Occupational sensitization to ribosome-inactivating proteins in researchers.
BACKGROUND
Ribosome-inactivating proteins (RIPs) are expressed in many plants. Because of their anti-infectious and anti-proliferative effects, intensive research is going on for applying these toxins in therapy against viral infections or malignancies. Recently, we demonstrated that type I allergy against RIPs from elderberry can occur.


OBJECTIVE
Stimulated by our study, a group of RIP researchers reported that some of the employees had suspected allergy to RIPs.


RESULTS
We tested their sera in ELISA on natural RIPs. Specific IgE in four subjects were found against dianthin30, gelonin, momordin, PAP-S, saporin, ricin and volkensin. In contrast, asparin and lychnin did not show any IgE binding. When separating extracts of plants containing the toxins in SDS-PAGE, RIPs appeared to be the predominant constituents. Interestingly, among the other plant proteins, they were exclusively recognized by IgE in immunoblot. RIPs derived from close botanical families share high sequence homologies. Nevertheless, in IgE inhibition experiments with human sera, cross-reactivity between RIPs also derived from non-related plants could be demonstrated.


CONCLUSIONS
We conclude that sensitization and IgE induction to RIPs may occur upon exposure. This has to be considered when applying them in therapy against malignancies or viral infections.
Szalai
K
K
Center of Physiology and Pathophysiology, University Children's Hospital, Medical University of Vienna, Austria.
Schöll
I
I
Förster-Waldl
E
E
Polito
L
L
Bolognesi
A
A
Untersmayr
E
E
Riemer
A B
AB
Boltz-Nitulescu
G
G
Stirpe
F
F
Jensen-Jarolim
E
E
D000328:Adult; D000368:Aged; D035843:Biomedical Research; D003429:Cross Reactions; D004342:Drug Hypersensitivity / Q000209:etiology* / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced* / Q000276:immunology; D016273:Occupational Exposure / Q000009:adverse effects; D010936:Plant Extracts / Q000009:adverse effects / Q000276:immunology; D010940:Plant Proteins / Q000009:adverse effects* / Q000276:immunology; D012108:Research Personnel; D012270:Ribosomes / Q000187:drug effects*
D010936:Plant Extracts; D010940:Plant Proteins; D007073:Immunoglobulin E