Baseline TGF-ß correlates with protection after immunization with Plasmodium falciparum sporozoites in the controlled human malaria infection model.

BACKGROUND: Here we assessed a possible relationship between baseline TGF-ß concentrations and acquisition of sterile immunity after Plasmodium falciparum sporozoite immunization. METHODS: TGF-ß concentrations were determined in samples of 65 malaria-naive volunteers in 4 studies either prior to and after challenge infection, or prior to and after first immunizing infection under chemoprophylaxis with P. falciparum sporozoites. RESULTS: High baseline TGF-ß concentrations were associated with rapid acquisition of sterile protection (p = 0.028). CONCLUSION: Baseline TGF-ß concentrations predict the efficiency of acquisition of sterile immunity following sporozoite immunization and may represent a steady-state regulatory mechanism to keep in check immune systems with a low threshold for activation.