Background:

Research:

1. Identification of immune regulatory mechanism in the central nervous system (CNS)

CNS has long been regarded as an immunologically privileged site due to absence of cells/organs primarily responsible for immune responses. However, recent studies have demonstrated that astrocyte and microglia act as professional antigen-presenting cells to activate T cell receptors. This result indicates that active immune regulating mechnisms are operating in the CNS. We observe the immune responses occurred in the brain and other tissue of pigs experimentally infected with T. solium metacestode, which is causative agent for neurocysticercosis (NCC). RNase protection assay is to be performed using the brain tissue to trace the differential expression of various cytokines and to be compared those obtained from other tissue. Chronological changes in the populations and activities of immune regulatory cells in peripheral blood mononuclear cells are to be analyzed by FACScan, proliferation assay and recall assay. Comprehensive analyses on the changes of gene expressions and the resulting biological implications are to be carried out at the whole gene levels by high density oligonucleotide cDNA microarray. These data will be collectively integrated to obtain detailed understanding on the immune responses of the CNS.

2. Identification of specific antigenic molecules for differential diagnosis of active stage NCC from chronic cases

Many cases with early active NCC can be treated with chemotherapeutic agents. Specific treatment can shorten and diminish the symptoms caused by inflammation associated with active stage NCC, and reduces the risk of headache and late-recurred refractory seizure. In contrast, chronic inactive stage or acephalic budding cysticercosis in the ventricles do not respond to anthelmintics currently available and often require surgical or symptomatic treatment. Therefore, it is important to identify and characterize antigens that are specific for active stage NCC. We have previously demonstrated that a 10-kDa protein of TsM was highly reliable in detecting specific antibodies in NCC patients. A recombinant form of this molecule (CyDA) identified over 90% of NCC, whose brain CT/MRI scan exhibited active lesions or mixed forms of active and inactive stages. At present, the biological function of the antigen is not clear although a recent study has demonstrated that this protein belongs to the family of cestode-specific oligomeric hydrophobic ligand binding protein (HLBP). We are under going to provide a framework for investigation to produce chimeric antigen or antigenic cocktails, which are likely to be used to increase the sensitivity and specificity of immunological tests for diagnosis.

Publications:

1. Cho SY, Lee NS, Shin MH, Kong Y (1999) Age-dependent infectivity of orally transferred juvenile Fasciola hepatica. J Parasitol, 85(4):739-742.
2. Chung JY, Bahk YY, Huh S, Kang SY, Kong Y, Cho SY (1999) A recombinant 10 kDa protein of Tania solium metacestodes specific to active neurocysticercosis. J Infect Dis, 180(4):1307-1315.
3. Hong SJ, Kang SY, Chung YB, Chung MH, Oh YJ, Kang I, Bahk YY, Kong Y, Cho SY (2000) Paragonimus westermani: A cytosolic glutathione S-transferase of a sigma-class in adult stage. Exp Parasitol, 94:180-189.
4. Kong Y, Cho SY (2000) Assessment of specificity of a recombinant 10 kDa protein antigen in differential diagnosis of neurocysticercosis. J Infect Dis, 181:1871-1872.
5. Yun DH, Chung JY, Chung YB, Bahk YY, Kang SY, Kong Y, Cho SY (2000) An antigenic 28 kDa cysteine protease of Paragonimus westermani expressed in the definitive host stage. Clin Diag Lab Immunol, 7(6):932-939.
6. Kang SY, Ahn IY, Park CY, Chung YB, Hong ST, Kong Y, Cho SY, Hong SJ (2001) Clonorchis sinensis: Molecular cloning and characterization of 28-kDa glutathione S-transferase. Exp Parasitol, 97:186-195.
7. Bae YA, Moon SY, Kong Y, Cho SY, Ryu MK (2001) CsRn1, a novel retrotransposon in a parasitic trematode, Clonorchis sinensis, discloses a new phylogenetic claude of Ty3/gypsy-like LTR retrotransposons. Mol Biol Evol, 18(8):1474-1483.
8. Kim TY, Joo IJ, Kang SY, Cho SY, Kong Y, Gan XX, Sukomtason K, Sukomtason K, Hong SJ (2002) Recombinant Paragonimus westermani yolk ferritin is a useful serodiagnostic antigen. J Infect Dis, 185:1373-1375.
9. Chung JY, Yun DH, Eom KS, Kang SY, Kong Y, Cho SY (2002) Taenia solium: Identification of specific antibody binding regions of metacestode 10-kDa protein. Exp Parasitol, 100(2):87-94.
10. Eom KS, Jeon HK, Kong Y, Hwang UW, Yang Y, Li X, Xu L, Feng Z, Rim HJ (2002) Identification of Taenia asiatica in China: Molecular, morphological, and epidemiological analysis of a Luzhai isolate. J Parasitol, 88(4):758-764.
11. Chung YB, Kong Y, Cho SY, Yang HJ (2002) Purification and localization of a 10 kDa calcareous corpuscle binding protein of Spirometra mansoni plerocercoid. Parasitol Res, in press.