Mast cell lineage diversion of T lineage precursors by the essential T cell transcription factor GATA-3

GATA-3 is essential for T cell development from the earliest stages. However, abundant GATA-3 can drive T lineage precursors to a non–T cell fate, depending on Notch signaling and developmental stage. Here, overexpression of GATA-3 blocked the survival of pro–T cells when Notch-Delta signals were present but enhanced viability in their absence. In fetal thymocytes at the double-negative 1 (DN1) stage and DN2 stage but not those at the DN3 stage, overexpression of GATA-3 rapidly induced respecification to the mast cell lineage with high frequency by direct transcriptional 'reprogramming'. Normal DN2 thymocytes also showed mast cell potential when interleukin 3 and stem cell factor were added in the absence of Notch signaling. Our results suggest a close relationship between the pro–T cell and mast cell programs and a previously unknown function for Notch in T lineage fidelity

Twist-2 Controls Myeloid Lineage Development and Function

Basic helix-loop-helix (bHLH) transcription factors play critical roles in lymphoid and erythroid development; however, little is known about their role in myeloid lineage development. In this study, we identify the bHLH transcription factor Twist-2 as a key negative regulator of myeloid lineage development, as manifested by marked increases in mature myeloid populations of macrophages, neutrophils, and basophils in Twist-2–deficient mice. Mechanistic studies demonstrate that Twist-2 inhibits the proliferation as well as differentiation of granulocyte macrophage progenitors (GMP) by interacting with and inhibiting the transcription factors Runx1 and C/EBPα. Moreover, Twist-2 was found to have a contrasting effect on cytokine production: inhibiting the production of proinflammatory cytokines such as interleukin-12 (IL-12) and interferon-γ (IFNγ) while promoting the regulatory cytokine IL-10 by myeloid cells. The data from further analyses suggest that Twist-2 activates the transcription factor c-Maf, leading to IL-10 expression. In addition, Twist-2 was found to be essential for endotoxin tolerance. Thus, this study reveals the critical role of Twist-2 in regulating the development of myeloid lineages, as well as the function and inflammatory responses of mature myeloid cells

Stochastic Cytokine Expression Induces Mixed T Helper Cell States

During eukaryotic development, the induction of a lineage-specific transcription factor typically drives differentiation of multipotent progenitor cells, while repressing that of alternative lineages. This process is often mediated by some extracellular signaling molecules, such as cytokines that can bind to cell surface receptors, leading to activation and/or repression of transcription factors. We explored the early differentiation of naive CD4 T helper (Th) cells into Th1 versus Th2 states by counting single transcripts and quantifying immunofluorescence in individual cells. Contrary to mutually exclusive expression of antagonistic transcription factors, we observed their ubiquitous co-expression in individual cells at high levels that are distinct from basal-level co-expression during lineage priming. We observed that cytokines are expressed only in a small subpopulation of cells, independent from the expression of transcription factors in these single cells. This cell-to-cell variation in the cytokine expression during the early phase of T helper cell differentiation is significantly larger than in the fully differentiated state. Upon inhibition of cytokine signaling, we observed the classic mutual exclusion of antagonistic transcription factors, thus revealing a weak intracellular network otherwise overruled by the strong signals that emanate from extracellular cytokines. These results suggest that during the early differentiation process CD4 T cells acquire a mixed Th1/Th2 state, instructed by extracellular cytokines. The interplay between extracellular and intracellular signaling components unveiled in Th1/Th2 differentiation may be a common strategy for mammalian cells to buffer against noisy cytokine expression.National Cancer Institute (U.S.). Physical Sciences-Oncology Center (U54CA143874)National Institutes of Health (U.S.) (Pioneer Award)National Institutes of Health (U.S.) (Grant R01-GM068957

Identification of Nine Novel Loci Associated with White Blood Cell Subtypes in a Japanese Population

