, 2000, Bull et al., 2007 and Reimann et al., 2000). Bull et al. (2007) showed that reducing the time taken from venipuncture to PBMC isolation has important effects on T cell viability, recovery and cytokine function after cryopreservation. There have been no such studies for isolation of cytobrush-derived PS-341 chemical structure T cells from the female genital tract. We found that approximately 50% of the cervical T cells could be recovered after cryopreservation, but that thawed cells were comparable in viability

to those processed immediately. The most likely explanation for the cell loss following cryopreservation was the initial composition and viability of the cytobrush sample. Cervical cytobrush processing typically yield few CD3+ T cells, and large frequencies of isolated cells express markers of apoptosis such as CD95 (Liebenberg et al., 2010). These apoptotic cells have compromised cell membranes and

would therefore be more susceptible to cell injury by the formation of intracellular and extracellular ice than healthy cells with stronger, intact membranes. In addition, these thawed cervical T cells from HIV-infected women were found to rapidly express apoptotic markers Annexin V and PI indicating that recovered cells were unlikely to be useful for subsequent functional analysis. Although the recovered low cell yields would not support subsequent functional studies, we show that Etofibrate ~ 50% of cryo-preserved samples could be polyclonally expanded to improve T cell yields. Given that ex vivo yields were relatively AZD4547 cost low and cryopreservation further reduced this by approximately half, the potential bottleneck in T cell clonality imposed by these sampling and storage issues restricts the usefulness of this approach. We show that the number of CD3+ T cells isolated from cytobrushing

and captured by flow cytometry predicts the frequency of IFN-γ responses following PMA/Ionomycin (positive control) and that cytobrush samples which fail to respond to the positive control generally have CD3 counts < 100 events. We describe here a useful tool based on ex vivo CD3 counts for predicting of whether cytobrush samples will pass or fail the assay positive control. Based on this cut-off, however, approximately half of the 98 cervical samples from HIV-infected women were adequate for use in further analysis. IFN-γ production in response to stimulation with mitogens PMA/Ionomycin and PHA as well as with viral antigen peptide pool CEF was assessed ex vivo and following delayed processing. Similar to lymphocyte recovery and viability over time, the ability of cervical T cells to produce IFN-γ following PMA/Ionomycin and PHA stimulation was similar in ex vivo experiments and following delayed processing.