Analysis of humoral immune response in human blastocystosis by Western Blotting

Init I¹, Mak JW², Yong HS³ and Lokman Hakim S¹

1. Parasitology Division, Institute for Medical Research, 50588 Kuala Lumpur, Malaysia

2. Faculty of Medicine & Health Sciences, University Putra Malaysia, 43400 UPM Serdang, Malaysia

3. Department of Zoology, University of Malaya, 59100 Kuala Lumpur, Malaysia

CITATION: Init I, Mak JW, Yong HS, Lokman Hakim S. Analysis of humoral immune response in human blastocystosis by Western Blotting. International Medical Research Journal. 1998;2(2):81–7. 

Download Full Article

ABSTRACT

Blastocystis hominis can be pathogenic but asyptomatic carriers are often seen. As part of the immunological studies on the infection, we carried out immunoblot analysis of sera from 20 blastocystosis patients using SDS-PAGE separated polypeptides of two axenic and 12 xenic B. hominis, Giardia lamblia, Entamoeba histolytica, Endolimax nana and Escherichia coli. B. hominis isolates showed two types of polypeptide patterns in SDS-PAGE. Axenic isolates had prominent bands at 55, 63, 66.4 and 97.2 kD, while common bands of xenic isolates were ac 34, 38, 55 and 68 kD. Prominent bands at 8.1, 12, 15, 21.5, 23.5, 26.6 and 32 kD were present in these B. hominis isolates as well as E. coli. The differences in pattern between the axenic and xenic isolates are mainly due to E. coli polypeptides. Sera from alI the blastocystosis patients did not react with antigens of G. lamblia, E. histolytica, and E. nana. Twelve sera showed reactive bands while 8 others had very weak or no reaction against B. hominis antigens. Eight showed reactivity against axenic isolates C and H; and another three sera crossreacted against at least nine B. hominis isolates tested. We believe that anti-B. hominis antibodies in patients' sera are heterogeneous, and the important B. hominis polypeptides recognised are those at 43, 55 and 66.4 kD. Negative reaction seen with eight of the above sera may be due to antigenic differences in the B. hominis strains involved. lmmunoblot reactive band patterns due to antibodies against B. hominis can be differentiated from those against E. coli polypeptides.

KEYWORDS: B. hominis, sera, SDS-PAGE, immunological