In vitro induction of immunological tolerance

Giovanni Biasi, Maria Mazzocchi, Paola Zanovello, Dino Collavo, Hilliard Festenstein

Research output: Contribution to journalArticlepeer-review


IL-2 was previously shown to induce cytotoxic effectors with a broad spectrum of target specificities in thymus and spleen cell cultures. This study was designed to show whether T cells activated by H-2 allogeneic cells in MLC or by syngeneic tumor cells in MLTC are also potential targets for these cytotoxic effectors. We found that thymocytes activated in vitro for 5 days by rIL-2 were capable of killing tumor cells as well as activated T cells. Thymocytes activated by IL-2 were accordingly utilized as a means of effecting clonal deletion of T cells activated by H-2 allogeneic target cells in MLC. To establish whether the unresponsiveness is specific, IL-2-activated thymocytes were added as third party cells to MLC and MLTC. The results showed that both T cells, proliferating in response to H-2 allogeneic cells, and CTL, reactive against syngeneic tumors or H-2 allogeneic cells, are eliminated from the T cell pool. Only alloreactive T cells are specifically eliminated in MLC by IL-2-activated thymocytes, as the remaining T cells are capable of proliferating and generating CTL in response to antigenically unrelated third party allogeneic cells. The possibility that unresponsiveness might be due to soluble factors was ruled out by studies performed with a diffusable "chamber insert" culture system. The results provide evidence that IL-2-activated thymocytes induce in vitro T cell tolerance.

Original languageEnglish
Pages (from-to)187-201
Number of pages15
JournalCellular Immunology
Issue number2
Publication statusPublished - 1989

ASJC Scopus subject areas

  • Cell Biology
  • Immunology


Dive into the research topics of 'In vitro induction of immunological tolerance'. Together they form a unique fingerprint.

Cite this