White blood cells (WBCs) mediate immune systems and consist of various subtypes with distinct roles. Elucidation of the mechanism that regulates the counts of the WBC subtypes would provide useful insights into both the etiology of the immune system and disease pathogenesis. In this study, we report results of genome-wide association studies (GWAS) and a replication study for the counts of the 5 main WBC subtypes (neutrophils, lymphocytes, monocytes, basophils, and eosinophils) using 14,792 Japanese subjects enrolled in the BioBank Japan Project. We identified 12 significantly associated loci that satisfied the genome-wide significance threshold of P<5.0×10−8, of which 9 loci were novel (the CDK6 locus for the neutrophil count; the ITGA4, MLZE, STXBP6 loci, and the MHC region for the monocyte count; the SLC45A3-NUCKS1, GATA2, NAALAD2, ERG loci for the basophil count). We further evaluated associations in the identified loci using 15,600 subjects from Caucasian populations. These WBC subtype-related loci demonstrated a variety of patterns of pleiotropic associations within the WBC subtypes, or with total WBC count, platelet count, or red blood cell-related traits (n = 30,454), which suggests unique and common functional roles of these loci in the processes of hematopoiesis. This study should contribute to the understanding of the genetic backgrounds of the WBC subtypes and hematological traits

Uporaba kemometrije za razvoj i validaciju RP-HPLC metode za simultano određivanje haloperidola i srodnih spojeva

A rapid resolution reversed-phase high performance liquid chromatographic (RR RP-HPLC) method has been developed and validated for simultaneous determination of haloperidol and six related compounds. Investigated matrix was a laboratory mixture of the therapeutic active substance haloperidol and its six related compounds in a concentration ratio 300:1. Experimental design was used during method optimization (full factorial 23 design) and robustness testing (Central Composite Circumscribed design). Three factors: organic phase variation during gradient elution, flow rate and gradient rise time were independent variables. To estimate the system response during the optimization procedure and robustness testing, resolution (Rs) and a chromatographic response function (CRF) were used. Chromatography was performed with the mobile phase containing phosphate buffer pH 6.5 and acetonitrile as organic modifier. Separation was achieved using gradient elution (organic phase fraction changed linearly from 20 to 72%) over 7 min. A Zorbax Eclipse XDB C18 Rapid Resolution HT 4.6 mm × 50 mm, 1.8 μm particle size, column was used at 25 °C at a flow rate of 1.5 mL min−1. UV detection was performed at 230 nm. The total time for chromatographic separation was 5.5 min with a total analysis time of 7.0 min. The method was validated for its linearity, precision, modal recovery and robustness.Razvijena je i validirana metoda reverzno-fazne tekućinske kromatografije visoke učinkovitosti i brze rezolucije (RR RP-HPLC) za simultano određivanje haloperidola i srodnih spojeva. U tu svrhu ispitivana je smjesa ljekovite tvari haloperidola i šest srodnih spojeva u omjeru 300:1. Za optimiranje metode korišten je eksperimentalni dizajn (23 faktorijalni dizajn) i testiranje robustnosti (Central Composite Circumscribed design). Tri faktora: variranje organske faze za eluaciju, brzina protoka i vrijeme uspostave gradijenta eluensa bile su nezavisne varijable. Za procjenu odgovora sustava za vrijeme optimizacije i testiranje robustnosti, korištene su rrazlučivanje (Rs) i funkcija kromatografskog odziva (CRF). Mobilna faza tijekom kromatografije bila je fosfatni pufer pH 6,5 i acetonitril kao organska faza. Razdvajanje je postignuto pomoću gradijenta eluacije (udio organske faze linearno se mijenjao od 20 do 72%) tijekom 7 min. Za rad je upotrebljena kolona Zorbax Eclipse XDB C18 Rapid Resolution HT kolona, dimenzije 4,6 mm × 50 mm, veličine čestica 1,8 μm. Kromatografija je provedena pri 25 °C, uz protok eluensa 1,5 mL min−1 i UV detekciju na 230 nm. Vrijeme kromatografskog razdvajanja bilo je 5,5 min, a ukupno vrijeme potrebno za kromatografiju 7,0 min. Metoda je u potpunosti validirana