Copyright © 1993, American Society for Microbiology An Approach to Development of Specific T-Lymphocyte Lines by Use of Preprocessed Antigens in Plasmodium vinckei vinckei Murine Malaria

The development of parasite-specific T-cell lines represents one approach to the potential identification of relevant immunogens in erythrocytic malarial infection. However, the use of parasitized-erythrocyte lysates as antigens inhibits the proliferation ofT cells. To circumvent this problem, we preincubated antigen-presenting cells (APCs) from spleens of malaria-naive, BALB/c mice with a Plasmodium vinckei vinckei (hereafter referred to as P. vinckei)-parasitized erythrocyte lysate. APCs were subsequently irradiated and washed prior to being incubated with T lymphocytes from P. vinckei-immune, histocompatible mice. After 8 to 10 cycles of antigenic stimulation and rest, two T-cell lines were analyzed. Both lines were predominantly CD4+. Proliferation assays demonstrated marked lymphocyte blastogenesis to syngeneic but not allogeneic APCs that had preprocessed malarial antigen. Antigen incubated directly with T cells and nonpulsed APCs in vitro did not result in T-cell proliferation. Assays of interleukin-2 (IL-2), IL-4, IL-5, and gamma interferon were compatible with one cell line being predominantly TH1 and the other being TH2. Thus, APCs that have preprocessed malarial antigen and are free of extraneous parasite material induce highly reactive, antigen-specific, major histocompatibility complex-restricted T-cell lines that functionally appear capable of inducing humoral and/or cell-mediated immunity. Malaria remains a leading cause of infant and child mor-tality worldwide, with an estimated 100 to 500 million case