Immunoblot analysis for serum antibodies to <i>Pneumocystis carinii</i> by age and intensity of infection in rats

, Hong, S T; , Lee, M; , Seo, M; , Choo, D H; , Moon, H R; , Lee, S H

doi:1995.33.3.187

Korean J Parasito > Volume 33(3):1995 > Article

Original Article


Korean J Parasitol. 1995 Sep;33(3):187-194. English. Published online Sep 20, 1995. http://dx.doi.org/10.3347/kjp.1995.33.3.187
Copyright © 1995 by The Korean Society for Parasitology


Immunoblot analysis for serum antibodies to Pneumocystis carinii by age and intensity of infection in rats
S T Hong,^*¹M Lee,¹M Seo,¹D H Choo,²H R Moon,² and S H Lee¹
Department of Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul 110-799, Korea.

Received August 05, 1995; Accepted August 14, 1995.
Abstract
The present study aims to observe changing patterns of serum antibody to Pneumocystis carinii in normal rats of different ages and in immunosuppressed rats. The serum IgG antibody was observed by immunoblotting with crude antigen of P. carinii which were purified from the lungs of infected rats. The crude antigens separated in SDS- PAGE resolved more than 20 protein bands from 20 to 200 kDa. Of them, 40-45, 50-55, 116 and 200 kDa bands were major antigens of P. carinii. Most of the normal rats of up to 4 weeks had the antibodies reacting the 4 bands, but none of 8-week-old rats revealed the specific antibody. After the rats grew for 40 weeks, all were found to have the antibody in their serum. Same pattern of serum antibody level by age was found in ELISA. When immunosuppressed rats became heavily infected, the antibody in their serum decreased distinctively. The present results suggest that antibodies in normal newborn rats are transferred from their mother and lowered up to 8 weeks. Thereafter, the levels of the antibodies begin to increase by natural exposure to P. carinii. It was also confirmed that the intensity of P. carinii infection is inversely related with levels of serum antibodies.

Figures


	Fig. 1 SDS-PAGE findings of crude antigen of P. carinii, Coomassie brilliant blue R-250 stained protein bands in 12.5% gel. Lane 1, size marker; lane 2, crude antigen of P. carinii sued in this experiment, W13-32.


	Fig. 2 Immunoblotting pattern between W13-32 P. carinii antigen and sera of normal rats of different ages. Lnaes 1, size marker; 2, amido black 10B stained protein bands; 3-7, 2 week old rats; 8-12, 4 week old rats; 13-17, 10 week old rats; 18-22, 40 week old rats.


	Fig. 3 Immunoblotting pattern between W13-32 P. carinii antigen and sera of immunosuppressed rats. Lanes 1, size marker; 2-6, sera of rats in intensity of infection I; 7-9, sera of rats in intensity of infection II; 10, serum of a rats in intensity of infection III; 11, serum of a rats in intensity of infection IV.


	Fig. 4 Immunoblotting pattern between W13-32 P. carinii antigen and sera of rats of 2-week immunosuppression. Lnaes 1, size marker; 2, amido black 10B stained protein bands; 3-6, sera of 2 week old rats; 7-11, sera of 5 week old rats; 12-16, 8 week old rats; 17-21, sera of 40 week old rats.


	Fig. 5 Anti-P. carinii antibody levels measured by ELISA according to intensity of infection in immunosuppressed rats. Con, sera of control rats of 40 weeks age; 0-IV, sera of immunosuppressed rats by intensity of infection; 0, no cysts in 20 immersion oil fields; I, less than 10 cysts; II, 10 to 19 systa; III, 20 to 99 cysts; IV, mort than 100 cysts.

Tables


	Table 1 The rats used for the present experiment


	Table 2 Anti-P. carinii IgG antibody in serum of normal rats by immunoblotting


	Table 3 Anti-P. carinii IgG antibody levels in serum by ELISA in normal rats


	Table 4 Anti-P. carinii IgG antibody patterns analyzed by intensity of infection


	Table 5 Anti-P. carinii IgG antibody levels by ELISA in serum of immunosuppressed rats

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