bluuebunny/crossref_metadata_2025 huggingface dataset:
Identifying innate immune regulators of Mycobacterium tuberculosis pathogenesis in macrophages
Authors: Choudhury Sreetama , Peterson Eliza , Maciag karolina , Akhade Ajay Suresh , Rostomily Clifford , Urdahl Kevin , Baliga Nitin , Subramanian Naeha
Published: February 2023

Tuberculosis (TB) is a leading infectious disease that contributes to approximately 1.4 million deaths annually worldwide. In the present situation of the COVID-19 pandemic and disrupted healthcare services, mathematical modelling predicts that there will be an additional 6.3 million new cases and 1.4 million more TB deaths by the end of 2025. Innate immune cells like macrophages are the frontline responders in host defense against Mycobacterium tuberculosis (MTB) and may also play a major role in disease establishment. A major roadblock in developing effective strategies against TB is the inability of current anti-TB drugs to target both replicating and non-replicating bacteria. We have found that lack of specific components of the host innate sensing machinery has a major impact on intracellular bacterial growth and the production of IL-1β and IFN-β during MTB infection of macrophages; the latter cytokines play major roles in host-protective and host-detrimental outcomes of infection respectively. RNA seq reveals that these innate immune modules differentially control the expression of genes implicated in host protein synthesis and MTB dissemination and escape from the granuloma. Ongoing work is utilizing Path-Seq for quantitative profiling of the MTB transcriptome within infected macrophages and investigating macrophage-dependent mechanisms of MTB restriction and persistence in vivo. Our study will potentially identify immune regulators that make the macrophage environment either permissive or restrictive for intracellular replication of MTB with important implications for developing combinatorial targeting approaches for host-directed treatment of TB.
Tregs facilitate obesity and insulin resistance via a Blimp-1-IL-10 axis
Authors: Beppu Lisa , Mooli Raja Gopal Reddy , Qu Xiaoyao , Marrero Giovanni , Finley Christopher , Fooks Allen , Mullen Zackary , Frias Adolfo , Sipula Ian , Xie Bingxian , Helfrich Katherine , Watkins Simon , Poholek Amanda , Ramakrishnan Sadeesh , Jurczak Michael , D’Cruz Louise
Published: February 2023

Adipose-resident Tregs protect against systemic inflammation and metabolic disease by limiting expansion of pro-inflammatory cells, preserving insulin sensitivity and maintaining glucose tolerance. Although their basic markers and roles have been studied, less is known about the transcriptional machinery regulating their differentiation and function.

B lymphocyte-induced maturation protein-1 (Blimp-1) is a transcriptional regulator known to be involved in development, polarization, and maintenance of various immune cells including CD4+ T cells. Using Blimp-1 reporter mice, we discovered that Blimp-1 is constitutively expressed in a subset of visceral adipose tissue (VAT) Tregs, and that Blimp-1+ VAT Tregs are phenotypically distinct from their Blimp-1-counterparts. We also found that Treg-specific Blimp-1 deletion led to altered differentiation and function of VAT and inguinal adipose tissue Tregs. Surprisingly, during diet-induced obesity, Blimp-1 Treg deficient mice gained less weight, had reduced body fat percentage, and exhibited improved insulin sensitivity compared to wild type mice. Furthermore, this was accompanied by upregulation of thermogenic genes such as Ucp1, Prdm16 and Dio2 in inguinal adipose tissue, and increased overall fatty acid oxidation. It has previously been shown that IL-10 can induce thermogenesis. Therefore, we repeated these experiments utilizing mice with Treg-specific deletion of IL-10 and found that they phenocopied the Blimp-1 Treg deficient mice. Based on these results, we hypothesize that cross-talk between Tregs and adipocytes via a Blimp-1-IL-10 axis suppresses thermogenesis, and that absence of Blimp-1+ Tregs is metabolically protective during diet-induced obesity.
Reconstituting T Cell Receptor Selection In-Silico
Authors: Ostmeyer Jared L , Cowell Lindsay , Greenberg Benjamin , Christley Scott
Published: February 2023

Each T cell receptor (TCR) gene is created without regard for which substances (antigens) the receptor can recognize. T cell selection culls developing T cells when their TCRs (i) fail to recognize major histocompatibility complexes (MHCs) that act as antigen presenting platforms or (ii) recognize with high affinity self-antigens derived from healthy cells and tissue. Here, we show that we can accurately predict from the TCR if any T cell is pre- or post-selection (and by extension if that T cell would be culled).

First, we analyze millions of TCR genes sequenced from mouse spleen using high-throughput receptor sequencing. To get examples of TCRs pre-selection, we develop a way to translate non-productive TCR genes that otherwise cannot express protein, obtaining candidate TCR protein sequences never subjected to T cell selection. To get examples of TCRs post-selection, we translate productive TCR genes sequenced from a peripheral location such as spleen, obtaining TCR protein sequences representing T cells that survived T cell selection. Next, we train a machine learning model to find sequence level patterns that discriminate between these two categories of TCR protein sequences, achieving a balanced classification accuracy of 73% (AUC of 0.8) on de-novo TCR β-chain protein sequences. This classification accuracy may be near the achievable limit using only the β-chain representing half of the TCR heterodimer.

