Summary
Thyrogiobulin (Tg) is a large glycoprotein with polymorphic structure and its heterogeneity
has been demonstrated by many investigators. In order to obtain appropriate antibodies
against human Tg which appear in the circulation of patients with thyroid carcinoma,
a number of rabbits (19) were immunized with poorly iodinated h-Tg (0.05%). During
the period of immunization the level of T3 and T4 was followed in sera, as well as
the titre of anti-h-Tg antibodies. The production of antibodies against h-Tg was observed
in all immunized rabbits (8,13,16 and 54 weeks from the first immunization). Titres
of anti-h-Tg antibodies in sera at the 16 and 54-week bleeding were very high (Ka
= 2.0 × 1010 M−1). A few immunized rabbits were found to have a very low concentration of serumT 4
(determined by RIA-PEG method). Sera from these animals contained antibodies against
T4, but not against T3. Their identification and characterization was performed by
a radioimmunological method.
In summary, our results show that after immunization of rabbits with low-iodinated,
i.e. hormone-poor human Tg, antibodies against thyroxine can be produced. However,
occurrence of anti-thyroxine antibodies in some immunized rabbits indicates that the
immunogenicity of hormone residues in poorly iodinated h-Tg is much lower than in
normal iodinated molecule.
Key words
Antithyroxine antibodies - Antithyroglobulin antibodies - Human thyrogiobulin (h-TG)
- Low iodinated h-Tg - Rabbit immunisation - Thyroxine RIA
