Increased Interferon Gamma Research Articles

Myeloperoxidase Attenuates Pathogen Clearance during Plasmodium yoelii Nonlethal Infection.

Myeloperoxidase (MPO), a leukocyte-derived enzyme mainly secreted by activated neutrophils, is known to be involved in the immune response during bacterial and fungal infection and inflammatory diseases. Nevertheless, the role of MPO in a parasitic disease like malaria is unknown. We hypothesized that MPO contributes to parasite clearance. To address this hypothesis, we used Plasmodium yoelii nonlethal infection in wild-type and MPO-deficient mice as a murine malaria model. We detected high MPO plasma levels in wild-type mice with Plasmodium yoelii infection. Unexpectedly, infected MPO-deficient mice did not show increased parasite loads but were able to clear the infection more rapidly than wild-type mice. Additionally, the presence of neutrophils at the onset of infection seemed not to be essential for the control of the parasitemia. The effect of decreased parasite levels in MPO-deficient mice was absent from animals lacking mature T and B cells, indicating that this effect is most likely dependent on adaptive immune response mechanisms. Indeed, we observed increased gamma interferon and tumor necrosis factor alpha production by T cells in infected MPO-deficient mice. Together, these results suggest that MPO modulates the adaptive immune response during malaria infection, leading to an attenuated parasite clearance.

Genome-Wide Association Study of Cell-Mediated Response in Dogs Naturally Infected by Leishmania infantum.

A genome-wide association study (GWAS) could unravel the complexity of the cell-mediated immunity (CMI) to canine leishmaniasis (CanL). Therefore, we scanned 110,165 single-nucleotide polymorphisms (SNPs), aiming to identify chromosomal regions associated with the leishmanin skin test (LST), lymphocyte proliferation assay (LPA), and cytokine responses to further understand the role played by CMI in the outcome of natural Leishmania infantum infection in 189 dogs. Based on LST and LPA, four CMI profiles were identified (LST-/LPA-, LST+/LPA-, LST-/LPA+, and LST+/LPA+), which were not associated with subclinically infected or diseased dogs. LST+/LPA+ dogs showed increased interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) levels and mild parasitism in the lymph nodes, whereas LST-/LPA+ dogs, in spite of increased IFN-γ, also showed increased interleukin-10 (IL-10) and transforming growth factor β (TGF-β) levels and the highest parasite load in lymph nodes. Low T cell proliferation under low parasite load suggested that L. infantum was not able to induce effective CMI in the early stage of infection. Altogether, genetic markers explained 87%, 16%, 15%, 11%, 0%, and 0% of phenotypic variance in TNF-α, TGF-β, LST, IL-10, IFN-γ, and LPA, respectively. GWAS showed that regions associated with TNF-α include the following genes: IL12RB1, JAK3, CCRL2, CCR2, CCR3, and CXCR6, involved in cytokine and chemokine signaling; regions associated with LST, including COMMD5 and SHARPIN, involved in regulation of NF-κB signaling; and regions associated with IL-10, including LTBP1 and RASGRP3, involved in T regulatory lymphocytes differentiation. These findings pinpoint chromosomic regions related to the cell-mediated response that potentially affect the clinical complexity and the parasite replication in canine L. infantum infection.

Abstract 4905: Effects of MAPK pathway inhibitors in the tumor immune microenvironment

