Abstract
Our bodies are constantly threatened with the invasion of pathogens, such as bacteria and virus. Immune responses against pathogens are evoked in collaboration with adaptive and innate ...immune systems. Adaptive immune cells including T and B cells recognize various antigens from pathogens through the antigen recognition receptors such as immunoglobulin (Ig) and T-cell receptor (TCR), and they evoke antigen-specific immune responses to eliminate the pathogens. This specific recognition of a variety of antigens relies on the V(D)J DNA recombination of Ig and TCR genes, which is generated by the Rag (recombination activation gene) 1/Rag2 protein complex. The expression of Rag1/2 genes is stringently controlled during the T and B cell development; Rag1/2 gene expression indicates the commitment towards adaptive lymphocyte lineages. In this review article, we will discuss the developmental bifurcation between adaptive and innate lymphoid cells, and the role of transcription factors, especially the E and Id proteins, upon the lineage commitment, and the regulation of Rag gene locus.
Cell type-specific gene expression is driven through the interplay between lineage-specific transcription factors (TFs) and the chromatin architecture, such as topologically associating domains ...(TADs), and enhancer-promoter interactions. To elucidate the molecular mechanisms of the cell fate decisions and cell type-specific functions, it is important to understand the interplay between chromatin architectures and TFs. Among enhancers, super-enhancers (SEs) play key roles in establishing cell identity. Adaptive immunity depends on the RAG-mediated assembly of antigen recognition receptors. Hence, regulation of the
and
(
) genes is a hallmark of adaptive lymphoid lineage commitment. Here, we review the current knowledge of 3D genome organization, SE formation, and
gene regulation during B cell and T cell differentiation.
Adaptive immunity relies on the V(D)J DNA recombination of immunoglobulin (Ig) and T cell receptor (TCR) genes, which enables the recognition of highly diverse antigens and the elicitation of ...antigen-specific immune responses. This process is mediated by recombination-activating gene (Rag) 1 and Rag2 (Rag1/2), whose expression is strictly controlled in a cell type-specific manner; the expression of Rag1/2 genes represents a hallmark of lymphoid lineage commitment. Although Rag genes are known to be evolutionally conserved among jawed vertebrates, how Rag genes are regulated by lineage-specific transcription factors (TFs) and how their regulatory system evolved among vertebrates have not been fully elucidated. Here, we reviewed the current body of knowledge concerning the cis-regulatory elements (CREs) of Rag genes and the evolution of the basic helix-loop-helix TF E protein regulating Rag gene CREs, as well as the evolution of the antagonist of this protein, the Id protein. This may help to understand how the adaptive immune system develops along with the evolution of responsible TFs and enhancers.
Immune responses are primarily mediated by adaptive and innate immune cells. Adaptive immune cells, such as T and B cells, evoke antigen-specific responses through the recognition of specific ...antigens. This antigen-specific recognition relies on the V(D)J recombination of immunoglobulin (
) and T cell receptor (
) genes mediated by recombination-activating gene (
)1 and
(
). In addition, T and B cells employ cell type-specific developmental pathways during their activation processes, and the regulation of these processes is strictly regulated by the transcription factor network. Among these factors, members of the basic helix-loop-helix (bHLH) transcription factor mammalian E protein family, including E12, E47, E2-2, and HEB, orchestrate multiple adaptive immune cell development, while their antagonists, Id proteins (Id1-4), function as negative regulators. It is well established that a majority of T and B cell developmental trajectories are regulated by the transcriptional balance between E and Id proteins (the E-Id axis). E2A is critically required not only for B cell but also for T cell lineage commitment, whereas Id2 and Id3 enforce the maintenance of naïve T cells and naïve regulatory T (Treg) cells. Here, we review the current knowledge of E- and Id-protein function in T cell lineage commitment and Treg cell differentiation.
Identification of sensitized allergens for patients with respiratory allergy is an important step in disease care and environmental allergen control. The Japanese archipelago belongs to various ...climate categories due to its length from north to south which transverse the subarctic in the north to the subtropical in the south, suggesting substantial regional differences in dominant environmental allergens. However, few studies have assessed the regional differences in the prevalence of sensitization to environmental allergens.
