In vitro sensitization of thymocytes. Role of H-21 I region determinants and cell-free mixed leukocyte culture supernates in generation of cytotoxic responses.

Abstract

Stimulation of thymocytes in vitro by spleen cells differing for the entire H-2 complex leads to a significant proliferative response without a significant cell-mediated lympholysis (CML) response. Addition of soluble cell-free supernates (SF), (taken from a 7-day mixed leukocyte culture) enables these cultures to develop CML response. For optimal CML response, the SF has to be added within 48 h of onset of cultures. Although with spleen cells as responding cells, SF could quantitatively replace I-region different stimulating cells for generation of CML responses, with thymocytes as responding cells, stimulation with I-region cells appeared obligatory for the generation of CML responses. The implications of these findings are discussed.

The Availability for Recognition of Normal H‐2 Antigens by Cytotoxic T Lymphocytes on a Rauscher‐Virus‐transformed Cell, RBL‐5A

“…I x 10^ responder cells cultured alone served as the non-sensilized controls. Cultures were incubated in humidified air wiih 5"^ CO;, for 5 days al 37 C. To obtain better recovery of cells, the medium fortheanii-H-2Dh sensitization was supplemented to 25",', (v/v) wiih a cell-free supernatant obtained on day 7 from a mixed lymphocyte culture (MLC) [26].…”

The Induction of Autoreactive T Lymphocytes by Allogeneic Effect Factor (AEF): Relevance to Normal Pathways of Lymphocyte Differentiation

“…These "conventional" properties of AEF are its ability to help weak CTL reactions (Altman & Cohen 1975, Plate 1976, Finke et al 1977, Talmage et al 1977, Simon et al 1977, Ryser et al 1978, Wagner & RoUinghoff 1978, Fyfe & Finke 1979, Friedman et al 1979), its costimulator (Paetkau et al 1976, Shaw etal. These "conventional" properties of AEF are its ability to help weak CTL reactions (Altman & Cohen 1975, Plate 1976, Finke et al 1977, Talmage et al 1977, Simon et al 1977, Ryser et al 1978, Wagner & RoUinghoff 1978, Fyfe & Finke 1979, Friedman et al 1979), its costimulator (Paetkau et al 1976, Shaw etal.…”

“…We refer to the latter as autonomous cytotoxicity, since its induction is independent of exogenous stimulator cells. It should be emphasized here that other helper factors which augment antigen-specific CTL responses require previous or simultaneous triggering by specific antigen in order to mediate their effects (Altman & Cohen 1975, Plate 1976, Finke et al 1977, Talmage et al 1977, Sopori ct al. 1977, Simon et al 1978, Ryser et al 1978, Fyfe & Finke 1979, Friedman et al 1979.…”

“…The first such report concerned the ability of a nonspecific soluble mediator (generated in a short-term murine MLC) to augment the sensitization of murine T lymphocytes against allogeneic fibroblasts in vitro as evidenced by a marked increase in the subsequent CTL responses (Altman & Cohen 1975). Such findings were interpreted as indicating that, as a result of stimulation of one subset of T lymphocytes by lymphocyte-defined (LD) antigens, a soluble mediator is released which facilitates the differentiation of another subset of T cells into functional CTL, Subsequent to those initial studies, ample documentation has been obtained for the ability of alloantigen-and mitogen-stimulated T cells to elaborate factors capable of augmenting suboptimal CTL responses (Plate 1976, Finke et al, 1977, Talmage et al 1977, Simon et al 1977, Ryser et al, 1978, Wagner & Roilinghoff 1978, Fyfe & Finke 1979, Friedman et al, 1979, In a more recent development, it was found that a T cell growth factor (TCGF) produced during mitogen or alloantigen stimulation of T cells is capable of supporting the long-term growth of antigen-activated T ceils (Morgan et al, 1976, Gillis & Smith 1977. These findings have significant theoretical and practical implications in allowing the cloning and mass culture of antigen-specific T cells.…”

Biological effects of allogeneic effect factor on T lymphocytes: in vitro induction of cytotoxic T lymphocytes manifesting preferential lytic activity against H-2-identical tumor cells.

“…This is in agreement with a recent report documenting the mitogenic effect of xenogeneic reconstitution factor, a soluble mediator derived from human MLC, on normal murine thymocytes (27). This could imply that our AEF contains one or more additional active moieties that may be missing from the other "helper" factors that have been similarly studied (4,(7)(8)(9)(11)(12)(13)(14)(15)(16).…”