Abstract Immunotherapeutic agents have shown great promise in the clinic in recent years and this has led to their approval as single agents or as immune doublet combinations in melanoma and lung cancer. In order to increase the extent of benefit from these agents and to extend immunotherapies to additional patients, combinations are being evaluated of immunotherapeutic agents with chemotherapy and targeted agents. Inhibitors of the mitogen-activated kinase protein kinase (MAPK) pathway, including BRAF and MEK inhibitors, have been approved in melanoma, and are being evaluated in additional indications. We evaluated the effects of MEK and ERK inhibitors on human T cells cultured in vitro as well as on the tumor microenvironment in preclinical syngeneic mouse models. In studies with human T cells in vitro, we find that MEK or ERK inhibition reduced proliferation of naïve T cells, but had little effect on the proliferation of central memory cells, suggesting a differential requirement on MAPK signaling for proliferation of these T cell subsets. In vivo, MEK and ERK inhibition resulted in an increase in CD8+ infiltration in the tumor, as well as a decrease of markers of T cell exhaustion such as PD-1 and EOMES. The combination of MEK or ERK inhibitors plus anti-PD-L1 resulted in increased CD8+ effector function as measured by increased interferon gamma (IFNg) levels. In some cases, the MEK and ERK inhibitors showed differences in their pharmacodynamic effects as single agents; however, in combination with anti-PD-L1, the effects were similar. For example, single agent MEK inhibition but not single agent ERK inhibition increased the number of CD4+ helper and regulatory T cells (Tregs) in the tumor. However, both of these CD4+ subsets, as well as CD4+ IFNg levels, were increased with MEK or ERK inhibitors combined with anti-PD-L1. Similarly, single agent MEK inhibition decreased the number of infiltrating CD11b+Ly6G+ myeloid cells whereas single agent ERK inhibition increased the number of infiltrating CD11b+Ly6C+ myeloid cells. However, in combination with anti-PD-L1, these changes in myeloid populations were less apparent. Taken together, these data show that MAPK pathway suppression can modulate multiple immune cell subtypes within the tumor, with many of these changes expected to activate the immune infiltrate. Despite the increase in Tregs in response to ERK and MEK inhibition in combination with anti-PD-L1, these combinations were efficacious. This suggests that the other immune stimulatory effects of these treatments are sufficient to drive efficacy despite the presence of increased Tregs. Our data suggest that the combination of MAPK inhibition plus anti-PD-L1 inhibition, such as with atezolizumab, is a promising hypothesis to test in the clinic. Citation Format: Marcia P. Belvin, Erin Williams, Shiuh-Ming Luoh, Jeanne Cheung, Christine Orr, Emily Chan, Peter Ebert, Ira Mellman, Jeong Kim, Mark Merchant. Effects of MAPK pathway inhibitors in the tumor immune microenvironment. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4905.

DNA-mediated adjuvant immunotherapy extends survival in two different mouse models of myeloid malignancies.

We have previously shown that a specific promyelocytic leukemia-retinoic acid receptor alpha (PML-RARA) DNA vaccine combined with all-trans retinoic acid (ATRA) increases the number of long term survivors with enhanced immune responses in a mouse model of acute promyelocytic leukemia (APL). This study reports the efficacy of a non-specific DNA vaccine, pVAX14Flipper (pVAX14), in both APL and high risk myelodysplastic syndrome (HR-MDS) models. PVAX14 is comprised of novel immunogenic DNA sequences inserted into the pVAX1 therapeutic plasmid. APL mice treated with pVAX14 combined with ATRA had increased survival comparable to that obtained with a specific PML-RARA vaccine. Moreover, the survival advantage correlated with decreased PML-RARA transcript levels and increase in anti-RARA antibody production. In HR-MDS mice, pVAX14 significantly improved survival and reduced biomarkers of leukemic transformation such as phosphorylated mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) 1. In both preclinical models, pVAX14 vaccine significantly increased interferon gamma (IFNγ) production, memory T-cells (memT), reduced the number of colony forming units (CFU) and increased expression of the adapter molecule signalling to NF-κB, MyD88. These results demonstrate the adjuvant properties of pVAX14 providing thus new approaches to improve clinical outcome in two different models of myeloid malignancies, which may have potential for a broader applicability in other cancers.