We requested three major clinical testing laboratories to provide us with summarized results of antigen-specific IgE-antibody (Ab) measurements. These measurements were collected for clinical purposes throughout Japan from 2002 through 2011. The prevalence of positivity for IgE-Ab against 19 environmental allergens was calculated for each prefecture in order to evaluate regional differences.
Test data on specific IgE-Ab of 19,969,753 orders were analyzed. The prevalence of positivity for house dust mites was high and the regional difference was low, whereas apparent regional differences were found for pollen, insects, and fungi. The prevalence of positivity for Japanese cedar was low in Hokkaido and Okinawa, while those to alder was highest in Hokkaido. Higher prevalence for insects was observed in southern areas (Okinawa and prefectures in Kyusyu).
Findings of this study clearly demonstrated regional differences in the prevalence of sensitization to environmental allergens in Japan and the study also provides useful information for the clinician when deciding which allergens should preferentially be measured for IgE-Ab after considering regional difference.
Classification of the prefectures according to the prevalence of sensitization to environmental allergens for Internal medicine/otolaryngology departments and pediatrics department. Display omitted
Innate and adaptive lymphoid development is orchestrated by the activities of E proteins and their antagonist Id proteins, but how these factors regulate early T cell progenitor (ETP) and innate ...lymphoid cell (ILC) development remains unclear. Using multiple genetic strategies, we demonstrated that E proteins E2A and HEB acted in synergy in the thymus to establish T cell identity and to suppress the aberrant development of ILCs, including ILC2s and lymphoid-tissue-inducer-like cells. E2A and HEB orchestrated T cell fate and suppressed the ILC transcription signature by activating the expression of genes associated with Notch receptors, T cell receptor (TCR) assembly, and TCR-mediated signaling. E2A and HEB acted in ETPs to establish and maintain a T-cell-lineage-specific enhancer repertoire, including regulatory elements associated with the Notch1, Rag1, and Rag2 loci. On the basis of these and previous observations, we propose that the E-Id protein axis specifies innate and adaptive lymphoid cell fate.
Display omitted
•E2A and HEB act in concert to specify T cell fate•E protein activity in lymphoid progenitors suppresses aberrant ILC development•E2A and HEB establish a T-lineage-specific program of gene expression•The E-Id protein axis specifies the adaptive and innate lymphoid cell fate
Previous studies established that E proteins act at multiple stages to promote T-cell-lineage development. Miyazaki et al. demonstrate that E proteins establish T cell identity and suppress the development of thymic ILCs by modulating enhancer repertoires of genes associated with Notch signaling and TCRβ locus assembly.
Tobacco is a major public health concern. A 12-week standard smoking cessation program is available in Japan; however, it requires face-to-face clinic visits, which has been one of the key obstacles ...to completing the program, leading to a low smoking cessation success rate. Telemedicine using internet-based video counseling instead of regular clinic visits could address this obstacle.
This study aimed to evaluate the efficacy and feasibility of an internet-based remote smoking cessation support program compared with the standard face-to-face clinical visit program among patients with nicotine dependence.
This study was a randomized, controlled, open-label, multicenter, noninferiority trial. We recruited nicotine-dependent adults from March to June 2018. Participants randomized to the telemedicine arm received internet-based video counseling, whereas control participants received standard face-to-face clinic visits at each time point in the smoking cessation program. Both arms received a CureApp Smoking Cessation smartphone app with a mobile exhaled carbon monoxide checker. The primary outcome was a continuous abstinence rate (CAR) from weeks 9 to 12. Full analysis set was used for data analysis.
We randomized 115 participants with nicotine dependence: 58 were allocated to the telemedicine (internet-based video counseling) arm and 57, to the control (standard face-to-face clinical visit) arm. We analyzed all 115 participants for the primary outcome. Both telemedicine and control groups had similar CARs from weeks 9 to 12 (81.0% vs 78.9%; absolute difference, 2.1%; 95% CI -12.8 to 17.0), and the lower limit of the difference between groups (-12.8%) was greater than the prespecified limit (-15%).
