HUMAN-ANTIBODY RESPONSE TO A PNEUMOCOCCAL VACCINE IN SCID-PBL-HU MICEAND SIMULTANEOUSLY VACCINATED HUMAN CELL DONORS

Severe combined immunodeficient (SCID) mice were transplanted intraper itoneally with human peripheral blood lymphocytes (PBL) From nine heal thy human donors (SCID-PBL-hu mice). None of the donors had ever recei ved pneumococcal vaccine. Ten days after transplantation. 62 out of 11 1 transplanted mice and six of the nine donors were vaccinated with a 23-valent pneumococcal polysaccharide vaccine. For each donor, human I gG was detected in 91.7-100% of the SCID-PBL-hu mice, whereas specific human IgG antipneumococcal antibodies were demonstrated in 16.7-100% of the vaccinated SCID-PBL-hu mice. Most of the mice transplanted with cells from the same donor showed similar antibody response patterns i n terms of kinetics and antibody levels. A significant antibody respon se was only obtained in mice that received cells from donors with rela tively high antipneumococcal antibody levels at the time of transplant ation, or donors that showed a substantial increase in antibody levels after vaccination The immune response in the SCID-PBL-hu mice did not always reflect the ability of the respective donor to produce antipne umococcal antibodies. The donor dependency of the antipneumococcal ant ibody response has great practical importance for the use of the SCID- PBL-hu-model. Donors should not be chosen randomly. By selecting donor s whose cells have been found to result in successful engraftment, fun ctional SCID-PBL-hu mice can be obtained for the study of human immune responses and function in an in vivo experimental model.