Modulation of the mucosal immune response of red tilapia (Oreochromis sp.) against columnaris disease using a biomimetic-mucoadhesive nanovaccine

Columnaris, a highly contagious bacterial disease caused by Flavobacterium columnare, is recognized as one of the most important infectious diseases in farmed tilapia, especially during the fry and fingerling stages of production. The disease is associated with characteristic lesions in the mucosa of affected fish, particularly their skin and gills. Vaccines delivered via the mucosa are therefore of great interest to scientists developing vaccines for this disease. In the present study, we characterized field isolates of F. columnare obtained from clinical columnaris outbreaks in red tilapia to select an isolate to use as a candidate for our vaccine study. This included characterizing its colony morphology, genotype and virulence status. The isolate was incorporated into a mucoadhesive polymer chitosan-complexed nanovaccine (CS-NE), the efficacy of which was determined by experimentally infecting red tilapia that had been vaccinated with the nanoparticles by immersion. The experimental infection was performed 30-days post-vaccination (dpv), which resulted in 89% of the unvaccinated control fish dying, while the relative percentage survival (RPS) of the CS-NE vaccinated group was 78%. Histology of the mucosal associated lymphoid tissue (MALT) showed a significantly higher presence of leucocytes and a greater antigen uptake by the mucosal epithelium in CS-NE vaccinated fish compared to control fish and whole cell vaccinated fish, respectively, and there was statistically significant up-regulation of IgT, IgM, TNF α, IL1-β and MHC-1 genes in the gill of the CS-NE vaccinated group. Overall, the results of our study confirmed that the CS-NE particles achieved better adsorption onto the mucosal surfaces of the fish, elicited great vaccine efficacy and modulated the MALT immune response better than the conventional whole cell-killed vaccine, demonstrating the feasibility of the mucoadhesive nano-immersion vaccine as an effective delivery system for the induction of a mucosal immune response against columnaris disease in tilapia.

Full recombinant flagellin B from Vibrio anguillarum (rFLA) and its recombinant D1 domain (rND1) promote a pro-inflammatory state and improve vaccination against P. salmonis in Atlantic salmon (S. salar)

Flagellin is the major component of the flagellum, and a ligand for Toll-like receptor 5. As reported, recombinant flagellin (rFLA) from Vibrio anguillarum and its D1 domain (rND1) are able to promote in vitro an upregulation of pro-inflammatory genes in gilthead seabream (Sparus aurata) and rainbow trout (Oncorhynchus mykiss) macrophages. This study evaluated the in vitro and in vivo stimulatory/adjuvant effect for rFLA and rND1 during P. salmonis vaccination in Atlantic salmon (Salmo salar). We demonstrated that rFLA and rND1 are molecules able to generate an acute upregulation of pro-inflammatory cytokines (IL-1β, IL-8, IL-12β), allowing the expression of genes associated with T-cell activation (IL-2, CD4, CD8β), and differentiation (IFNγ, IL-4/13, T-bet, Eomes, GATA3), in a differential manner, tissue/time dependent way. Altogether, our results suggest that rFLA and rND1 are valid candidates to be used as an immuno-stimulant or adjuvants with existing vaccines in farmed salmon.

Human Commensal Prevotella histicola Ameliorates Disease as Effectively as Interferon-Beta in the Experimental Autoimmune Encephalomyelitis

Gut microbiota has emerged as an important environmental factor in the pathobiology of multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system (CNS). Both genetic and environmental factors have been shown to play an important role in MS. Among genetic factors, the human leukocyte antigen (HLA) class II allele such as HLA-DR2, DR3, DR4, DQ6, and DQ8 show the association with the MS. We have previously used transgenic mice expressing MS susceptible HLA class II allele such as HLA-DR2, DR3, DQ6, and DQ8 to validate significance of HLA alleles in MS. Although environmental factors contribute to 2/3 of MS risk, less is known about them. Gut microbiota is emerging as an imporatnt environmental factor in MS pathogenesis. We and others have shown that MS patients have distinct gut microbiota compared to healthy control (HC) with a lower abundance of Prevotella. Additionally, the abundance of Prevotella increased in patients receiving disease-modifying therapies (DMTs) such as Copaxone and/or Interferon-beta (IFNβ). We have previously identified a specific strain of Prevotella (Prevotella histicola), which can suppress experimental autoimmune encephalomyelitis (EAE) disease in HLA-DR3.DQ8 transgenic mice. Since Interferon-β-1b [IFNβ (Betaseron)] is a major DMTs used in MS patients, we hypothesized that treatment with the combination of P. histicola and IFNβ would have an additive effect on the disease suppression. We observed that treatment with P. histicola suppressed disease as effectively as IFNβ. Surprisingly, the combination of P. histicola and IFNβ was not more effective than either treatment alone. P. histicola alone or in combination with IFNβ increased the frequency and number of CD4+FoxP3+ regulatory T cells in the gut-associated lymphoid tissue (GALT). Treatment with P. histicola alone, IFNβ alone, and in the combination decreased frequency of pro-inflammatory IFN-γ and IL17-producing CD4+ T cells in the CNS. Additionally, P. histicola alone or IFNβ alone or the combination treatments decreased CNS pathology, characterized by reduced microglia and astrocytic activation. In conclusion, our study indicates that the human gut commensal P. histicola can suppress disease as effectively as commonly used MS drug IFNβ and may provide an alternative treatment option for MS patients.

Organized lymphatic tissue (BALT) in lungs of rhesus monkeys after air pollutant exposure

The presence of bronchus-associated lymphoid tissue (BALT) and its size in humans largely depends upon age. It is detected in 35% of children less than 2 years of age, but absent in the healthy adult lung. Environmental gases or allergens may have an effect on the number of BALT. Lungs of rhesus macaque monkeys were screened by histology for the presence, size, and location of BALT after exposure to filtered air for 2, 6, 12, or 36 months or 12 and 36 months to ozone or 2, 12, or 36 months of house dust mite or a combination of ozone and house dust mite for 12 months. In the lungs of monkeys housed in filtered air for 2 months, no BALT was identified. After 6, 12, or 36 months, the number of BALT showed a significantly increased correlation with age in monkeys housed in filtered air. After 2 months of episodic house dust mite (HDM) exposure, no BALT was found. Monkeys exposed to HDM or HDM + ozone did not show a significant increase in BALT compared to monkeys housed in filtered air. However, monkeys exposed to ozone alone did show significant increases in BALT compared to all other groups. In particular, there were frequent accumulations of lymphocytes in the periarterial space of ozone exposed animals. In conclusion, BALT in rhesus monkeys housed under filtered air conditions is age-dependent. BALT significantly increased in monkeys exposed to ozone in comparison with monkeys exposed to HDM.

B Cell Activating Factor (BAFF) Is Required for the Development of Intra-Renal Tertiary Lymphoid Organs in Experimental Kidney Transplantation in Rats

Intra-renal tertiary lymphoid organs (TLOs) are associated with worsened outcome in kidney transplantation (Ktx). We used an anti-BAFF (B cell activating factor) intervention to investigate whether BAFF is required for TLO formation in a full MHC-mismatch Ktx model in rats. Rats received either therapeutic immunosuppression (no rejection, NR) or subtherapeutic immunosuppression (chronic rejection, CR) and were sacrificed on d56. One group additionally received an anti-BAFF antibody (CR + AB). Intra-renal T (CD3⁺) and B (CD20⁺) cells, their proliferation (Ki67⁺), and IgG⁺ plasma cells were analyzed by immunofluorescence microscopy. Formation of T and B cell zones and TLOs was assessed. Intra-renal expression of TLO-promoting factors, molecules of T:B crosstalk, and B cell differentiation was analyzed by qPCR. Intra-renal B and T cell zones and TLOs were detected in CR and were associated with elevated intra-renal mRNA expression of TLO-promoting factors, including CXCL13, CCL19, lymphotoxin-β, and BAFF. Intra-renal plasma cells were also elevated in CR. Anti-BAFF treatment significantly decreased intra-renal B cell zones and TLO, as well as intra-renal B cell-derived TLO-promoting factors and B cell differentiation markers. We conclude that BAFF-dependent intra-renal B cells promote TLO formation and advance local adaptive alloimmune responses in chronic rejection.

Induction of systemic immunity through nasal-associated lymphoid tissue (NALT) of mice intranasally immunized with Brucella abortus malate dehydrogenase-loaded chitosan nanoparticles

Infection with Brucella abortus causes contagious zoonosis, brucellosis, and leads to abortion in animals and chronic illness in humans. Chitosan nanoparticles (CNs), biocompatible and nontoxic polymers, acts as a mucosal adjuvant. In our previous study, B. abortus malate dehydrogenase (Mdh) was loaded in CNs, and it induced high production of pro-inflammatory cytokines in THP-1 cells and systemic IgA in BALB/C mice. In this study, the time-series gene expression analysis of nasal-associated lymphoid tissue (NALT) was performed to identify the mechanism by which Mdh affect the target site of nasal immunization. We showed that intranasal immunization of CNs-Mdh reduced cell viability of epithelial cells and muscle cells at first 1 h, then induced cellular movement of immune cells such as granulocytes, neutrophils and lymphocytes at 6h, and activated IL-6 signaling pathway at 12h within NALT. These activation of immune cells also promoted signaling pathway for high-mobility group box 1 protein (HMGB1), followed by the maturation of DCs required for mucosal immunity. The CNs also triggered the response to other organism and inflammatory response, showing it is immune-enhancing adjuvant. The ELISA showed that significant production of specific IgA was detected in the fecal excretions and genital secretions from the CNs-Mdh-immunized group after 2 weeks-post immunization. Collectively, these results suggest that B. abortus Mdh-loaded CNs triggers activation of HMGB1, IL-6 and DCs maturation signaling within NALT and induce production of systemic IgG and IgA.