Increasing cellular immunogenicity to peptide-based vaccine candidates using a fluorocarbon antigen delivery system

Traditionally, synthetic peptide vaccines for infectious diseases and cancer require adjuvants to achieve optimal immunogenicity. Here we describe a novel method of peptide modification using a fluorocarbon chain which can substantially increase peptide-specific cellular immune responses in the absence of adjuvant. We demonstrate that fluorocarbon-modified peptides (fluoropeptides) derived from HIV, influenza and hepatitis C virus can significantly increase interferon gamma ELISpot responses against cytotoxic and T-helper epitopes compared to unmodified peptides or lipopeptides in mice. Increases in both T-helper1 and T-helper2 cytokines are observed. Fluoropeptides show enhanced ability of the antigen to persist at the site of administration and persistence is associated with a prolonged and elevated immune response. Additionally we demonstrate that fluoropeptides have increased proteolytic resistance thereby potentially supporting their increased half-life in vivo. Fluorocarbon-modification of peptides provides a valuable tool for increasing cellular immunogenicity of vaccines for infectious diseases and cancer without requirement for traditional adjuvants.

Development of a new DNA vaccine based on mycobacterial ESAT-6 antigen delivered by recombinant invasive Lactococcus lactis FnBPA+.

The use of the food-grade bacterium Lactococcus lactis as a vehicle for the oral delivery of DNA vaccine plasmids constitutes a promising strategy for vaccination. The delivery of DNA plasmids into eukaryotic cells is of critical importance for subsequent DNA expression and effectiveness of the vaccine. In this context, the use of the recombinant invasive L. lactis FnBPA+ (fibronectin-binding protein A) strain for the oral delivery of the eukaryotic expression vector vaccination using lactic acid bacteria (pValac), coding for the 6-kDa early secreted antigenic target (ESAT-6) gene of Mycobacterium tuberculosis, could represent a new DNA vaccine strategy against tuberculosis. To this end, the ESAT-6 sequence was cloned into the pValac vector; the L. lactis fibronectin-binding protein A (FnBPA)+ (pValac:ESAT-6) strain was obtained, and its immunological profile was checked in BALB/c mice. This strain was able to significantly increase interferon gamma (IFN-γ) production in spleen cells, showing a systemic T helper 1 (Th1) cell response. The mice also showed a significant increase in specific secretory immunoglobulin A (sIgA) production in colon tissue and fecal extracts. Thus, this is the first time that L. lactis has been used to deliver a plasmid DNA harboring a gene that encodes an antigen against tuberculosis through mucous membranes.

Dietary rice bran protects against rotavirus diarrhea and promotes Th1-type immune responses to human rotavirus vaccine in gnotobiotic pigs.

Rice bran (RB) contains a distinct stoichiometry of phytochemicals that can promote gut mucosal immune responses against enteric pathogens. The effects of RB on rotavirus diarrhea and immunogenicity of an attenuated human rotavirus (HRV) vaccine were evaluated in gnotobiotic pigs. The four treatment groups studied were RB plus vaccine, vaccine only, RB only, and mock control. Pigs in the RB groups were fed the amount of RB that replaced 10% of the pigs' total daily calorie intake from milk starting from 5 days of age until they were euthanized. Pigs in the vaccine groups were orally inoculated with two doses of the attenuated HRV vaccine. A subset of pigs from each group was orally challenged with the homologous virulent HRV on postinoculation day 28. Diarrhea and virus shedding were monitored daily from postchallenge day 0 to day 7. RB feeding significantly protected against diarrhea upon virulent HRV challenge and enhanced the protective rate of the vaccine against rotavirus diarrhea. Consistent with protection, RB significantly increased gamma interferon (IFN-γ)-producing CD4(+) and CD8(+) T cell responses in intestinal and systemic lymphoid tissues. Furthermore, RB also increased the number of total IgM- and IgA-secreting cells, total serum IgM, IgG, and IgA titers, and HRV-specific IgA titers in intestinal contents. RB reduced the numbers of intestinal and systemic HRV-specific IgA and IgG antibody-secreting cells and reduced serum HRV-specific IgA and IgG antibody titers before the challenge. These results demonstrate clear beneficial effects of RB in protection against rotavirus diarrhea and stimulation of nonspecific and HRV-specific immune responses, as well as its biased Th1-type adjuvant effect for the vaccine.

