CD4 and infection: A significant loss of jejunum CD4+ T cells was detected in infected RMs where CD4+ population decreased more than 6-fold during acute infection and remained low during chronic infection (Table 1 and Figure 9A). In summary, there was a significant decrease in CD4+ T cell population during acute (mean ± SE: 11.5 ± 1.8%; p < 0.0001) and chronic (1.4 ± 0.6%; p < 0.0001) compared to pre infection (45.2 ± 2.3%) (Figure 9B).