Longitudinal bioluminescent imaging of HIV-1 infection during antiretroviral therapy and treatment interruption in humanized mice

Non-invasive bioluminescent imaging (NIBLI) of HIV-1 infection dynamics allows for real-time monitoring of viral spread and the localization of infected cell populations in living animals. In this report, we describe full-length replication-competent GFP and Nanoluciferase (Nluc) expressing HIV-1 reporter viruses from two clinical transmitted / founder (T/F) strains: TRJO.c and Q23.BG505. By infecting humanized mice with these HIV-1 T/F reporter viruses, we were able to directly monitor longitudinal viral spread at whole-animal resolution via NIBLI at a sensitivity of as few as 30-50 infected cells. Bioluminescent signal strongly correlated with HIV-1 infection and responded proportionally to virus suppression in vivo in animals treated daily with a combination antiretroviral therapy (cART) regimen. Longitudinal NIBLI following cART withdrawal visualized tissue-sites that harbored virus during infection recrudescence. Notably, we observed rebounding infection in the same lymphoid tissues where infection was first observed prior to ART treatment. Our work demonstrates the utility of our system for studying in vivo viral infection dynamics and identifying infected tissue regions for subsequent analyses.

Secondary lymphoid tissue and costimulation-blockade resistant rejection: A nonhuman primate renal transplant study

Naïve T cell activation requires antigen presentation combined with costimulation through CD28, both of which optimally occur in secondary lymphoid tissues such as lymph nodes and the spleen. Belatacept impairs CD28 costimulation by binding its ligands, CD80 and CD86, and in doing so, impairs de novo alloimmune responses. However, in most patients belatacept is ineffective in preventing allograft rejection when used as a monotherapy, and adjuvant therapy is required for control of costimulation-blockade resistant rejection (CoBRR). In rodent models, impaired access to secondary lymphoid tissues has been demonstrated to reduce alloimmune responses to vascularized allografts. Here we show that surgical maneuvers, lymphatic ligation, and splenectomy, designed to anatomically limit access to secondary lymphoid tissues, control CoBRR and facilitate belatacept monotherapy in a nonhuman primate model of kidney transplantation without adjuvant immunotherapy. We further demonstrate that animals sustained on belatacept monotherapy progressively develop an increasingly naïve T and B cell repertoire, an effect that is accelerated by splenectomy and lost at the time of belatacept withdrawal and rejection. These pilot data inform the role of secondary lymphoid tissues on the development of CoBRR and the use of costimulation molecule-focused therapies.

Protective Effect of Hesperidin on the Oxidative Stress Induced by an Exhausting Exercise in Intensively Trained Rats

Intensive exercise can lead to oxidative stress, which can be particularly deleterious for lymphoid tissues. Hesperidin has demonstrated its antioxidant activity, but few studies focus on its influence on intensive training. The aim of this study was to assess the impact of hesperidin on the oxidant/antioxidant status of lymphoid tissues after an intensive training program. Wistar rats were trained for five weeks (five days per week), including two exhaustion tests plus three trainings per week. During this period, animals were orally administrated with 200 mg/kg of hesperidin or vehicle (three days per week). The oxidative status was determined before, immediately after and 24 h after an additional exhaustion test. The production of reactive oxygen species (ROS) by peritoneal macrophages, superoxide dismutase (SOD) and catalase activities in spleen, thymus and liver, and hepatic glutathione peroxidase activity (GPx) were assessed. Hesperidin prevented an increase in ROS production induced by the additional exhaustion test. Likewise, hesperidin avoided a decrease in SOD and catalase activities in the thymus and spleen that was found after the additional exhaustion test. The antioxidant effects of hesperidin were associated with a higher performance in the assessed training model. These results suggest that hesperidin, acting as an antioxidant, can prevent oxidative stress induced by exercise and improve exercise performance.

Selenium Rescues Aflatoxin B1-Inhibited T Cell Subsets and Cytokine Levels in Cecal Tonsil of Chickens

Cecal tonsil is the largest peripheral lymphoid organ of the gut-associated lymphoid tissue executing immune function. To evaluate the protective effect of selenium (Se) on the cecal tonsil of chicken exposed to aflatoxin B₁ (AFB₁), 144 1-day-old healthy Cobb chickens were randomly divided into four groups, and fed with basal diet (control group), 0.6 mg/kg AFB₁ (AFB₁ group), 0.4 mg/kg Se supplement (+Se group), and 0.6 mg/kg AFB₁ + 0.4 mg/kg Se supplement (AFB₁ + Se group) for 21 days, respectively. The results showed that AFB₁ significantly decreased the percentages of CD3⁺, CD3⁺CD4⁺, CD3⁺CD8⁺ T cells, and the CD4⁺/CD8⁺ ratio, and suppressed the expressions of IL-2, IL-4, TNF-α, and IFN-γ mRNA in the cecal tonsil. However, Selenium (Se) supplied in the diets restored the percentages of T cell subsets, the CD4⁺/CD8⁺ ratio, and mRNA expressions of cytokines in the AFB₁ group to be close to those in the control group, and did not exhibit obvious toxicity to the cecal tonsil. These results indicated that Se exerted protective effect against AFB₁ on the functions of cecal tonsil, and also partially uncovered a new role of Se that could protect cecal tonsil of chickens from immunotoxicity of AFB₁.

Hesperidin Effects on Gut Microbiota and Gut-Associated Lymphoid Tissue in Healthy Rats

Hesperidin, found in citrus fruits, has shown a wide range of biological properties. Nonetheless, a more in-depth investigation is required on the effects on the immune system, and in particular, on the gut-associated lymphoid tissue, together with its relationship with the gut microbiota. Therefore, we aimed to establish the influence of oral hesperidin administration on the intestinal lymphoid tissue and on the gut microbiota composition in healthy animals. Lewis rats were orally administrated 100 or 200 mg/kg hesperidin three times per week for four weeks. Microbiota composition and IgA-coated bacteria were determined in caecal content. Mesenteric lymph node lymphocyte (MLNL) composition and functionality were assessed. IgA, cytokines, and gene expression in the small intestine were quantified. Hesperidin administration resulted in a higher number of bacteria and IgA-coated bacteria, with changes in microbiota composition such as higher Lactobacillus proportion. Hesperidin was also able to increase the small intestine IgA content. These changes in the small intestine were accompanied by a decrease in interferon-γ and monocyte chemotactic protein-1 concentration. In addition, hesperidin increased the relative proportion of TCRαβ+ lymphocytes in MLNL. These results show the immunomodulatory actions of hesperidin on the gut-associated lymphoid tissue and reinforce its role as a prebiotic.

Can benign lymphoid tissue changes in 18F-FDG PET/CT predict response to immunotherapy in metastatic melanoma?

BACKGROUND

An association between immune-related adverse events (irAEs) caused by immunotherapeutic agents and the clinical benefit of immunotherapy has been suggested. We retrospectively evaluated by means of 18F-FDG PET/CT lymphoid tissue changes in the mediastinal/hilar lymph nodes and the spleen in response to ipilimumab administration in metastatic melanoma.

METHODS

A total of 41 patients with unresectable metastatic melanoma underwent 18F-FDG PET/CT before the start of ipilimumab (baseline PET/CT), after two cycles (interim PET/CT) and at the end of treatment (late PET/CT). Data analysis was focused on the mediastinal/hilar lymph nodes and the spleen. The patients' best clinical response (BCR) was used as reference.

RESULTS

According to the BCR reference, 31 patients showed disease control (DC) and 10 patients showed progressive disease (PD). Mediastinal/hilar lymph node evaluation revealed that in total 4 patients in the interim or late PET/CT (10%) demonstrated a 'sarcoid-like lymphadenopathy' as response to treatment (LN-positive). All LN-positive patients responded to ipilimumab with DC. On the other hand, no significant differences between the DC and PD groups regarding both semi-quantitative and quantitative 18F-FDG PET spleen-related parameters at baseline and as response to treatment were detected.

CONCLUSION

Based on our findings, 10% patients in the interim or late PET/CT showed 'sarcoid-like lymphadenopathy' as response to treatment. All these patients showed disease control, implying a relation between the appearance of sarcoid-like lymphadenopathy and the clinical benefit of anti-CTLA-4 therapy. On the other hand, quantitative 18F-FDG PET analysis of the spleen showed a poor performance in predicting clinical benefit to ipilimumab.

