CEF-specific responses were rarely observed in the female genital tract ex vivo, with dual PMA/Ionomycin- and CEF-specific responses detectable in the CD8+ and CD4+ T cell populations of only 2/18 and 1/18 women respectively ( Table 4). Interestingly, the odds of detecting a response to CEF was generally higher in cervical T cells subjected to delayed processing ( Table 2). Even so, the magnitudes of PMA/Ionomycin-specific IFN-γ responses were consistently higher than CEF-specific learn more responses in the cervical T cells ( Fig. 4). Despite the finding that delayed processing did not
reduce T cell responses to PMA/Ionomycin compared to cells processed immediately, the magnitude of IFN-γ responses to CEF by cells held at 37 °C for 24 h was significantly higher than cells processed immediately (p < 0.001 for CD8+ and CD4+ T cells; Fig. 4). This result was similar in the blood for CD8+
T cells (p = 0.04), and was observed as a trend in the CD4+ population (p = 0.08; data not shown). These observations suggest that cervical T cell responses to viral antigens may be best detected when samples are transported at 37 °C rather than at the other conditions tested. Epigenetics inhibitor It is widely accepted that understanding T cell-mediated immunity to HIV in the female genital tract is important in devising prevention strategies to combat the epidemic (Abdool Karim et al., 2010, Hasselrot, 2009, Hladik and McElrath, 2008 and Shattock et al., 2008). Despite the recognised importance of incorporating mucosal testing of HIV vaccine-induced responses, PIK-5 mucosal sampling typically yields few cells and most analyses that have been performed were carried out ex vivo in laboratories close to the clinics from which samples were obtained ( McElrath et al., 2008 and Karim et al., 2010). Since HIV vaccine efforts involve
clinical sites around the globe, it is important to thoroughly evaluate and understand the robustness of cellular responses from currently available mucosal samples and the feasibility of cryopreservation or delayed processing of such specimens. We and others have previously shown that cervical cytobrushing provides a useful means of obtaining mononuclear cells from the female genital tract for ex vivo measurement of HIV-specific T cell responses ( Cohen et al., 2010, Gumbi et al., 2008, Kaul et al., 2000, Kaul et al., 2003, Liebenberg et al., 2010, Musey et al., 2003, Nkwanyana et al., 2009, Quayle et al., 2007 and Shacklett et al., 2000). Here we have investigated whether cervical T cells, obtained by cytobrushing, could be subjected to delayed processing or cryopreservation without loss of cell number, viability or function. We found that cervical cytobrushes processed immediately yielded a median of 65 416 CD3+ T cells with a median viability of 99.95%. Neither CD3 T cell recovery nor viability was significantly different between cytobrushes subjected to a delayed processing compared to those processed immediately.