Leucocyte interactions with the mouse cremaster muscle microcirculation in vivo in response to tumour-conditioned medium

Abstract

Summary Leucocyte interactions with the cremaster muscle microcirculation in vivo were investigated in response to culture medium conditioned with different cell types in 25 adult male Swiss mice. Animals were divided into five groups. Three groups received ex vivo fluorescently labelled lymphokine activated killer (LAK) cells systemically and had either tumour (murine melanoma K1735)-conditioned medium (TCM), fibroblast (murine 3T3)-conditioned medium (FCM) or fresh culture medium administered topically to the cremaster muscle. In the two remaining groups, the host leucocytes were labelled fluorescently by systemic administration of acridine red, and either TCM or FCM was applied topically to the cremaster muscle. There was an immediate but transient increase in the frequency of rolling and adherent LAK cells, and a subsequent (90-120 min later) increase in rolling and adherent host leucocytes, demonstrating temporal differences in the response to topical administration of TCM. These increases in contact with the vascular endothelium occurred in all vessel types, venules, arterioles and capillaries, with the greatest response observed in the venules. The FCM and normal culture medium did not affect the distribution and localization of either LAK cells or host leucocytes. These data suggest that there are one or more soluble tumour-specific chemoattractants for leucocytes present in the conditioned medium. The mouse cremaster muscle microcirculation is therefore a useful model to investigate the mechanism of leucocyte-endothelium interactions in tumour biology.

Trafficking of activated lymphocytes into the RENCA tumour microcirculation in vivo in mice

“…The model used in these studies is in vivo microscopy of the mouse cremaster preparation (Brown and Reed, 1997), modified from the original technique described in the rat (Baez, 1973). We have observed the selective recruitment and localization of IL-2-activated splenocytes into the tumour microcirculation, and established the potential of this model for defining further effector cell, tumour endothelial interactions.…”

“…Another thermistor was placed between the animal and the warming pad to prevent over-heating. The cremaster muscle, with intact neurovascular supply was prepared for in vivo microscopy, as described in detail in a previous publication (Brown and Reed, 1997).…”

“…The technique of in vivo microscopy permits dynamic visualization of fluorescently labelled effector cells (Brown and Reed, 1997;Sasaki et al, 1991). Cells can be visualized moving through the microcirculation, migrating across the endothelium and basement membrane and localizing within the tumour.…”

Trafficking of tumor peptide‐specific cytotoxic T lymphocytes into the tumor microcirculation

“…Lymphocytes entering the microcirculation of the normal cremaster muscle or the CT26 tumors were subdivided into 3 categories as previously described: 16 no contact with the vessel wall, i.e., flying; adherent to but moving along the vessel wall, i.e., rolling; adherent and stationary within the vessel for more than 30 sec, i.e., adherent.…”

“…Cells adhered within the first 5 min reached a maximum at 60 min [tumor vs. normal 20 (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24) vs. 1 (1-2)] and were elevated for the duration of the study period. Neither population adhered to the endothelium of the normal microcirculation.…”