Induction of immunity to antigens expressed by recombinant adeno-associated virus depends on the route of administration.

Recombinant adeno-associated virus (rAAV) is a replication-defective parvovirus which is being explored as a vector for gene therapy because of its broad host range, excellent safety profile, and durable transgene expression in infected hosts. rAAV has also been reported by several groups to induce little or no immune response to its encoded transgene products. In this study we examined the immunogenicity of rAAV by studying the immune response of C57BL/6 mice to a single dose of rAAV-encoding ovalbumin (AAV-Ova) administered by a variety of routes.

Central nervous correlates of chemical communication in humans.

The recording of chemosensory event-related potentials (CSERPs) has been established as an objective method in the assessment of central odor processing in humans. In the present study CSERPs were used to investigate whether human body odor is genetically determined by the major histocompatibility complex (MHC), referred to in humans as the human leukocyte antigen (HLA). The immunological function of the MHC is the discrimination of self/nonself within the immune system.

Graft-versus-leukaemia activity can be predicted by natural cytotoxicity against leukaemia cells.

We have investigated graft-versus-leukaemia (GVL) effects after allogeneic bone marrow transplantation (BMT), using three murine leukaemia models, A20 (B lymphocytic), WEHI-3 (myelomonocytic) and PU5-1R (myeloid). Injection of leukaemia cells in a high number (10(6) cells) into syngeneic Balb/c mice (H-2d) invariably led to death with a median survival time of 22 d (A20), 18 d (WEHI-3) and 45 d (PU5-1R). A lower tumour load of A20 (5 x 10(5) cells) was used in some experiments resulting in a leukaemic death rate of 94%.

Induction of graft-versus-leukemia (GVL) activity in murine leukemia models after IL-2 pretreatment of syngeneic and allogeneic bone marrow grafts.

To investigate GVL effects, Balb/c mice (H-2d) received 5 x 10(5) A20 (B cell leukemia) or 1 x 10(6) WEHI-3 (myelomonocytic leukemia) cells. These cell lines lead to death after a median of 19 (WEHI-3) or 30 days (A20). A lethal dose of total body irradiation followed by syngeneic BMT resulted in significantly prolonged survival of leukemia-bearing animals.

Influence of donor lymphocytes on the incidence of primary graft failure after allogeneic bone marrow transplantation in a murine model.

We used a murine model to determine the impact of donor lymphocyte subsets on the incidence of primary marrow graft failure after transplantation of lymphocyte-depleted bone marrow. After lethal irradiation with 7.5 Gy, Balb/c mice received 1 x 10(5) to 4 x 10(7) GvH-nonreactive (C57 x Balb)F1 or GvH-reactive C57Bl/6 marrow cells.

Graft-versus-leukemia activity after bone marrow transplantation does not require graft-versus-host disease.

Clinical data have suggested that graft-versus-host disease (GVHD) plays a crucial role in the antileukemic effects of bone marrow grafts. We investigated (a) whether bone marrow cells unable to induce GVHD can effect graft-versus-leukemia (GVL) activity and (b) whether such antileukemic capacity depends on the presence of T lymphocytes in the graft. Balb/c mice were inoculated with A20 cells, a B-cell lymphoma/leukemia of Balb/c origin.

Influence of cell dose and graft-versus-host reactivity on rejection rates after allogeneic bone marrow transplantation.

The number of cells transplanted and their capacity to induce graft-versus-host reactivity (GvHR) are two factors that are suspected to influence the engraftment of allogeneic bone marrow. We have investigated their impact on graft rejection rates in busulfan-treated LEW rats. In a series of experiments, we varied (1) the number of marrow cells transferred (1, 5, 10, 20, 30, and 40 x 10(7)), (2) the degree of pretransplant immunosuppression (1.

High-dose cytostatic agents in allogeneic bone marrow transplantation: comparison of the engraftment promoting potential.

We investigated the potential of various cytostatic agents for preventing graft rejection following allogeneic bone marrow transplantation. LEW rats received a lethal dose (35 mg/kg) of busulfan followed by injection of 1 x 10(8) F1(CAP x LEW) marrow cells, which are unable to induce a graft-versus-host reaction in LEW recipients. Rejection of the marrow graft was assessed by monitoring haematocrit and granulocyte counts.

Effect of post-transplant methotrexate, cyclosporin A and prednisolone on graft rejection after allogeneic bone marrow transplantation.

Methotrexate, cyclosporin A and prednisolone have been shown to improve graft survival rates in solid organ transplantation. However, little is known concerning their capacity to promote lasting engraftment of allogeneic bone marrow. Therefore, we tested these agents in LEW rats receiving MHC-mismatched marrow after pretreatment with a myeloablative dose of busulfan plus different doses of total body irradiation (TBI).

Ifosfamide and ACNU in experimental allogeneic bone marrow transplantation.

We have tested ifosfamide and ACNU for their effectiveness in preventing graft rejection following allogeneic bone marrow transplantation. The engraftment-promoting potency of both was compared to that of the standard agent cyclophosphamide. LEW rats received a lethal dose (35 mg/kg) of busulfan followed by injection of 1 x 10(8) (CAP x LEW) F1 marrow cells, which are unable to induce a graft vs host reaction in LEW recipients.

Human lymphocyte reactivity after in vitro exposure to technical and analytical grade pentachlorophenol.

To investigate the potential effects of technical pentachlorophenol (PCP-T, contaminated with polychlorinated dioxins and furans) and of analytical grade pentachlorophenol (PCP-A) on the human immune system, in vitro assays with freshly prepared human peripheral blood lymphocytes were used as an alternative to experimental animals. Both cell-mediated and humoral immune functions were examined after direct lymphocyte exposure to PCP-T or PCP-A at concentrations ranging from 0-200 microM. In each case the viability of the treated cells remained within the control value range.

Comparison of cyclophosphamide, cytarabine, and etoposide as immunosuppressive agents before allogeneic bone marrow transplantation.

Etoposide and cytarabine have been shown to exert high antileukemic activity and are currently under study as preparatory agents before allogeneic bone marrow transplantation. However, data concerning their engraftment-promoting potency are scarce. Therefore, we tested these agents in LEW rats receiving a myeloablative dose of busulfan followed by transfer of F1 (CAP X LEW) marrow, which is unable to induce a graft-v-host reaction (GVHR).