Engagement of immune effector cells by trastuzumab induces HER2/ERBB2 downregulation in cancer cells through STAT1 activation

IntroductionTrastuzumab has been widely used for the treatment of human epidermal growth factor receptor 2 (HER2) overexpressing breast cancer for more than a decade. However, reports on the involvement of HER2 downregulation in trastuzumab’s mechanism of action are inconsistent. The aim of this study is to investigate if the dependence of trastuzumab-mediated cancer cell HER2 downregulation on immune effector cells represents a novel mechanism of action for trastuzumab.MethodsHER2 expression was evaluated by Western blotting, flow cytometry, and real-time polymerase chain reaction (PCR) in cell lysates from co-cultures of multiple cancer cell lines with peripheral blood mononuclear cells (PBMCs) in the presence or absence of trastuzumab. The engagement of immune cells by trastuzumab through Fc gamma receptors (FcγRs) was tested using three trastuzumab variants with compromised or no Fc (fragment crystallizable) functions and FcγRs blocking experiments. The engagement of immune cells by trastuzumab in HER2 downregulation was also evaluated in in vivo mouse xenograft tumor models.ResultsHER2 downregulation of cancer cells by trastuzumab occurred only when trastuzumab was actively engaged with immune cells and cancer cells, as demonstrated consistently in co-cultures of cancer cell lines with PBMCs and in vivo mouse xenograft tumor models. We further demonstrated that HER2 downregulation in cancer cells by immune-cell-engaged trastuzumab was at the transcriptional level, not through the HER2 degradation pathway. Activation of signal transducer and activator of transcription 1 (STAT1) in cancer cells by the increased interferon gamma (IFN-γ) production in immune cells played an important role in downregulating HER2 in cancer cells upon engagement of immune cells by trastuzumab. Furthermore, HER2 downregulation in cancer cells induced by trastuzumab engagement of immune cells was correlated with the antibody’s antitumor efficacy in vivo.ConclusionsThis study reveals that engagement of immune effector cells by trastuzumab induces HER2 downregulation in HER2-expressing cancer cells, which represents a new function of immune cells in trastuzumab-mediated antitumor efficacy and serves as a novel mechanism of action for trastuzumab. Our results imply that HER2 downregulation in cancer cells treated by trastuzumab may predict active engagement of immune effector cells in tumor microenvironment.

Combination of IMOD™ and Arbidol to increase their immunomodulatory effects as a novel medicine to prevent and cure influenza and some other infectious diseases

• A better choice to prevent and cure viral infectious diseases will be established. • Individual treatment effects of IMOD and Arbidol will be increased. • Infectious diseases such as influenza and hepatitis B/C can be targeted. • Antioxidant properties and (IFN-γ) inducing effects increase CD4 lymphocytes. • A safe medicine will be produced to prevent spread of infections. Viral diseases such as influenza, which are easily transferable from person to person or even country to country, pose one of the biggest threats to health today. Viruses such as avian influenza viruses (N1H5 and H9N1) have been reported to spread in the present decade and, very recently, the novel coronavirus that has caused many life-threatening illnesses and deaths all around the world has received much attention. To prevent these highly contagious viral infections, we have proposed the combination of IMOD™ and Arbidol to increase their immunomodulatory effects as a novel medicine to prevent and cure influenza and some other infectious diseases such as hepatitis B and C. On the one hand, IMOD™ within the last few years has been proven to safely and effectively increase the life expectancy for human immunodeficiency virus (HIV)-infected individuals by increasing CD4 lymphocytes. On the other hand, Arbidol, an antiviral agent has been used safely and effectively in the past two decades to prevent and cure all types of influenza and flu. Therefore, the combination of both in a single dosage to further increase CD4 lymphocytes and interferon gamma (IFN-γ) could be a better choice for treatment of viral infections. This proposal tries to provide enough support and background for approval of a randomized clinical trial by a relevant team of investigators.

