Red Pulp Areas Research Articles

Effects of the commensal microbiota on spleen and mesenteric lymph node immune function: investigation in a germ-free piglet model.

Commensal microbial-host interaction is crucial for host metabolism, growth, development, and immunity. However, research on microbial-host immunity in large animal models has been limited. This study was conducted to investigate the effects of the commensal microbiota on immune function in two model groups: germ-free (GF) and specific-pathogen-free (SPF) piglets. The weight and organ index of the spleen of the GF piglet were larger than those in the SPF piglet (P < 0.05). The histological structure of the red pulp area and mean area of germinal centers were larger in the SPF piglet than in the GF piglet (P < 0.05), whereas the areas of staining of B cells and T cells in the spleen and mesenteric lymph nodes (MLNs) were lower in the GF piglet (P < 0.05). We identified immune-related genes in the spleen and MLNs using RNA sequencing, and used real-time quantitative PCR to analyze the expression of core genes identified in gene set enrichment analysis. The expression levels of genes in the transforming growth factor-β/SMAD3 signaling pathway, Toll-like receptor 2/MyD88/nuclear factor-κB signaling pathway, and pro-inflammatory factor genes IL-6 and TNF-α in the spleen and MLNs were higher in the SPF piglet and in splenic lymphocytes compared with those in the GF and control group, respectively, under treatment with acetic acid, propionic acid, butyric acid, lipopolysaccharide (LPS), or concanavalin A (ConA). The abundances of plasma cells, CD8++ T cells, follicular helper T cells, and resting natural killer cells in the spleen and MLNs were significantly greater in the SPF piglet than in the GF piglet (P < 0.05). In conclusion, the commensal microbiota influenced the immune tissue structure, abundances of immune cells, and expression of immune-related pathways, indicating the importance of the commensal microbiota for spleen and MLNs development and function. In our study, GF piglet was used as the research model, eliminating the interference of microbiota in the experiment, and providing a suitable and efficient large animal research model for exploring the mechanism of "microbial-host" interactions.

Glomerular Hypertrophy and Splenic Red Pulp Degeneration Concurrent with Oxidative Stress in 3xTg-AD Mice Model for Alzheimer's Disease and Its Exacerbation with Sex and Social Isolation.

The continuously expanding field of Alzheimer's disease (AD) research is now beginning to defocus the brain to take a more systemic approach to the disease, as alterations in the peripheral organs could be related to disease progression. One emerging hypothesis is organ involvement in the process of Aβ clearance. In the present work, we aimed to examine the status and involvement of the kidney as a key organ for waste elimination and the spleen, which is in charge of filtering the blood and producing lymphocytes, and their influence on AD. The results showed morphological and structural changes due to acute amyloidosis in the kidney (glomeruli area) and spleen (red pulp area and red/white pulp ratio) together with reduced antioxidant defense activity (GPx) in 16-month-old male and female 3xTg-AD mice when compared to their age- and sex-matched non-transgenic (NTg) counterparts. All these alterations correlated with the anxious-like behavioral phenotype of this mouse model. In addition, forced isolation, a cause of psychological stress, had a negative effect by intensifying genotype differences and causing differences to appear in NTg animals. This study further supports the relevance of a more integrative view of the complex interplay between systems in aging, especially at advanced stages of Alzheimer's disease.

Effects of cage vs. net-floor mixed rearing system on goose spleen histomorphology and gene expression profiles.

Due to the demands for both environmental protection and modernization of the goose industry in China, the traditional goose waterside rearing systems have been gradually transitioning to the modern intensive dryland rearing ones, such as the net-floor mixed rearing system (MRS) and cage rearing system (CRS). However, the goose immune responses to different dryland rearing systems remain poorly understood. This study aimed to investigate and compare the age-dependent effects of MRS and CRS on the splenic histomorphological characteristics and immune-related genes expression profiles among three economically important goose breeds, including Sichuan White goose (SW), Gang goose (GE), and Landes goose (LD). Morphological analysis revealed that the splenic weight and organ index of SW were higher under CRS than under MRS (p < 0.05). Histological observations showed that for SW and LD, the splenic corpuscle diameter and area as well as trabecular artery diameter were larger under MRS than under CRS at 30 or 43 weeks of age (p < 0.05), while the splenic red pulp area of GE was larger under CRS than under MRS at 43 weeks of age (p < 0.05). Besides, at 43 weeks of age, higher mRNA expression levels of NGF, SPI1, and VEGFA in spleens of SW were observed under MRS than under CRS (p < 0.05), while higher levels of HSPA2 and NGF in spleens of LD were observed under MRS than under CRS (p < 0.05). For GE, there were higher mRNA expression levels of MYD88 in spleens under CRS at 30 weeks of age (p < 0.05). Moreover, our correlation analysis showed that there appeared to be more pronounced positive associations between the splenic histological parameters and expression levels of several key immune-related genes under MRS than under CRS. Therefore, it is speculated that the geese reared under MRS might exhibit enhanced immune functions than those under CRS, particularly for SW and LD. Although these phenotypic differences are assumed to be associated with the age-dependent differential expression profiles of HSPA2, MYD88, NGF, SPI1, and VEGFA in the goose spleen, the underlying regulatory mechanisms await further investigations.

