Associations between NK Cells in Different Immune Organs and Cellular SIV DNA and RNA in Regional HLADR- CD4+ T Cells in Chronically SIVmac239-Infected, Treatment-Naïve Rhesus Macaques.

With the development of NK cell-directed therapeutic strategies, the actual effect of NK cells on the cellular SIV DNA levels of the virus in SIV-infected macaques in vivo remains unclear. In this study, five chronically SIVmac239-infected, treatment-naïve rhesus macaques were euthanized, and the blood, spleen, pararectal/paracolonic lymph nodes (PaLNs), and axillary lymph nodes (ALNs) were collected. The distributional, phenotypic, and functional profiles of NK cells were detected by flow cytometry. The highest frequency of NK cells was found in PBMC, followed by the spleen, while only 0~0.5% were found in LNs. Peripheral NK cells also exhibited higher cytotoxic potential (CD56- CD16+ NK subsets) and IFN-γ-producing capacity but low PD-1 and Tim-3 levels than those in the spleen and LNs. Our results demonstrated a significant positive correlation between the frequency of NK cells and the ratios of cellular SIV DNA/RNA in HLADR- CD4+ T cells (r = 0.6806, p < 0.001) in SIV-infected macaques, despite no discrepancies in the cellular SIV DNA or RNA levels that were found among the blood, spleen, and LNs. These findings showed a profile of NK cell frequencies and NK cytotoxicity levels in different immune organs from chronically SIVmac239-infected, treatment-naïve rhesus macaques. It was suggested that NK cell frequencies could be closely related to SIV DNA/RNA levels, which could affect the transcriptional activity of SIV proviruses. However, the cytotoxicity effect of NK cells on the latent SIV viral load in LNs could be limited due to the sparse abundance of NK cells in LNs. The development of NK cell-directed treatment approaches aiming for HIV clearance remains challenging.

Application of single-cell real-time imaging flow cytometry in rapid detection of pathogenic fungi in clinical liquid specimens.

Rapid and direct observation of fungal spores or hyphae in clinical liquid specimens poses a challenge for the diagnosis of invasive fungal infection. To allow rapid detection of fungal pathogens, we designed a new method of fungal cell detection involving double fluorescence staining with calcium fluorescent white (CFW) and SYTOX green combined with single-cell real-time imaging flow cytometry (IFC). IFC allowed quick detection and analysis of detailed morphology of the spores and pseudohyphae of Candida albicans, and small hyphae and typical truncated large mycelia of Aspergillus fumigatus. Further, cell sorting based on fluorescence, the width-to-height ratio and bright-field parameters preferentially identified spores or hyphae with a typical cell wall. The specificity and overall coincidence rate of IFC for fungi detection in common clinical samples were 100% and 98.18%, respectively. Moreover, the detection rate by IFC (102/105, 97.14%) was significantly higher (P = 0.002) than that by wet mount method (89/105, 84.5%). Therefore, IFC is a reliable diagnostic method with a high potential for application for rapid diagnosis of fungal infection in the clinic.

HCV coinfection aggravated the decrease of platelet counts, but not mean platelet volume in chronic HIV-infected patients.

Either HIV or HCV monoinfection could result in an abnormal status of platelets. As two key indicators reflecting activation and function of platelets, the changes of platelet counts and mean platelet volume (MPV) in HIV/HCV-coinfected patients have not been clearly identified. In the present study, a total of 318 former plasma donors were investigated in 2006, and 66% (201 individuals) of primary recruiters were followed up in 2014. By horizontal comparison in 2006, the decrease of platelet counts in HIV/HCV coinfection was greater than that in HIV or HCV monoinfection. MPV scores were lower in HIV monoinfection compared with healthy controls, while no difference was found in HIV/HCV coinfection. Platelet counts were shown to be negatively correlated with MPV scores in total recruited population (r = 0.432, P < 0.001). Interestingly, by comparison of data from two time points of 2006 and 2014, significant decrease of platelets (P = 0.004) and increase of MPV (P = 0.004) were found only in HCV monoinfected patients, which may associate with slow progression of hepatic fibrosis induced by chronic HCV infection. Nonetheless, no significant changes of platelet counts and MPV were found from 2006 to 2014 in coinfected patients. In conclusion, HCV coinfection aggravated the decrease of platelet counts, but not MPV score in chronic HIV infection. MPV showed poor applicability in reflecting the status of platelets in HIV/HCV-coinfected patients.