Work

High Levels of Antibodies to Plasmodium falciparum Liver Stage Antigen-1 in Naturally Infected Individuals in Myanmar

Year: 2008

Type: article

Abstract: The sporozoites of malaria parasites transmitted from the saliva of infected mosquitoes rapidly travel to the liver and invade hepatocytes, where they develop into the exoerythrocytic stage referred to as the tissue schizont.During this stage, the parasites express stage-specific antigens.Liver stage antigen-1 of Plasmodium falciparum (PfLSA-1) is a surface protein which is solely expressed in infected hepatocytes and is believed to play a role in liver schizogony and the release of merozoites [1,2].PfLSA-1 induced specific humoral, cellular, and cytokine immune responses in infected individuals [3,4] and have been considered a vaccine candidate for P. falciparum, due to their antigenic and protection-including immunogenic properties [5,6].In the current study, we evaluated antibody responses against PfLSA-1 in naturally infected individuals in Myanmar in order to expand our knowledge regarding the antigenic properties of PfLSA-1, and to evaluate its potential as an antigen for vaccine development and serodiagnosis of P. falciparum infection.Blood samples were collected from inhabitants who visited the Wet-Won Station Hospital, in Pyin Oo Lwin Township, Mandalay Division, Myanmar, with clinical symptoms associated with malaria.Thin and thick blood smears were prepared from blood collected from individuals' fingertips for microscopic diagnosis.A local health unit employee read the Giemsastained blood smears, and treatment was administered to those individuals testing positive for malaria, on the basis of the guidelines established by The Department of Health of The Union of Myanmar.Additional blood samples of approximately 1 ml were collected from a total of 116 individuals in whom P. falciparum infection has been confirmed via microscopic examination, and these were utilized in this study.For negative controls, 50 serum samples from healthy volunteers were employed.All healthy volunteers worked at National Institute of Health, Korea Centers for Disease Control and Prevention, and had never been exposed to malaria nor visited malaria-endemic areas.Informed consent was acquired from all the participating individuals.The study protocol was approved by the Department of Health (Upper Myanmar) of The Union of Myanmar, and were carefully reviewed and approved by the Ethical Committees of the National Institute of Health, Korea Centers for Disease Control and Prevention.The genomic DNA of P. falciparum was extracted from the patients' whole blood using a NucleoSpin Blood Kit (Macherey- High Levels of Antibodies to Plasmodium falciparum Liver Stage Antigen-1 in Naturally Infected Individuals in Myanmar

Source: Korean Journal of Parasitology

DOI: 10.3347/kjp.2008.46.3.195