Toll-Like Receptor 7 Agonist Imiquimod in Combination with Influenza Vaccine Expedites and Augments Humoral Immune Responses against Influenza A(H1N1)pdm09 Virus Infection in BALB/c Mice

Toll-like receptors (TLRs) of the innate immune system are known targets for enhancing vaccine efficacy. We investigated whether imiquimod, a synthetic TLR7 agonist, can expedite the immune response against influenza virus infection when combined with influenza vaccine. BALB/c mice were immunized intraperitoneally with monovalent A(H1N1)pdm09 vaccine combined with imiquimod (VCI) prior to intranasal inoculation with a lethal dose of mouse-adapted A(H1N1)pdm09 virus. For mice immunized 3 days before infection, the survival rates were significantly higher in the VCI group (60%, mean survival time[MST], 11 days) than in the vaccine-alone (30%; MST, 8.8 days), imiquimod-alone (5%; MST, 8.4 days), and phosphate-buffered saline (PBS) (0%; MST, 6.2 days) groups (P < 0.01). In the VCI group, 45 and 35% of the mice survived even when they were infected 2 days or 1 day after immunization. Virus-specific serum IgM, IgG, and neutralizing antibodies appeared earlier with higher geometric mean titers in the VCI group than in the control groups. The pulmonary viral load was significantly lower at all time points postinfection in the VCI, vaccine-alone, and imiquimod-alone groups than in the PBS control group (P < 0.05). The protection induced by VCI was specific for A(H1N1)pdm09 virus but not for A(H5N1) virus. Since imiquimod combined with RNase-treated vaccine is as protective as imiquimod combined with untreated vaccine, mechanisms other than TLR7 may operate in expediting and augmenting immune protection. Moreover, increased gamma interferon mRNA expression and IgG isotype switching, which are markers of the Th1 response induced by imiquimod, were not apparent in our mouse model. The mechanisms of imiquimod-induced immune protection deserve further study.

Post-kala-Azar dermal leishmaniasis: A diagnostic dilemma in a nonendemic area.

Post-kala-Azar dermal leishmaniasis: A diagnostic dilemma in a nonendemic area.

STAT6 polymorphisms are associated with neonatal regulatory T cells and cytokines and atopic diseases at 3 years

The transcription factor STAT6 is crucial for activation of the interleukin (IL)-4/IL-13 pathway and has been linked to regulatory T cells (Tregs). Associations of STAT6 polymorphisms with IgE levels were described; however, their impact on neonatal immune responses and early disease development is unknown. STAT6 polymorphisms were genotyped in cord blood mononuclear cells by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Gene expression was assessed by real-time polymerase chain reaction (PCR) and cytokines by Multiplex. At age 3years, atopic diseases were assessed by questionnaires. STAT6 rs324011 but not rs1059513 polymorphism was associated with significant or borderline significant decreased mRNA expression of Treg-associated genes (FOXP3, GITR, LAG3). Heterozygotes and minor allele homozygotes of rs324011 had low levels of tumor necrosis factor alpha (TNF-α) and increased interferon gamma (IFN-γ) (P≤0.04), while heterozygotes and minor allele homozygotes of rs1059513 had increased TNF-α and Granulocyte-macrophage colony-stimulating factor (GM-CSF) (P≤0.05). In minor allele homozygotes of rs324011, expression of Treg-associated genes was strongly inverse correlated with IFN-γ (unstimulated, r=-0.7, P=0.111; LpA stimulation, r=-0.8, P=0.011), but not in heterozygotes or major allele homozygotes. Heterozygotes and minor allele homozygotes of rs324011 presented a lower risk of atopic dermatitis and obstructive bronchitis until age 3years. Two STAT6 polymorphisms were associated with altered immune responses already at birth. STAT6 rs324011 was associated with lower neonatal Treg and increased Th1 response. Those neonates had a lower risk of atopic dermatitis and obstructive bronchitis until 3years. Our data suggest a role for STAT6 polymorphisms in early immune regulation and implications on early atopic disease development.

