Research on the mechanism of regulating spleen-deficient obesity in rats by bawei guben huashi jiangzhi decoction based on multi-omics analysis

ETHNOPHARMACOLOGY RELEVANCE

Bawei Guben Huashi Jiangzhi Decoction (BGHJ), a traditional Chinese compound formula, comprises eight Chinese medicinal herbs: Codonopsis Radix, Atractylodis Macrocephalae Rhizoma, Cassiae Semen, Lysimachiae Herba, Edgeworthiae Gardner Flos, Oryzae Semen cum Monasco, Nelumbinis Folium, and Alismatis Rhizoma. It has the therapeutic effects of improving digestive and absorptive functions of the gastrointestinal tract, reducing cholesterol levels, and helping to lose weight. Therefore, BGHJ is mainly used to treat spleen-deficient obesity (SDO) clinically.

AIM OF THE STUDY

This study aims to examine the efficacy and mechanism of BGHJ in a model of SDO in rats, as well as the potentially involved constituents entering the blood and differential metabolites.

METHODS

The SDO rat model was replicated utilizing a high-fat and high-sugar diet in conjunction with exhaustive swimming. Subsequently, the rats were subjected to a six-week intervention comprising varying dosages of BGHJ and a positive control, orlistat. To evaluate the efficacy of BGHJ on SDO model rats, we first measured the rats' body weight, body surface temperature, spleen index, as well as biochemical indicators in the serum and colon, and then assessed the pathological state of the colon and liver. Afterward, we analyzed the 16S rDNA gut microbiota, non-targeted serum metabolomics, and serum pharmacology to study the main active components of BGHJ and its action mechanism against SDO model rats. In addition, we constructed a network diagram for overall visualization and analysis, and experimentally verified the predicted results. Finally, we used quantitative polymerase chain reaction (qPCR) to detect the gene expression of proopiomelanocortin (POMC) and neuropeptide Y (NPY) indicators in rat hypothalamic neurons. We quantitatively targeted the detection of neurotransmitters dopamine (DA), acetylcholine (Ach), 5-hydroxytryptamine (5-HT), and noradrenaline (NA) in rat hypothalamus.

RESULTS

The results demonstrated that all dosage regimens of BGHJ exhibited the capacity to moderately modulate parameters including body weight, surface temperature, spleen index, total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), glucagon-like peptide-1 (GLP-1), cholecystokinin (CCK), 5-HT, interleukin 6 (IL-6) and interleukin 17 (IL-17), while concurrently reducing hepatic lipid droplet deposition and restoring intestinal integrity. Subsequent experimental results showed that we successfully identified 27 blood components of BGHJ and identified 52 differential metabolites in SDO model rats. At the same time, the experiment proved that BGHJ could effectively inhibit the metabolic pathway of arachidonic acid. In addition, BGHJ can also restore the intestinal microbiota composition of SDO model rats. Finally, we also found that BGHJ could regulate the expression of hypothalamic neurons and neurotransmitters.

CONCLUSIONS

The research revealed the main active ingredients of BGHJ and its mechanism against SDO model rats through gut microbiota, non-target serum metabolomics, and serum drug chemistry.

Oral subacute polypropylene microplastics administration effect on potential immunotoxicity in ICR mice

Exposure to microplastics may be associated with damage of immune system. Polypropylene microplastics (PP-MPs) with a wide range of beneficial applications have not been extensively studied with respect to the immune system. The aim of this investigation is to examine the influence of two different sizes of PP-MPs (5.2 and 23.9 μm diameter) on immune system components in ICR mice. PP-MPs were administered orally to female and male mice at 0 (corn oil vehicle), 500, 1000, or 2000 mg/kg/d for single and daily for 4-week repeated toxicity test, respectively. No significant differences were observed in number of thymic CD4+, CD8+, CD4+CD8+ T lymphocytes, splenic helper T cells, cytotoxic T cells, and B cells. The ratio of interferon-γ to interleukin-4 in culture supernatants from activated splenocytes ex vivo (48 hr) was lower in females which were repeatedly administered with PP-MPs compared to vehicle irrespective of PP-MPs size and dose. In contrast, the opposite trend was observed in males. Production of tumor necrosis factor-α was upregulated in females that were repeatedly exposed to PP-MPs. The serum IgG2a/IgG1 ratio was lowered in female receiving large-size PP-MPs. Data suggest that immune disturbances resulting in predominant type-2 helper T cell reactivity may occur in mice, especially in females, when repeatedly exposed to PP-MPs. Further investigations with longer exposure periods are necessary to determine the immunotoxicities attributed to PP-MPs.

Widespread Reactive Lymphatic and Splenic FDG Avidity After mRNA COVID Vaccination

ABSTRACT

A 75-year-old woman with history of metastatic lung adenocarcinoma in remission develops new widespread FDG-avid lymphadenopathy in the neck, chest, abdomen, and pelvis on surveillance PET/CT, as well as intense FDG uptake in the spleen, without evidence of local recurrence. Short-term follow-up PET demonstrates near-complete resolution of FDG-avid lymphatic and splenic FDG avidity without interval change in management. Further history reveals that the patient received her fifth dose of COVID mRNA vaccine 6 days before the abnormal PET. Although unilateral axillary adenopathy after COVID vaccination is well-recognized, this widespread symmetric lymphatic and splenic FDG avidity is a significantly rarer phenomenon.

Insights into Q-markers of honey-fried licorice in treating spleen deficiency based on substance and energy metabolism regulation

BACKGROUND

Honey-fried Licorice (HFL) is a dosage form of Glycyrrhizae Radix et Rhizome processed with honey, which has been recorded to exhibit better efficacy in tonifying the spleen compared to the raw product. In contrast, different processing methods of Glycyrrhizae Radix et Rhizome exhibit different efficacies and applications, but their current quality control index components remain consistent.

PURPOSE

Based on the discovery and research strategy of traditional Chinese medicine decoction piece quality marker (Q-marker), this study aimed to conduct a multidimensional integration of constituents absorbed into the body and metabolomics based on the tonifying spleen and stomach effects of HFL to effectively identify the Q-marker of HFL.

METHODS

In this study, a spleen deficiency rat model was established using the "exhausted swimming + poor diet" method to investigate the pharmacodynamics of tonifying the spleen and stomach by HFL. The constituents absorbed into blood was conducted using UPLC-Q-TOF/MS, correlation analysis between metabolomics and constituents absorbed into blood recognized the Q-Marker of HFL.

RESULTS

The pharmacodynamic data demonstrated that HFL exhibited a significant regulatory effect on the disordered levels of PP, trypsin, chymase, PL, α-Glu, MTL, GAS, VIP, IL-2, IFN-γ, and IgA in the spleen deficiency model. Furthermore, HFL was found to improve the pathological changes in the spleen and intestine in the spleen deficiency model, highlighting its significant "tonifying spleen and stomach" effect. In the serum containing HFL, a total of 17 constituents were identified as being absorbed into the blood. Among these, 11 were prototypical components, while 6 were metabolites. Metabolomics data revealed that 9 differentially expressed metabolic markers were observed. Furthermore, the analysis of endogenous metabolic markers indicated that 10 components exhibited significant correlations with these biomarkers.

CONCLUSION

The effect of "tonifying spleen and stomach" of HFL is closely related to the regulation of the material and energy metabolism pathway. The Q-Marker of HFL is glycyrrhizic acid and 18β-glycyrrhetinic acid as the main control standards and liquiritin, isoliquiritin, liquiritin, isoliquiritin, isolicorice flavonol, licorice chalcone C and Formononetin were used as auxiliary standards.

Blood defense system - Proposal for a new concept of an immune system against blood borne pathogens comprising the liver, spleen and bone marrow

Blood-borne pathogen (BBP) infections can rapidly progress to life-threatening sepsis and must therefore be promptly eliminated by the host's immune system. Intravascular macrophages of the liver sinusoid, splenic marginal zone and red pulp and perisinusoidal macrophage protrusions in the bone marrow (BM) directly phagocytose BBPs in the blood as an innate immune response. The liver, spleen and BM thereby work together as the blood defence system (BDS) in response to BBPs by exerting their different immunological roles. The liver removes the vast majority of these invading organisms via innate immunity, but their complete elimination is not possible without the actions of antibodies. Splenic marginal zone B cells promptly produce IgM and IgG antibodies against BBPs. The splenic marginal zone transports antigenic information from the innate to the adaptive immune systems. The white pulp of the spleen functions as adaptive immune tissue and produces specific and high-affinity antibodies with an immune memory against BBPs. The BM works to maintain immune memory by supporting the survival of memory B cells, memory T cells and long-lived plasma cells (LLPCs), all of which have dedicated niches. Furthermore, BM perisinusoidal naïve follicular B cells promptly produce IgM antibodies against BBPs in the BM sinusoid and the IgG memory B cells residing in the BM rapidly transform to plasma cells which produce high-affinity IgG antibodies upon reinfection. This review describes the complete immune defence characteristics of the BDS against BBPs through the collaboration of the liver, spleen and BM with combined different immunological roles.

