LAPTM5 mediates immature B cell apoptosis and B cell tolerance by regulating the WWP2-PTEN-AKT pathway.

Elimination of autoreactive developing B cells is an important mechanism to prevent autoantibody production. However, how B cell receptor (BCR) signaling triggers apoptosis of immature B cells remains poorly understood. We show that BCR stimulation up-regulates the expression of the lysosomal-associated transmembrane protein 5 (LAPTM5), which in turn triggers apoptosis of immature B cells through two pathways. LAPTM5 causes BCR internalization, resulting in decreased phosphorylation of SYK and ERK. In addition, LAPTM5 targets the E3 ubiquitin ligase WWP2 for lysosomal degradation, resulting in the accumulation of its substrate PTEN. Elevated PTEN levels suppress AKT phosphorylation, leading to increased FOXO1 expression and up-regulation of the cell cycle inhibitor p27Kip1 and the proapoptotic molecule BIM. In vivo, LAPTM5 is involved in the elimination of autoreactive B cells and its deficiency exacerbates autoantibody production. Our results reveal a previously unidentified mechanism that contributes to immature B cell apoptosis and B cell tolerance.

A Novel Homozygous RHOH Variant Associated with T Cell Dysfunction and Recurrent Opportunistic Infections.

RHOH, an atypical small GTPase predominantly expressed in hematopoietic cells, plays a vital role in immune function. A deficiency in RHOH has been linked to epidermodysplasia verruciformis, lung disease, Burkitt lymphoma and T cell defects. Here, we report a novel germline homozygous RHOH c.245G > A (p.Cys82Tyr) variant in a 21-year-old male suffering from recurrent, invasive, opportunistic infections affecting the lungs, eyes, and brain. His sister also succumbed to a lung infection during early adulthood. The patient exhibited a persistent decrease in CD4+ T, B, and NK cell counts, and hypoimmunoglobulinemia. The patient's T cell showed impaired activation upon in vitro TCR stimulation. In Jurkat T cells transduced with RHOHC82Y, a similar reduction in activation marker CD69 up-regulation was observed. Furthermore, the C82Y variant showed reduced RHOH protein expression and impaired interaction with the TCR signaling molecule ZAP70. Together, these data suggest that the newly identified autosomal-recessive RHOH variant is associated with T cell dysfunction and recurrent opportunistic infections, functioning as a hypomorph by disrupting ZAP70-mediated TCR signaling.

Implementation of nondiffracting Bessel beam sources in FDTD for scattering by complex particles.

In this paper, the nondiffracting Bessel beam sources are implemented in finite-difference time-domain (FDTD) method. The high-order scattered-field algorithm of the FDTD (SF-FDTD (2, 4)) method is employed to investigate the scattering of particles illuminated by Bessel beams. In the SF-FDTD (2, 4) method, the scattered fields of the whole region are calculated directly by time stepping and the incident fields are obtained by the vector expressions of the diffraction-free Bessel beam. Some numerical results are included to illustrate the validity and capability of the proposed method. This study is expected to provide a new efficient method to investigate the interactions between nondiffracting beams and complex particles.

Scattering of a Laguerre-Gaussian beam by complicated shaped biological cells.

In this paper, we generalize the method of moments (MOM) based on the surface integral equation (SIE) method to investigate the scattering properties of complicated shaped biological cells illuminated by a Laguerre-Gaussian beam (LGB). We introduce the Lorentz-gauge vector potential with slowly varying envelope amplitude which satisfies the paraxial wave equation to obtain the electric and magnetic field components of the incident beam. The SIE method is applied to compute the scattering field of arbitrary shaped biological cells, the MLFMA is utilized to efficiently solve the resulting matrix equations, and a home-made FORTRAN program is written. Then we explore the influence of the beam parameters (radial parameter, azimuthal parameter, waist radius, and beam center position of a LGB) on the differential scattering cross section (DSCS) for a red blood cell at great length. Some numerical results on the DSCS for complicated shaped biological cells, such as a fusiform cell and a bacteriophage anatomy illuminated by a LGB are given, showing the powerful capability of our approach. As a rapidly advancing field, the investigation of the scattering properties on complicated shaped biological cells illuminated by a LGB will hold a wealth of potential for the study of fundamental properties of light and exciting applications in the medical field.

Tissue engineering applications of recombinant human collagen: a review of recent progress.

With the rapid development of synthetic biology, recombinant human collagen has emerged as a cutting-edge biological material globally. Its innovative applications in the fields of material science and medicine have opened new horizons in biomedical research. Recombinant human collagen stands out as a highly promising biomaterial, playing a pivotal role in crucial areas such as wound healing, stroma regeneration, and orthopedics. However, realizing its full potential by efficiently delivering it for optimal therapeutic outcomes remains a formidable challenge. This review provides a comprehensive overview of the applications of recombinant human collagen in biomedical systems, focusing on resolving this crucial issue. Additionally, it encompasses the exploration of 3D printing technologies incorporating recombinant collagen to address some urgent clinical challenges in regenerative repair in the future. The primary aim of this review also is to spotlight the advancements in the realm of biomaterials utilizing recombinant collagen, with the intention of fostering additional innovation and making significant contributions to the enhancement of regenerative biomaterials, therapeutic methodologies, and overall patient outcomes.

