Using Rapid-Cycle Change to Improve COVID-19 Vaccination Strategy in Primary Care.

During the COVID-19 pandemic, misinformation and distrust exacerbated disparities in vaccination rates by race and ethnicity throughout the United States. Primary care, public health systems, and community health centers have shifted their vaccination outreach strategies toward these disparate, unvaccinated populations. To support primary care, we developed the SAVE Sprint model for implementing rapid-cycle change to improve vaccination rates by overcoming community outreach barriers and workforce limitations. Participants were recruited for the 10-week SAVE Sprint program through partnerships with the National Association of Community Health Centers (NACHC) and the Resilient American Communities (RAC) Initiative. The majority of the participants were from community health centers. Data were evaluated during the program through progress reports and surveys, and interviews conducted three months post-intervention were recorded, coded, and analyzed. The SAVE Sprint model of rapid-cycle change exceeded participants' expectations and led to improvements in patient education and vaccination among their vulnerable populations. Participants reported building new skills and identifying strategies for targeting specific populations during a public health emergency. However, participants reported that planning for rapid-pace change and trust-building with community partners prior to a health care crisis is preferable and would make navigating an emergency easier.

PLZF Acetylation Levels Regulate NKT Cell Differentiation.

The transcription factor promyelocytic leukemia zinc finger (PLZF) is encoded by the BTB domain-containing 16 (Zbtb16) gene. Its repressor function regulates specific transcriptional programs. During the development of invariant NKT cells, PLZF is expressed and directs their effector program, but the detailed mechanisms underlying PLZF regulation of multistage NKT cell developmental program are not well understood. This study investigated the role of acetylation-induced PLZF activation on NKT cell development by analyzing mice expressing a mutant form of PLZF mimicking constitutive acetylation (PLZFON) mice. NKT populations in PLZFON mice were reduced in proportion and numbers of cells, and the cells present were blocked at the transition from developmental stage 1 to stage 2. NKT cell subset differentiation was also altered, with T-bet+ NKT1 and RORγt+ NKT17 subsets dramatically reduced and the emergence of a T-bet-RORγt- NKT cell subset with features of cells in early developmental stages rather than mature NKT2 cells. Preliminary analysis of DNA methylation patterns suggested that activated PLZF acts on the DNA methylation signature to regulate NKT cells' entry into the early stages of development while repressing maturation. In wild-type NKT cells, deacetylation of PLZF is possible, allowing subsequent NKT cell differentiation. Interestingly, development of other innate lymphoid and myeloid cells that are dependent on PLZF for their generation is not altered in PLZFON mice, highlighting lineage-specific regulation. Overall, we propose that specific epigenetic control of PLZF through acetylation levels is required to regulate normal NKT cell differentiation.

Characterization of the developmental landscape of murine RORγt+ iNKT cells.

Invariant natural killer T (iNKT) cells expressing the retinoic acid receptor-related orphan receptor γt (RORγt) and producing IL-17 represent a minor subset of CD1d-restricted iNKT cells (iNKT17) in C57BL/6J (B6) mice. We aimed in this study to define the reasons for their low distribution and the sequence of events accompanying their normal thymic development. We found that RORγt+ iNKT cells have higher proliferation potential and a greater propensity to apoptosis than RORγt- iNKT cells. These cells do not likely reside in the thymus indicating that thymus emigration, and higher apoptosis potential, could contribute to RORγt+ iNKT cell reduced thymic distribution. Ontogeny studies suggest that mature HSAlow RORγt+ iNKT cells might develop through developmental stages defined by a differential expression of CCR6 and CD138 during which RORγt expression and IL-17 production capabilities are progressively acquired. Finally, we found that RORγt+ iNKT cells perceive a strong TCR signal that could contribute to their entry into a specific 'Th17 like' developmental program influencing their survival and migration. Overall, our study proposes a hypothetical thymic developmental sequence for iNKT17 cells, which could be of great use to study molecular mechanisms regulating this developmental program.

