Figure 3. PARP inhibition modulates macrophage phenotype.
a-g, Mice bearing BRCA-deficient TNBC tumors were treated with either vehicle or 50 mg kg−1 of Olaparib. Tumors were harvested and immunophenotyping was performed by flow cytometry. a, Following Olaparib therapy, there was an increase in macrophages (CD45+F480+) that express co-stimulatory (CD80) and activation (CD40) markers. b, The CD80+CD86+ and CD40+ populations were significantly increased in both the CD206 positive and negative macrophage populations. c, The anti-tumor to pro-tumor macrophage ratio was increased after Olaparib treatment. d, pTBK1 was increased in macrophages (F480+) and mature macrophages (F480+MHCII+) in tumors of Olaparib-treated mice. e, The proportion of PD-L1+ macrophages (PD-L1+F480+) and tumor cells (CD45(neg)) increased following Olaparib treatment, as did CSF-1R expression on macrophages (F480+CSF-1R+ (f)) including an increase in the double positive population of (PD-L1+CSF-1R+) (g). Error bars represent standard error of mean (±SEM). Statistical analyses were performed using two tailed t-test with n=5 mice per group. h-p, CD14+ cells were isolated from healthy human donors and differentiated to mature myeloid cells with either IL-4 plus GM-CSF (h-n) or M-CSF (o,p) in the presence or absence of Olaparib for 5 days, and analysis was performed by flow cytometry. Shown are changes in h, CD14+ cells, i, CD163, j, CD80 and CD86 on different myeloid populations. The same flow plots are used for k and l; highlighted quadrants in each figure are plotted. m-n, Olaparib increased the expression of pTBK1 and PD-L1 on CD11b+ myeloid cells. o-p, M-CSF differentiated macrophages treated with Olaparib increased expression of CSF-1R and CD206+. Error bars represent standard error of mean (±SEM). Statistical analyses were performed using two tailed t-test with n=4 healthy human donors. Exact p values indicated in each panel for each comparison.