Lymphoreticular cells isolated by centrifugal elutriation from a mammary adenocaricinoma. i. characterization of an in situ lymphocyte suppressor population by surface markers and functional reactivity
✍ Scribed by Scott C. Buessow; Ronald D. Paul; Alan M. Miller; Diana M. Lopez
- Publisher
- John Wiley and Sons
- Year
- 1984
- Tongue
- French
- Weight
- 714 KB
- Volume
- 33
- Category
- Article
- ISSN
- 0020-7136
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✦ Synopsis
Abstract
The procedure of centrifugal elutriation was evaluated as a means of purifying large numbers of in situ lymphocytes from enzymatically disaggregated mouse mammary tumors. The eluate obtained at a flow rate of 3.0 ml/min was optimal for high levels of lymphocyte recovery with low levels of contaminating tumor cells, polymorphonuclear leukocytes, and macrophages. The majority of the tumor infiltrating lymphocytes (90%) expressed the Thy 1.2 antigen, while less than 5% possessed surface immunoglobulin. Further analysis of the T lymphocyte population was accomplished by flow cytometric analysis of in situ lymphocytes stained with fluorescein‐conjugated monoclonal anti‐Lyt 2 antibodies. The results of such studies reveal an increase in the levels of Lyt 2^+^ lymphocytes within the in situ population. To determine whether these Lyt 2^+^ cells were functionally active as suppressor cells, the ISL^1^ were mixed with spleen cells from tumor bearers and then tested for their ability to respond to mitogen and TAA‐induced blast transformation of tumor‐bearer spleen cells. Removal of macrophages from ISL by Sephadex G‐10 columns did not alter the suppression. Treatment with monoclonal anti‐Lyt 1 antibody and complement did not affect the inhibition observed. However, treatment of ISL with anti‐Lyt 2^+^ monoclonal antibody and complement resulted in the elimination of the suppressor cell activity. We concluded that within the tumor‐infiltrating lymphoreticular cells there is a population of Thy 1.2^+^ Lyt 2.2^+^ lymphocytes responsible for the suppression of mitogen and tumor‐antigen‐induced blastogenesis.