Culturing of human peripheral blood cells reveals unsuspected lymphocyte responses relevant to HIV disease

Recombinant HIV-Tat (Tat) induces extensive apoptosis in peripheral blood mononuclear cells (PBMCs) cultured in typical CO2 incubators, which are equilibrated with air (21% O2). However, as we show here, Tat apoptosis induction fails in PBMCs cultured at physiological oxygen levels (5% O2). Under these conditions, Tat induces PBMCs to divide, efficiently primes them for HIV infection, and supports virus production by the infected cells. Furthermore, Tat takes only 2 h to prime PBMCs under these conditions. In contrast, PHA/IL-2, which is widely used to prime cells for HIV infection, takes 2–3 days. These findings strongly recommend culturing primary cells at physiological oxygen levels. In addition, they suggest HIV-Tat as a key regulator of HIV disease progression

Correlation matrix for the different T cell subpopulations in cord blood, spearman correlation coefficients and p-values are presented, correlations with p<0.05 denoted in bold.

<p>Correlation matrix for the different T cell subpopulations in cord blood, spearman correlation coefficients and p-values are presented, correlations with p<0.05 denoted in bold.</p

Selected characteristics of the New Hampshire Birth Cohort Study participants included in the present study (n = 63^*).

<p>Selected characteristics of the New Hampshire Birth Cohort Study participants included in the present study (n = 63^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179606#t001fn002" target="_blank">*</a>}).</p

Associations¹ between maternal arsenic concentrations in postpartum toenail and immune cell subpopulations (n = 57^*).

<p>Statistically significant associations are denoted in bold font. The beta values are the percent of changes in the relative immune cell numbers per doubling of arsenic exposure.</p

Associations¹ between maternal cadmium concentrations in postpartum toenail and immune cell subpopulations (n = 57^*).

<p>Statistically significant associations are denoted in bold font. The beta values are the percent of changes in the relative immune cell numbers per doubling of cadmium exposure.</p

Cord blood T cell subpopulations and associations with maternal cadmium and arsenic exposures

<div><p>Background</p><p>Arsenic and cadmium are environmental pollutants, and although the evidence for adverse immune effects after prenatal arsenic and cadmium exposures is increasing, little is known about the underlying immunological mechanisms.</p><p>Methods</p><p>We investigated the relationship between prenatal arsenic and cadmium exposures and a variety of T cell subpopulations measured in cord blood for 63 participants in the New Hampshire Birth Cohort Study. Post-partum toenail concentrations of arsenic and cadmium were used as an estimate of maternal exposure during pregnancy. The characteristics of cord blood proportions of T lymphocytes and subpopulations (expression of markers for Th1, Th2, Th17, Th1Th17, induced and natural regulatory T cells and NKTs) are presented.</p><p>Results</p><p>In regression analyses, maternal arsenic exposure levels were inversely associated with cord blood T helper memory cells (-21%, 95% CI: -36%, -3%) and the association was found to be stronger in females. They were also inversely associated with activated T helper memory cells, particularly in males (-26%, 95% CI: -43%, -3%). Similarly, inverse associations were observed between cadmium exposure levels and activated T helper memory cells (-16%, 95% CI: -30%, -1%) and also for T helper memory cells in females (-20%, 95% CI: -35%, -3%).</p><p>Conclusion</p><p>The results suggest that prenatal exposures to relatively low levels of arsenic and cadmium may contribute to altered distribution of T cell populations at birth. These changes in theory, could have contributed to the previously reported immunosuppressive effects observed later in infancy/childhood.</p></div

Relative amounts of selected immune cell populations in cord blood samples collected at birth (n = 63^*).

<p>Relative amounts of selected immune cell populations in cord blood samples collected at birth (n = 63^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179606#t003fn001" target="_blank">*</a>}).</p

Molecular Imaging of Chimeric Antigen Receptor T Cells by ICOS-ImmunoPET

Purpose: Immunomonitoring of chimeric antigen receptor (CAR) T cells relies primarily on their quantification in the peripheral blood, which inadequately quantifies their biodistribution and activation status in the tissues. Noninvasive molecular imaging of CAR T cells by PET is a promising approach with the ability to provide spatial, temporal, and functional information. Reported strategies rely on the incorporation of reporter transgenes or ex vivo biolabeling, significantly limiting the application of CAR T-cell molecular imaging. In this study, we assessed the ability of antibody-based PET (immunoPET) to noninvasively visualize CAR T cells. Experimental design: After analyzing human CAR T cells in vitro and ex vivo from patient samples to identify candidate targets for immunoPET, we employed a syngeneic, orthotopic murine tumor model of lymphoma to assess the feasibility of in vivo tracking of CAR T cells by immunoPET using the 89Zr-DFO-anti-ICOS tracer, which we have previously reported. Results: Analysis of human CD19-CAR T cells during activation identified the Inducible T-cell COStimulator (ICOS) as a potential target for immunoPET. In a preclinical tumor model, 89Zr-DFO-ICOS mAb PET-CT imaging detected significantly higher signal in specific bone marrow-containing skeletal sites of CAR T-cell-treated mice compared with controls. Importantly, administration of ICOS-targeting antibodies at tracer doses did not interfere with CAR T-cell persistence and function. Conclusions: This study highlights the potential of ICOS-immunoPET imaging for monitoring of CAR T-cell therapy, a strategy readily applicable to both commercially available and investigational CAR T cells.See related commentary by Volpe et al., p. 911.</p