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.

CD11b+ миелоидные клетки селезенки при карциномах

Introduction. Splenic myeloid cells include monocytes and myeloid suppressor cells, which are deposited in the spleen and recruited to the sites of chronic inflammation, reparative tissues, and tumor microenvironment. In vivo experiments are mainly used to study the influence of the splenic system on the development and progression of the malignant neoplasm. The characteristics of myeloid elements with a common marker (CD11b) that are located in different splenic morphological and functional zones and their relation to metastases are still poorly studied. We aimed to compare the number and phenotypic features of CD11b+ myeloid cells considering their location in different splenic structural and functional areas in cohorts of patients with and without a malignant neoplasm, as well as depending on hematogenous and lymphogenous metastases in patients with carcinomas of various locations. Materials and methods. To estimate the number of CD11b+ cells with different variants of CD45, CD34, and CD90 expression, we applied the TSA technique. The number of cells of each phenotype per 1 mm2 of follicular, marginal, and red pulp areas was calculated in both groups. The association of cell number with lymphogenic and distant metastases was investigated in the group of patients with malignant neoplasms. Results. The CD11b+ myeloid cell population is heterogeneous and represented by cells at different stages of monocyte/MDSC differentiation, whose numbers predominate in the red pulp. The following changes are associated with carcinomas: a 17-fold increase in the number of promonocytes in the red pulp, a 2-fold decrease in the number of myelopoiesis progenitors in the marginal zone, and a reduction in the quantity of immature monocytoid cells/monoblasts in the marginal zone and the red pulp (5- and 12.5-fold, respectively). The number of CD11b+ myeloid cells with such phenotypes decreased even more in the cases with lymphogenic metastases. No association was found with distant metastases. Conclusion. The number of CD11b+ splenic myeloid cells is associated with carcinomas and lymphogenic metastases. Keywords: spleen, myeloid cells, CD11b, carcinomas, metastasis

Immunohistochemical analyses reveal FoxP3 expressions in spleen and colorectal cancer in mice treated with AOM/DSS, and their suppression by glycyrrhizin.

We previously demonstrated that glycyrrhizin (GL) suppressed inflammation and carcinogenesis in an azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced murine model of colorectal cancer (CC). In this study, we found an accumulation of regulatory T cells (Tregs) in the spleen and suppression by GL in model mice. ICR mice were divided into four groups: Control, GL, CC, and GL-treated CC (CC+GL), and were sacrificed 20 weeks after AOM/DSS treatment. We measured spleen weight, areas of white and red pulp, and CD8+ T cells (cytotoxic T lymphocytes, CTL), and CD11c-positive cells (dendritic cells) in splenic tissues and forkhead box protein 3 (FoxP3)-positive cells (Tregs) in colorectal and splenic tissues. In all cases, the CC group showed a significant increase compared with those in Control group, and GL administration significantly attenuated this increase. These results indicate that Tregs accumulated in the spleen may participate in inflammation-related carcinogenesis by suppressing CTL. We also suggest that GL which binds to high-mobility group box 1 (HMGB1), suppresses carcinogenesis with decreasing Tregs in the spleen. Furthermore, there was an expression of FoxP3 in cancer cells, indicating that it may be involved in the malignant transformation of cancer cells.