Participation of the spleen in the IgA immune response in the gut

The role of the spleen in the induction of an immune response to orally administered antigens is still under discussion. Although it is well known that after oral antigen administration specific germinal centres are not only formed in the Peyers patches (PP) and the mesenteric lymph nodes (mLN) but also in the spleen, there is still a lack of functional data showing a direct involvement of splenic B cells in an IgA immune response in the gut. In addition, after removal of mLN a high level of IgA+ B cells was observed in the gut. Therefore, in this study we analysed the role of the spleen in the induction of IgA+ B cells in the gut after mice were orally challenged with antigens. Here we have shown that antigen specific splenic IgM+ B cells after in vitro antigen stimulation as well as oral immunisation of donor mice were able to migrate into the gut of recipient mice, where they predominantly switch to IgA+ plasma cells. Furthermore, stimulation of recipient mice by orally administered antigens enhanced the migration of the splenic B cells into the gut as well as their switch to IgA+ plasma cells. Removal of the mLN led to a higher activation level of the splenic B cells. Altogether, our results imply that splenic IgM+ B cells migrate in the intestinal lamina propria, where they differentiate into IgA+ plasma cells and subsequently proliferate. In conclusion, we demonstrated that the spleen plays a major role in the gut immune response serving as a reservoir of immune cells that migrate to the site of antigen entrance.

Developmental Exposure to a Mixture of 23 Chemicals Associated With Unconventional Oil and Gas Operations Alters the Immune System of Mice

Chemicals used in unconventional oil and gas (UOG) operations have the potential to cause adverse biological effects, but this has not been thoroughly evaluated. A notable knowledge gap is their impact on development and function of the immune system. Herein, we report an investigation of whether developmental exposure to a mixture of chemicals associated with UOG operations affects the development and function of the immune system. We used a previously characterized mixture of 23 chemicals associated with UOG, and which was demonstrated to affect reproductive and developmental endpoints in mice. C57Bl/6 mice were maintained throughout pregnancy and during lactation on water containing two concentrations of this 23-chemical mixture, and the immune system of male and female adult offspring was assessed. We comprehensively examined the cellularity of primary and secondary immune organs, and used three different disease models to probe potential immune effects: house dust mite-induced allergic airway disease, influenza A virus infection, and experimental autoimmune encephalomyelitis (EAE). In all three disease models, developmental exposure altered frequencies of certain T cell sub-populations in female, but not male, offspring. Additionally, in the EAE model disease onset occurred earlier and was more severe in females. Our findings indicate that developmental exposure to this mixture had persistent immunological effects that differed by sex, and exacerbated responses in an experimental model of autoimmune encephalitis. These observations suggest that developmental exposure to complex mixtures of water contaminants, such as those derived from UOG operations, could contribute to immune dysregulation and disease later in life.

The role of salivary gland histopathology in primary Sjögren's syndrome: promises and pitfalls

The formation of lymphomononuclear cell infiltrates organising as periductal infiltrates in the salivary glands of patients with primary Sjögren's syndrome (pSS) is one of the hallmarks of the disease. Historically, the clinical role of salivary gland histopathology, most commonly performed on labial salivary gland biopsies, has been confined to the clinical classification and diagnosis of pSS whereby according to the ACR-EULAR a positive histopathology finding is a requirement for the diagnosis of pSS in the absence of anti-Ro/SSA antibodies. In recent years, further understanding of the heterogeneity of the immune cell infiltration and organisation within the salivary glands of pSS patients and its correlation with clinical manifestations of the disease has led to propose salivary gland histopathology as a novel tool able to identify patients at higher risk of developing more severe extraglandular manifestations and lymphoma. Furthermore, recent clinical developments in ongoing randomised clinical trials with novel biologics in pSS have focused on salivary glands histopathology to inform on patients stratification based on target validation, proof of drug efficacy and mechanisms of response/resistance to therapy. However, lack of standardisation of methodology and analysis has hindered the reproducibility of data from different groups and no definitive evidence in support of the use of salivary glands histopathology to inform clinical management of patients with pSS has been provided. In this review, we summarise recent evidence highlighting the promises and pitfalls of salivary glands histopathology in pSS emphasising the need for an international consensus on standardisation of methodology with validation in large prospective multicentre initiatives.

Chronic Consumption of Sweeteners and Its Effect on Glycaemia, Cytokines, Hormones, and Lymphocytes of GALT in CD1 Mice

BACKGROUND

The consumption of sweeteners has increased in recent years, being used to control body weight and blood glucose. However, they can cause increased appetite, modification of immune function, and secretion of hormones in the GALT.

OBJECTIVE

To assess the effect of chronic sweetener consumption on glycaemia, cytokines, hormones, and GALT lymphocytes in CD1 mice.

MATERIAL AND METHODS

72 CD1 mice divided into 3 groups were used: (a) baseline, (b) middle, and (c) final. Groups (b) and (c) were divided into 4 subgroups: (i) Control, (ii) Sucrose, (iii) Sucralose, and (iv) Stevia. The following were determined: body weight, hormones (GIP, insulin, and leptin), lymphocytes CD3+T cells and CD19+B cells, IgA+ plasma cells, and cytokines (IL-4, IL-5, IFN-γ, and TNF-α).

RESULTS

Sucralose reduces secretion of GIP and glycaemia but does not modify insulin concentration, increases body weight, and reduces food intake. Stevia increases the secretion of GIP, insulin, leptin, body weight, and glycaemia but keeps food consumption normal. Sucralose and Stevia showed a higher percentage of CD3+T cells, CD19+B cells, and IgA+ plasma cells in Peyer's patches, but only Stevia in lamina propria.

CONCLUSION

Sweeteners modulate the hormonal response of cytokines and the proliferation of lymphocytes in the intestinal mucosa.

Increased HIV-1 transcriptional activity and infectious burden in peripheral blood and gut-associated CD4+ T cells expressing CD30

HIV-1-infected cells persist indefinitely despite the use of combination antiretroviral therapy (ART), and novel therapeutic strategies to target and purge residual infected cells in individuals on ART are urgently needed. Here, we demonstrate that CD4⁺ T cell-associated HIV-1 RNA is often highly enriched in cells expressing CD30, and that cells expressing this marker considerably contribute to the total pool of transcriptionally active CD4⁺ lymphocytes in individuals on suppressive ART. Using in situ RNA hybridization studies, we show co-localization of CD30 with HIV-1 transcriptional activity in gut-associated lymphoid tissues. We also demonstrate that ex vivo treatment with brentuximab vedotin, an antibody-drug conjugate (ADC) that targets CD30, significantly reduces the total amount of HIV-1 DNA in peripheral blood mononuclear cells obtained from infected, ART-suppressed individuals. Finally, we observed that an HIV-1-infected individual, who received repeated brentuximab vedotin infusions for lymphoma, had no detectable virus in peripheral blood mononuclear cells. Overall, CD30 may be a marker of residual, transcriptionally active HIV-1 infected cells in the setting of suppressive ART. Given that CD30 is only expressed on a small number of total mononuclear cells, it is a potential therapeutic target of persistent HIV-1 infection.

Previous studies have shown that higher levels of soluble CD30 are associated with HIV-1 disease progression. Many of these studies, however, were performed prior to the implementation of combination ART, and the relationship between surface CD30 expression, soluble CD30 and HIV-1 infection in ART suppressed individuals, or those with viremic control off ART, is not known. We demonstrate that cell-associated HIV-1 RNA is highly enriched in CD4⁺ T cells expressing CD30, a member of the tumor necrosis factor receptor superfamily. These findings were observed in several HIV-1 infected donor groups, regardless of whether or not the participants were receiving suppressive ART. Furthermore, we demonstrate that ex vivo treatment with brentuximab vedotin, an antibody-drug conjugate that targets CD30, reduces the total amount of HIV-1 DNA in PBMC obtained from infected individuals. Finally, we show through in situ RNA hybridization studies that CD30 and HIV transcriptional activity co-localize in cells from gut biopsies obtained from HIV-1 infected donors. These data suggest that CD30 may be a marker of residual, transcriptionally active HIV-1 infected cells in the setting of suppressive ART.

Immunomodulatory Effect of Tremella Polysaccharides against Cyclophosphamide-Induced Immunosuppression in Mice

Polysaccharides are closely associated with immune regulation, but there are different polysaccharide effects from different sources. In this study, the aim was to investigate the effect of tremella polysaccharides (TP) in cyclophosphamide-induced immunodeficient mice. We observed the thymus and spleen index, liver and spleen pathological changes, and the levels of IL-2, IL-12, INF-γ, TGF-β and Ig G in serum, and we also noted the mRNA expression of IL-1β, IL-4, IL-12 and TGF-β in liver and spleen. Besides, we also measured the best effects of different doses of TP (Low-TP was 20 mg/kg·BW, Middle-TP was 40 mg/kg·BW, and High-TP was 80 mg/kg·BW) on cyclophosphamide-induced immunosuppressed mice. The results were remarkable, and suggested that TP had a significant effect for enhancing immunity in cyclophosphamide-induced immunosuppression, and the immune enhancement of High-TP had the best results in TP-treated mice. It could significantly increase the thymus and spleen index, alleviate pathological features of immunosuppression such as the arrangement of liver sinusoid and hepatic plates was disordered, massive inflammatory cells infiltrated and fatty degeneration of hepatocytes in liver, and red pulp and white pulp were intermixed, splenic corpuscles demolished and disappeared, splenic sinusoid extended, and lymphocytes of spleen were reduced in spleen. Besides, it could also up-regulate serum levels of IL-2, IL-12, INF-γ and Ig G, reduce the level of TGF-β in serum, markedly promote mRNA expression of IL-1β, IL-4 and IL-12 in liver and spleen, and suppress mRNA expression of TGF-β. Above all, TP showed preventive effect for cyclophosphamide-induced immunosuppressed mice.

