Interactions between dendritic cells and CD4+ T cells during Plasmodium infection.

Background: During infection, dendritic cells (DCs) encounter pathogenic microorganisms that can modulate their function and shape the T cell responses generated. During the process of T cell activation, DCs establish strong, long-lasting interactions with naïve T cells.

Methods: Using a mouse malaria model, the interactions of DCs and naïve CD4+ T cells have been analysed.

Results: DCs, either incubated in vitro with infected erythrocytes or isolated from infected mice, are able to present exogenous antigens by MHC-II, but are not able to establish prolonged effective interactions with naïve CD4+ T cells and do not induce T cell activation. It was also found that effective T cell activation of naïve CD4+ T cells is impaired during late Plasmodium yoelii infection.

Conclusion: These data may provide a mechanism for the lack of effective adaptive immune responses induced by the Plasmodium parasite.