Splenic irradiation for myelofibrosis prior to hematopoietic cell transplantation: A global collaborative analysis

Splenomegaly is the clinical hallmark of myelofibrosis. Splenomegaly at the time of allogeneic hematopoietic cell transplantation (HCT) is associated with graft failure and poor graft function. Strategies to reduce spleen size before HCT especially after failure to Janus kinase (JAK) inhibition represent unmet clinical needs in the field. Here, we leveraged a global collaboration to investigate the safety and efficacy of splenic irradiation as part of the HCT platform for patients with myelofibrosis. We included 59 patients, receiving irradiation within a median of 2 weeks (range, 0.9-12 weeks) before HCT. Overall, the median spleen size prior to irradiation was 23 cm (range, 14-35). Splenic irradiation resulted in a significant and rapid spleen size reduction in 97% of patients (57/59), with a median decrease of 5.0 cm (95% confidence interval, 4.1-6.3 cm). The most frequent adverse event was thrombocytopenia, with no correlation between irradiation dose and hematological toxicities. The 3-year overall survival was 62% (95% CI, 48%-76%) and 1-year non-relapse mortality was 26% (95% CI, 14%-38%). Independent predictors for survival were severe thrombocytopenia and anemia before irradiation, transplant-specific risk score, higher-intensity conditioning, and present portal vein thrombosis. When using a propensity score matching adjusted for common confounders, splenic irradiation was associated with significantly reduced relapse (p = .01), showing a 3-year incidence of 12% for splenic irradiation versus 29% for patients with immediate HCT and 38% for patients receiving splenectomy. In conclusion, splenic irradiation immediately before HCT is a reasonable approach in patients experiencing JAK inhibition failure and is associated with a low incidence of relapse.

The impact of Lactococcus lactis KUST48 on the transcription profile of Aeromonas hydrophila-infected zebrafish spleen

Aeromonas hydrophila, an aquatic pathogenic bacterium, has been found to infect many fish species and cause huge aquaculture losses. Antibiotics are the most common drugs used to treat these infections. However, antibiotic abuse can lead to the development of antibiotic resistance. Probiotics have the potential to replace antibiotics for preventing infections. Zebrafish (Danio rerio) is a model organism used to study the innate immune system and host-pathogen interactions. Currently, there is little information on how the fish immune system responds to A. hydrophila and probiotic treatment. To increase the understanding of the molecular mechanisms behind the zebrafish defense against A. hydrophila and provide evidence that antibiotics can be replaced by probiotics, a transcriptome analysis of the zebrafish spleen was conducted 48 hours after infection by A. hydrophila, as well as after treatment using Lactococcus lactis KUST48 4 hours after infection. A total of 36,499 genes were obtained. There were 3,337 genes found to have significant differential expression between treatment and control groups. According to further annotation and enrichment analysis, differentially expressed genes (DEGs) were involved in signal transduction, endocrine system cancer, and the immune system. Insulin resistance disappeared in the zebrafish after treatment. Quantitative real-time PCR was performed to confirm the significant regulation of immune defense DEGs, the results of which were consistent with the RNA-sequencing data. These results could serve as a basis for future studies on the immune response to A. hydrophila and provide suggestions for probiotic alternatives to antibiotics, which will be of great significance to aquaculture and environmental protection.IMPORTANCEIn recent years, the unreasonable use of antibiotics has led to the emergence of drug-resistant pathogenic bacteria, antibiotic residues, cross infection, toxic side effects, and so on, which has caused a serious threat to human food safety and life health. In recent years, many studies have demonstrated the potential of probiotics as a substitute for antibiotics, but there is still a lack of understanding of the molecular mechanisms underlying probiotic therapy. We conduct a research on the impact of Lactococcus lactis KUST48 on the transcription profile of Aeromonas hydrophila-infected zebrafish spleen. Mortality of zebrafish infected with A. hydrophila was significantly reduced after treatment with L. lactis KUST48. Our results can help to strengthen our understanding of the pathogenic mechanisms of zebrafish and provide a valuable reference for the molecular mechanisms of probiotic therapy.

Aflatoxin B1 exposure causes splenic pyroptosis by disturbing the gut microbiota-immune axis

Aflatoxin B1 (AFB1) causes serious immunotoxicity and has attracted considerable attention owing to its high sensitivity and common chemical-viral interactions in living organisms. However, the sensitivity of different species to AFB1 widely varies, which cannot be explained by the different metabolism in species. The gut microbiota plays a crucial role in the immune system, but the interaction of the microbiota with AFB1-induced immunotoxicity still needs to be determined. Our results indicated that AFB1 exposure disrupted the structure of the gut microbiota and damaged the gut barrier, which caused translocation of microbiota metabolites, lipopolysaccharides, to the spleen. Subsequently, pyroptosis of the spleen was activated. Interestingly, AFB1 exposure had little effect on the splenic pyroptosis of pseudo-germfree mice (antibiotic mixtures eliminated their gut microbiota, ABX). Then, fecal microbiota transplant (FMT) and sterile fecal filtrate (SFF) were employed to validate the function of the gut microbiota and its metabolites in AFB1-induced splenic pyroptosis. The AFB1-disrupted microbiota and its metabolites significantly promoted splenic pyroptosis, which was worse than that in control mice. Overall, AFB1-induced splenic pyroptosis is associated with the gut microbiota and its metabolites, which was further demonstrated by FMT and SFF. The mechanism of AFB1-induced splenic pyroptosis was explored for the first time, which paves a new way for preventing and treating the immunotoxicity from mycotoxins by regulating the gut microbiota.

How Early Can Checkpoint Inhibitors Induce a Complete Metabolic Response in Chemorefractory Hodgkin Lymphoma?

ABSTRACT

A 24-year-old man with classical Hodgkin lymphoma was lost to follow-up after metabolic complete remission (mCR). He presented 4 years later with B-symptoms and impaired clinical condition. Relapsed classical Hodgkin lymphoma was diagnosed. PET/CT revealed stage IVB with liver and spleen involvement. Two liver function-adjusted salvage attempts were ineffective. Pembrolizumab was instituted with gradual clinical improvement. PET was missed before treatment for a life-threatening condition and was performed on day +10 showing a near mCR. A mCR was confirmed before cycle 2, on day +21, underlining-for the first time in the literature-the possibility to achieve very early mCR with pembrolizumab.

Slc43a2+ T cell metastasis from spleen to brain in RGNNV infected teleost

The origin of T cells in the teleost's brain is unclear. While viewing the central nervous system (CNS) as immune privileged has been widely accepted, previous studies suggest that T cells residing in the thymus but not in the spleen of the teleost play an essential role in communicating with the peripheral organs. Here, we identified nine T cell subpopulations in the thymus and spleen of orange-spotted grouper (Epinephelus coioices) through single-cell RNA-sequencing analysis. After viral CNS infection with red-spotted grouper nervous necrosis virus (RGNNV), the number of slc43a2+ T cells synchronously increased in the spleen and brain. During the infection tests in asplenic zebrafish (tlx1▲ zebrafish model), no increase in the number of slc43a2+ T cells was observed in the brain. Single-cell transcriptomic analysis indicated that slc43a2+ T cells mature and functionally differentiate within the spleen and then migrate into the brain to trigger an immune response. This study suggests a novel route for T cell migration from the spleen to the brain during viral infection in fish.

Effectiveness and safety of Jiawei Xiaoyao pill in the treatment of premenstrual syndrome (liver depression, spleen deficiency, and blood-heat syndrome): a multi-center, randomized, placebo-controlled trial

OBJECTIVE

To investigate the effectiveness and safety of Jiawei Xiaoyao pill (，JXP) in the treatment of symptoms associated with premenstrual syndrome (PMS).

METHODS

A total of 144 regularly menstruating women with PMS were recruited at 8 sites in China from August 2017 to December 2018, and randomized to receive either a JXP or a matching placebo (12 g/d, 6 g twice a day) for 3 menstrual cycles. The primary indicator was the reduced Daily Record of Severity of Problems (DRSP) scores in the luteal phase after 3 months of treatment. The safety outcomes included clinical adverse events (AEs), adverse reactions (ARs), changes in vital signs, and laboratory tests.

RESULTS

JXP surpassed the placebo in reducing DRSP scores (psychological/somatic dysfunction) in the luteal phase over 3 menstrual cycles of treatment (PFAS = 0.002, PPPS = 0.001). Additionally, there were no significant differences in the incidence of AEs, severe AEs, withdrawal due to AEs and ARs between the two groups (all P > 0.05), and no clinically significant adverse medical events related to the test drug observed.

CONCLUSIONS

JXP was superior to the placebo in relieving the symptoms associated with PMS, which signified that JXP may be effective, safe, and well-tolerated as an alternative therapy.

Impact of COVID-19 on people with non-functioning spleens in Australia

BACKGROUND

COVID-19 has had enormous impact on health and social systems, with stringent public health measures enacted across Australia. The virus itself disproportionately affects immunocompromised individuals including people without functioning spleens. We thus sought to characterise the psychological and physical impact of COVID-19 and such measures upon this oft-neglected patient group.

METHODS

Adults ≥ 18 years old identified from the Spleen Australia (SA) database were invited to participate in an online survey in November to December 2021 to assess the impact of the COVID-19 pandemic. Stata (v17, StataCorps, Texas, USA) was used to conduct descriptive and frequency analyses.

RESULTS

2864 respondents were surveyed. The majority were female (1473/2838, 51.9%), Australian-born (2257/2835, 79.6%), and living in Victoria (1755/2822, 62.2%). The largest age group was 61-70 years-old (841/2858, 29.4%). Trauma was the commonest reason for asplenia (826/2724, 30.3%). Respondents reported the pandemic reduced their ability to visit a GP (753/2864, 26.3%), access food (153/2864, 5.3%), medications (179/2864, 6.3%) or spleen-specific vaccines (120/2864, 4.2%), maintain relationships (503/2864, 17.6%), or care for children (127/2864, 4.4%). 84.8% of participants reported at least one impact of COVID, including negative physical health (1463/2864, 51.1%), mental health (733/2864, 25.6%) and financial repercussions (509/2864, 17.8%). 96.9% (2743/2831) had received at least one dose of COVID-19 vaccines.