Cell-mediated immune responses in the head-associated lymphoid tissues induced to a live attenuated avian coronavirus vaccine

Humoral immunity is important for controlling viral diseases of poultry, but recent studies have indicated that cytotoxic T cells also play an important role in the immune response to infectious bronchitis virus (IBV). To better understand the cell mediated immune responses to IBV in the mucosal and systemic immune compartments chickens were ocularly vaccinated with IBV. This induced a lymphocyte expansion in head-associated lymphoid tissues (HALT) and to a lesser extent in the spleen, followed by a rapid decline, probably due to homing of lymphocytes out of these organs and contraction of the lymphocyte population. This interpretation was supported by observations that changes in mononuclear cells were mirrored by that in CD3+CD44+ T cell abundance, which presumably represent T effector cells. Increased interferon gamma (IFN-γ) expression was observed in the mucosal immune compartment, i.e., HALT, after primary vaccination, but shifted to the systemic immune compartment after boosting. In contrast, the expression of cytotoxicity-associated genes, i.e., granzyme A (GZMA) and perforin mRNA, remained associated with the HALT after boosting. Thus, an Ark-type IBV ocular vaccine induces a central memory IFN-γ response in the spleen while the cytotoxic effector memory response, as measured by GZMA and perforin mRNA expression, remains associated with CALT after boosting.

Infection with Francisella tularensis LVSclpBLeads to an Altered yet Protective Immune Response

Bacterial attenuation is typically thought of as reduced bacterial growth in the presence of constant immune pressure. Infection with Francisella tularensis elicits innate and adaptive immune responses. Several in vivo screens have identified F. tularensis genes necessary for virulence. Many of these mutations render F. tularensis defective for intracellular growth. However, some mutations have no impact on intracellular growth, leading us to hypothesize that these F. tularensis mutants are attenuated because they induce an altered host immune response. We were particularly interested in the F. tularensis LVS (live vaccine strain) clpB (FTL_0094) mutant because this strain was attenuated in pneumonic tularemia yet induced a protective immune response. The attenuation of LVS clpB was not due to an intracellular growth defect, as LVS clpB grew similarly to LVS in primary bone marrow-derived macrophages and a variety of cell lines. We therefore determined whether LVS clpB induced an altered immune response compared to that induced by LVS in vivo. We found that LVS clpB induced proinflammatory cytokine production in the lung early after infection, a process not observed during LVS infection. LVS clpB provoked a robust adaptive immune response similar in magnitude to that provoked by LVS but with increased gamma interferon (IFN-γ) and interleukin-17A (IL-17A) production, as measured by mean fluorescence intensity. Altogether, our results indicate that LVS clpB is attenuated due to altered host immunity and not an intrinsic growth defect. These results also indicate that disruption of a nonessential gene(s) that is involved in bacterial immune evasion, like F. tularensis clpB, can serve as a model for the rational design of attenuated vaccines.

KIR2DL4 copy number variation is associated with CD4+ T-cell depletion and function of cytokine-producing NK cell subsets in SIV-infected Mamu-A*01-negative rhesus macaques.

Here, we demonstrate that KIR2DL4 copy number variation (CNV) is associated with CD4(+) T-cell decline and functionality of cytokine-producing NK cells during primary simian immunodeficiency virus (SIV) infection in Mamu-A*01(-) Indian-origin rhesus macaques, with higher KIR2DL4 copy numbers being associated with a better preservation of CD4(+) T cells and an increased gamma interferon (IFN-γ) production from stimulated cytokine-producing NK cell subsets during acute SIVmac251 infection. These findings underscore the crucial role of activating killer-cell immunoglobulin-like receptors (KIRs) in NK cell-mediated SIV responses during early SIV infection.

