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

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 ISL1 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.

Tumor infiltrating lymphocytes of spontaneous versus transplanted mouse mammary tumors

“…Our data agree with the reported phenotypic profile of infiltrates from human breast cancer, namely, a predominance of OKT8-positive lymphocytes and decrease in OKT4-positive lymphocytes, relative to peripheral lymphoid organs [26,30]. Phenotypic studies of TILs from other rodent tumors have generally been performed on long-term passaged tumors [2,10,16]. Lala and McKenzie [10] reported that lyt-2-positive cells were greatly increased in T1L relative to peripheral lymphoid organs in mice bearing MPC-11 plasmacytoma and WEHI-164 fibrosarcoma lines.…”

Up-Regulation of Matrix Metalloproteinase-9 in T Lymphocytes of Mammary Tumor Bearers: Role of Vascular Endothelial Growth Factor

“…The up-regulated expression of MMP-9 is found not only in splenic T cells but, more importantly, in the T cells infiltrating the tumor microenvironment, and this increased expression correlates with tumor growth. Our previous studies (58) and those of many other investigators (19,59) have shown the infiltration of the tumor microenvironment by lymphocytes through a process involving adhesion molecules (60). The presence of MMP-9 in tumor bearers' lymphocytes may also play a role, because this metalloproteinase has the potential to degrade matrix protein and to promote leukocyte traffic.…”

Recruitment and activation of tumor‐specific immune t cells in situ: Functional studies using a sponge matrix model

“…is, however, still unclear (Miescher et al, 1986). For example, CD8+ (Lyt 2 + ) T effector cells can be found at tumor sites (Vollmer et al, 1986;Whiteside et al, 1986~;Buessow et a[., 1984b), but are often functionally inactive when isolated and tested in vitro.…”