Relationship Between Spleen Pathologic Changes and Spleen Stiffness in Portal Hypertension Rat Model

The aim of the study described here was to explore the influence of splenic pathology and hemodynamic parameters on spleen stiffness in portal hypertension (PH). A Sprague‒Dawley rat model of PH (n=34) induced by CCl4 was established, and 9 normal rats were used as controls. All animals underwent a routine ultrasound examination, spleen stiffness measurement (SSM), liver stiffness measurement (LSM), portal vein pressure (PVP) measurement and histopathologic assessment. The diagnostic performance of SSM and LSM in PH was evaluated. SSMs were compared among the groups at different pathologic and hemodynamic levels. Multiple linear regression was used to analyze the factors affecting SSM. SSM had excellent diagnostic efficacy for PH (area under the receiver operating characteristic curve [AUC]=0.900) and was superior to LSM (AUC=0.794). In a rat model of PH, pathologic changes such as splenic sinus widening, thickening of the splenic capsule and an increase in collagen fibers were observed in the spleen. There were significant differences in SSM at different splenic capsule thicknesses and splenic sinus widths (all p values <0.05), but there were no significant differences in the SSM at different levels of the splenic collagen fiber area and red pulp area (all p values >0.05). In addition, there were significant differences in SSM at different levels of portal vein diameter, blood flow and congestion index (all p values <0.05). Multiple linear regression analysis revealed that PVP, portal vein congestion index and splenic capsule thickness were significantly associated with SSM. SSM is a good non-invasive way to assess PH. PVP, splenic capsule thickness and portal vein congestion index are responsible for spleen stiffness but not the proliferation of splenic fibrous tissue.

Additive Therapy of Plasmodium berghei-Induced Experimental Cerebral Malaria via Dihydroartemisinin Combined with Rapamycin and Atorvastatin.

Cerebral malaria (CM), caused by Plasmodium falciparum, is the primary cause of death from severe malaria. Even after immediate parenteral therapy with antimalarial drugs, the mortality rate remains 15 to 25%. Currently, no effective therapeutic agents are available for the radical treatment of CM. Thus, further in-depth explorations of adjuvant therapies in combination with antimalarial drugs are urgently needed. The experimental cerebral malaria (ECM) model was established by infecting C57BL/6 mice with Plasmodium berghei ANKA. Subsequently, infected mice were continuously treated with dihydroartemisinin (DHA) in combination with rapamycin (RAP) and atorvastatin (AVA) for 5 days at different time points, including day 0, day 3, and day 6 postinfection (p.i.). Treatment efficacy was evaluated by comparing behavioral scores, body weight, parasitemia, survival rate, blood-brain barrier (BBB) integrity, and histopathology. The optimal combination therapy of DHA, RAP, and AVA on day 3 p.i. was selected for ECM. This strategy significantly improved survival rate, reduced parasitemia, improved the rapid murine coma and behavioral scale scores and permeability of the BBB, attenuated cerebrovascular and hepatic central venous obstruction and hemozoin deposition in the liver, and decreased the red pulp area of the spleen, which effectively ameliorated neurological damage in ECM. It also improved histopathology and neurological damage caused by ECM. In this study, the optimal therapeutic strategy for ECM was selected, which is expected to be a potential therapy for human CM. IMPORTANCE Although artemisinin-based combination therapies (ACTs) have greatly improved the clinical outcome of cerebral malaria (CM) as a fatal disease that can permanently disable a significant proportion of children even if they survive, new treatment options are needed as Plasmodium falciparum develops resistance to antimalarial drugs. Recent reports suggest that basal treatment with artemisinin derivatives often fails to protect against cell death, neurological damage, and cognitive deficits. In this study, the combination of dihydroartemisinin with rapamycin and atorvastatin improved the current antimalarial outcomes by overcoming the limitations of current antimalarials for CM morbidity and neurological sequelae. This combination offers a new adjunctive treatment for the clinical treatment of human CM in susceptible populations, including children under 5 years old and pregnant women.

Correction of morphofunctional changes in mice thymus and spleen by Rhaponticum uniflorum (L.) DC. extract at cyclophosphamide immunosupression