Virological and immunological responses to raltegravir and dolutegravir in the gut-associated lymphoid tissue of HIV-infected men and women

BACKGROUND

Raltegravir (RTG) and dolutegravir (DTG) have different pharmacokinetic patterns in the gastrointestinal tract. To determine if this results in pharmacodynamic differences, we compared HIV RNA, HIV DNA and immunological markers in gut-associated lymphoid tissue (GALT) of HIV-infected participants receiving RTG or DTG with tenofovir+emtricitabine (TDF/FTC).

METHODS

GALT specimens from the terminal ileum, splenic flexure and rectum were obtained by colonoscopy at a single time point in 20 adults treated with RTG (n=10) or DTG (n=10) with HIV RNA <50 copies/ml. Flow cytometry, drug concentrations, and HIV RNA and DNA were analysed in tissue. CD4/8+ T-cells were tested for γδ TCR, and markers of T-cell activation and exhaustion. Data are reported as median (Q1-Q3).

RESULTS

A total of 15 men and 5 women were enrolled. There was no difference in time since HIV diagnosis for those on RTG (9.5 [4-22] years) and DTG (17 [1-24] years; P=0.6), although time on RTG (5.4 [2.3-6.7] years) was greater than DTG (1.0 [0.1-1.5] years; P<0.001). Concentrations of RTG and DTG in rectal tissue were similar to previous reports: median tissue:plasma ratio was 11.25 for RTG and 0.44 for DTG. RNA:DNA ratios were 1.14 (0.18-5.10) for the RTG group and 0.90 (0.30-18.87) for the DTG group (P=0.95). No differences (P≥0.1) between CD4+ and CD8+ T-cell markers were found.

CONCLUSIONS

RTG produced higher tissue exposures than DTG, but no significant differences in GALT HIV RNA, DNA or most immunological markers were observed. ClinicalTrials.gov NCT02218320.

[18F]-Fluorodeoxyglucose Uptake in Lymphoid Tissue Serves as a Predictor of Disease Outcome in the Nonhuman Primate Model of Monkeypox Virus Infection

Real-time bioimaging of infectious disease processes may aid countermeasure development and lead to an improved understanding of pathogenesis. However, few studies have identified biomarkers for monitoring infections using in vivo imaging. Previously, we demonstrated that positron emission tomography/computed tomography (PET/CT) imaging with [18F]-fluorodeoxyglucose (FDG) can monitor monkeypox disease progression in vivo in nonhuman primates (NHPs). In this study, we investigated [18F]-FDG-PET/CT imaging of immune processes in lymphoid tissues to identify patterns of inflammation in the monkepox NHP model and to determine the value of [18F]-FDG-PET/CT as a biomarker for disease and treatment outcomes. Quantitative analysis of [18F]-FDG-PET/CT images revealed differences between moribund and surviving animals at two sites vital to the immune response to viral infections, bone marrow and lymph nodes (LNs). Moribund NHPs demonstrated increased [18F]-FDG uptake in bone marrow 4 days postinfection compared to surviving NHPs. In surviving, treated NHPs, increase in LN volume correlated with [18F]-FDG uptake and peaked 10 days postinfection, while minimal lymphadenopathy and higher glycolytic activity were observed in moribund NHPs early in infection. Imaging data were supported by standard virology, pathology, and immunology findings. Even with the limited number of subjects, imaging was able to differentiate the difference between disease outcomes, warranting additional studies to demonstrate whether [18F]-FDG-PET/CT can identify other, subtler effects. Visualizing altered metabolic activity at sites involved in the immune response by [18F]-FDG-PET/CT imaging is a powerful tool for identifying key disease-specific time points and locations that are most relevant for pathogenesis and treatment.IMPORTANCE Positron emission tomography and computed tomography (PET/CT) imaging is a universal tool in oncology and neuroscience. The application of this technology to infectious diseases is far less developed. We used PET/CT imaging with [18F]-labeled fluorodeoxyglucose ([18F]-FDG) in monkeys after monkeypox virus exposure to monitor the immune response in lymphoid tissues. In lymph nodes of surviving monkeys, changes in [18F]-FDG uptake positively correlated with enlargement of the lymph nodes and peaked on day 10 postinfection. In contrast, the bone marrow and lymph nodes of nonsurvivors showed increased [18F]-FDG uptake by day 4 postinfection with minimal lymph node enlargement, indicating that elevated cell metabolic activity early after infection is predictive of disease outcome. [18F]-FDG-PET/CT imaging can provide real-time snapshots of metabolic activity changes in response to viral infections and identify key time points and locations most relevant for monitoring the development of pathogenesis and for potential treatment to be effective.

Tissue Pharmacologic and Virologic Determinants of Duodenal and Rectal Gastrointestinal-Associated Lymphoid Tissue Immune Reconstitution in HIV-Infected Patients Initiating Antiretroviral Therapy

Plasma, duodenal, and rectal tissue antiretroviral therapy (ART) drug concentrations, human immunodeficiency virus (HIV) RNA and HIV DNA copy numbers, and recovery of mucosal immunity were measured before and 9 months after initiation of 3 different ART regimens in 26 subjects. Plasma and tissue HIV RNA correlated at baseline and when 9-month declines were compared, suggesting that these compartments are tightly associated. Antiretroviral tissue:blood penetration ratios were above the 50% inhibitory concentration values in almost 100% of cases. There were no correlations between drug concentrations and HIV DNA/RNA. Importantly, no evidence was found for residual viral replication or deficient tissue drug penetration to account for delayed gastrointestinal-associated lymphoid tissue immune recovery.

The C-Terminal Heptapeptide of Bombesin Reduces the Deleterious Effect of Total Parenteral Nutrition (TPN) on Gut-Associated Lymphoid Tissue (GALT) Mass but Not Intestinal Immunoglobulin AIn Vivo

BACKGROUND

Bombesin, the amphibian analog of mammalian gastrin-releasing peptide, reverses total parenteral nutrition (TPN)-induced atrophy of gut-associated lymphoid tissue and increases intestinal and respiratory immunoglobulin A (IgA) levels. Structure-activity studies suggested that the biologically active portion of bombesin is a C-terminal heptapeptide (7AA). This study investigates the effect of 7AA on lymphocytes counts of the Peyer's patches (PP), the lamina propria (LP) and the intraepithelial layer (IE).

METHODS

Forty-eight male mice were randomized to receive chow (n = 13), TPN only (n = 9), TPN + 15 microg 7AA 3 times per day (n = 13) or TPN + 150 microg 7AA 3 times per day (n = 13). After 5 days of feeding, PP, LP, and IE lymphocytes were determined. Intestinal IgA levels were measured with ELISA. Groups were compared with ANOVA.

RESULTS

All TPN-fed mice lost more weight than mice fed chow (p < .04). Lymphocyte counts in PP, LP, and IE were significantly lower in the TPN group than in the 3 other groups but did not differ between the groups fed chow, TPN + 15 microg 7AA 3 times per day, or TPN + 150 microg 7AA 3 times per day. Intestinal IgA levels were higher in chow-fed mice (148.4 +/- 16.9) than in mice fed TPN (98.4 +/- 14.0, p = .008), TPN + 15 microg 7AA 3 times per day (96.9 +/- 7.7, p = .003) or TPN + 150 microg 7AA 3 times per day (87.3 +/- 6.7, p = .001).

CONCLUSIONS

The C-terminal heptapeptide of bombesin prevented the TPN-induced decrease in intestinal lymphocyte populations but not the reduction in intestinal IgA levels.

5-Fluorouracil Infusion Reduces Gut-Associated Lymphoid Tissue Cell Number and Mucosal Immunoglobulin A Levels

BACKGROUND

Anticancer drugs have been demonstrated to affect gut mucosal morphology and cause gastrointestinal symptoms. We hypothesized that even small doses of 5-fluorouracil (5-FU) would reduce gut-associated lymphoid tissue (GALT) mass and function.

METHODS

Mice underwent IV cannulation and received continuous infusion of normal saline or 10 mg/kg of 5-FU for 5 days. GALT cell numbers, phenotypes, and mucosal immunoglobulin A (IgA) levels were measured.

RESULTS

During the infusion, there were no significant differences in food intake or body weight change between the 2 groups. Cell yields from the intraepithelial space and lamina propria of the small intestine were lower in the 5-FU than the control group. The lamina propria CD4/CD8 ratio was reduced in the 5-FU compared with the control group. Intestinal and respiratory tract IgA levels were lower in the 5-FU than in the control group.

