1 [8]. This reporter line was used to screen newly generated mouse-human hybrid antigen-presenting cell lines
for their capacity to www.selleckchem.com/products/Imatinib-Mesylate.html activate the reporter line in presence of the PAg HMBPP and the PAg-inducing agent zoledronate or the alkylamine sec-butylamine. Mouse-human hybrids are known to successively lose human chromosomes over time in culture. To identify those human chromosome(s) mandatory for PAg presentation, hybrid cells were cloned and tested for induction of reporter cell stimulation in the presence of 1 nM HMBPP. PCR karyotyping showed that loss of human chromosomes 2, 3, 7, 8, 9, 10, 11, 13, 17, 18, 20, 21, and X had no effect on PAg-mediated activation of the reporter cells, while cells without Chr6 failed to induce activation of the reporter cells in the presence of HMBPP or zoledronate. For
reasons so far unknown, 2 of 6 of the Chr6-bearing hybridoma cell lines stimulate the reporter cells in the presence of HMBPP and zoledronate but not in the presence of 2 mM sec-butylamine. This loss of the capacity to stimulate in presence of alkylamine did not correlate with loss of distinct human chromosomes. To test whether Chr6 alone would be sufficient for HMBPP-induced reporter cell activation, we tested Chinese hamster ovary cells monosomal for human Chr6 (CHO Chr6 cells) as presenters. We compared their responses to HMBPP, zoledronate, sec-butylamine or mAb 20.1 using CHO cells, CHO cells transduced with BTN3A1 and CHO Chr6 cells with or without transduced BTN3A1 as antigen-presenting cells. Figure 1 shows that the reporter cells responded selleck screening library to zoledronate and HMBPP in the presence of CHO Chr6 cells. This is in full agreement with the reported requirement of Chr6 for PAg presentation [12]. As previously reported for human cells as PAg-presenters [8, 9, 12], BTN3A1 transduction increased PAg-induced stimulation but only for CHO Chr6 cells (CHO Chr6 BTN3A1). Importantly, CHO cells expressing only the PAg-presenting BTN3A1 molecule (CHO BTN3A1) but lacking Chr6 activated neither in the presence of HMBPP nor zoledronate (Fig. 1A and B). Figure 1C shows that, in the presence of mAb 20.1, CHO Chr6 BTN3A1
cells Selleckchem Ribociclib and even more strikingly CHO BTN3A1 cells massively stimulated the reporter cells. In contrast to our study, Vavassorri et al. [12] showed no data on whether BTN3A1 would be sufficient to render murine cells PAg presenters and Harly et al. [8] only mentioned as an “unpublished observation” that BTN3A1-transduced mouse cells fail to present PAg. However, such a negative result is difficult to interpret unless a suitable positive control is provided. Indeed, it is conceivable that Vγ9Vδ2 T cell-mediated activation requires additional features, e.g. the expression of certain co-stimulatory molecules. Therefore it is important that BTN3A1-transduced CHO and BTN3A1-transduced CHO Chr6 cells induce a strong response to mAb 20.