Vaccine development

Recombinant viruses expressing a human malaria antigen can elicit potentially protective immune CD8 + responses in mice.

Miyahira, Y. et al. Proc. Natl. Acad. Sci. USA 95, 3954?3959 (2001)

The immunogenicity of vaccines depends on the regimen used. Miyahira et al. describe total protection against malaria, in all mice injected with a replication-defective recombinant adenovirus expressing the circumsporozoite protein of Plasmodium yoelli, followed by a booster with an attenuated recombinant vaccinia virus expressing the same antigen. Long-lasting protection depended on the generation of memory T and B cells.

Innate immunity

Inducible IL-2 production by dendritic cells revealed by global gene expression analysis.

Granucci et al. Nature Immunol. 2, 882?888 (2001)

Immature dendritic cells (DCs) are specialized for antigen uptake but inflammatory signals induce their maturation into non-phagocytic cells capable of stimulating naive T-cell responses. Granucci et al. undertook a kinetic study of gene expression in DCs in response to bacterial stimulation and show that IL-2 is expressed by DCs, but not macrophages, as early as 4 hours after stimulation. These results help explain the unique T-cell stimulatory capacity of DCs.

Neuroimmunology

Infected splenic dendritic cells are sufficient for prion transmission to the CNS in mouse scrapie.

Aucouturier, P. et al. J. Clin. Invest. 108, 703?708 (2001)

Colonization of lymphoid tissues is an essential preliminary step in the prions' journey to the central nervous system. But how prions are transmitted from the immune system to the nervous system is unknown. Here, injection of dendritic cells (DCs) from scrapie-infected mice directly into the blood stream of Rag1−/− mice, was sufficient to cause prion disease. It remains to be seen whether DCs are physiologically important in prion neuroinvasion.

Autoimmunity

A pathogenic role for myelin-specific CD80 + T cells in a model for multiple sclerosis.

Huseby, E.S. et al. J Exp. Med. 194, 669?676 (2001)

CD4+ T cells have been the focus of research into multiple sclerosis, a disease characterized by autoimmune destruction of myelin. CD8+ T cells are also found at the scene of the crime; however, their role in pathogenesis has not been investigated. Myelin-basic-protein-specific CD8+ T-cell clones were transferred into mice, causing a rapid neurological disease. The clinical signs and pathology differ from that seen in the more convention experimental autoimmune encephaltis model, which is caused by CD4+ myelin-specific T cells.