Leishmania P4 nuclease protects mice against leishmaniasis.

2004 JAN 7 - (NewsRx.com & NewsRx.net) -- DNA immunization with the gene encoding P4 nuclease of Leishmania amazonensis protects mice against cutaneous leishmaniasis.

According to recent research published in the journal Infection and Immunity, "Infection with the protozoan parasite Leishmania amazonensis can cause diverse clinical forms of leishmaniasis. Immunization with purified P4 nuclease protein has been shown to elicit a protective response in mice challenged with L. amazonensis and L. pifanoi."

"To explore the potential of a DNA-based vaccine, we tested the L. amazonensis gene encoding P4 nuclease as well as adjuvant constructs encoding murine interleukin-12 (IL-12) and L. amazonensis HSP70," said Kimberly Campbell and colleagues at the University of Texas in the United States. "Susceptible BALB/c mice were immunized with the DNA encoding P4 alone, P4/IL-12, or P4/HSP70 prior to challenge with L. amazonensis promastigotes. Mice given P4/IL-12 exhibited no lesion development and had a three- to four-log reduction in tissue parasite burdens compared to controls."

"This protection corresponded to significant increases in gamma interferon and tumor necrosis factor alpha production and a reduction in parasite-specific immunoglobulin G1, suggesting an enhancement in Th1 responses," said Campbell and collaborators. "Moreover, we immunized mice with the L. amazonensis vaccines to determine if this vaccine regimen could provide cross-protection against a genetically diverse species, L. major. While ...