CONCLUSIONS

A small dose of 5-FU reduces GALT cell number and mucosal IgA levels, regardless of food intake.

Antiretroviral Drug Activity in Macaques Infected during Pre-Exposure Prophylaxis Has a Transient Effect on Cell-Associated SHIV DNA Reservoirs

Background

Pre-exposure prophylaxis (PrEP) with emtricitabine and tenofovir disoproxil fumarate (FTC/TDF) is a novel HIV prevention strategy. Suboptimal PrEP adherence and HIV infection creates an opportunity for continued antiretroviral drug activity during undiagnosed infection. We previously showed that macaques infected with SHIV during PrEP with FTC/TDF display reduced acute plasma viremias and limited virus diversity. We investigated the effect of PrEP on acute SHIV DNA dynamics and on the size of the persistent virus reservoir in lymphoid tissues.

Design

Cell-associated SHIV DNA levels in PBMCs were measured in 8 macaques infected during PrEP with FTC/TDF or single-agent TAF and was compared to those seen in untreated infections (n = 10). PrEP breakthrough infections continued treatment with 1–2 weekly drug doses to model suboptimal drug exposure during undiagnosed HIV infection in humans. SHIV DNA was also measured in lymphoid tissues collected from FTC/TDF PrEP breakthroughs after 1 year of infection.

Results

Compared to untreated controls, PrEP infections had reduced plasma RNA viremias both at peak and throughout weeks 1–12 (p<0.005). SHIV DNA levels were also reduced at peak and during the first 12 weeks of infection (p<0.043) but not throughout weeks 12–20. At 1 year, SHIV DNA reservoirs in lymphoid tissues were similar in size among macaques that received PrEP or placebo.

Conclusions

Antiviral drug activity due to PrEP limits acute SHIV replication but has only a transient effect on cell-associated SHIV DNA levels. Our model suggests that suboptimal drug exposure in persons that are taking PrEP and become infected with HIV may not be sufficient to reduce the pool of HIV-infected cells, and that treatment intensification may be needed to sustain potential virological benefits from the PrEP regimen.

Effect of Ketamine on Cocaine-Induced Immunotoxicity in Rats

The abuse of cocaine (COC) with ketamine (KET) is currently popular among young drug abusers and has been associated with increased risk of human immunodeficiency virus (HIV) infection. The effect of subacute exposure to COC and KET alone and in combination on the immune system was assessed in adult male Sprague-Dawley (SD) rats. To simulate the route and mode of human exposure, rats were treated with COC alone (5 mg/kg, IV), KET alone (100 mg/kg, PO) or KET followed immediately by COC (same doses and routes of administration) once-a-day for 7 consecutive days. Rats were sacrified 30 minutes following the last treatment. Total circulating leukocyte and lymphocyte counts were decreased with relative neutrophilia, whereas immunoglobulin M (Ig M) antibody response to sheep erythrocytes (SRBCs) was increased in animals treated with COC. Moreover, treatment with COC alone increased serum interleukin-10 (IL-10) concentration; however, it did not affect serum interferon gamma (INF-γ) concentration. Spleen histology showed hyperplasia of white pulp whereas thymus gland demonstrated mild cortical degeneration. On the other hand, KET treatment did not produce any significant change of any of these parameters. However, when coadministered with COC, significant reduction of bodyweight, spleen/bodyweight, and thymus/bodyweight ratios with degeneration of splenic white pulp and thymic cortex occurred. Moreover, the primary immunoglobulin response to SRBC and serum IL-10 concentration were decreased without significant change in serum IFN-γ or circulating leukocytic counts. COC caused a significant increase in serum corticosterone concentration that KET effectively prevented. On the other hand, a significant increase in plasma and tissue concentrations of norcocaine (NC) resulted following KET and COC administration in combination. Daily SKF-525A pretreatment at a dose of 30 mg/kg, IP, for 7 days 1 hour prior to KET and COC in combination effectively reversed the effects of this combination on body weight, organ/bodyweight ratios, histopathology, and serum Ig M and IL-10 concentrations without affecting leukocytic counts. On the other hand, SKF-525A pretreatment did not change the immunomodulatory effects of COC compared to non-pretreated animals. The results suggest that COC-induced immunomodulation most likely occurred through neuroendocrinal mechanisms. On the other hand, enhanced oxidative metabolism of COC in the presence of KET-induced immunosuppression.

Beneficial health characteristics of native and hydrolysed konjac (Amorphophallus konjac) glucomannan

The impact of ingesting glucomannans on health is not limited to colonic-focused fermentation into short-chain fatty acids (SCFAs), which might have some local health benefits; it also helps in treating disease states and enhancing the body's immune system, both within the gut and in/on other parts of the body. The local and systemic roles of hydrolysed glucomannans, especially konjac glucomannans, in the mouth, oesophagus, stomach, small intestine, large intestine, gut-associated lymphoid tissue (GALT), skin and vagina, are highlighted. Therapeutic applications are discussed. © 2015 Society of Chemical Industry.

Safety of Aquaflor (Florfenicol, 50% Type A Medicated Article), Administered in Feed to Channel Catfish, Ictalurus punctatus

Aquaflor, a feed premix containing the broad spectrum antibacterial agent florfenicol (50% w/w), is being developed for use to control enteric septicemia (ESC) in channel catfish Ictalurus punctatus caused by the gram-negative enterobacterium Edwardsiella ictaluri. The recommended dose of Aquaflor to control ESC is 10 mg/kg body weight (BW)/day for 10 days. The study objective was to determine the safety of Aquaflor administered in feed to channel catfish at doses of 0 (control), 10, 30, and 50 mg/kg BW/day for 20 consecutive days. Parameters evaluated included daily mortality, behavioral (appetite, distribution, flight/fright response), and water chemistry observations, initial and terminal weight measurements, and gross and microscopic pathology. Medicated feed consumption was 67—86% of target with group mean doses of 8.5 mg/kg BW/day, 24.6 mg/kg BW/day, and 34.9 mg/kg BW/day. There were no mortalities or clinically observable changes noted at any of the dose levels tested. Aquaflor-related changes were limited to the food consumption and histopathology data. Although Aquaflor-related decreased feed consumption was noted in the 30 and 50 mg/kg BW/day groups, there were no differences in fish growth among the treatment groups. Aquaflor-related histopathology findings were limited to a histomorphologically evident dose-dependent decrease in hematopoietic/lymphopoietic tissue in the anterior kidneys, posterior kidneys, and spleens of channel catfish.

Key cytokines of adaptive immunity are differentially induced in rainbow trout kidney by a group of structurally related geranyl aromatic derivatives

Filifolinone is a semi-synthetic terpenoid derivative obtained from Heliotropium filifolium that increases the expression level of pro-inflammatory and anti-inflammatory cytokines in kidney cells of salmon. Because cytokines are produced in response to a foreign organism and by distinct other signals modulating immune responses, we further studied the potential immunomodulatory effects of a group of structural related terpenoid derivatives from H. filifolium on salmonids to determine the relationship between the chemical structure of the derivatives and their ability to modify cytokine expression and the lymphoid content. The resin and four 3H-spiro 1-benzofuran-2,1'-cyclohexane derivatives were tested in vivo in rainbow trout (Oncorhynchus mykiss) by quantifying the transcript levels of antiviral and T helper-type cytokines and T and B cells in the kidney. Three of the four terpenoids differ only in the C-7'substituent of the cyclohexane and the presence of the ketone group at this position in Filifolinone appeared responsible of an important up-regulation of IFN-α1, IFN-γ, IL-4/13A and IL-17D in the kidney of the treated trout. In addition, the absence of a methoxy group in carbon 7 of the benzene ring, found in all compounds but not in Folifolinoic acid, produced a significant reduction of IFN-γ, IL-12 and IL-4/13A transcripts. B cells were not affected by the compound treatment but Filifolinoic acid and the resin induced a significant reduction of T cells. Altogether, results showed that immunomodulating responses observed in the trout by effect of 3H-spiro 1-benzofuran-2,1'-cyclohexane derivatives is related to the presence of the ketone group in the carbon 7' and the methoxy group in carbon 7 of the benzene ring, being Filifolinone the most active immunostimulatory compound identified.