To verify our approach, we show our machine learning model accurately predicts that (i) productive TCRs from thymus (where T selection occurs) are predominantly pre-selection and (ii) productive TCRs from peripheral tissues like skin are post-selection.
Pleiotropic adipose Treg subsets, defined by Atf3 expression, modulate adipocyte energy expenditure and weight loss
Authors: D’Cruz Louise M , Marrero Giovanni , Fooks Allen , Finley Christopher , Hyzny Eric , Frias Adolfo B , Beppu Lisa , Sipula Ian , Xie Bingxian , Jurczak Michael
Published: February 2023

Chronic obesity occurs when there is imbalance between caloric intake and energy expenditure. It is now clear that immune cells, through their communication with adipocytes, can drive or suppress adipocyte energy expenditure, thus regulating weight gain and obesity. Adipose tissue resident regulatory T cells (aTregs) are a dominant, unique CD4+ T cell population in the adipose tissue depots of mice and humans. Here we show that the transcription factor Activating Transcription Factor 3 (Atf3), defines a population of aTregs that secrete opioid-like peptides called Methionine-Enkephalins (Met-Enk). We show that aTreg-derived Met-Enk increases adipocyte function and energy expenditure by upregulating Uncoupling Protein 1 (Ucp-1) and other genes associated with adipocyte thermogenesis. Loss of Atf3 expression in aTregs, resulted in loss of Met-Enk expressing aTregs and conversely, resulted in increased Interelukin-10 (IL-10)-secreting aTregs. Physiologically, Atf3+ aTregs are required to maintain metabolic homeostasis and loss of Atf3+ aTregs increased insulin resistance in mice. Taken together, our data reveal that distinct aTreg populations with unique gene expression and cytokine secretion profiles, work together to modulate adipocyte function and energy expenditure.
Interleukin-2 inducible T cell kinase functions as a molecular switch to fine tune differentiation of naive T helper cells in pro/anti-inflammatory effector T cell lineages
Authors: Anannya Orchi , August Avery
Published: February 2023

Naïve CD4+ T helper cells differentiate into effector CD4+ T cells with pro/anti-inflammatory functions upon receipt of signals from the T cell receptor (TCR) in presence of cytokines in the environment. Interleukin-2 inducible T cell kinase (ITK) has been shown to control the strength of signals downstream of the TCR. Here we have investigated the potential of ITK to act as a molecular switch in controlling T cell differentiation fate. Our results demonstrate in the absence of ITK expression/activity, naïve CD4+ T cells activated under conditions that promote differentiation into pro-inflammatory T helper type-17 (Th17) cells fail to differentiate into Th17 cells and instead switch into T cells expressing the T regulatory (Treg) lineage specific transcription factor Forkhead Box P3 (FoxP3). Similarly, we found that naïve CD4+ T cells activated to differentiate into anti-inflammatory Type 1 regulatory (Tr1) cells in the absence of ITK expression/activity fail to differentiate into Tr1 cells and instead switch into expressing the T helper type-1 (Th1) lineage specific T-box transcription factor (T-Bet). The switched FoxP3 expressing T cells resemble Tregs by their expression of Treg specific markers and have anti-inflammatory properties in suppressing effector T cell proliferation. In addition the switched T-Bet expressing T cells resemble Th1 cells by their expression of Th1 specific markers and the Th1 effector cytokine Interferon γ (IFNγ). This work suggest that signals regulated by ITK may function as a molecular switch to control Th17/Treg and Tr1/Th1 axes, highlighting the potential of manipulating ITK to control the balance of pro/anti-inflammatory T cells in immune disorders.
HOP homeobox (HOPX) represses activation-induced human T cell proliferation
Authors: Yang Qian , Patrick Michael , Lu Jian , Weng Nanping
Published: February 2023

Aging is associated with the decline function of T cells including reduced activation-induced proliferation. HOP homeobox (HOPX), a homeodomain protein, is reported to regulate functions of T helper type 1 and regulatory T cells in murine model. However, its role in human T cells has not been examined. Here, we report that HOPX mRNA was detected in human CD4+ and CD8+ T cells and increased via anti-CD3/28 activation. Additionally, HOPX level was 1.5-fold higher in isolated CD4+ T cells from old health subjects (≥70 years) than from young subjects (≤40 years). Expression of HOPX in Jurkat T cells via lentiviral transduction significantly reduced the proliferation compared to sham viral transduced control. Furthermore, the reduced proliferation was also observed in HOPX induced primary human CD4+ and CD8+ T cells as measured by dilution of CFSE tracking dye and cell number. The overexpression of HOPX did not appear to increase cell death as measured by cell viability dye. Currently, we are investigating the mechanism underlying the HOPX mediated suppression of T cell proliferation and its role in T cell aging.
Pro-survival IL-7-stimulated weak strength of mTORC1-S6K signaling controls T cell memory via transcriptional FOXO1 and metabolic AMPK pathways
Authors: Xiang Jim
Published: February 2023