MZB1-mediated IgA secretion suppresses the development and progression of colorectal cancer triggered by gut inflammation.

Colorectal cancer (CRC) ranks among the top causes of mortality globally. Gut inflammation is one crucial risk factor that augments CRC development since patients suffering from inflammatory bowel disease have an increased incidence of CRC. The role of immunoglobulin (Ig)A in maintaining gut homeostasis and preventing inflammation has been well established. Our earlier work demonstrated that the marginal zone and B1 cell-specific protein (MZB1) promotes gut IgA secretion and its absence results in pronounced dextran sulfate sodium salt (DSS)-induced colitis. In the present study, we explored the role of MZB1 in CRC development using the azoxymethane (AOM)/DSS-induced CRC model. We observed an increase in both the number and size of the tumor nodules in Mzb1-/- mice compared with Mzb1+/+ mice. The increase in CRC development and progression in Mzb1-/- mice was associated with reduced intestinal IgA levels, altered gut flora, and more severe gut and systemic inflammation. Oral administration of the monoclonal IgA, W27, alleviated both the gut inflammation and AOM/DSS-induced CRC. Notably, cohousing Mzb1+/+ and Mzb1-/- mice from the 10th day after birth led to similar CRC development. Our findings underscore the pivotal role of MZB1-mediated IgA secretion in suppressing the onset and progression of CRC triggered by gut inflammation. Moreover, our study highlights the profound impact of microbiota composition, modulated by gut IgA levels, on gut inflammation. Nonetheless, establishing a direct correlation between the severity of colitis and subsequent CRC development and the presence or absence of a particular microbiota is challenging.

Impact of different genetic mutations on granulocyte development and G-CSF responsiveness in congenital neutropenia.

ABSTRACT: Congenital neutropenia (CN) is a genetic disorder characterized by persistent or intermittent low peripheral neutrophil counts, thus increasing susceptibility to bacterial and fungal infections. Various forms of CN, caused by distinct genetic mutations, exhibit differential responses to granulocyte colony-stimulating factor (G-CSF) therapy, with the underlying mechanisms not fully understood. This study presents an in-depth comparative analysis of clinical and immunological features in 5 CN patient groups (severe congenital neutropenia [SCN]1, SCN3, cyclic neutropenia [CyN], warts, hypogammaglobulinaemia, infections and myelokathexis [WHIM], and Shwachman-Bodian-Diamond Syndrome [SBDS]) associated with mutations in ELANE, HAX1, CXCR4, and SBDS genes. Our analysis led to the identification of 11 novel mutations in ELANE and 1 each in HAX1, CXCR4, and G6PC3 genes. Investigating bone marrow (BM) granulopoiesis and blood absolute neutrophil count after G-CSF treatment, we found that SCN1 and SCN3 presented with severe early-stage disruption between the promyelocyte and myelocyte, leading to a poor response to G-CSF. In contrast, CyN, affected at the late polymorphonuclear stage of neutrophil development, showed a strong G-CSF response. WHIM, displaying normal neutrophil development, responded robustly to G-CSF, whereas SBDS, with moderate disruption from the early myeloblast stage, exhibited a moderate response. Notably, SCN1 uniquely impeded neutrophil development, whereas SCN3, CyN, WHIM, and SBDS also affected eosinophils and basophils. In addition, SCN1, SCN3, and CyN presented with elevated serum immunoglobulins, increased BM plasma cells, and higher A Proliferation-Inducing Ligand levels. Our study reveals a strong correlation between the stage and severity of granulocyte development disruption and the efficacy of G-CSF therapy.

B cell abnormalities and autoantibody production in patients with partial RAG deficiency.

Mutations in the recombination activating gene 1 (RAG1) and RAG2 in humans are associated with a broad spectrum of clinical phenotypes, from severe combined immunodeficiency to immune dysregulation. Partial (hypomorphic) RAG deficiency (pRD) in particular, frequently leads to hyperinflammation and autoimmunity, with several underlying intrinsic and extrinsic mechanisms causing a break in tolerance centrally and peripherally during T and B cell development. However, the relative contributions of these processes to immune dysregulation remain unclear. In this review, we specifically focus on the recently described tolerance break and B cell abnormalities, as well as consequent molecular and cellular mechanisms of autoantibody production in patients with pRD.

Sophoricoside attenuates autoimmune­mediated liver injury through the regulation of oxidative stress and the NF­κB signaling pathway.