CONCLUSIONS

Overall, we found detailed evidence of the negative psychological and physical impacts of the pandemic upon this cohort. We recommend that providers consider people without functioning spleens as requiring extra social and psychological support in circumstances such as the COVID-19 pandemic.

Spleno-Sigmoid Knotting - An Unfamiliar Cause of Intestinal Obstruction

INTRODUCTION

Spleno-sigmoid knotting is the twisting of the spleen around the sigmoid colon, causing obstruction of the sigmoid colon. It is an uncommon cause of intestinal obstruction. To our knowledge, there has been no previous case report of spleno-sigmoid knotting before our case.

CASE REPORT

Here, we present the case of an 18-year-old female patient who visited the surgical emergency outpatient department with diffuse and progressive abdominal pain lasting for one and a half days. She also experienced obstipation and frequent episodes of vomiting of ingested matter. Upon initial evaluation, she exhibited tachycardia and tachypnea, and her abdomen was grossly distended with diffuse direct and rebound tenderness. Further investigation revealed significant leukocytosis with neutrophil predominance. Emergency laparotomy was performed with a possible diagnosis of generalized peritonitis secondary to gangrenous sigmoid volvulus, which revealed gangrenous spleno-sigmoid knotting.

DISCUSSION

Various types of intestinal knots have been reported, with ileo-sigmoid knots being the most common and ileo-ileal knots being the rarest. Wandering spleen is a rare congenital anomaly with a variable clinical presentation ranging from asymptomatic to mild abdominal pain or acute abdomen due to torsion or acute pancreatitis. It can also cause intestinal obstruction, which may be the initial presentation.

CONCLUSION

In patients presenting with acute abdominal pain and features of bowel obstruction, the possibility of spleno-sigmoid knotting should be considered, and early intervention should be instituted to prevent gangrenous progression and sepsis.

Quercetin counteracts monosodium glutamate to mitigate immunosuppression in the thymus and spleen via redox-guided cellular signaling

BACKGROUND

Chronic inflammation brought on by oxidative stress can result in several immunopathologies. Natural compounds with antioxidant characteristics, like quercetin, have shown effectiveness in reducing oxidative damage and regulating the immune response.

PURPOSE

The commonly used food additive monosodium glutamate (M) causes immunosuppression by disrupting redox equilibrium and inducing oxidative stress. The goal of this work is to examine the therapeutic potential of quercetin against immunotoxicity brought on by M, revealing the molecular route implicated in such immunopathology by targeting the thymus and spleen, to support the development of future anti-inflammatory and antioxidant therapies.

STUDY DESIGN AND METHODS

M-fed rats were employed as an immunotoxicity model and were supplemented with quercetin for four weeks. Hematological and biochemical parameters were measured; H&E staining, immunohistochemistry, flow cytometry, real-time quantitative PCR, and western blotting were performed.

RESULTS

Based on the findings, TLR4 was activated by M to cause oxidative stress-mediated inflammation, which was alleviated by the supplementation of quercetin by modulating redox homeostasis to neutralize free radicals and suppress the inflammatory response. To prevent M-induced inflammation, quercetin demonstrated anti-inflammatory functions by blocking NF-kB activation, lowering the production of pro-inflammatory cytokines, and increasing the release of anti-inflammatory cytokines. By normalizing lipid profiles and lowering the potential risk of immunological deficiency caused by M, quercetin also improves lipid metabolism. Additionally, it has shown potential for modifying insulin levels, suggesting a possible function in controlling M-induced alteration in glucose metabolism. The addition of quercetin to M enhanced the immune response by improving immunoglobulin levels and CD4/CD8 expression in the thymus and spleen. Additionally, quercetin inhibited apoptosis by controlling mitochondrial caspase-mediated cellular signaling, suggesting that it may be able to halt cell death in M-fed rats.

CONCLUSION

The results of this study first indicate that quercetin, via modulating redox-guided cellular signaling, has a promising role in reducing immune disturbances. This study illuminates the potential of quercetin as a safe, natural remedy for immunopathology caused by M, including thymic hypoplasia and/or splenomegaly, and paves the way for future anti-inflammatory and antioxidant supplements.

Prognostic value of diffuse reduction of spleen density on postoperative survival of pancreatic ductal adenocarcinoma: A retrospective study

PURPOSE

It is difficult to predict the prognosis of patients with pancreatic ductal adenocarcinoma (PDAC) before radical operation. The purpose of this study was to explore the connection between the diffuse reduction of spleen density on computed tomography (DROSD) and the postoperative prognosis of patients with PDAC.

PATIENTS AND METHODS

A total of 160 patients with PDAC who underwent radical surgery in the First Affiliated Hospital of Wenzhou Medical University were enrolled. Cox regression analysis was used to cast the overall survival (OS) and evaluate the prognostic factors. Nomogram was used to forecast the possibility of 1-year, 3-year, and 5-year OS. The prediction accuracy and clinical net benefit are performed by concordance index (C-index), calibration curve, time-dependent receiver operating characteristics (tdROC), and decision curve analysis.

RESULTS

In multivariable Cox analysis, DROSD is independently related to OS. Advanced age, TNM stage, neutrophil/lymphocyte ratio, and severe complications were also independent prognostic factors. The calibration curves of nomogram showed optimal agreement between prediction and observation. The C-index of nomogram is 0.662 (95%CI, 0.606-0.754). The area under tdROC curve for a 3-year OS of nomogram is 0.770.

CONCLUSION

DROSD is an independent risk factor for an OS of PDAC. We developed a nomogram that combined imaging features, clinicopathological factors, and systemic inflammatory response to provide a personalized risk assessment for patients with PDAC.

Differential splenic responses to hyperoxic breathing at high altitude in Sherpa and lowlanders

The human spleen contracts in response to stress-induced catecholamine secretion, resulting in a temporary rise in haemoglobin concentration ([Hb]). Recent findings highlighted enhanced splenic response to exercise at high altitude in Sherpa, possibly due to a blunted splenic response to hypoxia. To explore the potential blunted splenic contraction in Sherpas at high altitude, we examined changes in spleen volume during hyperoxic breathing, comparing acclimatized Sherpa with acclimatized individuals of lowland ancestry. Our study included 14 non-Sherpa (7 female) residing at altitude for a mean continuous duration of 3 months and 46 Sherpa (24 female) with an average of 4 years altitude exposure. Participants underwent a hyperoxic breathing test at altitude (4300 m; barrometric pressure = ∼430 torr;P O 2 ${P_{{{\mathrm{O}}_{\mathrm{2}}}}}$  = ∼90 torr). Throughout the test, we measured spleen volume using ultrasonography and monitored oxygen saturation (S p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ ). During rest, Sherpa exhibited larger spleens (226 ± 70 mL) compared to non-Sherpa (165 ± 34 mL; P < 0.001; effect size (ES) = 0.95, 95% CI: 0.3-1.6). In response to hyperoxia, non-Sherpa demonstrated 22 ± 12% increase in spleen size (35 ± 17 mL, 95% CI: 20.7-48.9; P < 0.001; ES = 1.8, 95% CI: 0.93-2.66), while spleen size remained unchanged in Sherpa (-2 ± 13 mL, 95% CI: -2.4 to 7.3; P = 0.640; ES = 0.18, 95% CI: -0.10 to 0.47). Our findings suggest that Sherpa and non-Sherpas of lowland ancestry exhibit distinct variations in spleen volume during hyperoxia at high altitude, potentially indicating two distinct splenic functions. In Sherpa, this phenomenon may signify a diminished splenic response to altitude-related hypoxia at rest, potentially contributing to enhanced splenic contractions during physical stress. Conversely, non-Sherpa experienced a transient increase in spleen size during hyperoxia, indicating an active tonic contraction, which may influence early altitude acclimatization in lowlanders by raising [Hb].

Structure of crude polysaccharides from Atractylodes lancea rhizome and treatment of diarrhea owing to spleen deficiency through intestinal flora

To optimize the extraction process of crude polysaccharides from Atractylodes and elaborate the mechanism of Atractylodes polysaccharides in treating diarrhea owing to spleen deficiency, so as to lay a foundation for further development and utilization of Atractylodes lancea, we used an orthogonal test to optimize the extraction process and established a model of spleen deficiency. It was further combined with histopathology and intestinal flora to elaborate the mechanism of Atractylodes polysaccharides in the treatment of spleen-deficiency diarrhea. The optimized extraction conditions were as follows: the ratio of material to liquid was 1:25; the rotational speed was 150 rpm; the extraction temperature was 60°C; the extraction time was 2 h; and the extraction rate was about 23%. The therapeutic effect of Atractylodes polysaccharides on a spleen-deficiency diarrhea model in mice showed that the water content of stools and diarrhea grade in the treatment group were alleviated, and the levels of gastrin, motilin and d-xylose were improved. The analysis results based on gut microbiota showed that the model group had a higher diversity of gut microbiota than the normal group and treatment group, and the treatment group could correct the diversity of gut microbiota in model mice. Analysis based on the level of phylum and genus showed that the treatment group could inhibit the abundance of Helicobacter pylori genus and increase beneficial bacteria genera. The conclusion was that the optimized extraction process of Atractylodes polysaccharides was reasonable and feasible, and had a good therapeutic effect on spleen deficiency diarrhea.