Distinct strengths of stimuli (DSS) is a well-known model for T cell memory. Two common γ-chain (γc)-family cytokines IL-2 and IL-7, which trigger the same mTORC1-S6K pathway, distinctly induce effector T (Te) cells and memory T (Tm) cell differentiation. However, their underlying mechanisms are elusive. In this study, we want to elucidate molecular mechanism for IL-7-induced Tm (IL-7/Tm) cells by performing in vitro and in vivo experiments using genetic and pharmacological tools. We show that IL-2 and IL-7 stimulate strong and weak S6K signals leading to IL-7R−CD62L−KLRG1+ Te and IL-7R+CD62L+KLRG1− Tm cell formation in our study model of adoptive transfer of T cells derived from wild-type and IL-7R knockout (KO)/OTI mice and L. monocytogenes rLmOVA infection. We further show that IL-7/Tm cells upregulate transcriptional factors (FOXO1, Id3 and TCF1) for regulating Tm’s differentiation and promote expression of autophagy/metabolic molecules (AMPK, ULK1 and ATG7) for controlling Tm’s fatty acid oxidation (FAO) metabolism by flow cytometry, Western blotting, confocal and electron microscopy and Seahorse assay analyses, and vice versa for IL-2-induced Te (IL-2/Te) cells. IL-7/Tm cells derived from AMPK KO/OTI mice abolish expression of ULK1 and ATG7, FAO metabolism and long-term survival, while IL-2/Te cells with S6K deficiency show Tm’s differentiation, metabolic/transcriptional pathways and prolonged survival. Taken together, our data demonstrate that pro-survival IL-7-stimulated weak S6K signaling controls T cell memory via transcriptional FOXO1 and metabolic AMPK pathways. The novel finding provides a new potential mechanism for DSS model in T cell memory and has a great impact on vaccine development and immunotherapy.
Receptor interacting protein kinase 1 (RIPK1) pathways regulate innate B cell developmental checkpoints and delay effector function
Authors: Parthasarathy Raksha , Hagglof Thomas , McLennan Alexandra , Mattke Aiden , Dudley Elizabeth , Kumagai Abigail , Leadbetter Elizabeth A
Published: February 2023

Mutations in RIP kinases underlie the recently described human autoimmune syndrome, CRIA, characterized by lymphadenopathy, splenomegaly, and autoantibody production. While disease mechanisms for CRIA remain undescribed, RIP kinases work together with Caspase-8 to regulate cell death, which is critical for normal differentiation of many cell types. Here, we describe a key role for RIPK1 in facilitating innate B cell differentiation and subsequent activation. By comparing RIPK1, RIPK3, and Caspase8 triple deficient and RIPK3, Caspase 8 double deficient mice, we identified selective contributions of RIPK1 to an accumulation of murine splenic Marginal Zone (MZ) B cells and B1-b cells. We used mixed bone-marrow chimeras to determine that innate B cell commitment required B cell-intrinsic RIPK1, RIPK3, and Casp8 sufficiency. RIPK1 regulated MZ B cell differentiation rather than development and RIPK1 mediates its innate immune effects independent of the RIPK1 kinase domain. NP-KLH/alum and NP-Ficoll vaccination of RIPK3, Casp8, and RIPK1 triple deficient mice revealed uniquely delayed T-dependent and T-independent IgG responses, abnormal splenic germinal center architecture, and reduced extrafollicular plasmablast formation compared to double deficient and WT mice. RIPK1 deficiency was beneficial for survival following lethal, systemic Streptococcus pneumoniae infection, confirming the functionality of innate B cell populations which increased in the absence of RIPK1. Thus, RIPK1 orchestrates B cell fate, and delayed effector function, through a B cell-intrinsic mechanism.
The AP1 transcription factor JunB is necessary for cell survival of activated CD4+ T cells
Authors: Hsieh Tsunghan , Sasaki Daiki , Taira Naoyuki , Chien Hsiaochiao , Sarkar Shukla , Ishikawa Hiroki
Published: February 2023

JunB, an AP-1 transcription factor, interacts with BATF and IRF4 and plays an essential role for differentiation of Th17 cells and effector T regulatory cells. BATF and IRF4 are also important for differentiation of Th1 and Th2 cells, but the role of JunB in those cells is largely unknown. Here we demonstrate that JunB is necessary for survival of Th1 and Th2 cells. JunB is homogenously induced in activated CD4 T cells, and Junb deficiency severely impairs the clonal expansion of those cells in mice immunized with adjuvants that induce Th1, Th2 and Th17 responses. Like BATF and IRF4, JunB promotes cell survival through repressing apoptosis in Th1, Th2 and Th17 cells. However, unlike BATF and IRF4, JunB is not required for regulation of cellular metabolism in those cells. Junb deficiency results in increase of expression of Th1 signature cytokine IFN-γ but does not affect expression of Th2 signature cytokines IL-4 and IL-13 in vivo. Mechanistically, JunB binds to a locus of Bcl2l11 together with BATF and IRF4 and inhibits its product Bim, an apoptosis inducer. Although JunB-mediated chromatin remodeling was observed, it was not linked with the regulation of Bcl2l11, Ifng and Il13. In conclusion, JunB is an essential transcription factor that cooperate with BATF and IRF4 to regulate activated CD4 T cell survival.
Development of group-3 innate lymphoid cells via Tox2-dependent pathway in gut.
Authors: Das Arundhoti , Wang Yueqiang , Lu Xiaoxiao , Kaye Jonathan , Bhandoola Avinash
Published: February 2023

Innate lymphoid cells (ILCs) are immune cells that lack specific antigen receptors but possess similar effector functions as T cells. Interestingly, ILCs and T cells express many of the same transcription factors. One such factor is TOX, a sequence non-specific nuclear transcriptional regulator that is crucial for development of both CD4 T cells and ILCs. TOX-deficient mice have significantly reduced number of early innate lymphoid progenitors (EILP) and ILC progenitors (ILCP). Consequently, the mature NK cells, ILC1, ILC2 and ILC3 subsets are greatly reduced in Tox−/− mice. Interestingly ILC3 numbers in gut are not reduced by the absence of TOX. We have discovered that TOX2, another member of the TOX family of HMG-box proteins, is highly expressed in ILC precursors. We generated Tox2−/− mice and found they have reduced ILC3 in gut; however, ILC3 cells in spleen or lymph node are intact. We also observed ILCP in fetal gut and adult gut were significantly reduced in Tox2−/−mice suggesting TOX2 is required for gut ILC3 development. However, ILCP numbers in adult gut of Tox−/− mice were unaffected. We are currently performing single-cell RNA-sequencing on gut ILC3 from Tox2−/− and Tox−/− mice to transcriptionally characterize these cells and to identify the heterogeneity within the ILC3 population. Taken together, our results indicate the existence of at least two pathways of ILC development: a central pathway in bone marrow and fetal liver that is TOX dependent; and a peripheral pathway of development of ILC3 in gut that requires TOX2.
Kdm6b regulates the generation of effector CD8+ T cells by inducing chromatin accessibility in effector-associated genes
Authors: Xu Tianhao , Schutte Alexander , Jimenez Leandro , Gonçalves Andre N.A. , Keller Ashleigh , Pipkin Matthew E. , Nakaya Helder , Pereira Renata M. , Martinez Gustavo J.
Published: February 2023