The prevalence of autoimmune hepatitis (AIH) is increasing, yet specific pharmacotherapies remain to be explored. The present study aimed to investigate the effects of sophoricoside (SOP), a bioactive component of medical herbs, on AIH and to elucidate the underlying mechanisms. Bioinformatic approaches were used to predict the potential targets and underlying regulatory mechanisms of SOP on AIH. The effects of SOP on AIH were evaluated by determining the expression levels of inflammatory cytokines, histological liver injury and hepatic fibrosis in an improved chronic cytochrome P450 2D6 (CYP2D6)­AIH mouse model and in a model of concanavalin­A (ConA)­induced acute immune­mediated liver injury. The antioxidant activity of SOP was detected in in vivo and in vitro experiments. The selected signal targeted by SOP in AIH was further confirmed using western blot analysis and immunofluorescence staining. The results of bioinformatic analysis revealed that the targets of SOP in AIH were related to oxidative stress and the NF­κB gene set. The NF­κB transcription factor family is a key player that controls both innate and adaptive immunity. The activation of the NF­κB signaling pathway is often associated with autoimmune disorders. In the animal experiments, SOP attenuated CYP2D6/ConA­induced AIH, as evidenced by a significant reduction in the levels of hepatic enzymes in serum, inflammatory cytokine expression and histological lesions in the liver. The oxidative response in AIH was also significantly inhibited by SOP, as evidenced by a decrease in the levels of hepatic malondialdehyde, and elevations in the total antioxidant capacity and glutathione peroxidase levels. The results of the in vivo and in vitro experiments revealed that SOP significantly reduced the enhanced expression and nuclear translocation of phosphorylated p65 NF­κB in the livers of mice with AIH and in lipopolysaccharide­stimulated AML12 cells. On the whole, the present study demonstrates the protective role of SOP in AIH, which may be mediated by limiting the oxidative response and the activation of the NF­κB signaling pathway in hepatocytes.

Pathophysiology, clinical manifestations and current management of IL-1 mediated monogenic systemic autoinflammatory diseases, a literature review.

BACKGROUND: Systemic autoinflammatory diseases (SAIDs) are hyperinflammatory and immune-dysregulation conditions that present in childhood. This kind of disease is a rare disease with early-onset, severe condition and difficult diagnosis, which seriously affects the growth and development of children. Most children need a genetic diagnosis. However, with the limitation of access to genetic testing and the detection of somatic mutations, the diagnosis of SAIDs remains challenging. IL-1 is one of the important cytokines involved in the pathogenesis of SAIDs. Here we briefly review monogenic SAIDs mediated by aberrant IL-1 production, with the aim to further understand the pathogenesis, clinical manifestations and treatments of IL-1 mediated SAIDs. METHODS: Literature reviews were performed using "PubMed" and "Web of Science" by searching for the terms "autoinflammatory diseases" and "IL-1". RESULTS: Monogenic SAIDs mediated by IL-1 include MKD, FMF, TRAPS, PAAND, PAPA, CAPS, DIRA, Majeed syndrome, NAIAD, NLRC4-MAS, PFIT, APLAID. Monogenic SAIDs have early onset, various clinical manifestations and difficult diagnosis, so early recognition and early treatment can reduce the complications and enhance the quality of life. CONCLUSIONS: There are many kinds of IL-1 mediated SAIDs. Pediatricians should be alert to SAIDs in the face of the patients with repeated fever, repeated rash and poor effect of routine treatment. The patients should be carried out with gene testing and treatment in time.

RAG1 splicing mutation causes enhanced B cell differentiation and autoantibody production.

Hypomorphic RAG1 or RAG2 mutations cause primary immunodeficiencies and can lead to autoimmunity, but the underlying mechanisms are elusive. We report here a patient carrying a c.116+2T>G homozygous splice site mutation in the first intron of RAG1, which led to aberrant splicing and greatly reduced RAG1 protein expression. B cell development was blocked at both the pro-B to pre-B transition and the pre-B to immature B cell differentiation step. The patient B cells had reduced B cell receptor repertoire diversity and decreased complementarity determining region 3 lengths. Despite B cell lymphopenia, the patient had abundant plasma cells in the BM and produced large quantities of IgM and IgG Abs, including autoantibodies. The proportion of naive B cells was reduced while the frequency of IgD-CD27- double-negative (DN) B cells, which quickly differentiated into Ab-secreting plasma cells upon stimulation, was greatly increased. Immune phenotype analysis of 52 patients with primary immunodeficiency revealed a strong association of the increased proportion of DN B and memory B cells with decreased number and proportion of naive B cells. These results suggest that the lymphopenic environment triggered naive B cell differentiation into DN B and memory B cells, leading to increased Ab production.