Two distinct subpopulations of marginal zone B cells exhibit differential antibody-producing capacities and radioresistance

Marginal zone (MZ) B cells, which are splenic innate-like B cells that rapidly secrete antibodies (Abs) against blood-borne pathogens, are composed of heterogeneous subpopulations. Here, we showed that MZ B cells can be divided into two distinct subpopulations according to their CD80 expression levels. CD80high MZ B cells exhibited greater Ab-producing, proliferative, and IL-10-secreting capacities than did CD80low MZ B cells. Notably, CD80high MZ B cells survived 2-Gy whole-body irradiation, whereas CD80low MZ B cells were depleted by irradiation and then repleted with one month after irradiation. Depletion of CD80low MZ B cells led to accelerated development of type II collagen (CII)-induced arthritis upon immunization with bovine CII. CD80high MZ B cells exhibited higher expression of genes involved in proliferation, plasma cell differentiation, and the antioxidant response. CD80high MZ B cells expressed more autoreactive B cell receptors (BCRs) that recognized double-stranded DNA or CII, expressed more immunoglobulin heavy chain sequences with shorter complementarity-determining region 3 sequences, and included more clonotypes with no N-nucleotides or with B-1a BCR sequences than CD80low MZ B cells. Adoptive transfer experiments showed that CD21+CD23+ transitional 2 MZ precursors preferentially generated CD80low MZ B cells and that a proportion of CD80low MZ B cells were converted into CD80high MZ B cells; in contrast, CD80high MZ B cells stably remained CD80high MZ B cells. In summary, MZ B cells can be divided into two subpopulations according to their CD80 expression levels, Ab-producing capacity, radioresistance, and autoreactivity, and these findings may suggest a hierarchical composition of MZ B cells with differential stability and BCR specificity.

Hydroxyurea is associated with later onset of acute splenic sequestration crisis in sickle cell disease: Lessons from the European Sickle Cell Disease Cohort-Hydroxyurea (ESCORT-HU) study

Acute splenic sequestration crisis (ASSC) is a potentially life-threatening complication of sickle cell disease (SCD), typically occurring in young patients under 5 years of age, with a median age at first episode of less than 2 years. Because a beneficial effect of hydroxyurea (HU) on spleen perfusion and splenic function has been suspected, we hypothesized that HU treatment might be associated with later onset of ASSC in patients with SCD. To investigate this hypothesis, we analyzed data from the ESCORT-HU study on a large cohort of patients with SCD receiving HU, enrolled between January 2009 and June 2017 with a follow-up of 7309 patient-years of observation. The median age at ASSC of the 14 patients who experienced a first episode of ASSC during the study period was 8.0 [IQR: 5.0-24.1] years. The median age at HU initiation was significantly lower in these 14 patients (4.8 [IQR: 3.3-18.7] years) compared to the 1664 patients without ASSC (19.9 [8.8-33.4] years, p = .0008). These findings suggest that ASSC may occur at an unusually late age in patients receiving HU, possibly reflecting longer preservation of spleen perfusion and function secondary to early initiation of HU. Further studies are needed to better characterize the effects of HU on spleen perfusion/function and on the occurrence of ASSC in patients with SCD (ClinicalTrials.gov identifier: NCT02516579; European registry ENCEPP/SDPP/10565).

Effect of feeding fermented distiller's grains diets on immune status and metabolomics of spleen and mesenteric lymph nodes in finishing cattle

To explore the effect of feeding fermented distiller's grains (FDG) diets on spleen and mesenteric lymph nodes (MLN) immune status and metabolomics in finishing cattle, eighteen Guanling crossbred cattle (18 months old, 250.0 ± 25 kg) were randomly divided into 3 groups: a basal diet (Control) group, an FDG-15% group, and an FDG-30% group (containing 0%, 15% and 30% FDG to partially replace the concentrates, respectively). After 75 days, the spleens and MLN were collected for detection of relative spleen weight, immune parameters, and metabolomic analysis. Compared with the Control group, FDG-30% group significantly increased (P<0.05) the relative spleen weight. In addition, the level of IL-17A in the spleen of the FDG-30% group was significantly higher than that of the FDG-15% group. Metabolomic analysis showed that differential metabolites (VIP＞1, P＜0.05) of spleen and MLN in FDG-15% and FDG-30% groups are mostly lipids and lipid molecules. KEGG analysis illustrated that choline metabolism in cancer, glycerophospholipid metabolism, biosynthesis of unsaturated fatty acids and insulin resistance were metabolic pathways in spleen shared by FDG-15% group vs.Control group and FDG-30% group vs.Control group, and choline metabolism in cancer was a metabolic pathway in MLN shared by FDG-15% group vs.Control group and FDG-30% group vs.Control group. These results suggest that feeding FDG may promote spleen development by regulating choline metabolism in cancer, glycerophospholipid metabolism, biosynthesis of unsaturated fatty acids and insulin resistance. Additionally, it may affect MLN development by regulating choline metabolism in cancer. SIGNIFICANCE: Fermented distiller's grains (FDG) is a high quality alternative to feed because it is rich in beneficial microorganisms and nutrients. The spleen and mesenteric lymph nodes (MLN) are important peripheral immune organs in animals, whose status reflects the health of the animal. However, there are few reports on the effect of feeding FDG diets on spleen and MLN immune status and metabolomics in domestic animals. In this study, we found that feeding FDG may promote spleen development by regulating choline metabolism in cancer, glycerophospholipid metabolism, biosynthesis of unsaturated fatty acids and insulin resistance metabolic pathways, and may affect MLN development by regulating choline metabolism in cancer. This study extends our understanding of the metabolomics of the spleen and MLN in FDG and helps to further understand of the immunomodulatory effects of the FDG diet.

The immunomodulatory effect of oral NaHCO3 is mediated by the splenic nerve: multivariate impact revealed by artificial neural networks

Stimulation of the inflammatory reflex (IR) is a promising strategy for treating systemic inflammatory disorders. Recent studies suggest oral sodium bicarbonate (NaHCO3) as a potential activator of the IR, offering a safe and cost-effective treatment approach. However, the mechanisms underlying NaHCO3-induced anti-inflammatory effects remain unclear. We investigated whether oral NaHCO3's immunomodulatory effects are mediated by the splenic nerve. Female rats received NaHCO3 or water (H2O) for four days, and splenic immune markers were assessed using flow cytometry. NaHCO3 led to a significant increase (p < 0.05, and/or partial eta squared > 0.06) in anti-inflammatory markers, including CD11bc + CD206 + (M2-like) macrophages, CD3 + CD4 + FoxP3 + cells (Tregs), and Tregs/M1-like ratio. Conversely, proinflammatory markers, such as CD11bc + CD38 + TNFα + (M1-like) macrophages, M1-like/M2-like ratio, and SSChigh/SSClow ratio of FSChighCD11bc + cells, decreased in the spleen following NaHCO3 administration. These effects were abolished in spleen-denervated rats, suggesting the necessity of the splenic nerve in mediating NaHCO3-induced immunomodulation. Artificial neural networks accurately classified NaHCO3 and H2O treatment in sham rats but failed in spleen-denervated rats, highlighting the splenic nerve's critical role. Additionally, spleen denervation independently influenced Tregs, M2-like macrophages, Tregs/M1-like ratio, and CD11bc + CD38 + cells, indicating distinct effects from both surgery and treatment. Principal component analysis (PCA) further supported the separate effects. Our findings suggest that the splenic nerve transmits oral NaHCO3-induced immunomodulatory changes to the spleen, emphasizing NaHCO3's potential as an IR activator with therapeutic implications for a wide spectrum of systemic inflammatory conditions.

The Efficacy of Chaihu-Guizhi-Ganjiang Decoction on Chronic Non-Atrophic Gastritis with Gallbladder Heat and Spleen Cold Syndrome and Its Metabolomic Analysis: An Observational Controlled Before-After Clinical Trial

Purpose

The aim of this study was to verify the effectiveness and explore the mechanism of Chaihu-Guizhi-Ganjiang decoction (CGGD) in the treatment of chronic non-atrophic gastritis (CNAG) with gallbladder heat and spleen cold syndrome (GHSC) by metabolomics based on UHPLC-Q-TOF/MS.

Patients and Methods

An observational controlled before-after study was conducted to verify the effectiveness of CGGD in the treatment of CNAG with GHSC from January to June 2023, enrolling 27 patients, who took CGGD for 28 days. 30 healthy volunteers were enrolled as the controls. The efficacy was evaluated by comparing the traditional Chinese medicine (TCM) syndrome and CNAG scores, and clinical parameters before and after treatment. The plasma levels of hormones related to gastrointestinal function were collected by ELISA. The mechanisms of CGGD in the treatment of CNAG with GHSC were explored using a metabolomic approach based on UHPLC-Q-TOF/MS.

Results

Patients treated with CGGD experienced a statistically significant improvement in TCM syndrome and CNAG scores (p < 0.01). CGGD treatment evoked the concentration alteration of 15 biomarkers, which were enriched in the glycerophospholipid metabolism, and branched-chain amino acids biosynthesis pathways. Moreover, CGGD treatment attenuated the abnormalities of the gastrointestinal hormone levels and significantly increased the pepsinogen level.

Conclusion

It was the first time that this clinical trial presented detailed data on the clinical parameters that demonstrated the effectiveness of CGGD in the treatment of CNAG with GHSC patients. This study also provided supportive evidence that CNAG with GHSC patients were associated with disturbed branched-chain amino acid metabolism and glycerophospholipid levels, suggesting that CNAG treatment based on TCM syndrome scores was reasonable and also provided a potential pharmacological mechanism of action of CGGD.

