scholarly journals Commercial horseradish peroxidase degrades myelin encephalitogenic protein during coupling for immunohistochemical studies.

1977 ◽  
Vol 25 (5) ◽  
pp. 329-336 ◽  
Author(s):  
A B Johnson ◽  
W Cammer

Conjugates of myelin encephalitogenic basic protein (EP) and commercial horseradish peroxidase (HRP) have been used for immunohistochemical demonstrations of anti-EP antibody in animals with experimental allergic encephalomyelitis. We performed gel electrophoresis studies on EP-HRP conjugates prepared with glutaraldehyde and on mixtures of EP and HRP incubated without glutaraldehyde. The results show that under conditions of one-and two-step coupling HRP causes rapid loss of the native EP band, apparently due to EP degradation. The EP-HRP mixtures are not encephalitogenic in rabbits, or encephalitogenic activity is lost during processing. The immunohistochemical reactivity of conjugates, however, signals some preservation of antibody-combining sites. The mechanism of the HRP effect on EP is unknown. The possibilities of a contaminating proteinase or direct peroxidatic attack are suggested. Until this action of HRP can be overcome, the effect of coupling procedures on the biological activities of EP will be difficult to assess, and EP-HRP conjugates cannot be expected to reveal sites that may bind encephalitogenic portions of the EP molecule.

1975 ◽  
Vol 141 (1) ◽  
pp. 72-81 ◽  
Author(s):  
D E McFarlin ◽  
S C Hsu ◽  
S B Slemenda ◽  
F C Chou ◽  
R F Kibler

After challenge with guiena pig basic protein (GPBP) Lewis (Le) rats, which are homozygous for the immune response experimental allergic encephalomyelitis (Ir-EAE) gene, developed positive delayed skin tests against GPBP and the 43 residue encephalitogenic fragment (EF); in addition, Le rat lymph node cells (LNC) were stimulated and produced migration inhibitory factor (MIF) when incubated in vitro with these antigens. In contrast Brown Norway (BN) rats, which lack the Ir-EAE gene, did not develop delayed skin tests to EF and their LNC were not stimulated and did not produce MIF when incubated in vitro with EF. These observations indicate that the Ir-EAE gene controls a T-cell response against the EF. Le rats produced measurable anti-BP antibody by radioimmunoassay after primary challenge. Although no antibody was detectable in BN rats by radioimmunoassay, radioimmunoelectrophoresis indicated that a small amount of antibody was formed after primary immunization. After boosting intraperitoneally, both strains of rat exhibited a rise in anti-BP antibody; which was greater in Le rats. In both strains of rat the anti-BP antibody reacted with a portion of the molecule other than the EF. Since EF primarily evokes a T cell response, it is suggested that the EF portion of the BP molecule may contain a helper determinant in antibody production.


1996 ◽  
Vol 184 (2) ◽  
pp. 771-775 ◽  
Author(s):  
B M Segal ◽  
E M Shevach

Inbred mice exhibit a spectrum of susceptibility to induction of experimental allergic encephalomyelitis (EAE). We have compared the immune responses of the susceptible SJL (H-2s) and resistant B10.S (H-2s) strains to determine factors other than the MHC background which control resistance/susceptibility to EAE. The resistance of the B10.S strain was found to be secondary to an antigen-specific defect in the generation of Th 1 cells that produce IFN gamma. This defect in IFN gamma production could be restored by exposure of the myelin basic protein (MBP)-reactive T cells to IL-12 with the subsequent induction of the ability to transfer EAE to naive recipients. These findings have important implications for the therapeutic use of IL-12 and IL-12 antagonists and may explain the association between relapses/exacerbation of autoimmune disease and infectious diseases.


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