The transcriptional and epigenetic regulation of CD8+ T cell differentiation is critical for balancing pathogen eradication and long-term immunity by effector and memory CTLs respectively. Here, we demonstrate that the Lysine Demethylase 6b (Kdm6b) is essential for the proper generation and function of effector CD8+ T cells during acute infection and tumor eradication. We found that cells lacking Kdm6b (by either T cell-specific KO mice or knockdown utilizing shRNA strategies) show an enhanced generation of memory precursor and early effector cells upon acute viral infection in a cell-intrinsic manner. We also demonstrate that Kdm6b is indispensable for proper effector functions and tumor protection, and that memory CD8+ T cells lacking Kdm6b displayed a defective recall response. Mechanistically, we identified that Kdm6b, through induction of chromatin accessibility in key effector-associated gene loci, allows for the proper generation of effector CTLs. Our results pinpoint the essential function of Kdm6b in allowing chromatin accessibility in effector-associated genes, and identify Kdm6b as a potential target for therapeutics in diseases with dysregulated effector responses.
ABCB7 deficiency causes ferroptosis in peripheral T cells
Authors: Lehrke Michael Jonathan , Belmonte Paul , Kennedy Madeleine , Rajcula Matthew , Shapiro Virginia Smith
Published: February 2023

ABCB7 exports iron-sulfur (Fe-S) clusters from the mitochondria into the cytoplasm. Conditional deletion of ABCB7 revealed that it is required for peripheral T cell homeostasis. CD4-cre ABCB7 cKO mice have normal thymic development, but a severe reduction in peripheral T cell numbers. A majority of the peripheral T cells in the ABCB7 cKO mice were recent thymic emigrants (RTEs), indicating a loss of more mature T cells in the periphery. T cell maturation markers were found to be normal and stimulation of ABCB7 cKO RTEs revealed normal levels of TNFα production. These data indicate that the loss of peripheral T cells in CD4-cre ABCB7 cKO mice was not due to a defect in development or maturation but a defect in peripheral homeostasis. ABCB7-deficient T cells did not have evidence of elevated apoptosis. We demonstrated iron accumulation was occurring in ABCB7-deficient peripheral T cells using the metal-specific dye Phen Green SK. Additionally, lipid peroxides levels were elevated in the ABCB7 cKO T cells. Lipid peroxides are a hallmark of ferroptosis, an iron-dependent form of regulated cell death. Expression of GPX4, the master regulator of ferroptosis, was normal in ABCB7 cKO T cells. In addition, levels of glutathione, which counteracts lipid peroxides were found to be normal, indicating the ferroptosis protection pathway was intact and that the iron overload was causing ferroptosis. Interestingly, treatment with the iron chelator deferoxamine did not rescue peripheral T cells in the CD4-cre ABCB7 cKO mice. Vitamin E, a potent antioxidant, also failed to rescue peripheral T cell homeostasis. Thus, ABCB7 is required to maintain iron homeostasis and its loss leads to peripheral T cell ferroptosis.
Blockade of the CD6-ALCAM pathway modulates effector T cell function
Authors: Ampudia Jeanette , Chu Dalena , Badrani Jana , Doherty Taylor , Connelly Stephen , Ng Cherie
Published: February 2023

CD6 is a T-cell costimulatory receptor predominantly expressed on T cells and promotes immune synapse formation, T-cell activation, and T-cell migration via interaction with activated leukocyte cell adhesion molecule (ALCAM). The CD6-ALCAM pathway has been linked to the pathogenesis of multiple autoimmune and inflammatory diseases. While the contribution of CD6 to T cell activation has been well described, less is known regarding the expression levels and role of CD6 on effector and memory T cells which contribute to ongoing disease. Consequently, the aim of this study was to determine the role of CD6 specifically on Th1, Th2 and Th17 effector T cells (Teff). Blockade of the CD6 pathway using itolizumab, a humanized mAb currently being tested in the clinic, during restimulation of fully differentiated Th1, Th2 or Th17 Teff cells in the presence of ALCAM inhibited multiple effector functions, including proliferation and changes in cell size. An average 40% decrease in proliferation was observed across multiple donors. Furthermore, treatment of Teff cells with itolizumab resulted in a significant decrease in relevant cytokines such as IFNγ and TNFα for Th1, IL-4 and IL-13 for Th2, TNFα and IL-17 for Th17, as well as in expression levels of T cell markers of activation and exhaustion such as CD69, CD25, and PD-1. This effect was exclusively observed in the presence of ALCAM, indicating that the effect was specific to blockade of the CD6-ALCAM pathway. This study is the first to characterize the CD6-ALCAM pathway as a key regulator of effector Teff cell function. As these are the cells that drive disease pathogenicity, these data support targeting the CD6-ALCAM pathway to inhibit effector Teff cell populations in autoimmune and inflammatory diseases.
IL-23 maintains tissue resident memory Th17 cells in murine and psoriatic skin
Authors: Whitley Sarah K , Li Mushi , Tabib Tracy , Weaver Casey T , McGeachy Mandy J , Lafyatis Robert A , Kaplan Daniel H
Published: February 2023