Dynamics of ex vivo cytokine transcription during experimental Toxocara canis infection in Balb/c mice

The cytokine microenvironment is crucial in generating and polarizing the immune response. A means of monitoring this environment would be of great value for better understanding Toxocara canis immune modulation. The aim of this study was to analyze the dynamics of cytokine transcription ex vivo, during early (24-48 hours) and late (15-30 days) times post-infection, in the mesenteric lymph nodes, spleen and intestinal mucosa of Balb/c mice experimentally infected with T. canis larvae. Mice in the treated group were infected with 100 third-stage larvae (L3), whereas mice in the control group were not infected. Analyses were performed at different times: 24-48 hours post-infection (HPI), 15-30 days post-infection (DPI). IL4, IL10, IL12 and Ym1 mRNA transcriptions were analyzed through qPCR. This study showed cytokine transcription mediated by migrating larvae in the mesenteric lymph nodes and spleen at 24-48 HPI, whereas cytokine transcription in the intestinal mucosa was observed only at late times (15-30 DPI). These results suggest that the T. canis larvae migration during infection might play a role in cytokine dynamics. Since the cytokine microenvironment is crucial in modulating immune response, knowledge of cytokine dynamics during T. canis infections pave the way to better understand its interaction with the host.

Melatonin alleviates T-2 toxin-induced oxidative damage, inflammatory response, and apoptosis in piglet spleen and thymus

T-2 toxin, an unavoidable contaminant in animal feeds, can induce oxidative stress and damage immune organs. Melatonin (MT), a natural and potent antioxidant, has shown promise as a detoxifier for various mycotoxins. However, the detoxifying effect of MT on T-2 toxin has not been previously reported. In order to investigate the protective effect of MT added to diets on the immune system of T-2 toxin-exposed piglets, twenty piglets weaned at 28d of age were randomly divided into control, T-2 toxin (1 mg/kg), MT (5 mg/kg), and T-2 toxin (1 mg/kg) + MT (5 mg/kg) groups(n = 5 per group). Our results demonstrated that MT mitigated T-2 toxin-induced histoarchitectural alterations in the spleen and thymus, such as hemorrhage, decreased white pulp size in the spleen, and medullary cell sparing in the thymus. Further research revealed that MT promoted the expression of Nrf2 and increased the activities of antioxidant enzymes CAT and SOD, while reducing the production of the lipid peroxidation product MDA. Moreover, MT inhibited the NF-κB signaling pathway, regulated the expression of downstream cytokines IL-1β, IL-6, TNF-α, and TGF-β1. MT also suppressed the activation of caspase-3 while down-regulating the ratio of Bax/Bcl-2 to reduce apoptosis. Additionally, MT ameliorated the T-2 toxin-induced disorders of immune cells and immune molecules in the blood. In conclusion, our findings suggest that MT may effectively protect the immune system of piglets against T-2 toxin-induced damage by inhibiting oxidative stress, inflammatory response, and apoptosis in the spleen and thymus. Therefore, MT holds the potential as an antidote for T-2 toxin poisoning.

Phospholipase D regulates ferroptosis signal transduction in mouse spleen hypoxia response

High-altitude hypoxia exposure can lead to phospholipase D-mediated lipid metabolism disorder in spleen tissues and induce ferroptosis. Nonetheless, the key genes underlying hypoxia-induced splenic phospholipase D and the ferroptosis pathway remain unclear. This study aimed to establish a hypoxia animal model. Combined transcriptomic and proteomic analyses showed that 95 predicted target genes (proteins) were significantly differentially expressed under hypoxic conditions. Key genes in phospholipase D and ferroptosis pathways under hypoxic exposure were identified by combining Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis techniques. Gene set enrichment analysis (GSEA) showed that the differential gene sets of the phospholipase D and ferroptosis signaling pathways were upregulated in the high-altitude hypoxia group. The genes in the phospholipase D signalling pathway were verified, and the expression levels of KIT and DGKG were upregulated in spleen tissues under hypoxic exposure. Subsequently, the mRNA and protein expression levels of genes from the exogenous pathway such as TFRC, SLC40A1, SLC7A11, TRP53, and FTH1 and those from the endogenous pathway such as GPX4, HMOX1, and ALOX15 differentials in the ferroptosis signalling pathway were verified, and the results indicated significant differential expression. In summary, exposure to high-altitude hypoxia mediated phospholipid metabolism disturbance through the phospholipase D signalling pathway and further induced ferroptosis, leading to splenic injury.

Alpha-ketoglutaric acid attenuates oxidative stress and modulates mitochondrial dynamics and autophagy of spleen in a piglet model of lipopolysaccharide-induced sepsis

Alpha-ketoglutaric acid (2-ketoglutaric acid or 2-oxoglutaric acid, AKG), a crucial intermediate in the tricarboxylic acid cycle, is pivotal in animal antioxidative process. The purpose of this study was to investigate whether AKG has the efficacy to mitigate spleen oxidative stress in lipopolysaccharide (LPS)-induced sepsis piglets through the modulation of mitochondrial dynamics and autophagy. Utilizing a 2 × 2 factorial design, the study encompassed 24 piglets subjected to varying diets (basal or 1% AKG) and immune stimulations (saline or LPS) over 21 days. Subsequently, they were injected intraperitoneally with either LPS or saline solution. The results showed that LPS decreased antioxidant capacity, whereas AKG supplementation increased antioxidant activities compared to control group. LPS elevated mitochondrial fission factor, mitochondrial elongation factor 1, mitochondrial elongation factor 2, dynamin-related protein 1, voltage-dependent anion channel 1, and fission 1 mRNA abundance, but reduced mRNA abundance of mitofusin 1, mitofusin 2, and optic atrophy 1 compared to controls. LPS elevated mRNA abundance of autophagy related protein 5, autophagy related protein 7, P62, Beclin1, and interleukin-1β mRNA abundance compared to controls. However, AKG supplementation mitigated these effects induced by LPS. Additionally, AKG intake was associated with lower protein expressions of microtubule-associated protein light chain 3, Parkin, and PTEN-induced putative kinase 1 compared to LPS-challenged piglets. These results suggested that AKG could alleviate spleen oxidative stress caused by LPS by regulating mitochondrial dynamics and autophagy.

A Case Report of Modified Pancreatic Transplantation With a Limited Splenic Arteriovenous Fistula to Elude Thrombosis

In classic pancreatic transplantation, the splenic artery and vein are ligated at the tail of the pancreas graft. This leads to slowed blood flow in the splenic vein and may cause thrombosis and graft loss. In this study, a patient received a pancreas after kidney transplantation. A modified surgical technique was used in the pancreatic graft preparation. The donor splenic artery and vein were anastomosed end to end at the tail of the pancreas. The splenic artery near the anastomosis was partially ligated, and an effective diameter of 2 mm was reserved to limit arterial blood pressure and flow. The patient recovered very well. Contrasted computed tomography scans on days 11 and 88 after pancreas transplantation indicated sufficient backflow of the splenic vein. We believe that this procedure may avoid the risk of splenic vein thrombosis after pancreas transplantation. This modified technique has not been reported in clinical cases previously and may help reduce the risk of thrombosis after pancreas transplantation.

Somatosensory cortex and central amygdala regulate neuropathic pain-mediated peripheral immune response via vagal projections to the spleen

Pain involves neuroimmune crosstalk, but the mechanisms of this remain unclear. Here we showed that the splenic T helper 2 (TH2) immune cell response is differentially regulated in male mice with acute versus chronic neuropathic pain and that acetylcholinergic neurons in the dorsal motor nucleus of the vagus (AChDMV) directly innervate the spleen. Combined in vivo recording and immune cell profiling revealed the following two distinct circuits involved in pain-mediated peripheral TH2 immune response: glutamatergic neurons in the primary somatosensory cortex (GluS1HL)→AChDMV→spleen circuit and GABAergic neurons in the central nucleus of the amygdala (GABACeA)→AChDMV→spleen circuit. The acute pain condition elicits increased excitation from GluS1HL neurons to spleen-projecting AChDMV neurons and increased the proportion of splenic TH2 immune cells. The chronic pain condition increased inhibition from GABACeA neurons to spleen-projecting AChDMV neurons and decreased splenic TH2 immune cells. Our study thus demonstrates how the brain encodes pain-state-specific immune responses in the spleen.

[Non-targeted metabolomics of spleen and liver metabolism in mice treated with Pruni Semen processed with different methods]

Ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) was employed to investigate the impacts of Pruni Semen processed with different methods(raw and fried) on the liver and spleen metabolism in mice. A total of 24 male mice were randomly assigned to three groups: raw Pruni Semen group, fried Pruni Semen group, and control(deionized water) group. Mice in the three groups were orally administrated with 0.01 g·mL~(-1) Pruni Semen decoction or deionized water for one week. After that, the liver and spleen tissues were collected, and liquid chromatography-mass spectrometry(LC-MS)-based metabolomic analysis was carried out to investigate the impact of Pruni Semen on the liver and spleen metabolism in mice. Compared with thte control group, the raw Pruni Semen group showed up-regulation of 11 metabolites and down-regulation of 57 metabolites in the spleen(P<0.05), as well as up-regulation of 15 metabolites and down-regulation of 58 metabolites in the liver(P<0.05). The fried Pruni Semen group showed up-regulation of 31 metabolites and down-regulation of 10 metabolites in the spleen(P<0.05), along with up-regulation of 26 metabolites and down-regulation of 61 metabolites in the liver(P<0.05). The differential metabolites identified in the raw Pruni Semen group were primarily associated with alanine, aspartate, and glutamate metabolism, purine metabolism, amino sugar and nucleotide sugar metabolism, and D-glutamine and D-glutamate metabolism. The differential metabolites identified in the fried Pruni Semen group predominantly involved riboflavin metabolism, amino sugar and nucleotide sugar metabolism, purine metabolism, alanine, aspartate, and glutamate metabolism, D-glutamine and D-glutamate metabolism, and glutathione metabolism. The findings suggest that both raw and fried Pruni Semen have the potential to modulate the metabolism of the liver and spleen in mice by influencing the glutamine and glutamate metabolism.