The transferability from rat subacute 4-week oral toxicity study to translational research exemplified by two pharmaceutical immunosuppressants and two environmental pollutants with immunomodulating properties

Exposure to chemicals may have an influence on the immune system. Often, this is an unwanted effect but in some pharmaceuticals, it is the intended mechanism of action. Immune function tests and in depth histopathological investigations of immune organs were integrated in rodent toxicity studies performed according to an extended OECD test guideline 407 protocol. Exemplified by two immunosuppressive drugs, azathioprine and cyclosporine A, and two environmental chemicals, hexachlorobenzene and benzo[a]pyrene, results of subacute rat studies were compared to knowledge in other species particular in humans. Although immune function has a high concordance in mammalian species, regarding the transferability from rodents to humans various factors have to be taken into account. In rats, sensitivity seems to depend on factors such as strain, sex, stress levels as well as metabolism. The two immunosuppressive drugs showed a high similarity of effects in animals and humans as the immune system was the most sensitive target in both. Hexachlorobenzene gave an inconsistent pattern of effects when considering the immune system of different species. In some species pronounced inflammation was observed, whereas in primates liver toxicity seemed more obvious. Generally, the immune system was not the most sensitive target in hexachlorobenzene-treatment. Immune function tests in rats gave evidence of a reaction to systemic inflammation rather than a direct impact on immune cells. Data from humans are likewise equivocal. In the case of benzo[a]pyrene, the immune system was the most sensitive target in rats. In the in vitro plaque forming cell assay (Mishell-Dutton culture) a direct comparison of cells from different species including rat and human was possible and showed similar reactions. The doses in the rat study had, however, no realistic relation to human exposure, which occurs exclusively in mixtures and in a much lower range. In summary, a case by case approach is necessary when testing immunotoxicity. Improvements for the translation from animals to humans related to immune cells can be expected from in vitro tests which offer direct comparison with reactions of human immune cells. This may lead to a better understanding of results and variations seen in animal studies.

Cutaneous lymphoproliferative disorders in organ transplant recipients: update 2014

Post-transplant lymphoproliferative disorders (PTLD) are lymphoid or plasmacytic proliferations that develop after solid organ, bone marrow or stem cell transplantation. PTLD are the leading cause of cancer-related mortality and graft loss in both pediatric and adult solid organ transplant recipients (ORT). These disorders comprise a spectrum ranging from usually EBV-driven, mostly B-cell polyclonal proliferations to B- and T-cell lymphomas indistinguishable from their counterparts occurring in immunocompetent individuals. PTLD usually present in extranodal sites; isolated skin involvement of PTLD is rare. A recent multicenter European case series showed that primary cutaneous T-cell PTLD are more common than primary cutaneous B-cell PTLD, and along with its folliculotropic variant, mycosis fungoides (MF) is the most frequent form of posttransplant primary cutaneous T-cell lymphoma (CTCL). This case series also disclosed that primary cutaneous CD30+ lymphoproliferative disorders is the second most common posttransplant CTCL subtype, indicating that the spectrum of primary CTCL in OTR is similar to that in the general population. However, in contrast with the immunocompetent individuals, the prognosis of primary cutaneous CD30+ anaplastic large T-cell lymphoma is worse than posttransplant MF and than its counterpart in the general population which has an excellent prognosis. The recent case series indicated that the spectrum of primary cutaneous B-cell PTLD differs significantly from cutaneous B-cell lymphoma in the general population, with a predominance of EBV-associated forms. Currently, the best therapeutic intervention(s) for primary cutaneous PTLD remains unknown.

Differential induction of isolated lymphoid follicles in the gut by 18β-glycyrrhetinic acid

18β-glycyrrhetinic acid (GRA) is a pharmacologically active component of licorice root with documented immunomodulatory properties. We reported that GRA administered orally to mice induces B cell recruitment to isolated lymphoid follicles (ILF) in the small intestine and shortens the duration of rotavirus antigen shedding. ILF are dynamic lymphoid tissues in the gut acquired post-natally upon colonization with commensal bacteria and mature through B cell recruitment to the follicles, resulting in up-regulation of IgA synthesis in response to changes in the composition of microbiota. In this study, we investigated potential mechanisms by which GRA induces ILF maturation in the ileum and the colon using mice depleted of enteric bacteria and a select group of mice genetically deficient in pattern recognition receptors. The data show GRA was unable to induce ILF maturation in ileums of mice devoid of commensal bacteria, MyD88^−/− or NOD2^−/− mice, but differentially induced ILF in colons. Increased expression of chemokine and chemokine receptor genes that modulate B and T cell recruitment to the mucosa were in part dependent on NOD2, TLR, and signaling adaptor protein MyD88. Together the results suggest GRA induces ILF through cooperative signals provided by bacterial ligands under normal conditions to induce B cell recruitment to ILF to the gut, but that the relative contribution of these signals differ between ileum and colon.

Vitamin A and dendritic cell differentiation

Vitamin A and its active metabolite retinoic acid are essential for the development and function of many tissues including the immune system. The induction of mucosal homing receptors on T and B cells by mucosal dendritic cells (DC) depends on the presence of vitamin A. Recent studies indicate that also the differentiation of CD11b+ DC subsets in the mucosa as well as the spleen depend on vitamin A signalling. As CD11b+ DC subsets exert non-redundant functions in anti-bacterial and anti-fungal immune responses, defects in CD11b+ DC differentiation will contribute to the clinical problems observed during vitamin A deficiency.

Cellular and mucosal immune responses in the respiratory tract of Nigerian goats following intranasal administration of inactivated Recombinant Mannheimia hemolytica bacterine

This experiment was conducted to evaluate the cellular and mucosal responses in the respiratory tract of Nigerian goats vaccinated intranasally with recombinant Mannheimia hemolytica bacterine. Twenty one goats were divided into five groups, five goats each in three vaccinated groups while three goats each in two other groups serve as positive and negative control. Group A was vaccinated once; group B was vaccinated twice at one week interval, and group D at twice at two weeks interval. Group C1 were the unvaccinated and challenged, while group C2 were unvaccinated and unchallenged. The bronchoalveolar lavage differential counts and bronchial associated lymphoid tissue (BALT) responses were measured using Giemsa stained thin smear of the cell fraction of the lavage and histomorphometry. ANOVA were employed and significance was at p&gt;0.05. The post-challenge macrophage to neutrophil (M:N) ratio values of group B goats was the highest and the ratio differed from other groups which had much lower M:N values. The exposure in group B resulted in significant increase in number and size of BALTs as well as the number of lymphocytes in BALT than those of the other groups. This study showed that intranasal vaccination of the recombinant Mannheimia hemolytica bacterine twice at a week interval was more efficient in inducing strong mucosal and defensive cellular responses in the respiratory tract.

A study on anti-tumour effect of Solanum lyratum Thunb. extract in S₁₈₀ tumour-bearing mice

The objective of the study was to investigate the anti-tumour effect of ethanol extract of Solanum lyratum Thunb. in S₁₈₀ tumour-bearing mice, and to preliminarily explore its mechanism of action.

METHODS

Mice were made into S₁₈₀ solid tumour model, grouped and administered. Tumour inhibition rate was measured by harvesting the tumours. Serum IL-2, TNF-a contents were measured by taking blood samples, and thymus index and spleen index were measured by harvesting the thymus and spleen. The results showed that the Solanum lyratum Thunb. extract had certain tumour inhibitory effect, which can elevate the serum IL-2, TNF-a contents, and increase the thymus and spleen indices to a certain extent. The study concluded that Solanum lyratum Thunb. extract has certain in vivo anti-tumour effect which may be exerted through enhancing the body immunity.

A multi-targeted drug candidate with dual anti-HIV and anti-HSV activity

Human immunodeficiency virus (HIV) infection is often accompanied by infection with other pathogens, in particular herpes simplex virus type 2 (HSV-2). The resulting coinfection is involved in a vicious circle of mutual facilitations. Therefore, an important task is to develop a compound that is highly potent against both viruses to suppress their transmission and replication. Here, we report on the discovery of such a compound, designated PMEO-DAPym. We compared its properties with those of the structurally related and clinically used acyclic nucleoside phosphonates (ANPs) tenofovir and adefovir. We demonstrated the potent anti-HIV and -HSV activity of this drug in a diverse set of clinically relevant in vitro, ex vivo, and in vivo systems including (i) CD4⁺ T-lymphocyte (CEM) cell cultures, (ii) embryonic lung (HEL) cell cultures, (iii) organotypic epithelial raft cultures of primary human keratinocytes (PHKs), (iv) primary human monocyte/macrophage (M/M) cell cultures, (v) human ex vivo lymphoid tissue, and (vi) athymic nude mice. Upon conversion to its diphosphate metabolite, PMEO-DAPym markedly inhibits both HIV-1 reverse transcriptase (RT) and HSV DNA polymerase. However, in striking contrast to tenofovir and adefovir, it also acts as an efficient immunomodulator, inducing β-chemokines in PBMC cultures, in particular the CCR5 agonists MIP-1β, MIP-1α and RANTES but not the CXCR4 agonist SDF-1, without the need to be intracellularly metabolized. Such specific β-chemokine upregulation required new mRNA synthesis. The upregulation of β-chemokines was shown to be associated with a pronounced downmodulation of the HIV-1 coreceptor CCR5 which may result in prevention of HIV entry. PMEO-DAPym belongs conceptually to a new class of efficient multitargeted antivirals for concomitant dual-viral (HSV/HIV) infection therapy through inhibition of virus-specific pathways (i.e. the viral polymerases) and HIV transmission prevention through interference with host pathways (i.e. CCR5 receptor down regulation).

