Effect of cancer and LM-OVA infection on coinhibitory receptor expression.

Abstract

<p>A) Data presented is following selection of the CD8⁺Thy1.1⁺ T cell population. CD8⁺Thy1.1⁺ T cells in cancer group had increased mean frequencies of BTLA⁺ T cells. They were 8.58±1.07% in control vs. 20.72±5.58% in cancer mice following infection (*p<0.05; n = 8–10) at day 5. Mean frequencies of 2B4 (n = 4–5) and PD-1 (n = 8–10) had a trend toward increased expression in the cancer group, but were not statistically significant. B) In the absence of infection (day 0), the control and cancer groups did not have any significant differences in the expression or co-expression of 2B4, BTLA, and PD-1 on CD4⁺ T cells. At day 5, however, CD4⁺ T cells in the cancer group expressed a higher frequency of BTLA (4.03±0.46 vs. 6.77±0.59) and 2B4 (2.67±0.22 vs. 3.95±0.25). The inhibitory profile was further altered when looking at co-expression. The cancer group had higher expression of PD-1⁺BTLA⁺ (3.76±0.47 vs. 5.65±0.42) and 2B4⁺PD-1⁺ (2.50±0.23 vs. 3.76±0.26) CD4⁺ T cells. Following resolution of infection at day 14, the expression of 2B4 (n = 4–5), 2B4⁺PD-1⁺ (n = 4–5), or PD-1 was no longer different in both groups, however, the frequency of expression CD4⁺ PD-1⁺BTLA⁺ T cells remained elevated in the cancer group (3.99±0.44 vs. 5.56±0.48). **p<0.01; *p<0.05; n = 8–10 at days 0, 5, and 14, unless otherwise stated. C) At baseline (day 0), cancer mice had reduced expression of CD8⁺PD-1⁺ T cells compared to control mice (14.03±0.61 in control vs. 11.91±0.47 in cancer). However, expression of 2B4, BTLA, 2B4⁺PD-1⁺ or PD-1⁺BTLA⁺ was unchanged prior to infection. At day 5 following infection, cancer mice had increased frequencies of expression of CD8⁺BTLA⁺ (8.78±0.95 vs. 13.66±0.64) and CD8⁺PD-1⁺BTLA⁺ (6.55±0.83 vs. 9.22±0.47) T cells. Following resolution of infection at day 14, only the mean frequency of BTLA expression in the cancer group remained elevated (6.72±1.40 vs. 8.76±2.03); **p<0.01; *p<0.05; n = 8–10.</p