Long-term maintenance of HLA-D restricted T cells specific for soluble antigens

Long-term growth in vitro of human cerebrospinal fluid T lymphocytes

Investigations of central nervous system cellular immune reactivity in human disease, as reflected in the responses of cerebrospinal fluid lymphocytes, have been limited primarily due to the low numbers of cerebrospinal fluid lymphocytes available during routine diagnostic lumbar punctures in normal individuals and most patients with demyelinating diseases. We report the use of a T-cell growth factor generated by by phytochemagglutinin-stimulated, irradiated normal peripheral blood lymphocytes to maintain long-term proliferating cultures of human cerebrospinal fluid lymphocytes. Cerebrospinal fluid lymphocytes. Cerebrospinal fluid T-cell cultures were initiated from 10 to 14 cerebrospinal fluid samples with up to 5000-fold expansion of initial cell numbers. Few, if any, macrophage or surface immunoglobulin-bearing cells were present, while 80 to 90% of the cultured cells were T cells as demonstrated by rosette formation with sheep red blood cells. Mixed lymphocyte cultures with cultured cerebrospinal fluid T cells and irradiated, freshly isolated allogeneic peripheral blood lymphocytes yielded a positive response in four of the five cultures tested.

The reversal immune surveillance hypothesis: part II

The first part of the reversal immune surveillance hypothesis (RISH. I) describes the conceptual framework of the immune system as a homoeostatic mechanism for the control of cell differentiation and replication. The thymic dependent lymphocytes (T-cells) are considered to be tissue specific and identify aberrations in the cell surface pattern (antigens), that represent that particular cell type. The T-cells may then recruit antibody forming B-lymphocytes (B-cells) to produce antibodies (humoral response) to the cell surface antigens in order to return the cell surface pattern to its correct state. The antigens may also be removed from the cell surface as immune complexes by the complement system, which under normal conditions does not cause cell lysis. The cellular arm of the immune system, that of killer cells or activated macrophages are considered to be primarily involved with tissue remodelling. Whether or not the humoral or cellular arm of the immune system is activated depends upon the antigens displayed by the stimulating cell. The proposed system, which is self monitoring, is considered to have evolved from the invertebrates through to the vertebrates to become more complex in the mammals. Therefore the immune system is considered to be based on the identification of self and self-foreignness, rather than on foreignness per se.

Antigen-specific human T-cell clones: development of clones requiring HLA-DR-compatible presenting cells for stimulation in presence of antigen

A method for cloning soluble antigen-specific proliferating human T lymphocytes directly from peripheral blood cells of individuals recently primed with the antigen is described. The soluble antigen was keyhole limpet hemocyanin. After expansion in liquid culture, these cells were shown to be antigen specific and to require HLA-DR-histocompatible presenting cells. Recloning of small numbers of these cells in soft agar under conditions of high plating efficiency yielded true clones (i.e., derived from a single cell) which retained specificity for the original stimulating antigen as shown by blastogenic responses measured by incorporation of [3H]thymidine. However, antigen-specific stimulation of clones was demonstrated only in the presence of an HLA-DR-compatible cooperating cell population together with the relevant antigen. Cells that manifested only HLA-A or B locus identity with the T-cell clone were not effective as presenting cells. Other antigens, such as tetanus toxoid, to which the donor of the clone or of the presenting cells was immune failed to stimulate the clone.