Haploinsufficiency of A20 (HA20): updates on the genetics, phenotype, pathogenesis and treatment.

BACKGROUND: A20, a protein encoded by the tumor necrosis factor alpha-induced protein 3 gene (TNFAIP3), plays a vital role in the negative regulation of inflammation and immunity. Loss-of-function mutation in TNFAIP3 leads to a new described autoinflammatory disease-haploinsufficiency of A20 (HA20). Since HA20 was first described in 2016, a number of new cases have been described in this literature, however, the disease and its pathogenesis are poorly understood. This review seeks to improve clinical recognition of this disorder, and promote both earlier diagnosis and initiation of targeted therapies to improve patients' outcomes. METHODS: We reviewed 26 papers about A20 and HA20, and we summarized genetic variants and clinical manifestations of a total of 61 reported patients from 26 families identified to have a genetic diagnosis of germline pathogenic variants in TNFAIP3/A20. Additionally, we discussed the pathogenesis and treatment of HA20. RESULTS: A total of 24 pathogenic variants of A20 had been reported. There was significant clinical heterogeneity, even among those with the same variants in TNFAIP3. Prior to receiving a molecular diagnosis of HA20, patients had been diagnosed with Behcet's disease, rheumatoid arthritis, rheumatic fever, juvenile idiopathic arthritis, systemic lupus erythematosus, and even adult-onset Stills' disease. The patients with HA20 that presented with inflammatory signatures in NF-κB signaling were mostly responsive to treatment. CONCLUSIONS: HA20 is a monogenic autoinflammatory disease with highly variable clinical manifestations. This extensive heterogeneity makes it difficult to set a clinical diagnostic criteria, and genetic sequencing is necessary for a definitive diagnosis of HA20.

Questionnaire assessment helps the self-management of patients with inflammatory bowel disease during the outbreak of Coronavirus Disease 2019.

OBJECTIVE: This study aimed to assess the disease conditions of patients with inflammatory bowel disease (IBD) in Hubei Province during the outbreak of Coronavirus Disease 2019 (COVID-19) by questionnaire online and guide their self-management during this epidemic. RESULTS: A total of 102 eligible questionnaires were included. No patient we surveyed reported a diagnosis of COVID-19. Our result showed that 67.86% of patients with ulcerative colitis (UC) and 80.43% of patients with Crohn's disease (CD) were in remission, 85.29%of patients had a good quality of life. Part of the patients (21.57%) reported their disease conditions worsening. The reduction in physical exercise was a risk factor for worsening conditions (OR=17.593, p=0.009). Some patients reported an alteration of medication regimens during the epidemic. CONCLUSIONS: The epidemic of COVID-19 might have a certain impact on many aspects of Hubei IBD patients within four weeks after the traffic control. Doctors could utilize the results from our questionnaire to guide IBD patients' self-management. METHODS: A questionnaire was designed containing the Harvey-Bradshaw Index (HBI), the 6-point Mayo Score, the short inflammatory bowel disease questionnaire (SIBDQ) and distributed to Hubei IBD patients online within four weeks of traffic control after the outbreak, it also included questions about patients' self-reported disease conditions and their epidemiological features of COVID-19.

Anti-High Mobility Group Box 1 Neutralizing-Antibody Ameliorates Dextran Sodium Sulfate Colitis in Mice.

High mobility group box 1 (HMGB1) is a ubiquitous nuclear protein in mammals. When released into the extracellular space, it acts as a damage-associated molecular pattern. This study investigates whether increased HMGB1 levels are found in the intestinal mucosa of ulcerative colitis (UC) patients, and whether an anti-HMGB1 neutralizing-antibody (HnAb) can inhibit the intestinal inflammation elicited by dextran sulfate sodium (DSS) in mice. Because toll-like receptor 4 (TLR4) is implicated in HMGB1-mediated immune cell activation, DSS colitis was also elicited in TLR4-deficient mice in the presence and absence of HnAb. The expression of HMGB1 in UC patients was examined. HnAb was administered via intraperitoneal injection to TLR4 deficient mice and their wild-type littermates, both being induced to colitis with DSS. Finally, the protective effect of HnAb and TLR4 deficiency were evaluated. In UC patients, HMGB1 was up-regulated in the inflamed colon. When administered during DSS application, HnAb alleviated the severity of colitis with a lower disease activity index, limited histological damages, and reduced production of proinflammatory cytokines. This antibody also limited colonic barrier loss, decreased colonic lamina propria macrophages and partially reversed the DSS treatment-associated dysbiosis. The protective effect of this antibody was enhanced in TLR4-deficient mice in some aspects, indicating that both additional HMGB1-mediated as well as TLR4-mediated inflammatory signaling pathways were involved in the induction of colitis by DSS. HnAb ameliorated colitis via macrophages inhibition and colonic barrier protection. It may therefore be a novel treatment option in colitis.