The aim of the study is to evaluate the effect of R. uniflorum dry extract on morphofunctional state of mice thymus and spleen at cyclophosphamide immunosuppression.Materials and methods. The experiments were carried out on F1 (CBAxC57Bl/6) mice 18–20 g of weight. Immune deficiency was simulated by a single intraperitoneal introduction of cyclophosphamide in the dose 250 mg/kg. R. uniflorum dry extract in the dose 100 mg/kg was administered per os for 14 days. The thymus and spleen were fixed for histological studies on day 16. The thymus total area, the cortex and medulla area, the connective tissue capsule thickness, the spleen white and red pulp area were used to measure on micropreparations stained with hematoxylineosin and azure-eosin. The cell density and the cellular composition were calculated in the thymus cortical substance.Results. The R. uniflorum extract increased the thymus total area and the corticomedullary index by 37 and 26 % (p ≤ 0.05), respectively. The cells density increased in the cortical substance, it decreased in the medulla, as a result “layer inversion” is not observed in any animal of the experimental group. The number of proliferating lymphocytes, blasts and large lymphocytes increased; the number of destructive cells and macrophages decreased in the cortical substance. The spleen white pulp relative volume was 39 % higher than in the control.Conclusions. The R. uniflorum dry extract had an immunocorrective effect on the thymus and spleen morphofunctional state at cyclophosphamid immunosuppression.

Hematological Profile and Spleen Histology Improvement in Diabetic Rats Treated with PLGA Nanoparticles-Ethanol Extract of Jengkol (Archidendron pauciflorum) Fruit Peel

Jengkol (Archidendron pauciflorum) fruit peel-ethanol extract (JFP) contains several chemical compounds that act as antioxidant agents and are considered to have the potential to treat chronic disorders such as diabetes mellitus. Plant extract is generally applied in polylactic-co-glycolic acid (PLGA) nanoparticles due to its efficiency in entering the target organs. This study aims to investigate the effect of PLGA nanoparticles-ethanol extract of jengkol fruit peel (PLGA nanoparticle-JFP) on improving the hematological profile and the spleen histology of streptozotocin-induced diabetic rats. The treatment group was divided into six groups: (1) control group, (2) streptozotocin control (STZ); (3) 10 mg/kg BW of glibenclamide (GLB); (4) 770 mg/kg BW of jengkol fruit peel-ethanol extract (JFP1); (5) 110 mg/kg BW of JFP (JFP2); and (6) 770 mg/kg BW PLGA nanoparticle-JFP (PLGA-JFP). PLGA-JFP group showed a significant increase in erythrocytes and leukocytes counts (7.73x106 ± 0.02 cell/mm3 and 9.68x103 ± 3.0 cell/mm3 respectively), a decrease in lymphocytes and neutrophils percentage (66.5%±0.5% and 28±1.4% respectively) compared to the STZ group, and no significant difference in monocyte, eosinophils, and basophils percentage within groups. On the spleen histology, the white pulp diameter and the red pulp area showed significantly smaller (168.31±10.69μm and 8,01.28± 480.33 μm2 respectively) compared to the STZ group. Almost all parameters showed no significant difference compared to the GLB group but are significantly different from the control group. The administration of PLGA nanoparticle-JFP was proven to reverse hematological parameters and improve the spleen histology but has not yet reversed the diabetic rats’ condition back to normal.

The human splenic microcirculation is entirely open as shown by 3D models in virtual reality

The human spleen is equipped with an organ-specific microcirculation. The initial part of the venous circulation is formed by spleen-specific large microvessels, the sinuses. Sinuses eventually fuse to form venules and veins. For more than 170 years there have been debates, whether splenic red pulp capillaries join sinuses, i.e., whether the microcirculation is closed or open—or even simultaneously closed and open. We have now solved this question by three-dimensional reconstruction of a limited number of immunostained serial sections of red and white pulp areas, which were visualized in virtual reality. Splenic capillaries have special end structures exhibiting multiple small diverging endothelial cell processes, which always keep a certain distance to the walls of sinuses. Only very few capillary ends were difficult to diagnose. Positive identification of these end structures permits to conclude that the human splenic microcirculation is entirely open. This is also true for the perifollicular capillary network and for capillaries close to red pulp venules. Follicles are supplied by a relatively dense open perifollicular capillary net, which is primarily, but not exclusively, fed by sheathed and few non-sheathed capillaries from the surrounding red pulp network.

LBMPL Vaccine Therapy Induces Progressive Organization of the Spleen Microarchitecture, Improved Th1 Adaptative Immune Response and Control of Parasitism in Leishmania infantum Naturally Infected Dogs.