[A Case of Repeat Pancreatectomy-Robotic Spleen-Preserving Distal Pancreatectomy after Robotic Pancreaticoduodenectomy]

Laparoscopic pancreaticoduodenectomy has been covered by insurance since 2016 in Japan, and advance laparoscopic and robotic pancreaticoduodenectomy has been also covered by insurance since 2020 in Japan. It has been reported that laparoscopic pancreatectomy causes few postoperative adhesions in the abdominal cavity and that repeat laparoscopic surgery could be performed. However, in robotic pancreatectomy, there have been no such reports yet. We reported that even after robotic pancreaticoduodenectomy, there were few adhesions in the abdominal cavity, and we were able to perform the robotic distal pancreatectomy with preservation of the splenic artery and vein. This suggested that robotic surgery was an effective treatment method for repeat pancreatectomy, given its low invasiveness and minimal adhesion.

Exercise reduces pro-inflammatory lipids and preserves resolution mediators that calibrate macrophage-centric immune metabolism in spleen and heart following obesogenic diet in aging mice

The study investigated the role of volunteer exercise and an obesogenic diet (OBD) in mice, focusing on the splenocardiac axis and inflammation-resolution signaling. Male C57BL/6J mice (2 months old) were assigned to control (CON) or OBD groups for ten months, then randomized into sedentary (Sed) or exercise (Exe) groups for two weeks. Leukocytes, heart function, structure, and spleen tissue examined for inflammation-resolution mediators and macrophage-centric gene transcripts. After two weeks of volunteer exercise, cardiac function shows limited changes, but structural changes were notable in the heart and spleen. Exercise induced cardiac nuclear hyperplasia observed in both CON and OBD groups. OBD-Sed mice showed splenic changes and increased neutrophils, whereas increased neutrophils were noted in the CON post exercise. OBD-Sed increased pro-inflammatory lipid mediators in the heart, reduced by exercise in OBD-Exe, while CON-Exe preserved resolution mediators. Chronic OBD-Sed depletes long chain fatty acids (DHA/EPA) in the heart and spleen, while exercise independently regulates lipid metabolism genes in both organs, affecting macrophage-centric lipid and lipoprotein pathways. Chronic obesity amplified cardiac inflammation, countered by exercise that lowered pro-inflammatory bioactive lipid mediators in the heart. OBD sustained inflammation in the heart and spleen, while exercise conserved resolution mediators in CON mice. In summary, these findings emphasize the interplay of diet with exercise and highlight the intricate connection of diet, exercise, inflammation-resolution signaling in splenocardiac axis and immune health.

Evaluation of immunogenicity and protective efficacy of the outer membrane porin F (OprF) against Pseudomonas plecoglossicida in large yellow croaker (Larimichthys crocea)

Large yellow croaker (Larimichthys crocea) farming dominates the marine aquaculture industry in China. However, the epidemic outbreaks of visceral white nodules disease (VWND), caused by bacterial pathogen Pseudomonas plecoglossicida, have emerged as a significant concern within the large yellow croaker industry. Although vaccination is considered to be an effective method for preventing and controlling P. plecoglossicida infection, there is currently no commercially available vaccine targeting this bacterium. In the present study, the outer membrane porin F (OprF) of P. plecoglossicida was characterized and revealed a high sequence similarity with that of other Pseudomonas species. The recombinant OprF protein (rOprF) produced in Escherichia coli was then evaluated for its immunogenicity and protective role against P. plecoglossicida in large yellow croaker. The rOprF was identified to have immunogenicity by Western blot using large yellow croaker anti-P. plecoglossicida sera. Additionally, the indirect immunofluorescence assay (IIFA) provided evidence indicating the surface exposure of OprF in P. plecoglossicida. Fish vaccinated twice via intraperitoneal (IP) injection with the purified rOprF combined with commercial adjuvant ISA 763A VG exhibited a relative percent survival (RPS) of 70.60% after challenge with virulent P. plecoglossicida strain through immersion. The administration of rOprF resulted in a notable increase in specific serum antibody levels and serum lysozyme activity compared to the control groups. The immune-related genes in the spleen and head kidney of rOprF-vaccinated fish were remarkably upregulated compared with the PBS-vaccinated sham group after the P. plecoglossicida challenge. In summary, the findings of this study suggest that rOprF exhibits considerable potential in inducing a robust immune response, making it a viable candidate for vaccination against P. plecoglossicida infection in large yellow croaker.

Discovery of D25, a Potent and Selective MNK Inhibitor for Sepsis-Associated Acute Spleen Injury

Mitogen-activated protein kinase-interacting protein kinases (MNKs) and phosphorylate eukaryotic initiation factor 4E (p-eIF4E) play a critical role in regulating mRNA translation and protein synthesis associated with the development of cancer, metabolism, and inflammation. This study undertakes the modification of a 4-(3-(piperidin-4-yl)-1H-pyrazol-5-yl)pyridine structure, leading to the discovery of 4-(3-(piperidin-4-yl)-1H-pyrazol-5-yl)-1H-pyrrolo[2,3-b]pyridine (D25) as a potent and selective MNK inhibitor. D25 demonstrated inhibitory activity, with IC50 values of 120.6 nM for MNK1 and 134.7 nM for MNK2, showing exceptional selectivity. D25 inhibited the expression of pro-inflammation cytokines in RAW264.7 cells, such as inducible NO synthase, cyclooxygenase-2, and interleukin-6 (IL-6). In the lipopolysaccharide-induced sepsis mouse model, D25 significantly reduced p-eIF4E in spleen tissue and decreased the expression of tumor necrosis factor α, interleukin-1β, and IL-6, and it also reduced the production of reactive oxygen species, resulting in improved organ injury caused by inflammation. This suggests that D25 may provide a potential treatment for sepsis and sepsis-associated acute spleen injury.

Novel insights into DEHP-induced zebrafish spleen damage: Cellular apoptosis, mitochondrial dysfunction, and innate immunity

DEHP (Di(2-ethylhexyl) phthalate) is the most abundant phthalate component detected in environmental samples as it is widely used in the manufacturing of children's toys, medical devices and furniture. Due to its wide prevalence and propensity to accumulate in the food chain, significant concerns have risen about the safety profile of DEHP. Here, we used a zebrafish model to investigate the toxicity mechanisms of DEHP. Our results indicated that exposure to DEHP altered the ROS content in zebrafish spleen and inhibited the activities of antioxidant enzymes SOD and CAT, detoxification enzyme GSH-Px and induced histopathological damage. In addition, elucidated the mechanism of DEHP significantly promoted apoptosis and caused damage in spleen cells through the bax/bcl-2 pathway. Further genetic testing demonstrated significant alterations in mitochondrial biogenesis, fission, and fusion-related genes and suggested potential mechanistic pathways, including GM10532/m6A/FIS1 axis, the STAT3/POA1 axis, and the NFR1/TFAM axis. Serological and genomic analysis indicated that DEHP exposure activated the C3 complement cascade immune pathway and interfered with innate immune function. IBRv2 analysis proposes that innate immunity may serve as a signal indicator of early toxic responses to DEHP pollutants. This study provided comprehensive cellular and genetic data for DEHP toxicity studies and emphasized the need for future management and remediation of DEHP contamination. It also provides data to specifically support the health risk assessments of DEHP, as well as contributing to broader health and environmental research.

[Efficacy of navel application of Jianpiwenyang Gel for chronic diarrhea of spleen and stomach weakness type: a randomized controlled trial and analysis of the mechanism]

OBJECTIVE

To investigate the efficacy of Jianpiwenyang Gel (SSWYG) for treating chronic diarrhea and explore its therapeutic mechanism.

METHODS

Eighty patients with chronic diarrhea of spleen and stomach weakness type were randomized into two groups for interventions with lifestyle adjustment and treatment with bifid triple viable capsules (control group, n=40) or naval application with SSWYG (treatment group, n=40) for one week, after which symptoms of chronic diarrhea were evaluated. The Chinese medicine system pharmacology analysis platform (TCMSP), GeneCards, NCBI, OMIM database and GEO database (GSE14841) were used to obtain the active ingredients and target proteins of SSWYG and chronic diarrhea-related targets. The key targets were obtained by topological analysis for Gene Ontology (GO) and KEGG analyses. The affinity and binding characteristics of SSWYG for specific targets were verified by molecular docking using AutoDock software.

RESULTS

In both groups, gastrointestinal symptom rating scale (GSRS), Bristol Scale and TCM syndrome scores significantly improved after the treatments (P < 0.05), and better effects were observed in the treatment group (P < 0.05). Sixtyeight targets of SSWYG in treating chronic diarrhea were obtained, and 33 most probable ones were screened out by topological analysis. GO and KEGG analyses identified several chronic diarrhea-related pathways including the TNF and IL-17 pathways. Molecular docking study showed good affinity of the core components of SSWYG for the key targets CASP3, JNK, IL1B, IL6, and AKT1. JUN and CASP3 had the lowest binding energy and the highest stable binding energy with multiple major active ingredients of SSWYG.

