At the Laboratory of Immunology, the following research projects are being studied:
Snake Venom Research
Snake venom poisonings account for over 125,000 deaths worldwide, mostly in developing countries. The most effective treatment is the administration of potent antivenoms (AVs) which are specific for the venoms in each locality. Surprisingly, effective AVs for many parts of Africa and Asia have not been prepared. We have worked out a highly effective yet simple immunization protocol which is now widely used. A simple, efficient and economical fractionation scheme for large scale fractionation of equine plasma has also been studied.
Snake venoms are rich sources of biologically active compounds, the study of which can lead to the elucidation/characterization of natural pathways/components. These molecules may also be useful as lead compounds in drug development. For example; a thrombin-like enzyme (Ancrod) from the Malayan pit viper has been used to treat thrombosis. Venom proteins with RGD (Arg-gly-asp) sequence of disintegrins have been used in the design of molecules with antiplatelet activity. It is therefore likely that proteins with important and novel biological activities can be found in the diverse population of venomous snakes in Thailand, and this is one of the areas we are working on.
The Laboratory of Immunology has been involved in developing simple immunodiagnostic tests based on immunochromatography (IC) for infectious agents that affect Thais and other people of this region.
The followings are examples:
An IC test for the diagnosis of human Pythiosis, an emerging infectious disease caused by Pythium insidiosum and which mostly affects farmers in the region. Due to lack of early diagnosis, the infection causes tissue necrosis of the limbs, often requiring amputation and sometimes resulting in death. The test kit enables early diagnosis, leading to successful treatment with antibiotics and has saved lives and limbs of many patients.
Development of an IC test for Fasciola gigantica, a liver parasite in ruminants. This disease causes economic loss of about half a billion Baht annually. The simple IC test of blood specimens, in place of fecal egg count, leads to treatment with anthelmintics which results in higher product value and reduces the spread of the disease.
Almost all the IC tests that have so far been developed are not sensitive enough to detect the lipopolysaccharide (LPS) of V. cholerae in human specimens, and require prior enrichment by culture or PCR. With a new IC format, we have manipulated the specific LPS (ca. 5x106 molecules/cell) into sterically favorable forms and thus enable detection at much higher sensitivity.
In addition, we have also studied the use of biotinylated liposome entrapped with chemiluminescent compounds as a generic signal generator to enhance the detection of specific interactions of antigen-antibody and of nucleotide hybridization. We are also developing tests based on fluorescence polarization immunoassay (FPIA) for the detection of drugs and food-borne toxins.
Accumulated evidence has shown that chemical pollutants could lead to adverse health effects; many of which can affect the immune system as suggested by a significant increase in incidence of allergy and asthma in the population. These environmental pollutants could impair host resistance against microbial pathogens and neoplasia, or lead to hypersensitivity and autoimmune reactions.
In 2007, Thailand imported 122,337 tons of pesticides (herbicides, insecticides and fungicides). Without strict and carefully monitored controls, Thai farmers are at great risk of pesticide poisoning. We have found that orchid farmers around Bangkok showed significant changes in some important immunological parameters. This information is being used by local health officers to improve the health status of the farmers and is also used as evidence of the need for better management of pesticides. Studies in rats are being carried out to delineate the details of the immunotoxicity of these pesticides.
updated: 1 June 2010