The spleen plays a central role in human and canine visceral leishmaniasis, where the activation of the immune response occurs in one of the tissues where Leishmania infantum reproduces. Therefore, this organ is both a target to understand the mechanisms involved in the parasite control and a parameter for assessing the therapeutic response. In this sense, this study aimed to evaluate the main histological, immunological and parasitological aspects in the spleen of symptomatic dogs naturally infected by L. infantum treated with the therapeutic vaccine LBMPL. For this, dogs were divided into four groups: dogs uninfected and untreated (NI group); L. infantum-infected dogs that were not treated (INT group); L. infantum-infected dogs that received treatment only with monophosphoryl lipid A adjuvant (MPL group); and L. infantum-infected dogs that received treatment with the vaccine composed by L. braziliensis promastigote proteins associated with MPL adjuvant (LBMPL group). Ninety days after the therapeutics protocol, the dogs were euthanized and the spleen was collected for the proposed evaluations. Our results demonstrated a reduction of hyperplasia of red pulp and follicular area of white pulp, increased mRNA expression of IFN-γ, TNF-α, IL-12 and iNOS, and decreased IL-10 and TGF-β1, and intense reduction of splenic parasitism in dogs treated with the LBMPL vaccine. These results possibly suggest that the pro-inflammatory environment promoted the progressive organization of the splenic architecture favoring the cellular activation, with consequent parasite control. Along with previously obtained data, our results propose the LBMPL vaccine as a possible treatment strategy for canine visceral leishmaniasis (CVL).

Microbial sophorolipids inhibit colorectal tumour cell growth in vitro and restore haematocrit in Apcmin+/− mice

Sophorolipids are glycolipid biosurfactants consisting of a carbohydrate sophorose head with a fatty acid tail and exist in either an acidic or lactonic form. Sophorolipids are gaining interest as potential cancer chemotherapeutics due to their inhibitory effects on a range of tumour cell lines. Currently, most anti-cancer studies reporting the effects of sophorolipids have focused on lactonic preparations with the effects of acidic sophorolipids yet to be elucidated. We produced a 94% pure acidic sophorolipid preparation which proved to be non-toxic to normal human colonic and lung cells. In contrast, we observed a dose-dependent reduction in viability of colorectal cancer lines treated with the same preparation. Acidic sophorolipids induced apoptosis and necrosis, reduced migration, and inhibited colony formation in all cancer cell lines tested. Furthermore, oral administration of 50 mg kg−1 acidic sophorolipids over 70 days to Apcmin+/− mice was well tolerated and resulted in an increased haematocrit, as well as reducing splenic size and red pulp area. Oral feeding did not affect tumour numbers or sizes in this model. This is the first study to show that acidic sophorolipids dose-dependently and specifically reduces colon cancer cell viability in addition to reducing tumour-associated bleeding in the Apcmin+/− mouse model.Key points• Acidic sophorolipids are produced by yeast species such as Starmerella bombicola.• Acidic sophorolipids selectively killed colorectal cells with no effect on healthy gut epithelia.• Acidic sophorolipids reduced tumour-associated gut bleed in a colorectal mouse model.Graphical abstract

The structure of spleen in the long-legged buzzard (Buteo rufinus): Histological and immunohistochemical study.

The aim of this study was to examine the structure of the spleen in the long-legged buzzard (Buteo rufinus) by histologically and the distribution of the catalase in the spleen by immunohistochemically. The tissue materials were taken from three healthy long-legged buzzards provided by permission of the General Directorate of Nature Protection and National Parks (Ankara, Turkey). The long-legged buzzard spleen is surrounded by smooth muscle cells and fibrous connective tissue. In addition, trabecular structures are not found in the capsule. The separation of white and red pulp areas could not be precisely determined. Plasma cells were detected especially around the lymphoid follicles and lymphatic follicles and Schweigger-Seidel cells were formed by reticulum strands. Alcian blue positive reaction was determined in Schweigger-Seidel cells and endothelial cells of the long-legged buzzard spleen. The intense cytoplasmic catalase immunoreactivity was observed in the Schweigger-Seidel cells and nuclear in some red pulp cells of the long-legged buzzard spleen.Consequently, determination of the histological structure and catalase immunoreactivity of the spleen on the long-legged buzzard by this study could be support for the future researches.