Tissue resident memory Th17 cells (TRM17) are the key cell type driving the chronic skin inflammation of psoriasis. Although IL-23 is strongly associated with autoimmunity and chronic inflammatory disorders including psoriasis, and anti-IL-23 biologic agents have remarkable efficacy in the treatment of psoriasis, the precise role of IL-23 in supporting IL-17-mediated skin inflammation remains unclear. In mice, we found that circulating memory T cells were dispensable for anamnestic protection from C. albicans skin infection, and TRM17 mediated protection from C. albicans reinfection required IL-23. Administration of anti-IL-23R antibody to dual Il17aCre Rosa26CAG-fl/fl-tdTomato Il17fThy1.1/Thy1.1 (17Fate) fate reporter mice following resolution of primary C. albicans infection resulted in a selective reduction in the number of CD69+CD103+TRM17 cells in skin compared with isotype controls. TRM17 proliferation was reduced and survival was unaffected. CD301b+ dermal dendritic cells (dDC) were an obligate source of IL-23 that supported TRM17 maintenance in skin after C. albicans challenge. These data demonstrate that locally produced IL-23 promotes in situ TRM17 proliferation to support their long term retention in skin. In normal human skin, we identified dermal cDC2 as the principal source of IL-23, although keratinocytes and CD4+ T cells were additional sources of IL-23 in psoriasis skin. Analysis of human psoriasis skin before and after clinical anti-IL-23 therapy revealed reduced TRM17 number and proliferation index, suggesting that targeted depletion of pathogenic TRM17 is the major mechanism by which anti-IL-23 therapy induces uniquely durable disease-free intervals in psoriasis patients.
Studying lymphocyte differentiation in the spleen via spatial transcriptomics
Authors: Williams Cameron Gerard , Engel Jessica A. , Soon Megan S.F. , Murray Evan , Chen Fei , Haque Ashraful
Published: February 2023

Immune cell positioning within secondary lymphoid tissues likely affects cell-cell interaction and subsequent immune responses. Techniques such as intra-vital imaging and multiplex immunohistochemistry provide insight into this, but require specialist reagents. To examine cell-cell interactions in dense tissue at whole-genome scale, we tested the feasibility of a single-cell spatial transcriptomics method, Slide-seq2. We first confirmed using murine gut tissue that small tertiary lymphoid structures, particularly rich in B cells, could be identified and examined at a cellular level in the small intestine. We then hypothesized that microanatomical alterations could be detected. To test this, we compared mouse spleens before and 7 days after infection with blood-stage malaria parasites. To increase the molecular resolution of our data, we integrated Slide-seq2 data with high-depth, droplet-based, scRNA-seq data, generated via Chromium controller from 10× Genomics. We found that Slide-seq2 produced sufficiently rich data to map cell types from an scRNA-seq reference. Some spatially defined transcriptomes appeared to derive from mixtures of cell types, indicating that further deconvolution of spatially resolved transcriptomic data was required. Via unsupervised clustering of whole transcriptomes, we confirmed that T and B cell zones within naïve mice became less ordered at the peak of malaria infection, reflecting T and B cell interaction. Ongoing analyses aim to define novel splenic T and B cell interactions during malaria, both in extra follicular areas as well as within the germinal center.
Histone deacetylase-1 controls IL-1β production through the regulation of NLRP3 expression and activation in tuberculosis infection
Authors: Moreira Jôsimar Dornelas , Vankayalapati Ramakrishna , Samten Buka
Published: February 2023

Although IL-1b is required for the protection against Mycobacterium tuberculosis (Mtb) infection, its uncontrolled production is associated with chronic inflammation and lung damage in Tuberculosis. Epigenetic effector molecules histone deacetylases (HDACs) play critical roles in tumorigenesis and immune regulation, however their roles in IL-1β production remain unexplored. Initial screening of 11 variants of HDAC with their chemical inhibitors identified that inhibition of HDAC-1 promotes secretion of IL-1β and increases the lysine acetylation of histone H3 by primary macrophages and dendritic cells (DCs) in response to LPS/CD40L, IFN-γ stimulation or Mtb infection without affecting pro-IL-1β and IL-6. Inhibition of NLRP3 or Caspase-1 reversed this effect of HDAC-1 inhibition without affecting cell viability, implying the involvement of NLRP3 inflammasome activation. Consistently, HDAC-1 inhibition further elevated the expression of both mRNA and protein of NLRP3 in macrophages and DCs under stimulation and increased levels of cleaved Caspase-1 and mature IL-1β in the culture supernatants. Mtb infection and stimulation with LPS/CD40L of these cells induced increased expression and phosphorylation of HDAC-1 and increased HDAC-1 activity in cell lysates which was suppressed by HDAC-1 inhibitor. Treatment of low dose aerosol Mtb-infected mice with HDAC-1 inhibitor increased IL-1β in mice lungs without affecting IL-6 production. These suggest that HDAC-1 controls IL-1β maturation via regulation of NLRP3 expression and activation, thus suggesting a novel mechanism for the regulation of IL-1β, a major inflammatory cytokine in tuberculosis infection and other inflammatory diseases.
Maternal Schistosomiasis Hinders B Cell Development Leading to Reduced Humoral Immunity Upon Immunization
Authors: Gibbs Lisa C , Oviedo Juan Marcos , Fairfax Keke
Published: February 2023

