Ablation of NK cell function during tumor growth favors Type 2-associated macrophages, leading to suppressed CTL generation.

Several reports describe regulatory interactions between NK cells and CTLs. We addressed the issue of NK participation in the early anti-tumor defense by inoculating alpha-ASGM-1 treated mice with BW-Sp3 T lymphoma. Rejection of BW-Sp3 depends on strong CTL responses.

Pattern recognition receptors and differentiation antigens define murine myeloid cell heterogeneity ex vivo.

Recruitment of myeloid cells during inflammatory reactions plays an important role in the propagation and resolution of inflammation. However, the identification and characterization of these cells in mice has been hampered by cellular heterogeneity at the functional and phenotypic level. We have defined criteria for the rapid flow-cytometric identification of monocytes (M(o)), macrophages (MPhi), neutrophils (N(eu)) and eosinophils (E(os)) in murine tissues using novel and established myeloid markers.

Morphometric analysis of cytolysis in cultured cell monolayers: a simple and versatile method for the evaluation of the lytic activity and the fate of LAK cells.

The assessment of cytolytic activity of killer cells may not only be useful to improve routine analysis, e.g., in clinical settings, but may also offer new opportunities for the fundamental analysis of the mutual interaction between cytotoxic cells and their targets.

Nitric oxide-independent CTL suppression during tumor progression: association with arginase-producing (M2) myeloid cells.

Most of the mice bearing a s.c. BW-Sp3 lymphoma tumor mount a CD8(+) T cell-mediated response resulting in tumor regression.

Antagonistic effect of NK cells on alternatively activated monocytes: a contribution of NK cells to CTL generation.

Natural killer (NK) cells fulfill essential accessory functions for the priming of antigen-specific cytotoxic T lymphocytes (CTLs). On the basis of a NKG2D-ligand-positive tumor model, we obtained results implicating NK-mediated regulatory as well as NK-mediated cytolytic activities in the initiation and persistence of CTL activity. Indeed, CD8(+) T-cell-dependent tumor rejection requires NK cell function in vivo, because tumors will progress both on depletion of NK cells or in the absence of optimal NK activity.

Morphometric analysis of cytolysis in cultured cell monolayers: a simple and versatile method for the evaluation of the cytotoxic activity and the fate of LAK cells.

In vitro techniques for the evaluation of the cytotoxicity of immune cells are important both for the routine assessment of the cytolytic activity in samples for clinical or experimental use and for basic studies of the interaction between killer and target cells. Especially in the latter case, it is important not only to quantify target cell death as an endpoint, but also to observe the interaction and to recover effectors and targets for further analysis. We present a new method that offers considerable improvements for both types of applications, in comparison with the standard radioactivity release assays used today.