Using the Elispot technique, we were indeed able to detect TT- and HBs-specific IFN–secreting T cells in the peritoneum of vaccinated mice, whereas control mice did not expose any specific IFN–secreting T cells

Using the Elispot technique, we were indeed able to detect TT- and HBs-specific IFN–secreting T cells in the peritoneum of vaccinated mice, whereas control mice did not expose any specific IFN–secreting T cells. the first 3 weeks after PBMC transfer. Moreover, specific memory reactions were elicited by vaccination with tetanus toxoid (TT) or hepatitis B disease (HBV) surface (HBs) antigen of chimeric mice transplanted with PBMC derived from TT- or HBV-immune donors. Substantially higher TT-specific B-cell frequencies were found during the first 3 weeks after vaccination in mice challenged with the specific antigen compared to the levels found in control animals. High numbers of TT-specific IFN–secreting T cells persisted in the peritoneum of vaccinated, but not of unvaccinated, animals during the entire observation period, but only low numbers of specific IL-4-secreting T cells were found in vaccinated mice. Related results were achieved following vaccination with HBs antigen of chimeric mice, transplanted with PBMC of HBV immunized donors. Therefore, TT or HBsAg-specific antibody reactions in our model correlate closely with the living of specific IFN–secreting T helper 1/0 cells. Furthermore, these results display that adoptive transfer of human being PBMC into lethally irradiated mice provides an efficient approach to generate specific B-cell fusion partners for Caldaret the production of human being monoclonal antibodies and specific T-cell lines for adoptive cell therapy of malignant or infectious diseases. == Intro == Severe combined immunodeficiency (SCID) mice do not reject transplants of xenogeneic cells or cells due to a congenital lack of adult B and T cells.1The transplantation of human being peripheral Rabbit polyclonal to IL24 blood mononuclear cells (PBMC) into SCID mice (hu-PBL-SCID mice) results in high serum levels of human being immunoglobulins.2Furthermore, specific antibody reactions were generated in such chimeric mice against several bacterial, protozoal or synthetic antigens and the induction of cytotoxic T lymphocyte (CTL) reactions has been reported in human being/SCID chimeras.29However, the detection of antigen-specific T-cell reactions in SCID mice still represents a major problem, most likely caused by the limited engraftment of transferred human being PBMC,10progressive restriction of B- and T-cell receptor repertoires,11,12T-cell anergy in long-term chimeras13and the lack of professional T-cell stimulation.14Furthermore, the frequencies of antigen-specific T cells are far too low to be detected from the conventional3H-thymidine uptake assay.13,15,16 An alternative approach to generate human being/mouse chimeras in lethally irradiated mice or rats radioprotected with SCID bone marrow (BM), was described by Lubinet al.17The major advantage of this magic size is the early engraftment of transferred human being PBMC, reaching its height within the first 3 weeks post-transplant with seeding of human being T and B cells in the fully preformed murine lymphoid organs and the generation of lymphoid follicles in peritoneum, lymph nodes (LN) and spleen.17,18High numbers of human being lymphocytes, can be transplanted into different strains of mice without induction of overt graft-versus-host (GVH) disease or EpsteinBarr virus (EBV) lymphomas that limit the transferrable cell numbers in the SCID mouse.9,19,20This advantageous kinetic and structural engraftment pattern facilitates the generation of antigen-specific primary and Caldaret secondary humoral and CTL responses by vaccination of human/BALB/c chimerasin vivo.21,22 No data are currently available on the frequencies of functional human being B and T cells after vaccination of chimeric mice adoptively transferred with human being PBMC. In the present study, human being/mouse radiation Caldaret chimera were transplanted with PBMC from previously TT-vaccinated or HBV-immunized donors, who had resolved from acute hepatitis B years before, and were revaccinatedin vivowith TT or HBs antigen. The frequencies and cytokine patterns of the antigen-specific T helper (Th) cells and B cells induced in response to recall antigens were studied using the highly sensitive Elispot technique.23,24Thus, we were able for the first time to quantify antigen-specific Th-cell and B-cell responses in a human/mouse chimeric model on a single cell level. Our analysis reveals a close correlation between the stimulation of strong antigen-specific Th1/0 cells and the development of high anti-TT and anti-HBs antibody levels in the serum of chimeric mice. == MATERIALS AND METHODS == == == == Mice == BALB/c mice (612-weeks-old from Olac Farms, Bicester, UK) were used as recipients of SCID BM and human PBMC. These mice were lethally irradiated by a modified split irradiation protocol as published recently (day 4: 35 Gy; day 1: 95 Gy).17Bone marrow was obtained from 48-week-old non-obese diabetic (NOD)/SCID mice (obtained from Animal Breeding Caldaret Center of the Weizmann Institute,.