Maternal helminth infections are a global public health concern that correlate with altered infant immune responses to childhood immunizations and infection. A mechanistic understanding of how maternal helminth infection alters the immune responses of offspring is critical to improve childhood vaccine regimens in endemic areas, decrease childhood morbidity, and to understand the consequences of specific defects in long-lived immunity. Our murine model of maternal Schistosoma mansoni infection demonstrated that pups born to mothers chronically infected with Schistosoma mansoni have reduced IL-4 production and B cell expansion. This defect continues following tetanus/diphtheria immunization, resulting in impaired immunity. To determine the origin of this humoral immunity defect, we began investigating lymphoid progenitors. We found an increase in the common lymphoid progenitors (CLPs) in the bone marrow of naïve mice from infected mothers. When immunized with a Tetanus/Diphtheria vaccination, there is a significant reduction in expansion of these progenitors in comparison to age matched controls from uninfected mothers coupled with a decrease in bone marrow B cells. RNA sequencing revealed a defect in stem cell pluripotency signaling pathway. Further analysis post-immunization shows a decrease in immature B cells in the bone marrow of pups from infected mothers, suggesting a more exclusive selection process or differential selective pressure, leading to lower B cell frequencies in the draining lymph node. We hypothesize that altered transcriptional regulation at the progenitor level caused by maternal Schistosomiasis is the mechanistic root of long-lived defects in humoral immunity to foreign antigens.
High resistance to intestinal nematode infection is associated with a strong bias for TFH cell responses, rapid IgG1 class switch and limited Th2 effector cell expansion
Authors: Zhang Hongwei , Rausch Sebastian , Hartmann Susanne
Published: February 2023

Gastrointestinal nematode infections are highly prevalent in nature, lead to considerable morbidity in infected humans and cause high economical loss in animal husbandry. While it is clear that type 2 responses orchestrated by CD4+GATA-3+ Th2 cells are pivotal for the control of GI nematodes, the basis for differential susceptibility of distinct host genetic backgrounds is less well understood.

The high resistance of ‘rapid responder’ SJL mice to infections with the small intestinal nematode H. polygyrus is evident in low parasite egg production and the termination of infection within a few weeks. Comparing the SJL line to slow responder C57BL/6 mice, we found that SJL mice generated relatively few Th2 effector cells, many follicular T helper cells and strong antibody responses in spleen and gut draining lymph nodes. These Th2 effector cells of SJL mice expressed high levels of the gut/mucosal homing markers CCR9/a4b7, resulting in the rapid accumulation of Th2 cells in the infected small intestine. Surprisingly, resistance was further associated with exceptionally high proportions of Treg in the spleen of SJL mice at steady state and the vigorous expansion of Treg in mLN after infection. This coincided with a bias for follicular T helper cells expansion in both mLN and spleen and, consequently, more extensive IgG1 class switching by GL7+ germinal center B cells in both organs. Infection-derived B cells transfer provides protection in SJL mice, not in B6 mice.

In conclusion, resistance versus susceptibility to primary H. polygyrus infection appears to be less dependent on the overall magnitude of Th2 responses, but rather seems to depend on rapid Th2 effector homing, follicular T helper cells and the rapid instruction of antibody responses.
IL-21 is necessary to both induce and sustain humoral immunity to Plasmodium
Authors: Surette Fionna , Butler Noah
Published: February 2023

Resistance to malaria depends on the generation of antibodies derived from germinal center (GC) responses. T follicular helper (Tfh) cells play a critical role in the selection of high-affinity GC B cells that can differentiate into either memory B cells or antibody secreting plasma cells. Mice deficient in IL-21 or its receptor fail to mount GC responses, secrete parasite-specific IgG and control primary Plasmodium infections. However, whether IL-21 exerts temporally distinct contributions to either the maintenance of GC reactions or memory, during primary anti-Plasmodium humoral immunity or memory recall responses, is not known. We hypothesize that CD4+ T cell derived IL-21 acts to support the maintenance of GC B cells and is critical for secondary humoral immune reactions orchestrated by memory Tfh. To test this hypothesis, we utilized IL-21-VFP reporters and developed cell type-specific and conditional IL-21 knockout systems. Our data show that Tfh-derived IL-21 expression peaks during the first week of infection as GC are initially forming. Following tamoxifen mediated deletion of CD4 derived IL-21 during an established GC reaction (days 16–18 p.i.), we observed significant reductions in GC B cells and loss of memory B cell-derived, parasite-specific IgG production following challenge. Thus, in addition to inducing GC responses, our experiments show that IL-21 is critical for sustaining GC responses and the formation of functional memory B cell responses.
Dual GM-CSF and IL-17A expressing CD8+ T cells mediate vaccine-immunity, but not immunopathology, against lethal fungal pneumonia in CD4+ T-cell deficient hosts
Authors: Nanjappa Som G. , Mudalagiriyappa Srinivasu
Published: February 2023

Opportunistic fungal infections are rising at alarming rates in immunocompromised individuals. There is no licensed fungal vaccine available, nor there a clear understanding of the protective host responses. In a mouse model of fungal vaccine-immunity in CD4+ T-cell lymphopenia, we have previously shown that vaccine-induced IL-17A producing CD8+ T (Tc17) cells are necessary for controlling lethal fungal pneumonia. However, we found a significant number of Tc17 cells that co-expressed GM-CSF (>50%), but their role has been implicated as ‘pathogenic’ in autoimmune disorders. In this study, using state-of-the-art approaches, we found that GM-CSF +Tc17 cells are essential for vaccine-immunity against lethal fungal pneumonia without precipitating an adverse immunopathology. Induction of GM-CSF+Tc17 cells, following vaccination, required signaling from cytokines, IL-1 and IL-23, that promoted differentiation and proliferation of effectors. Unexpectedly, IL-23 was dispensable for memory homeostasis of GM-CSF+Tc17 cells. Following the lethal pulmonary fungal challenge, IL-23 was required for the GM-CSF+Tc17 cells responses, but not for their re-differentiation, and was necessary to mitigate the immunopathology of the lungs. Collectively, GM-CSF+Tc17 cells are required for vaccine-mediated immunity against lethal fungal pneumonia.
A georeferenced dataset of living and sedimentary remains of diatom community in Lake Maggiore
Authors: Musazzi Simona , Austoni Martina , Marchetto Aldo
Published: February 2023

