Pre-clinical pharmacokinetics of recombinant heat shock protein 65-mucin 1 fusion protein vaccine / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE To study the pharmacokinetics of heat shock protein 65-mucin 1 (HSP65-MUC1) recombinant fusion protein vaccine in Macaca mulatta monkeys and tumor-bearing mice. METHODS HSP65-MUC1 was labeled by radioactive isotope 125I. M. mulatta monkeys were randomly divided into sc and iv administration groups. Simultaneously, sc administration group was designed as a multiple dose group in which M. mulatta monkeys were sc given [ 125I] HSP65-MUC1 40 μg·g-1, once every 2 weeks for a total of 3 times. Size exclusion chromatography ( SEC) was used to determine concentrations of HSP65-MUC1 in serum samples. The tumor-bearing mice were randomly divided into 0.5, 1.5, 4, 8 and 24 h groups. Mice were sc given [125I] HSP65-MUC1 550 μg·kg-1, tissues were collected and tissue distribution of [125I] HSP65-MUC1 in tumor-bearing mice was studied using trichloroacetic acid (TCA) precipitation method. RESULTS The absolute bioavailability of [125I]HSP65-MUC1 was 38.33% after M. mulatta monkeys were sc given [125I]HSP65-MUC1. In multiple dose group, concentrations of [125I]HSP65-MUC1 after the third dose administration was compared to that of the first dose administration. The accumulation factor (AUC3/AUC1) was 1.17 ±0.25. Distribution of [ 125I]HSP65-MUC1 was significantly different compared with general polypeptide and protein drugs after sc in tumor-bearing mice. The concentration in lymph nodes was the highest. The concentration in other immune tissues, such as thymus and spleen, were not relatively high, but their declined tendency was slow after reaching the peak concentration (cmax ). However, the concentrations in the serum and some other tissues with a large blood volume, such as the heart, liver, and lung, were relatively low and declined quickly after reaching cmax. Its level in the tumor was not very high. [125 I] HSP65-MUC1 was excreted mainly by the kidneys. CONCLUSION The bioavailability of [125I]HSP65-MUC1 is 38.33% after sc administration in M. mulatta. After multiple-dose administration, the vaccine does not accumulate in the body, whose concentration is the highest in lymph nodes after [1251] HSP65-MUC1 was sc given in tumor-bearing mice, but is not very high in tumor. Besides, the vaccine declined tendency is slow after reaching cmax in immune tissues such as thymus and spleen compared with other tissues with a large blood volume.