Radiation‐induced loss of cell surface CD47 enhances immune‐mediated clearance of human papillomavirus‐positive cancer

The increasing incidence of human papillomavirus (HPV) related oropharyngeal squamous cell carcinoma (OSSC) demands development of novel therapies. Despite presenting at a more advanced stage, HPV(+) oropharyngeal squamous cell carcinoma (OSCC) have a better prognosis than their HPV(-) counterparts. We have previously demonstrated that clearance of HPV(+) OSCC during treatment with radiation and chemotherapy requires an immune response which is likely responsible for the improved clinical outcomes. To further elucidate the mechanism of immune-mediated clearance, we asked whether radiation therapy induces tumor cell changes that allow the body to recognize and aid in tumor clearance. Here, we describe a radiation-induced change in tumor surface protein expression that is critical for immune-mediated clearance. Radiation therapy decreases surface expression of CD47, a self-marker. CD47 is frequently overexpressed in head and neck squamous cell carcinoma and radiation induces a decrease of CD47 in a dose-dependent manner. We show that both in vitro and in vivo tumor cell CD47 protein levels are restored over time after sublethal radiation exposure and that protein levels on adjacent, normal tissues remain unaffected. Furthermore, reduction of tumor cell CD47 increases phagocytosis of these cells by dendritic cells and leads to increased interferon gamma and granzyme production from mixed lymphocytes. Finally, decreasing tumor cell CD47 in combination with standard radiation and chemotherapy results in improved immune-mediated tumor clearance in vivo. These findings help define an important mechanism of radiation-related immune clearance and suggest that decreasing CD47 specifically on tumor cells may be a good therapeutic target for HPV related disease.

Effects of feeding an herbal preparation to sows on immunological performance of offspring1

The objective of this study was to determine the effects of feeding Chinese herbal ultra-fine (CHU) powder to sows during the last week of gestation and during the lactation period on immunological performance of the offspring. In this experiment, 15 pregnant sows (mean BW = 235.6 ± 3.7 kg) were randomly assigned to 1 of 3 treatments including no additive (Control), 0.75% CHU powder (Group A), or 1.5% CHU powder (Group B) added to a maize- and soybean meal-based diet. Blood from 10 piglets per group was collected at d 7, d 14, or d 21 of age to measure serum metabolites, lymphocyte proliferating activity, and serum antibody and cytokine concentrations. Dietary supplementation of sows with CHU powder increased (P < 0.05) serum concentrations of total protein, albumin, and triglycerides of offspring, whereas the concentration of glucose was reduced (P < 0.05) compared with Controls. The CHU powder enhanced (P < 0.05) serum concentrations of IgG in Group B offspring on d 7 and IgM in Group A offspring on d 7 and d 14, increased IL-10 in Group A offspring on d 7, as well as IL-2 in offspring from Groups A and B on all days of determination. The CHU powder increased interferon gamma in Group A offspring on d 14 and in Group B offspring on d 14 and d 21, and increased tumor necrosis factor alpha in offspring of Group A on d 14 and in Group B on all days surveyed. Compared with Controls, a greater number (P < 0.05) of T lymphocyte subpopulations were detected in Group A and B offspring including CD4+ cells in Group A on d 7 and d 21, CD4+ cells in Group B on d 14 and d 21, and CD8+ cells in Group A on d 7 and d 14. Collectively, these findings indicate a beneficial effect of CHU powder treatment of sows in later gestation and during lactation on serum metabolism and cellular and humoral immune responses of their offspring.

Small bowel fibrosis and systemic inflammatory response after ileocolonic anastomosis in IL-10 null mice

BackgroundCrohn’s disease recurrence after an ileocecal resection is common; yet, its pathophysiology is poorly understood and available treatment is suboptimal. The purpose of this study was to examine the bacterial, local, and systemic immune changes that follow ileocolonic anastomosis in a rodent model of Crohn’s disease, the interleukin-10 gene–deficient (IL-10 null) mice. Materials and methodsWe divided wild-type and IL-10 null mice into three treatment groups: ileocolonic anastomosis, sham operation (ileo-ileal anastomosis), and control group without an operation. We sacrificed mice at 6 and 15 wks after the operation. At 6 wks, we assessed bacterial changes using the denaturing gel electrophoresis and similarity coefficient calculation. At both time points, we examined the small bowel for inflammation and fibrosis with histology. We measured the interferon gamma secretion by splenocytes stimulated with gastrointestinal bacterial antigens and splenocyte composition as a marker of systemic response. ResultsAt 6 wks, ileocolonic anastomosis resulted in increased similarity in bacterial species between the ileum and colon. The ileocolonic anastomosis did not lead to significant inflammation in the small intestine, but it resulted in an increased collagen deposition in all animals undergoing surgery, the most pronounced fibrosis of which was present in IL-10 null mice 15 wks after ileocolonic anastomosis. Furthermore, this was associated with significantly increased interferon gamma secretion by bacterial antigen-stimulated splenocytes and a decreased number of CD11+ cells in the same experimental group. ConclusionsIleocolonic anastomosis leads to bacterial changes in the terminal ileum. In the genetically susceptible host, it is associated with small bowel fibrosis and systemic immune alterations. The composition of immune cells in the spleen is altered and splenocytes hypersecrete proinflammatory cytokine (interferon gamma) when challenged with gastrointestinal bacterial antigens.