We publish a dataset on planktonic and benthic diatom occurrence in Lake Maggiore, the second Italian lake for depth and surface. Despite their extensive use in water quality biomonitoring, and their relevance among phytoplankton groups, research on benthic diatoms in Lake Maggiore are scarce. Diatoms have been collected from surface sediments, littoral stones, macrophytes and water column, in different times and with different purposes during the last 40 years of the trophic history of the lake. Dataset includes 4124 occurrences relating to 293 taxa, 269 of which were identified at species level, 16 at subspecies level and 8 at the genus level. All occurrences are georeferenced.
The case report of a non-resident Indian with Plasmodium ovale curtisi from Kerala, India
Authors: Sharma Supriya , Meenakshy V , Sasi MS , Ahmed Naseem , Eapen Alex , Shini KK , Sharma Amit , Srivastava Bina
Published: February 2023

India’s target of malaria elimination by 2030 may not be achieved solely by detecting Plasmodium falciparum and P. vivax, the two common Plasmodium species causing infections in humans. Sporadic reports have been documented on other Plasmodium species in the country, associated mostly with travel history. A febrile patient of Indian origin (Non-resident Indian (NRI)) was diagnosed with an infection of Plasmodium ovale curtisi malaria on his arrival from Sudan. A case report from Kerala was published in December 2020 and this is second report. Due to the inaccessibility of molecular techniques for routine diagnosis, this neglected non-falciparum malaria goes undetected. For an accurate diagnosis, suspected malaria cases should be tested using PCR and other advanced methods.
Comparative Evaluation of Fibrin Network Formation after Root Conditioning using Erbium, Chromium-Doped Yttrium Scandium Gallium and Garnet Laser, Ethylene-Diamine-Tetra-Acetic Acid, and Tetracycline on Dentin: A Scanning Electron Microscopic Study
Authors: Satish Riya Liza , Peter Maya Rajan , Bhaskar Anuradha , Vylopillil Rajesh , Balakrishnan Biju , Suresh Reshma
Published: February 2023

Context:

Regeneration of periodontal tissues depend on the adhesion and development of fibrin clots to the root surface. Demineralization of the root surface ensures removal of smear layer uncovering dentin tubules and collagen matrix. Root conditioning agents were introduced to remove the smear layer and enhance the adhesion of blood components.

Aims:

The aim of the study was to determine the effect of erbium, chromium-doped yttrium, scandium, gallium and garnet (Er, Cr: YSGG) laser on smear layer removal (SLR) and fibrin network formation when compared to tetracycline, and ethylene-diamine-tetra-acetic acid (EDTA) for periodontal regeneration.

Settings and Design:

The study was conducted at Amrita school of dentistry and the study design involves in vitro comparative study.

Subjects and Methods:

Forty dentinal sections were prepared from freshly extracted teeth that were periodontally affected. The samples were divided into four groups: Scaling and root planing (SRP), tetracycline, EDTA, and Er, Cr: YSGG laser. The samples were assessed using a scanning electron microscope and photomicrographs were taken and analyzed for removal of smear layer, blood component adhesion (BCA), and fibrin network formation.

Statistical Analysis Used:

Analysis of variance test and Kruskal–Wallis test with P < 0.05 considered to be statistically significant.

Results:

There was a significant difference between Er, Cr: YSGG laser, tetracycline hydrochloride, and EDTA categories when compared with SRP categories. There was no significant difference between Er, Cr: YSGG laser, tetracycline, and EDTA according to SLR scoring and BCA scoring.

Conclusions:

It can be concluded that Er, Cr: YSGG laser-treated samples presented complete elimination of smear layer, formation of fibrin network, and BCA along with desensitizing effect for a better reduction in dentin hypersensitivity.
Comparative Evaluation of the Bonding Efficacy of Multimode Adhesive, Two-Step Self-Etch Adhesive, and a Total-Etch System to Pulpal Floor Dentin – An In vitro Study
Authors: Valsan Dhanya , Bhaskaran Sajeev , Mathew Joy , Hari Krishnan , Joy Joseph
Published: February 2023

Background:

Postendodontic restoration with composite resins has gained popularity due to the development of more reliable adhesives with simplified bonding procedures and less technique sensitivity. Pulpal floor dentin is a complex biological structure and a more challenging bonding substrate. Hence, appropriate selection of the bonding agent for these regions of the tooth is important.

Aims:

To compare the shear bond strength of a new generation of dental adhesives referred to as multimode adhesives, two-step self-etch adhesive, and a total-etch system to pulpal floor dentin.

Materials and Methods:

Sixty human mandibular molars were sectioned with a slow speed diamond disc to expose the pulp chamber and divided into four groups of 15 teeth each, based on the bonding agent used. Group A: Single bond universal (self-etch); Group B: Single Bond Universal (etch-and-rinse), Group C: Clearfil SE Bond, Group D: Adper Single Bond 2. Using a split Teflon mold, composite cylinders were built on the prepared dentinal surfaces. The shear bond strength was then evaluated with the universal testing machine.

