su larva. Rev. lat-amer. Microbiol., 34: 33-38, 1992.

6. PONCE DE LEÓN, P.; VALVERDE, J. & ZDERO, M. - Preliminary studies on antigenic mimicry of Ascaris lumbricoides. Rev. Inst. Med. trop. S. Paulo, 42: 295-296, 2000.

7. PROKOP, O. & SCHLESINGER, D. - Uber das vorkommen von P1. Blut gruppen substanz oder einer P1-like substance bei Lumbricus terrestris. Acta biol. Med. germ., 15: 180-181, 1965.

8. PROKOP, O. & SCHLESINGER, D. - Uber das vorkommen von P1. Blut gruppen substanz order einer P1-like substance bei Ascaris suum. Dtsch. Gesundh.-Wes., 20: 1584, 1965.

9. SALMON, C.H. - Les groupes sanguins ou l'écriture des genes. Paris, Masson, 1997.

10. SCHENKEL- BRUNNER, H.- Human blood groups. Chemical and Biochemical basis on antigen specificity. New York, Springer Verlagwiem, 2000.

Received: 19 March 2002

Accepted: 09 April 2002

Publication Dates

  • Publication in this collection
    15 Oct 2002
  • Date of issue
    Apr 2002
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