Increased Protection from Vaccinia Virus Infection in Mice Genetically Prone to Lymphoproliferative Disorders

Mutations in the genes that encode Fas or Fas ligand (FasL) can result in poor restraints on lymphocyte activation and in increased susceptibility to autoimmune disorders. Because these mutations portend a continuously activated immune state, we hypothesized that they might in some cases confer resistance to infection. To examine this possibility, the immune response to, morbidity caused by, and clearance of vaccinia virus (VACV) Western Reserve was examined in 5- to 7-week-old Fas mutant (lpr) mice, before an overt lymphoproliferative disorder was observable. On day 6 after VACV infection, C57BL/6-lpr (B6-lpr) mice had decreased morbidity, decreased viral titers, and an increased percentage and number of CD4(+) and CD8(+) T cells. As early as day 2 after infection, B6-lpr mice had decreased liver and spleen viral titers and increased numbers of and increased gamma interferon (IFN-γ) production by several different effector cell populations. Depletion of individual effector cell subsets did not inhibit the resistance of B6-lpr mice. Uninfected B6-lpr mice also had increased numbers of NK cells, γδ(+) T cells, and CD44(+) CD4(+) and CD44(+) CD8(+) T cells compared to uninfected B6 mice. Antibody to IFN-γ resulted in increased virus load in both B6 and B6-lpr mice and eliminated the differences in viral titers between them. These results suggest that IFN-γ produced by multiple activated leukocyte populations in Fas-deficient hosts enhances resistance to some viral infections.

Interleukin-17A Deficiency Accelerates Unstable Atherosclerotic Plaque Formation in Apolipoprotein E-Deficient Mice

Interleukin(IL)-17A, an inflammatory cytokine, has been implicated in atherosclerosis, in which inflammatory cells within atherosclerotic plaques express IL-17A. However, its role in the development of atheroscelrosis remains to be controversial. To directly examine the role of IL-17A in atherosclerosis, we generated apolipoprotein E (ApoE)/IL-17A double-deficient (ApoE(-/-)IL-17A(-/-)) mice. Mice were fed with high-fat diet (HFD) for either 8 or 16 weeks, both starting at ages of 6 to 8 weeks. We found that splenic CD4(+) T-cells produced high amounts of IL-17A in ApoE(-/-) mice after HFD feeding for 8 weeks. Atherosclerosis was significantly accelerated in HFD-fed ApoE(-/-)IL-17A(-/-) mice compared with ApoE(-/-) mice. Splenic CD4(+) T-cells of ApoE(-/-)IL-17A(-/-) mice after HFD feeding for 8 weeks, but not for 16 weeks, exhibited increased interferon gamma and decreased IL-5 production. Importantly, formation of vulnerable plaque as evidenced by reduced numbers of vascular smooth muscle cells and reduced type I collagen deposition in the plaque was detected in ApoE(-/-)IL-17A(-/-) mice after HFD feeding for 8 weeks. These results suggest that IL-17A regulates the early phase of atherosclerosis development after HFD feeding and plaque stability, at least partly if not all by modulating interferon gamma and IL-5 production from CD4(+) T-cells.