Exposure to a combination of MWCNTs and DBP causes splenic toxicity in mice

The large conjugated π bond in the molecular structure of carbon nanotubes (CNTs) interacts with the benzene ring structure in di (n-butyl) phthalates (DBP) through a π - π bond. Compounds of CNTs and DBP form easily, becoming another environmental pollutant of concern. We explore whether CNTs entering animals slow down the degradation of the DBP adsorbed in the CNT cavity, thereby prolonging the "hormonal activity" of DBP. In our study, male BALb/c mice were used as experimental subjects divided into four groups: the control group; the multi-walled carbon nanotubes (MWCNTs) exposure group (10mg/kg/d); the DBP exposure group (2.15 mg/kg/d); and the compound exposure group (MWCNTs + DBP). After 30 days of exposure, the mice were sacrificed and their spleens used for immunotoxicology study. The results showed that the exposure groups exhibited splenomegaly and suffered severe oxidative damage to the spleen. In the compound exposure group: levels of IgA and IgG in the serum of the mice changed, and were significantly different from levels in both the MWCNTs and DBP exposure groups (p <0.05); the pathological sections of the spleen showed that the boundary between the white pulp area (WP) and the red pulp area (RP) was blurred, that the cell arrangement was loose, and that more red blood cells were retained in the spleen. Proteomics mass spectrometry analysis showed that compared with the control group, 70 proteins were up-regulated and 27 proteins were down-regulated in the MWCNTs group, 36 proteins were up-regulated and 23 proteins were down-regulated in the DBP group, 87 proteins were up-regulated and 21 proteins were down-regulated in the compound exposure group. The results of GO enrichment analysis and KEGG enrichment analysis of the differentially expressed proteins showed that the compound exposure harmed the spleen antigen recognition, processing, and presentation, inhibited the activation and proliferation of B cells and T cells, and hindered the adaptive immune responses. Our results showed that MWCNTs and DBP compounds can damage the spleen, and impair the innate and adaptive immune functions of the body.

A New Murine Model of Primary Autoimmune Hemolytic Anemia (AIHA).

Loss of humoral tolerance to red blood cells (RBCs) can lead to autoimmune hemolytic anemia (AIHA), a severe, and sometimes fatal disease. Patients with AIHA present with pallor, fatigue, decreased hematocrit, and splenomegaly. While secondary AIHA is associated with lymphoproliferative disorders, infections, and more recently, as an adverse event secondary to cancer immunotherapy, the etiology of primary AIHA is unknown. Several therapeutic strategies are available; however, there are currently no licensed treatments for AIHA and few therapeutics offer treatment-free durable remission. Moreover, supportive care with RBC transfusions can be challenging as most autoantibodies are directed against ubiquitous RBC antigens; thus, virtually all RBC donor units are incompatible. Given the severity of AIHA and the lack of treatment options, understanding the cellular and molecular mechanisms that facilitate the breakdown in tolerance would provide insight into new therapeutics. Herein, we report a new murine model of primary AIHA that reflects the biology observed in patients with primary AIHA. Production of anti-erythrocyte autoantibodies correlated with sex and age, and led to RBC antigen modulation, complement fixation, and anemia, as determined by decreased hematocrit and hemoglobin values and increased reticulocytes in peripheral blood. Moreover, autoantibody-producing animals developed splenomegaly, with altered splenic architecture characterized by expanded white pulp areas and nearly diminished red pulp areas. Additional analysis suggested that compensatory extramedullary erythropoiesis occurred as there were increased frequencies of RBC progenitors detectable in the spleen. No significant correlations between AIHA onset and inflammatory status or microbiome were observed. To our knowledge, this is the first report of a murine model that replicates observations made in humans with idiopathic AIHA. Thus, this is a tractable murine model of AIHA that can serve as a platform to identify key cellular and molecular pathways that are compromised, thereby leading to autoantibody formation, as well as testing new therapeutics and management strategies.

Combining microfluidics with machine learning algorithms for RBC classification in rare hereditary hemolytic anemia

Combining microfluidics technology with machine learning represents an innovative approach to conduct massive quantitative cell behavior study and implement smart decision-making systems in support of clinical diagnostics. The spleen plays a key-role in rare hereditary hemolytic anemia (RHHA), being the organ responsible for the premature removal of defective red blood cells (RBCs). The goal is to adapt the physiological spleen filtering strategy for in vitro study and monitoring of blood diseases through RBCs shape analysis. Then, a microfluidic device mimicking the slits of the spleen red pulp area and video data analysis are combined for the characterization of RBCs in RHHA. This microfluidic unit is designed to evaluate RBC deformability by maintaining them fixed in planar orientation, allowing the visual inspection of RBC’s capacity to restore their original shape after crossing microconstrictions. Then, two cooperative learning approaches are used for the analysis: the majority voting scheme, in which the most voted label for all the cell images is the class assigned to the entire video; and the maximum sum of scores to decide the maximally scored class to assign. The proposed platform shows the capability to discriminate healthy controls and patients with an average efficiency of 91%, but also to distinguish between RHHA subtypes, with an efficiency of 82%.