CONCLUSION

SSWYG can significantly improve clinical symptoms of chronic diarrhea possibly by regulating the TNF and IL-17 as well as other pathways via CASP3 and JUN, suggesting a complex therapeutic mechanism of SSWYG involving multiple ingredients and targets and coordinated regulation of multiple pathways.

Peanut oil odor enhances the immunomodulatory effect on immunosuppressed mice by regulating the cAMP signaling pathway via the brain-spleen axis

The role of sniffing relative to immune function has attracted considerable attention. The present study investigated the immunomodulatory effects of peanut oil odor on cyclophosphamide (CTX)-induced immunosuppressed mice. The subset of mice subjected to prolonged (8 h) sniffing peanut oil odor (PL) demonstrated significantly elevated levels of agouti-related peptide, neuropeptide Y, and glutamate (p < 0.05), whereas it significantly down-regulated the level of γ-aminobutyric acid in the brain (p < 0.05). Furthermore, immunohistochemistry results indicated significantly increased expression of mGluR1/5 and decreased expression of GABABR in the hippocampus and hypothalamus (p < 0.05) of the PL group. Additionally, the PL group had significantly up-regulated expression levels of cAMP, Epac, Rap1, ERK1/2 and PKA (p < 0.05) and remarkably increased phosphorylation of CREB in the cAMP signaling pathway (p < 0.05), which influenced the central nervous system. Moreover, compared with CTX-induced mice, the percentages of peripheral blood T lymphocytes (CD3+CD4+ and CD3+CD8+) and the levels of splenic cytokines (IL-2, IL-4, and TNF-α) were significantly increased following PL treatment (p < 0.05). The PL group also showed significantly up-regulated expression levels of cAMP, p-p65, and p-IκBα in the spleen (p < 0.05) by western blot analysis. In summary, PL intervention significantly up-regulated the expression levels of cAMP in the brain (p < 0.05), with subsequent transfer of cAMP to the spleen which promoted phosphorylation of p65 and IκBα. This series of events enhanced the immunity of mice, which confirmed the regulatory effect of PL on the cAMP signaling pathway, thereby enhancing immune function via the brain-spleen axis.

Schistosome Infection Impacts Hematopoiesis

Helminth infections are common in animals. However, the impact of a helminth infection on the function of hematopoietic stem cells (HSCs) and other hematopoietic cells has not been comprehensively defined. In this article, we describe the hematopoietic response to infection of mice with Schistosoma mansoni, a parasitic flatworm that causes schistosomiasis. We analyzed the frequency or number of hematopoietic cell types in the bone marrow, spleen, liver, thymus, and blood and observed multiple hematopoietic changes caused by infection. Schistosome infection impaired bone marrow HSC function after serial transplantation. Functional HSCs were present in the infected liver. Infection blocked bone marrow erythropoiesis and augmented spleen erythropoiesis, observations consistent with the anemia and splenomegaly prevalent in schistosomiasis patients. This work defines the hematopoietic response to schistosomiasis, a debilitating disease afflicting more than 200 million people, and identifies impairments in HSC function and erythropoiesis.

Low-intensity pulsed ultrasound activated the anti-tumor immunity by irradiating the spleen of mice in 4 T-1 breast cancer

Tumor immunotherapy is booming around the world. However, strategies to activate the immune system and alleviate the immunosuppression still need to be refined. Here, we demonstrate for the first time that low-intensity pulsed ultrasound (LIPUS, spatial average time average intensity (Isata) is 200 mW/cm2, frequency is 0.3 MHz, repetition frequency is 1 kHz, and duty cycle is 20%) triggers the immune system and further reverses the immunosuppressive state in the mouse models of breast cancer by irradiating the spleen of mice. LIPUS inhibited tumor growth and extended survival in mice with 4 T-1 tumors. Further studies had previously shown that LIPUS enhanced the activation of CD4+ and CD8+ T cells in the spleen and led to significant changes in cytokines, as well as induced upregulation of mRNA levels involved in multiple immune regulatory pathways in the spleen. In addition, LIPUS promoted tumor-infiltrating lymphocyte accumulation and CD8+ T cell activation and improved the dynamics of cytokines/chemokines in the tumor microenvironment, resulting in a reversal of the immunosuppressive state of the tumor microenvironment. These results suggest a novel approach to activate the immune response by irradiating the spleen with LIPUS.

Anti-Toxoplasma gondii effect of tylosin in vitro and in vivo

BACKGROUND

Toxoplasma gondii is an important protozoan pathogen with medical and veterinary importance worldwide. Drugs currently used for treatment of toxoplasmosis are less effective and sometimes cause serious side effects. There is an urgent need for the development of more effective drugs with relatively low toxicity.

METHODS

The effect of tylosin on the viability of host cells was measured using CCK8 assays. To assess the inhibition of tylosin on T. gondii proliferation, a real-time PCR targeting the B1 gene was developed for T. gondii detection and quantification. Total RNA was extracted from parasites treated with tylosin and then subjected to transcriptome analysis by RNA sequencing (RNA-seq). Finally, murine infection models of toxoplasmosis were used to evaluate the protective efficacy of tylosin against T. gondii virulent RH strain or avirulent ME49 strain.

RESULTS

We found that tylosin displayed low host toxicity, and its 50% inhibitory concentration was 175.3 μM. Tylsoin also inhibited intracellular T. gondii tachyzoite proliferation, with a 50% effective concentration of 9.759 μM. Transcriptome analysis showed that tylosin remarkably perturbed the gene expression of T. gondii, and genes involved in "ribosome biogenesis (GO:0042254)" and "ribosome (GO:0005840)" were significantly dys-regulated. In a murine model, tylosin treatment alone (100 mg/kg, i.p.) or in combination with sulfadiazine sodium (200 mg/kg, i.g.) significantly prolonged the survival time and raised the survival rate of animals infected with T. gondii virulent RH or avirulent ME49 strain. Meanwhile, treatment with tylosin significantly decreased the parasite burdens in multiple organs and decreased the spleen index of mice with acute toxoplasmosis.

CONCLUSIONS

Our findings suggest that tylosin exhibited potency against T. gondii both in vitro and in vivo, which offers promise for treatment of human toxoplasmosis.

Fabrication of Decellularized Spleen Matrix Derived from Rats

Liver transplantation is the primary treatment for end-stage liver disease. However, the shortage and inadequate quality of donor organs necessitate the development of alternative therapies. Bioartificial livers (BALs) utilizing decellularized liver matrix (DLM) have emerged as promising solutions. However, sourcing suitable DLMs remains challenging. The use of a decellularized spleen matrix (DSM) has been explored as a foundation for BALs, offering a readily available alternative. In this study, rat spleens were harvested and decellularized using a combination of freeze-thaw cycles and perfusion with decellularization reagents. The protocol preserved the microstructures and components of the extracellular matrix (ECM) within the DSM. The complete decellularization process took approximately 11 h, resulting in an intact ECM within the DSM. Histological analysis confirmed the removal of cellular components while retaining the ECM's structure and composition. The presented protocol provides a comprehensive method for obtaining DSM, offering potential applications in liver tissue engineering and cell therapy. These findings contribute to the development of alternative approaches for the treatment of end-stage liver disease.

Serological Antibodies against Kidney, Liver, and Spleen Membrane Antigens as Potential Biomarkers in Patients with Immune Disorders

Immune disorders arise from complex genetic and environmental factors, which lead to dysregulation at the cellular and inflammatory levels and cause tissue damage. Recent research highlights the crucial role of reactive antibodies in autoimmune diseases and graft rejection, but their complex determination poses challenges for clinical use. Therefore, our study aimed to ascertain whether the presence of reactive antibodies against membrane antigens in tissues from both animal models and humans could serve as biomarkers in patients with autoimmune disorders. To address this issue, we examined the binding profile of serological antibodies against a diverse panel of cell membranes from the spleen, liver, and kidney tissues of monkeys, rats, and humans. After developing the cell membrane microarrays, human sera were immunologically assayed. The study was first conducted on sera from two groups, healthy subjects and patients with inflammatory and autoimmune disorders, and then optimized for kidney transplant patient sera. A significant increase in antibody reactivity against specific monkey kidney and spleen membranes was observed in the serum of patients with lupus nephritis, while kidney transplant patients showed a significant enhancement against human tissues and human embryonic kidney 293 cells. These results show the potential importance for clinical and basic research purposes of studying the presence of specific IgG against membrane antigens in patients' serum as potential biomarkers of immune disorders. However, it is important to note that these results need to be verified in further studies with a larger sample size to confirm their relevance.

Quercetin inhibits NF-kB and JAK/STAT signaling via modulating TLR in thymocytes and splenocytes during MSG-induced immunotoxicity: an in vitro approach

BACKGROUND

The most widely used food additive monosodium glutamate (MSG) has been linked to immunopathology. Conversely, quercetin (Q), a naturally occurring flavonoid has been demonstrated to have immunomodulatory functions. Therefore, the purpose of the study is to determine if quercetin can mitigate the deleterious effects of MSG on immune cells, and the possible involvement of TLR, if any.  METHODS AND RESULTS: This study was conducted on Q, to determine how it affects the inflammatory response triggered by MSG in primary cultured thymocytes and splenocytes from rats (n = 5). Q shielded cells by augmenting cell survival and decreasing lactate dehydrogenase leakage during MSG treatment. It decreased IL-1β, IL-6, IL-8, and TNF-α expression and release by hindering NF-kB activation and by inhibiting the JAK/STAT pathway. Moreover, Q prevented NLRP3 activation, lowered IL-1β production, and promoted an anti-inflammatory response by increasing IL-10 production. Q reduced MSG-induced cellular stress and inflammation by acting as an agonist for PPAR-γ and LXRα, preventing NF-kB activation, and lowering MMP-9 production via increasing TIMP-1. Additionally, Q neutralized free radicals, elevated intracellular antioxidants, and impeded RIPK3, which is involved in inflammation induced by oxidative stress, TNF-α, and TLR agonists in MSG-treated cells. Furthermore, it also modulated TYK2 and the JAK/STAT pathway, which exhibited an anti-inflammatory effect.