To contain the HIV-1 epidemic, it is necessary to develop antivirals that prevent HIV-1 transmission. It is well known that HIV infection might be accompanied by other pathogens, which often are engaged with HIV-1 in a vicious circle of mutual facilitation. One of the most common of these pathogens is herpes simplex virus (HSV) type 2. Since there is an urgent need for a next generation antivirals that are multi-targeted, we can now report on the development of the first antiviral of this new generation that efficiently suppresses both HIV-1 and HSV-2. We found that the dual-targeted antiviral drug affects several targets for viral replication. It uniquely combines in one molecule three important abilities: (i) to efficiently suppress HSV-encoded DNA polymerase, (ii) to efficiently suppress HIV-1-encoded reverse transcriptase, and (iii) to stimulate secretion of CC-chemokines that downregulate the HIV-1 coreceptor CCR5. The compound suppresses both viruses in a wide-range of in vitro, ex vivo, and in vivo experimental models. The ability of one molecule to suppress HIV-1 and HSV-2 by combining direct activity against their two key enzymes and indirect immunomodulatory effects is unique in the antiviral field.

Melatonin ameliorates oxidative stress and induces cellular proliferation of lymphoid tissues of a tropical rodent, Funambulus pennanti, during reproductively active phase

Effect of melatonin treatment on free radical production was assessed with simultaneous investigation of hormonal level (melatonin and testosterone), blastogenic response, stimulation index, and histological observation of lymphoid organs (spleen, thymus, and bone marrow) in male Indian palm squirrel (Funambulus pennanti) during reproductively active phase (RAP). Low endogenous melatonin and high testosterone level were noted during RAP. Daily subcutaneous injection of melatonin (25 μg/100 g B wt.) at 17.30-18.00 h to squirrels for 60 consecutive days during May-June significantly decreased the thiobarbituric acid reactive substances (TBARS) level compared to control squirrels. Melatonin treatment significantly increased % stimulation ratio (%SR) of splenocytes and thymocytes against T cell mitogen concanavalin A. Pinealectomy (Px) led to a significant increase in TBARS level whereas a significant decrease was observed in blastogenic response and stimulation index was noted. Melatonin injection to Px squirrels showed restoration in %SR of thymocytes and splenocytes with a significant decrease in the TBARS level of the lymphoid tissues. Further, free radical load was induced by lipopolysaccharide (LPS; 400 μg/ml) in lymphatic tissue homogenates and noted that melatonin supplementation (2 mM/ml) led to a significant decrease in TBARS level compared to the control and LPS-supplemented groups. Histological observation showed dense cellularity of thymocytes and splenocytes. Acridine orange staining technique shows a significant increase in thymocyte apoptosis Px squirrels when compared with melatonin-treated squirrels. These findings suggest that endogenous and exogenous melatonin might be responsible for the maintenance of immune system to adapt this seasonal breeder for the rigors of the environmental changes.

Macrophage activity and histopathology of the lymphohematopoietic organs in male Wistar rats orally exposed to single or mixed pesticides

The noxious effects of low or effective dose exposure to single or mixed pesticides on macrophage activity and the lymphohematopoietic organs were investigated. Male Wistar rats were orally exposed to dichlorvos, dicofol, endosulfan, dieldrin and permethrin, either as single or combined mixtures during a 28-day study containing eight groups: one group received a semipurified diet (non-treated); two groups received a semipurified diet containing low dose mixture (dieldrin 0.025 mg/kg, endosulfan, 0.6 mg/kg, dicofol 0.22 mg/kg, dichlorvos 0.23 mg/kg, permethrin 5 mg/kg) or an effective dose mixture (dichlorvos 2.3 mg/kg, dicofol 2.5 mg/kg, endosulfan 2.9 mg/kg, dieldrin 0.05 mg/kg and permethrin 25.0 mg/kg), respectively; the other five groups received a semipurified diet containing each single pesticide in effective doses. At sacrifice, the thymus, spleen, mesenteric lymph nodes, Payer's patches and bone marrow were removed for histological analysis. Peritoneal macrophages were obtained to determine the phagocytosis and spreading indexes and tumoral necrosis factor alpha (TNF-α), nitric oxide (NO) and H₂O₂ production. Exposure to pesticide mixtures did not alter the percentage of macrophage phagocytosis and spreading, TNF-α production or the NO and H₂O₂ release when compared to the non-treated group. Neither was there any apparent evidence that a pesticide mixture at low or effective doses altered the histological structure of the lymphohematopoietic organs. The findings indicate that short-term treatment with pesticide mixtures did not induce an apparent immunotoxic effect in male Wistar rats.

[Effect of nanodispersed manganese oxide (III, IV) on morphological properties of various tissues and body systems]

The study of morphological features of tissue organs of experimental animals after a single intragastric administration of an aqueous suspension nanodis-dispersed manganese (III, IV) at doses of 2000, 3500 and 5000 mg/kg showed complex of morphological changes in the form of circulatory disorders up to hemostasis and bleeding which lead to changes in the structure of organs, enhanced apoptosis, activation of macrophage system by proliferation and macrophage phagocytosis of degradation products of cells, hypertrophy of lymphoid tissue of immune system; development of histiocytic infiltrates in parenchymal organs and central nervous system. With the introduction of microsized analogues in the same doses of the morphological changes in the circulatory system, macrophage system and immune organsfound predominantly in a dose of 5000 mg/kg. Changes were less significant and were presented as activation of macrophages in the liver in the form of activation of Kupffer cells, proliferation of lymphoid tissue in the spleen, lymph histiocytic infiltrates in the liver, kidney, medium size.

18β-glycyrrhetinic acid delivered orally induces isolated lymphoid follicle maturation at the intestinal mucosa and attenuates rotavirus shedding

Glycyrrhizin, an abundant bioactive component of the medicinal licorice root is rapidly metabolized by gut commensal bacteria into 18β-glycyrrhetinic acid (GRA). Either or both of these compounds have been shown to have antiviral, anti-hepatotoxic, anti-ulcerative, anti-tumor, anti-allergenic and anti-inflammatory activity in vitro or in vivo. In this study, the ability of GRA to modulate immune responses at the small intestinal mucosa when delivered orally was investigated. Analysis of cytokine transcription in duodenal and ileal tissue in response to GRA treatment revealed a pattern of chemokine and chemokine receptor gene expression predictive of B cell recruitment to the gut. Consistent with this finding, GRA induced increases in CD19(+) B cells in the lamina propria and B220(+) B cell aggregates framed by CD11c(+) dendritic cells in structures resembling isolated lymphoid follicles (ILF). Using a mouse model of rotavirus infection, GRA reduced the duration of viral antigen shedding, and endpoint serum antibody titers were higher in GRA-treated animals. Together the data suggest GRA delivered orally augments lymphocyte recruitment to the intestinal mucosa and induces maturation of B cell-rich ILF independently of ectopic antigenic stimulus. These results provide further support a role for dietary ligands in modulation of dynamic intestinal lymphoid tissue.

Intra-peritoneal sRAGE treatment induces alterations in cellular distribution of CD19(+), CD3 (+) and Mac-1 (+) cells in lymphoid organs and peritoneal cavity

Receptor for advanced glycation end products (RAGE) is a pattern recognition receptor that binds a variety of pro-inflammatory ligands. Its soluble form, sRAGE, can compete for ligand binding and thereby have an anti-inflammatory effect. We have recently reported that sRAGE also exerts pro-inflammatory and chemotactic properties suggesting a dual role for sRAGE in immune modulation. Our present aim was to analyse the immunomodulatory properties of sRAGE in vivo with respect to acquired immunity. Naive mice were treated intra-peritoneally with sRAGE and cells from peritoneal lavage, spleens and bone marrow were examined. Mice treated with sRAGE displayed an increased leucocyte count in the peritoneal cavity, enlarged spleens and increased cellularity compared with vehicle-treated animals. Furthermore, sRAGE-treated mice had a significantly increased frequency and number of CD19(+) B cells in spleen and a reduced frequency of CD19(+) B cells in bone marrow compared with controls. Functionally, splenocytes from sRAGE-treated mice showed elevated IgG production and up to a four-fold increased IgM secretion compared with control animals and produced significantly higher levels of interleukin-10, interferon-γ and interleukin-6 in response to lipopolysaccharide stimulation. Our results suggest that sRAGE has immunomodulatory properties, since intra-peritoneal administration of sRAGE into healthy mice leads to rearrangements in cellular composition in the bone marrow and spleen. Moreover, the administration of sRAGE directs B cells into the spleen and towards differentiation. Our novel findings indicate that sRAGE exerts an effect on the cells of adaptive immunity.

