Natural killer cell activity in a population of leukemia‐prone wild mice (mus musculus)

Abstract

Natural cell-mediated cytotoxicity against YAC-I targets was measured in splenocytes from leukemia-prone wild mice trapped near Lake Casitas (LC) in southern California. Cytotoxicity was mediated by cells that were non-adherent to nylon wool, non-phagocytic and resistant to thy-1.2 antiserum plus complement. Natural MuLV viremia in LC mice did not impair splenic cytotoxicity against TAC-I target cells, Cells infected with amphotropic and ecotropic MuLV of wild mouse origin were not appreciably lysed by LC splenic effectors. Although variable levels of cytotoxicity were detected against TAC-1 by normal spleen cells, consistently low levels of cytotoxicity against allogenic LC lymphoma, sarcoma and carcinoma targets were found using the same splenocytes. These results indicate that LC mice possess splenocytes with the characteristics of natural killer (NK) cells as defined in inbred mice. The resistance of LC-derived targets to lysis by LC NK cells suggests that NK cells may not be involved in natural tumor immunosurveillance or that the development of spontaneous tumors may involve escape from NK-mediated effector mechanisms.

Macrophage and Lymphocyte Antibody-Dependent Cellular Cytotoxicity in Spontaneous Leukemogenesis of AKR/J Mice

“…Although cytotox icity mediated by NK has been widely con sidered to be the better arm of defense against neoplasia [14], this has been ques tioned lately [ 15], The possibility that spon taneous tumors, like the one used here, can escape NK mechanisms [16] encouraged us to use ADCC in our model. Moreover, ADCC has a high discriminating power and is more sensitive [8],…”

Natural killer cells in free-living Mus musculus have a primed phenotype

“…2011). Otherwise, little is known about NK cells of feral mice; although NK cells of traditional laboratory mouse strains have occasionally been compared to outbred wild‐derived strains (Scott et al. 1981; Scalzo et al.…”

“…2005), these were usually merely offspring of wild specimens, born and housed under SPF or similar hygienic conditions, thus only revealing genetic influences. However, in one of these studies, NK cells in feral mice were indeed also tested immediately after capture, apparently showing stronger cytotoxic capacity than in mice housed hygienically for long periods (Scott et al. 1981).…”

“…A generally more activated immune status in terms of antibody responses and cellular immunity has been observed in such feral mice, although spleen NK cell levels were equal to C57BL ⁄ 6 mice (Abolins et al 2011). Otherwise, little is known about NK cells of feral mice; although NK cells of traditional laboratory mouse strains have occasionally been compared to outbred wild-derived strains (Scott et al 1981;Scalzo et al 2005), these were usually merely offspring of wild specimens, born and housed under SPF or similar hygienic conditions, thus only revealing genetic influences. However, in one of these studies, NK cells in feral mice were indeed also tested immediately after capture, apparently showing stronger cytotoxic capacity than in mice housed hygienically for long periods (Scott et al 1981).…”

“…Otherwise, little is known about NK cells of feral mice; although NK cells of traditional laboratory mouse strains have occasionally been compared to outbred wild-derived strains (Scott et al 1981;Scalzo et al 2005), these were usually merely offspring of wild specimens, born and housed under SPF or similar hygienic conditions, thus only revealing genetic influences. However, in one of these studies, NK cells in feral mice were indeed also tested immediately after capture, apparently showing stronger cytotoxic capacity than in mice housed hygienically for long periods (Scott et al 1981). In the present study, we show that NK cells of mice captured in their natural habitat (hereafter 'feral') have an activated phenotype and respond rapidly to cytokine stimulation, indicating that these mice harbour a primed type of NK cells, unlike the commonly used C57BL ⁄ 6 (hereafter 'lab') mice.…”