CONCLUSIONS

MSG exposure is associated with immune cell dysfunction, inflammation, and oxidative stress, and Q modulates TLR to inhibit NF-kB and JAK/STAT pathways, providing therapeutic potential. Further research is warranted to understand Q's downstream effects and explore its potential clinical applications in inflammation.

Comparative transcriptomics analysis identifies crucial genes and pathways during goose spleen development

As the largest peripheral lymphoid organ in poultry, the spleen plays an essential role in regulating the body's immune capacity. However, compared with chickens and ducks, information about the age- and breed-related changes in the goose spleen remains scarce. In this study, we systematically analyzed and compared the age-dependent changes in the morphological, histological, and transcriptomic characteristics between Landes goose (LG; Anser anser) and Sichuan White goose (SWG; Anser cygnoides). The results showed a gradual increase in the splenic weights for both LG and SWG until week 10, while their splenic organ indexes reached the peak at week 6. Meanwhile, the splenic histological indexes of both goose breeds continuously increased with age, reaching the highest levels at week 30. The red pulp (RP) area was significantly higher in SWG than in LG at week 0, while the splenic corpuscle (AL) diameter was significantly larger in LG than in SWG at week 30. At the transcriptomic level, a total of 1710 and 1266 differentially expressed genes (DEGs) between week 0 and week 30 were identified in spleens of LG and SWG, respectively. Meanwhile, a total of 911 and 808 DEGs in spleens between LG and SWG were identified at weeks 0 and 30, respectively. Both GO and KEGG enrichment analysis showed that the age-related DEGs of LG or SWG were dominantly enriched in the Cell cycle, TGF-beta signaling, and Wnt signaling pathways, while most of the breed-related DEGs were enriched in the Neuroactive ligand-receptor interaction, Cytokine-cytokine receptor interaction, ECM-receptor interaction, and metabolic pathways. Furthermore, through construction of protein-protein interaction networks using significant DEGs, it was inferred that three hub genes including BUB1, BUB1B, and TTK could play crucial roles in regulating age-dependent goose spleen development while GRIA2, GRIA4, and RYR2 could be crucial for the breed-specific goose spleen development. These data provide novel insights into the splenic developmental differences between Chinese and European domestic geese, and the identified crucial pathways and genes are helpful for a better understanding of the mechanisms regulating goose immune functions.

Differences in Immune Characteristics and Related Gene Expression in Spleen among Ningxiang, Berkshire Breeds and Their Hybrid Pigs

To investigate the differential immunology in Ningxiang and Berkshire pigs and their F1 offspring (F1 offspring), physiological and biochemical indicators in the plasma and spleen were analyzed. Then, transcriptomic analysis of the spleen identified 1348, 408, and 207 differentially expressed genes (DEGs) in comparisons of Ningxiang vs. Berkshire, Berkshire vs. F1 offspring, and Ningxiang vs. F1 offspring, respectively. In Ningxiang vs. Berkshire pigs, the gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that the DEGs included CD163, MARCO, CXCL14, CCL19, and PPBP, which are associated with immunity. GO and KEGG analyses were also conducted comparing F1 offspring and their parents. The DEGs, including BPIFB1, HAVCR2, CD163, DDX3X, CCR5, and ITGB3, were enriched in immune-related pathways. Protein-protein interaction (PPI) analysis indicated that the EGFR and ITGA2 genes were key hub genes. In conclusion, this study identifies significant immune DEGs in different pig breeds, providing data to support the exploration of breeding strategies for disease resistance in local and crossbred pig populations.

GPR55 Inactivation Diminishes Splenic Responses and Improves Neurological Outcomes in the Mouse Ischemia/Reperfusion Stroke Model

Although strokes are frequent and severe, treatment options are scarce. Plasminogen activators, the only FDA-approved agents for clot treatment (tissue plasminogen activators (tPAs)), are used in a limited patient group. Moreover, there are few approaches for handling the brain's inflammatory reactions to a stroke. The orphan G protein-coupled receptor 55 (GPR55)'s connection to inflammatory processes has been recently reported; however, its role in stroke remains to be discovered. Post-stroke neuroinflammation involves the central nervous system (CNS)'s resident microglia activation and the infiltration of leukocytes from circulation into the brain. Additionally, splenic responses have been shown to be detrimental to stroke recovery. While lymphocytes enter the brain in small numbers, they regularly emerge as a very influential leukocyte subset that causes secondary inflammatory cerebral damage. However, an understanding of how this limited lymphocyte presence profoundly impacts stroke outcomes remains largely unclear. In this study, a mouse model for transient middle cerebral artery occlusion (tMCAO) was used to mimic ischemia followed by a reperfusion (IS/R) stroke. GPR55 inactivation, with a potent GPR55-specific antagonist, ML-193, starting 6 h after tMCAO or the absence of the GPR55 in mice (GPR55 knock out (GPR55ko)) resulted in a reduced infarction volume, improved neurological outcomes, and decreased splenic responses. The inhibition of GPR55 with ML-193 diminished CD4+T-cell spleen egress and attenuated CD4+T-cell brain infiltration. Additionally, ML-193 treatment resulted in an augmented number of regulatory T cells (Tregs) in the brain post-tMCAO. Our report offers documentation and the functional evaluation of GPR55 in the brain-spleen axis and lays the foundation for refining therapeutics for patients after ischemic attacks.

Splenocytes with fucosylation deficiency promote T cell proliferation and differentiation through thrombospondin-1 downregulation

Fucosylation plays a critical role in cell-to-cell interactions and disease progression. However, the effects of fucosylation on splenocytes and their interactions with T cells remain unclear. In this study, we aimed to explore the transcriptome profiles of splenocytes deficient in fucosyltransferase (FUT) 1, an enzyme that mediates fucosylation, and investigate their impact on the proliferation and differentiation of T cells. We analysed and compared the transcriptomes of splenocytes isolated from Fut1 knockout (KO) mice and those from wild-type (WT) mice using RNA-seq. Additionally, we examined the effects of Fut1 KO splenocytes on CD4 T cell proliferation and differentiation, in comparison to WT splenocytes, and elucidated the mechanisms involved. The comparative analysis of transcriptomes between Fut1 KO and WT splenocytes revealed that thrombospondin-1, among the genes related to immune response and inflammation, was the most highly downregulated gene in Fut1 KO splenocytes. The reduced expression of thrombospondin-1 was further confirmed using qRT-PCR and flow cytometry. In coculture experiments, Fut1 KO splenocytes promoted the proliferation of CD4 T cells and drove their differentiation toward Th1 and Th17 cells, compared with WT splenocytes. Moreover, the levels of IL-2, IFN-γ and IL-17 were increased, while IL-10 was decreased, in T cells cocultured with Fut1 KO splenocytes compared with those with WT splenocytes. These effects of Fut1 KO splenocytes on T cells were reversed when thrombospondin-1 was replenished. Taken together, our results demonstrate that splenocytes with Fut1 deficiency promote CD4 T cell proliferation and Th1/Th17 differentiation at least in part through thrombospondin-1 downregulation.

Cell atlas of the Atlantic salmon spleen reveals immune cell heterogeneity and cell-specific responses to bacterial infection

The spleen is a conserved secondary lymphoid organ that emerged in parallel to adaptive immunity in early jawed vertebrates. Recent studies have applied single cell transcriptomics to reveal the cellular composition of spleen in several species, cataloguing diverse immune cell types and subpopulations. In this study, 51,119 spleen nuclei transcriptomes were comprehensively investigated in the commercially important teleost Atlantic salmon (Salmo salar L.), contrasting control animals with those challenged with the bacterial pathogen Aeromonas salmonicida. We identified clusters of nuclei representing the expected major cell types, namely T cells, B cells, natural killer-like cells, granulocytes, mononuclear phagocytes, endothelial cells, mesenchymal cells, erythrocytes and thrombocytes. We discovered heterogeneity within several immune lineages, providing evidence for resident macrophages and melanomacrophages, infiltrating monocytes, several candidate dendritic cell subpopulations, and B cells at distinct stages of differentiation, including plasma cells and an igt + subset. We provide evidence for twelve candidate T cell subsets, including cd4+ T helper and regulatory T cells, one cd8+ subset, three γδT subsets, and populations double negative for cd4 and cd8. The number of genes showing differential expression during the early stages of Aeromonas infection was highly variable across immune cell types, with the largest changes observed in macrophages and infiltrating monocytes, followed by resting mature B cells. Our analysis provides evidence for a local inflammatory response to infection alongside B cell maturation in the spleen, and upregulation of ccr9 genes in igt + B cells, T helper and cd8+ cells, and monocytes, consistent with the recruitment of immune cell populations to the gut to deal with Aeromonas infection. Overall, this study provides a new cell-resolved perspective of the immune actions of Atlantic salmon spleen, highlighting extensive heterogeneity hidden to bulk transcriptomics. We further provide a large catalogue of cell-specific marker genes that can be leveraged to further explore the function and structural organization of the salmonid immune system.