HIV-induced T-cell activation/exhaustion in rectal mucosa is controlled only partially by antiretroviral treatment

Peripheral blood T-cells from untreated HIV-1-infected patients exhibit reduced immune responses, usually associated with a hyperactivated/exhausted phenotype compared to HAART treated patients. However, it is not clear whether HAART ameliorates this altered phenotype of T-cells in the gastrointestinal-associated lymphoid tissue (GALT), the main site for viral replication. Here, we compared T-cells from peripheral blood and GALT of two groups of chronically HIV-1-infected patients: untreated patients with active viral replication, and patients on suppressive HAART. We characterized the T-cell phenotype by measuring PD-1, CTLA-4, HLA-DR, CD25, Foxp3 and granzyme A expression by flow cytometry; mRNA expression of T-bet, GATA-3, ROR-γt and Foxp3, and was also evaluated in peripheral blood mononuclear cells and rectal lymphoid cells. In HIV-1+ patients, the frequency of PD-1⁺ and CTLA-4⁺ T-cells (both CD4+ and CD8+ T cells) was higher in the GALT than in the blood. The expression of PD-1 by T-cells from GALT was higher in HIV-1-infected subjects with active viral replication compared to controls. Moreover, the expression per cell of PD-1 and CTLA-4 in CD4⁺ T-cells from blood and GALT was positively correlated with viral load. HAART treatment decreased the expression of CTLA-4 in CD8⁺ T cells from blood and GALT to levels similar as those observed in controls. Frequency of Granzyme A⁺ CD8⁺ T-cells in both tissues was low in the untreated group, compared to controls and HAART-treated patients. Finally, a switch towards Treg polarization was found in untreated patients, in both tissues. Together, these findings suggest that chronic HIV-1 infection results in an activated/exhausted T-cell phenotype, despite T-cell polarization towards a regulatory profile; these alterations are more pronounced in the GALT compared to peripheral blood, and are only partiality modulated by HAART.

[The application of the cryosurgical and lymphotropic technologies for the combined treatment of postintubation tracheal stenosis]

The combined treatment of 10 patients presenting with postintubation thracheal stenosis was carried out with the application of the cryosurgical and lymphotropic technologies. Cryogenic treatment of ciatrical stenosis was performed through the tracheostoma using a titanium nickelide cryoappliactor. The effect of the cryogenic treatment was enhanced by a lymphotropic mixture composed of diprospan and longidaza and administered retrosternally as a course of up to three injections once in a week. In the intervals between the injections and after the termination of the course, the patients were asked to inhale longidaza dissolved in a broncho- or mucolytic preparation through a nebulizer (up to 5 inhalations). All the treated patients reported the recovery of normal breathing through the natural airways.

Protective effects of Ligustrazine, Kakonein and Panax Notoginsenoside on the small intestine and immune organs of rats with severe acute pancreatitis

BACKGROUND

Severe acute pancreatitis (SAP) is characterized by fatal pathogenic conditions and a high mortality. It is important to study SAP complicated with multiple organ injury. In this study we compared the protective effects of three traditional Chinese medicines (Ligustrazine, Kakonein and Panax Notoginsenoside) on the small intestine and immune organs (thymus, spleen and lymph nodes) of rats with SAP and explored their mechanism of action.

METHODS

One hundred forty-four rats with SAP were randomly divided into model control, Ligustrazine-treated, Kakonein-treated, and Panax Notoginsenoside-treated groups (n=36 per group). Another 36 normal rats comprised the sham-operated group. According to the different time points after operation, the experimental rats in each group were subdivided into 3-, 6- and 12-hour subgroups (n=12). At various time points after operation, the mortality rate of rats and pathological changes in the small intestine and immune organs were recorded and the serum amylase levels were measured.

RESULTS

Compared to the model control groups, the mortality rates in all treated groups declined and the pathological changes in the small intestine and immune tissues were relieved to different degrees. The serum amylase levels in the three treated groups were significantly lower than those in the model control group at 12 hours. The pathological severity scores for the small intestinal mucosa, thymus and spleen (at 3 and 12 hours) in the Ligustrazine-treated group, for the thymus (at 3 and 12 hours) and spleen (at 3 and 6 hours) in the Kakonein-treated group, and for the thymus (at 3 hours) and spleen (at 3 hours) in the Panax Notoginsenoside-treated group were significantly lower than those in the model control group. The pathological severity scores of the small intestinal mucosa (at 6 and 12 hours) and thymus (at 6 hours) in the Ligustrazine-treated group were significantly lower than those in the Kakonein- and Panax Notoginsenoside-treated groups.

CONCLUSIONS

All the three traditional Chinese drugs significantly alleviated the pathological changes in the small intestine and immune organs of SAP rats. Ligustrazine was the most effective one among them.

The effect of different levels of organic and inorganic chromium supplementation on production performance, carcass traits and some blood parameters of broiler chicken under heat stress condition

A total of 250 broilers in a completely randomized design selected to evaluate the effect of different levels of chromium (Cr) supplementation on performance, carcass traits and some blood parameters of heat-stressed broiler chicks. All birds were kept under heat stress temperature (33 ± 3°C) and divided into five treatments groups. Each treatment consisted of five pens with 10 birds in each pen. The basal diets were supplemented with 0 ppb (control), 800 ppb Cr-L-Met (T(1)), 1,200 ppb Cr-L-Met (T(2)) or 800 ppb CrCl(3) (T(3)), and 1,200 ppb CrCl(3) (T(4)). The feed intake and body mass were measured at 10, 21, and 42 days of age. Blood samples were collected from two birds in each replicates to determine biological and hematological values at 28 and 42 days of age. There were no significant difference in mass gain and feed conversion of broilers that received Cr supplementations compared with controls. The serum glucose concentration decreased in broilers received organic chromium methionine supplements compared with other treatments groups. Slight but not significant increases were observed in serum high-density lipoprotein (HDL) concentration of treated groups than controls while the mean serum HDL concentration was significantly higher in T(2) group compared with control group. Serum low-density lipoprotein level decreased in broiler received organic Cr supplements (p < 0.05).

Coexposure to mercury increases immunotoxicity of trichloroethylene

We have shown previously that chronic (32 weeks) exposure to occupationally relevant concentrations of the environmental pollutant trichloroethylene (TCE) induced autoimmune hepatitis (AIH) in autoimmune-prone MRL+/+ mice. In real-life, individuals are never exposed to only one chemical such as TCE. However, very little is known about the effects of chemical mixtures on the immune system. The current study examined whether coexposure to another known immunotoxicant, mercuric chloride (HgCl(2)), altered TCE-induced AIH. Female MRL+/+ mice were treated for only 8 weeks with TCE (9.9 or 186.9 mg/kg/day in drinking water) and/or HgCl(2) (260 μg/kg/day, sc). Unlike mice exposed to either TCE or HgCl(2) alone, mice exposed to both toxicants for 8 weeks developed significant liver pathology commensurate with early stages of AIH. Disease development in the coexposed mice was accompanied by a unique pattern of anti-liver and anti-brain antibodies that recognized, among others, a protein of approximately 90 kDa. Subsequent immunoblotting showed that sera from the coexposed mice contained antibodies specific for heat shock proteins, a chaperone protein targeted by antibodies in patients with AIH. Thus, although TCE can promote autoimmune disease following chronic exposure, a shorter exposure to a binary mixture of TCE and HgCl(2) accelerated disease development. Coexposure to TCE and HgCl(2) also generated a unique liver-specific antibody response not found in mice exposed to a single toxicant. This finding stresses the importance of including mixtures in assessments of chemical immunotoxicity.

[Side-effects of antiepileptic treatment: the current state of the problem]

The current treatment of epilepsy is directed not only at the control of seizures and comorbid states but at the improvement of quality of life and destigmatization that is the key strategic direction. The basis of treatment of epilepsy is a long-term regular taking of antiepileptic drugs (AED). However, it has been shown that quality of life of patients depends not only on clinical presentations of the disease, including seizures and higher mental functions, but on the tolerability of AED. The safety of these drugs becomes the most important component of the treatment even compared to the control of seizures. Therefore, tolerability and compliance (a patient's adherence to a recommended course of treatment, common understanding between a doctor and a patient as well as his/her relatives) receive special attention. The timed detection and correction of side-effects is an integral component of treatment of epilepsy. In some cases, the presence of rare seizures with minimal clinical presentations and even more frequent seizures that are not danger for a patient seems to be more appropriate than the increase in the number and doses of AED reducing quality of life. The balance between therapeutic and toxic effects of AED is a key issue of treatment of epilepsy.

Sphingosine-1-phosphate activates the AKT pathway to protect small intestines from radiation-induced endothelial apoptosis

A previous in vitro study showed that sphingosine-1-phosphate (S1P), a ceramide antagonist, preserved endothelial cells in culture from radiation-induced apoptosis. We proposed to validate the role of S1P in tissue radioprotection by inhibiting acute gastrointestinal (GI) syndrome induced by endothelial cell apoptosis after high dose of radiation. Retro-orbital S1P was injected in mice exposed to 15 Gy, a dose-inducing GI syndrome within 10 days. Overall survival and apoptosis on intestines sections were studied. Intestinal cell type targeted by S1P and early molecular survival pathways were researched using irradiated in vitro cell models and in vivo mouse models. We showed that retro-orbital S1P injection before irradiation prevented GI syndrome by inhibiting endothelium collapse. We defined endothelium as a specific therapeutic target because only these cells and not intestinal epithelial cells, or B and T lymphocytes, were protected. Pharmacologic approaches using AKT inhibitor and pertussis toxin established that S1P affords endothelial cell protection in vitro and in vivo through a mechanism involving AKT and 7-pass transmembrane receptors coupled to Gi proteins. Our results provide strong pharmacologic and mechanistic proofs that S1P protects endothelial cells against acute radiation enteropathy.