Results:

Two step self-etch adhesives recorded higher shear bond strength than total-etch and multimode/universal adhesives applied in both self-etch and etch-and-rinse techniques.

Conclusion:

The self-etching/priming system bonded more strongly to the pulpal floor dentin than multimode adhesive and total-etch system.
COVID-19 disease presenting as orbital cellulitis – A case series
Authors: Dhawan Munish , Sethi Neha K. , Chadha Charu , Singh Navchint
Published: February 2023

Coronavirus infection most commonly presents with mild influenza-like symptoms. The most common ocular presentation is conjunctivitis. We report four patients of COVID-19 infection presenting as orbital cellulitis. They all were incidentally found COVID-19 positive on reverse transcription polymerase chain reaction. All had painful edema of eyelids, extraocular movement restriction, and other symptoms of orbital cellulitis at presentation. Three of 4 had uncontrolled diabetes and one had coronary artery disease. Proven mucormycosis was present in two patients; cerebral involvement (abscess and stroke in 1 each) in two patients. Two of them died, one underwent orbital exenteration and one developed hemiplegia due to stroke. COVID can present as orbital cellulitis and carries a very grave prognosis.
Transformation of ophthalmology education during the Coronavirus Disease 2019 pandemic by E-learning in India
Authors: Pathania Meenakshi , Chaudhary Rajat , Attri Jyotsana
Published: February 2023

Purpose:

The purpose of this study was to assess the impact of the coronavirus disease 2019 pandemic imposed social distancing measures on the learning of ophthalmology in the institutions involved in the training of the ophthalmologists and the use of alternate E-learning methods to maintain the standard of education.

Materials and Methods:

This study was conducted among the postgraduate residents and faculty involved in ophthalmology-related education from October 15, 2020, to September 15, 2021. The study was based on a questionnaire performed based on a Google Form that was sent to the participants.

Results:

A total of 345 participants completed the survey. Most of the participants were using conventional learning methods such as lectures, ward rounds, clinical meets, and journal clubs. E-learning techniques showed a statistically significant increase during the pandemic (P < 0.001). Theoretical studies continued but the surgical training of the residents and fellows was significantly reduced.

Conclusion:

During the pandemic due to the imposed challenges in ophthalmology learning, even though surgical learning suffered, there was a significant increase in the utilization of E-learning alternatives, opening a new arena of learning opportunities.
Effect of TENS and stabilization exercises on pelvic pain in pelvic cancer survivors following multimodal treatment
Authors: Mathias Oshin Diana , Pattanshetty Renu B
Published: February 2023

Background:

Pelvic floor muscle (PFM) dysfunction and pain are common complications seen in pelvic cancers including the gynecological and genitourinary systems before and after treatments such as chemotherapy, radiotherapy, and surgeries and may contribute to significant morbidity as the survival rates increase in these patients.

Objective:

The objective of the clinical trial was to evaluate the effect of transcutaneous electrical nerve stimulation (TENS) and stabilization exercises on pelvic pain in pelvic cancer survivors following multimodal treatment.

Materials and Methods:

Thirty-one patients including both male and female adults treated for pelvic cancers were recruited in the study. Outcome measures in terms of pain were assessed at baseline and at the end of the study by the visual analog scale and genitourinary pain index (GUPI) scale, abdominal muscle strength by pressure biofeedback unit for transverse abdominal (TrA) muscle, and quality of life (QOL) by functional assessment of cancer therapy general questionnaire. Pelvic stabilization exercises and TENS were administered once daily approximately 30 min during the acute hospitalization.

Results:

Pelvic stabilization exercises and TENS demonstrated to be effective in ameliorating pelvic pain (P < 0.001) and improving in the GUPI scores of pain, incontinence, increasing strength of TrA musculature (P < 0.001), and improving overall QOL (P < 0.005).

Conclusion:

The trial suggests that a combination of pelvic stabilization exercises and conventional TENS may be used as a strategic tool to reduce pain and improve PFM strength after multimodal treatments in pelvic cancer survivors in the clinical setup of an Indian Scenario.
Validation of a simple technique for accurate treatment delivery for bilateral breast irradiation using the electronic portal imaging device
Authors: Dhar Debojoyti , Mallik Suman , Goswami Jyotirup
Published: February 2023

Background and Aims:

While bilateral breast cancer is rare, the challenge for the radiation oncologist is to limit the dose to multiple important organs-at-risk and reducing the chance of overlapping tangential fields to limit hotspots. In this study, we present a simple technique to verify the setup accuracy of breast tangential fields using the electronic portal imaging device (EPID) for bilateral breast cancer.

Patients and Methods:

A 74-year-old female, with bilateral breast cancers, right staged as T1N0M0 and the left T2N1M0, received postoperative radiotherapy following bilateral breast conservative surgery. Standard CT-based simulation and target delineation were done, followed by treatment planning using classical field arrangements with two separate isocenters, one for each breast (keeping identical anteroposterior and superior-inferior coordinates). The planned doses were 45 Gy/25 # for whole breasts, plus tumor bed boost of 15 Gy/6 # and 50 Gy/25 # to left supraclavicular fossa. After setting up the patient, two small lead wires were placed at the medial borders of medial tangents (as seen on light fields) of each breast (longer one for left), followed by EPID imaging (dual exposure: One lateral tangent field image and other larger to include lead wires) of respective contralateral lateral tangential fields to verify that there was no actual overlapping with the opposite medial tangential field, as indicated by the lead wires.

Conclusion:

The study has validated a simple EPID-based technique for routine use in the field matching for radiotherapy of bilateral breast cancer.