The application of telemedicine using internet-based video counseling as a smoking cessation program had a similar CAR from weeks 9 to 12 as that of the standard face-to-face clinical visit program. The efficacy of the telemedicine-based smoking cessation program was not inferior to that of the standard visit-based smoking cessation program.
University Hospital Medical Information Network Clinical Trials Registry: UMIN000031620; https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000035975.
Group 1 innate lymphoid cells (G1-ILCs), including circulating natural killer (NK) cells and tissue-resident type 1 ILCs (ILC1s), are innate immune sentinels critical for responses against infection ...and cancer. In contrast to relatively uniform NK cells through the body, diverse ILC1 subsets have been characterized across and within tissues in mice, but their developmental and functional heterogeneity remain unsolved. Here, using multimodal in vivo approaches including fate-mapping and targeting of the interleukin 15 (IL-15)-producing microenvironment, we demonstrate that liver parenchymal niches support the development of a cytotoxic ILC1 subset lacking IL-7 receptor (7 R
ILC1s). During ontogeny, fetal liver (FL) G1-ILCs arise perivascularly and then differentiate into 7 R
ILC1s within sinusoids. Hepatocyte-derived IL-15 supports parenchymal development of FL G1-ILCs to maintain adult pool of 7 R
ILC1s. IL-7R
(7R
) ILC1s in the liver, candidate precursors for 7 R
ILC1s, are not essential for 7 R
ILC1 development in physiological conditions. Functionally, 7 R
ILC1s exhibit killing activity at steady state through granzyme B expression, which is underpinned by constitutive mTOR activity, unlike NK cells with exogenous stimulation-dependent cytotoxicity. Our study reveals the unique ontogeny and functions of liver-specific ILC1s, providing a detailed interpretation of ILC1 heterogeneity.
We present a case of annular psoriasiform drug eruption by durvalumab. Histopathologically, scaly annular erythema showed histopathological psoriasis‐like epidermal thickening and sites where ...necrosis of epidermal keratinized cells was observed as the infiltration of many CD8‐positive T cells and TIA‐positive cells was seen. This suggests that durvalumab‐induced psoriasiform dermatitis was associated with histopathological keratinocyte apoptosis by the activation of cytotoxic T cells.
The primary goal of this open-label, multicenter, randomized phase III trial was to determine whether treatment with carboplatin plus the oral fluoropyrimidine derivative S-1 was noninferior versus ...that with carboplatin plus paclitaxel with regard to overall survival (OS) in chemotherapy-naive patients with advanced non-small-cell lung cancer (NSCLC).
A total of 564 patients were randomly assigned to receive either carboplatin (area under the curve, 5) on day 1 plus oral S-1 (40 mg/m2 twice per day) on days 1 to 14 or carboplatin (area under the curve, 6) plus paclitaxel (200 mg/m2) on day 1 every 21 days.
At the planned interim analysis, with a total of 268 death events available, the study passed the O'Brien-Fleming boundary of 0.0080 for a positive result and noninferiority of carboplatin and S-1 compared with carboplatin and paclitaxel was confirmed for OS (hazard ratio, 0.928; 99.2% CI, 0.671 to 1.283). Median OS was 15.2 months in the carboplatin and S-1 arm and 13.3 months in the carboplatin and paclitaxel arm, with 1-year survival rates of 57.3% and 55.5%, respectively. Rates of leukopenia or neutropenia of grade 3/4, febrile neutropenia, alopecia, and neuropathy were more frequent in the carboplatin and paclitaxel arm, whereas thrombocytopenia, nausea, vomiting, and diarrhea were more common in the carboplatin and S-1 arm. The carboplatin and S-1 arm had significantly more dose delays than the carboplatin and paclitaxel arm.
Oral S-1 with carboplatin was noninferior in terms of OS compared with carboplatin and paclitaxel in patients with advanced NSCLC, and is thus a valid treatment option.
PDF