TCR density in early iNKT cell precursors regulates agonist selection and subset differentiation in mice.

It is established that iNKT cells are a cell type that require strong TCR signal for their proper development and represent a model for thymic agonist selection. The nature of the signal perceived by iNKT cells promoting their specification is not well understood. To address this question, we analyzed iNKT cell development in relevant TCR Vα14-Jα18 alpha chain transgenic mice (Vα14Tg). In CD4-Vα14Tg mice, where the transgene is driven by CD4 promoter, we identified a block in iNKT cell development at early developmental stages due to a reduced expression of key transcription factors accompanied with a reduced TCR expression levels. This indicates that TCR signal strength control iNKT cell differentiation. Importantly, we found in WT mice that early precursors of iNKT cells express higher TCR levels compared to positively selected precursors of mainstream T cells showing that TCR levels could contribute to the strength of iNKT cell TCR signaling. Overall, our study highlights TCR signal strength associated with a higher TCR density as an important regulator of iNKT cell lineage specification.

STAT5 induces miR-21 expression in cutaneous T cell lymphoma.

In cutaneous T cell lymphomas (CTCL), miR-21 is aberrantly expressed in skin and peripheral blood and displays anti-apoptotic properties in malignant T cells. It is, however, unclear exactly which cells express miR-21 and what mechanisms regulate miR-21. Here, we demonstrate miR-21 expression in situ in both malignant and reactive lymphocytes as well as stromal cells. qRT-PCR analysis of 47 patients with mycosis fungoides (MF) and Sezary Syndrome (SS) confirmed an increased miR-21 expression that correlated with progressive disease. In cultured malignant T cells miR-21 expression was inhibited by Tofacitinib (CP-690550), a clinical-grade JAK3 inhibitor. Chromatin immunoprecipitation (ChIP) analysis showed direct binding of STAT5 to the miR-21 promoter. Cytokine starvation ex vivo triggered a decrease in miR-21 expression, whereas IL-2 induced an increased miR-21 expression in primary SS T cells and cultured cytokine-dependent SS cells (SeAx). siRNA-mediated depletion of STAT5 inhibited constitutive- and IL-2-induced miR-21 expression in cytokine-independent and dependent T cell lines, respectively. IL-15 and IL-2 were more potent than IL-21 in inducing miR-21 expression in the cytokine-dependent T cells. In conclusion, we provide first evidence that miR-21 is expressed in situ in CTCL skin lesions, induced by IL-2 and IL-15 cytokines, and is regulated by STAT5 in malignant T cells. Thus, our data provide novel evidence for a pathological role of IL-2Rg cytokines in promoting expression of the oncogenic miR-21 in CTCL.

Potential role of IL-17-producing iNKT cells in type 1 diabetes.

We explored in this study the status and potential role of IL-17-producing iNKT cells (iNKT17) in type 1 diabetes (T1D) by analyzing these cells in patients with T1D, and in NOD mice, a mouse model for T1D. Our analysis in mice showed an increase of iNKT17 cells in NOD vs control C57BL/6 mice, partly due to a better survival of these cells in the periphery. We also found a higher frequency of these cells in autoimmune-targeted organs with the occurrence of diabetes, suggesting their implication in the disease development. In humans, though absent in fresh PMBCs, iNKT17 cells are detected in vitro with a higher frequency in T1D patients compared to control subjects in the presence of the proinflammatory cytokine IL-1ß, known to contribute to diabetes occurrence. These IL-1ß-stimulated iNKT cells from T1D patients keep their potential to produce IFN-γ, a cytokine that drives islet ß-cell destruction, but not IL-4, with a reverse picture observed in healthy volunteers. On the whole, our results argue in favour of a potential role of IL-17-producing iNKT cells in T1D and suggest that inflammation in T1D patients could induce a Th1/Th17 cytokine secretion profile in iNKT cells promoting disease development.