Volume 26, Issue 1 pp. 7-17

Early treatment during a primary malaria infection modifies the development of cross immunity

M. Legorreta-Herrera

Corresponding Author

M. Legorreta-Herrera

Laboratorio de Immunología Molecular, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónomia de Mexico, Iztapalapa, Mexico

Dr Martha Legorreta-Herrera, Laboratorio de Immunología Molecular, FES Zaragoza, UNAM, Batalla 5 de Mayo esq. Fuerte de Loreto, Ejército de Oriente 09320, Itzapalapa, Mexico (e-mail: [email protected]).Search for more papers by this author
M. L. Ventura-Ayala

M. L. Ventura-Ayala

Laboratorio de Immunología Molecular, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónomia de Mexico, Iztapalapa, Mexico

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R. N. Licona-Chávez

R. N. Licona-Chávez

Laboratorio de Immunología Molecular, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónomia de Mexico, Iztapalapa, Mexico

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I. Soto-Cruz

I. Soto-Cruz

Laboratorio de Immunología Molecular, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónomia de Mexico, Iztapalapa, Mexico

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F. F. Hernández-Clemente

F. F. Hernández-Clemente

Laboratorio de Immunología Molecular, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónomia de Mexico, Iztapalapa, Mexico

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First published: 15 June 2004
Citations: 22

SUMMARY

We have used a murine model to study the kinetics of cross-protection when a primary infection is halted at different times. We analysed how parasitaemia is modified during a second infection with the homologous parasite, a heterologous parasite, or a mixture of the two. In addition, possible mechanisms involved in cross-protection were analysed. Results show that treatment with pyrimethamine on day 5 during a primary infection with P. chabaudi AS (non-lethal), prevents the generation of cross-protection to a new challenge with lethal P. yoelii 17XL. In contrast, when treatment is on day 7, mice survive a P. yoelii infection. Differences between both groups suggest that in order for ‘preimmune’ mice to survive a lethal challenge, a predominantly TH2-type response is required, with a higher mRNA expression level of IL-4 and IL-10, and a lower mRNA expression of IFN-γ. This work shows that an early treatment of a malaria infection produced by a non-lethal parasite drives the immune response towards a loss of cross-protection to further infections, in particular with more virulent parasites. This finding should be taken into account for the development of effective malaria vaccines.

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