Progressive growth of a murine T cell lymphoma alters population kinetics and cell viability of macrophages in a tumor-bearing host.

Tumor progression induces infiltration of immune cell populations at the site of tumor growth. Infiltrated leukocyte population including monocyte and macrophages interacts with tumor cells and tumor microenvironment and results in the suppression of macrophage functions. Impaired functions of macrophages result in the suppression/inhibition of cell-mediated immunity leading to inefficient antitumor immune responses. Impaired macrophage population invariably helps in immune selection of tumor leading to uninterrupted growth and progression in the host. Murine T cell lymphoma designated as Dalton's lymphoma is highly immunosuppressive and invasive tumor of T cell origin, which completely paralyzes the host's immune system resulting in a very short life span of the host. Progressive growth of Dalton's lymphoma (DL) cells has been known to inhibit the release of inflammatory cytokines and effector mediator molecules. In this study, we demonstrate that intraperitoneal transplant of DL cells in normal healthy host induces a rapid increase in macrophage cell population during early stage of tumor progression and progressive decrease in tumor-associated macrophage population and reduced survival of macrophages in advance stage of tumor burden.