Fig. 4

Neospora caninum infection induces Th1 cytokine production and increases infiltration of CD8⁺ T cells and macrophages into the tumor microenvironment. Twenty-one days after B16F10 cells inoculation, cytokine expression in tumors (a) and spleens (b) were detected by RT-PCR analysis. Graphs show fold change relative to control (mean ± SD; n = 5). CD8⁺ T cells (c) and macrophages (d) in the tumor microenvironment were stained with anti-CD8 and anti-CD68 (brownish yellow), respectively; the nuclei (blue) were stained with hematoxylin. The top row shows the entire tumor area; the bottom row shows enlargement of a section of the tumor bed; bars = 1000 μm and 50 μm, respectively. The graph shows the quantitative analysis of CD8⁺ and CD68⁺ cells (mean ± SD; n = 5). Data were analyzed by the two-tailed Student t-test (a–d). *P < 0.05, **P < 0.01, ***P < 0.001. Abbreviations: normal, blank control group