Gross and Histopathological Findings of Naturally Occurring Anaplasma marginale Infection in Cattle

Background: Bovine anaplasmosis is a haemolytic disease of cattle caused by an obligate intra-erythrocytic bacterium Anaplasma marginale and is characterized by high fever, dyspnoea, anaemia, icterus, decreased milk production and death. The present study was undertaken to study the gross and histopathological changes caused by naturally occurring A. marginale infection in cattle. Methods: History and clinical examination of animals revealed inappetance/anorexia, presence of tick infestation, high fever, pale or icteric mucous membranes, tachycardia, dyspnoea and lymphadenomegaly. The diagnosis of A. marginale infection was done by blood smear examination and further confirmed by polymerase chain reaction and sequencing analysis. During the present study, two animals did not respond to treatment and were succumbed to A. marginale infection. A systematic post-mortem examination was performed on the animals and gross lesions were recorded. The tissue samples from various vital organs such as heart, lungs, liver, spleen and kidneys were collected in 10% neutral buffered formalin and processed for histopathological examination. Result: The post-mortem examination revealed emaciated carcass with yellowish discoloration of serosal surfaces of the abdominal organs, haemorrhagic heart, congestion of lungs, hepatomegaly, distension of the gallbladder and splenomegaly. The major histopathological changes noticed included myocardial degeneration and necrosis, interstitial pneumonic changes, degenerative changes in hepatocytes and renal tubular epithelial cells, enlargement of red pulp area of spleen with histiocytic proliferation and hemosiderosis. Histopathology also revealed inflammatory process characterized by infiltration of mononuclear cells in various organs. Very few reports are available on the pathological aspects of A. marginale infection and thus the outcome of the present study can yield valuable information to aid in the diagnosis of bovine anaplasmosis under field conditions.

Morphohistometric Evaluation of Embryonic Development of Spleen in Chicken

The aim of this study was to evaluate the morphohistometric development of chick spleen by considering specific embryonic periods. For the study, spleens obtained from 18 Babcock White Leghorn chick embryos on the 13th, 16th and 21st days of incubation were used. The sections were stained with Crossmon’s trichrome stain and Pappenheim’s panoptic stain and differential leukocyte counts were made in the blood smears. In the measurements, an increase in the spleen volume, embryo weight and vitellus sac weight were determined. There was an increase between the 13th and 16th21st days in spleen volume. The highest heterophil granulocytes (74.83%) and lowest lymphocyte ratio (23%) were found on the 21st day. On the 13th day, there were very few lymphocytes around the vessels. On the 16th day, arteria centralis were frequently encountered and periarteriolar lymphoid tissue formation with lymphocyte accumulations around them started to develop in the spleen parenchyma. The red and white pulp areas could be easily distinguished in splenic parenchyma on the 21st day. It was concluded that the structures characterised by lymphocyte infiltrations in the spleen parenchyma were formed and caused changes in the number of lymphocytes in peripheral blood during the embryonal period.

Xylosyltransferase 2 deficiency and organ homeostasis.

In this paper we characterize the function of Xylosyltransferase 2 (XylT2) in different tissues to investigate the role XylT2 has in the proteoglycan (PG) biochemistry of multiple organs. The results show that in all organs examined there is a widespread and significant decrease in total XylT activity in Xylt2 knock out mice (Xylt2-/-). This decrease results in increased organ weight differences in lung, heart, and spleen. These findings, in addition to our previous findings of increased liver and kidney weight with loss of serum XylT activity, suggest systemic changes in organ function due to loss of XylT2 activity. The Xylt2-/- mice have splenomegaly due to enlargement of the red pulp area and enhanced pulmonary response to bacterial liposaccharide. Tissue glycosaminoglycan composition changes are also found. These results demonstrate a role of XylT2 activity in multiple organs and their PG content. Because the residual XylT activity in the Xylt2-/- is due to xylosyltransferase 1 (XylT1), these studies indicate that both XylT1 and XylT2 have important roles in PG biosynthesis and organ homeostasis.