Differences In Immune Response Research Articles

Differential Immune Response to Infection and Acute Inflammation Along the Epididymis.

The epididymis is a tubular structure connecting the vas deferens to the testis. This organ consists of three main regions—caput, corpus, and cauda—that face opposing immunological tasks. A means of combating invading pathogens is required in the distally located cauda, where there is a risk of ascending bacterial infections originating from the urethra. Meanwhile, immune tolerance is necessary at the caput, where spermatozoa with immunogenic neo-antigens originate from the testis. Consistently, when challenged with live bacteria or inflammatory stimuli, the cauda elicits a much stronger immune response and inflammatory-inflicted damage than the caput. At the cellular level, a role for diverse and strategically positioned mononuclear phagocytes is emerging. At the mechanistic level, differential expression of immunoprotective and immunomodulatory mediators has been detected between the three main regions of the epididymis. In this review, we summarize the current state of knowledge about region-specific immunological characteristics and unveil possible underlying mechanisms on cellular and molecular levels. Improved understanding of the different immunological microenvironments is the basis for an improved therapy and counseling of patients with epididymal infections.

Loci Associated With Antibody Response in Feral Swine (Sus scrofa) Infected With Brucella suis.

Feral swine (Sus scrofa) are a destructive invasive species widespread throughout the United States that disrupt ecosystems, damage crops, and carry pathogens of concern for the health of domestic stock and humans including Brucella suis—the causative organism for swine brucellosis. In domestic swine, brucellosis results in reproductive failure due to abortions and infertility. Contact with infected feral swine poses spillover risks to domestic pigs as well as humans, companion animals, wildlife, and other livestock. Genetic factors influence the outcome of infectious diseases; therefore, genome wide association studies (GWAS) of differential immune responses among feral swine can provide an understanding of disease dynamics and inform management to prevent the spillover of brucellosis from feral swine to domestic pigs. We sought to identify loci associated with differential antibody responses among feral swine naturally infected with B. suis using a case-control GWAS. Tissue, serum, and genotype data (68,516 bi-allelic single nucleotide polymorphisms) collected from 47 feral swine were analyzed in this study. The 47 feral swine were culture positive for Brucella spp. Of these 47, 16 were antibody positive (cases) whereas 31 were antibody negative (controls). Single-locus GWAS were performed using efficient mixed-model association eXpedited (EMMAX) methodology with three genetic models: additive, dominant, and recessive. Eight loci associated with seroconversion were identified on chromosome 4, 8, 9, 10, 12, and 18. Subsequent bioinformatic analyses revealed nine putative candidate genes related to immune function, most notably phagocytosis and induction of an inflammatory response. Identified loci and putative candidate genes may play an important role in host immune responses to B. suis infection, characterized by a detectable bacterial presence yet a differential antibody response. Given that antibody tests are used to evaluate brucellosis infection in domestic pigs and for disease surveillance in invasive feral swine, additional studies are needed to fully understand the genetic component of the response to B. suis infection and to more effectively translate estimates of Brucella spp. antibody prevalence among feral swine to disease control management action.

The differential immune responses to COVID-19 in peripheral and lung revealed by single-cell RNA sequencing

Understanding the mechanism that leads to immune dysfunction in severe coronavirus disease 2019 (COVID-19) is crucial for the development of effective treatment. Here, using single-cell RNA sequencing, we characterized the peripheral blood mononuclear cells (PBMCs) from uninfected controls and COVID-19 patients and cells in paired broncho-alveolar lavage fluid (BALF). We found a close association of decreased dendritic cells (DCs) and increased monocytes resembling myeloid-derived suppressor cells (MDSCs), which correlated with lymphopenia and inflammation in the blood of severe COVID-19 patients. Those MDSC-like monocytes were immune-paralyzed. In contrast, monocyte-macrophages in BALFs of COVID-19 patients produced massive amounts of cytokines and chemokines, but secreted little interferons. The frequencies of peripheral T cells and NK cells were significantly decreased in severe COVID-19 patients, especially for innate-like T and various CD8+ T cell subsets, compared to healthy controls. In contrast, the proportions of various activated CD4+ T cell subsets among the T cell compartment, including Th1, Th2, and Th17-like cells were increased and more clonally expanded in severe COVID-19 patients. Patients’ peripheral T cells showed no sign of exhaustion or augmented cell death, whereas T cells in BALFs produced higher levels of IFNG, TNF, CCL4, CCL5, etc. Paired TCR tracking indicated abundant recruitment of peripheral T cells to the severe patients’ lung. Together, this study comprehensively depicts how the immune cell landscape is perturbed in severe COVID-19.

Differential immune responses of immunoglobulin Z subclass members in antibacterial immunity in a zebrafish model.

Immunoglobulin Z (IgZ) or its equivalent immunoglobulin T (IgT) is a newly identified immunoglobulin (Ig) class from teleost fish. This Ig class is characterized by its involvement in mucosa-associated lymphoid tissues (MALTs) for mucosal defence against pathogen infection. Recently, several subclass members of IgZ/IgT, such as IgZ, IgZ2, Igτ1, Igτ2 and Igτ3, have been further identified from zebrafish, common carp and rainbow trout. However, the functional diversity and correlation among these subclasses remain uncertain. Here, we explored the differential immune reactions of the IgZ and IgZ2 subclasses in antibacterial immunity in a zebrafish model. IgZ was extensively distributed in the peripheral serum and skin/gill MALTs and showed a rapid induction upon bacterial infection. IgZ2 was specialized in skin/gill MALTs and showed a strong induction following IgZ production. Correspondingly, the IgZ+ B cells had a wider distribution in the systemic primary/secondary lymphoid tissues and MALTs than the IgZ2+ B cells, which were predominant in MALTs. IgZ and IgZ2 exhibited a complementary effect in antibacterial immunity by possessing differential abilities. That is, IgZ is preferentially involved in bactericidal reaction that is in part C1q-dependent, and IgZ2 participates in neutralization action through bacteria-coating activity. The production of IgZ largely depended on the αβ T/CD4+ T cells, whereas that of IgZ2 did not, suggesting the different dependencies of IgZ and IgZ2 on systemic immunity. Our findings demonstrate that the functional behaviour and mechanism of the IgZ/IgT family are more diverse than previously recognized and thus improve the current knowledge about this ancient Ig class.

Single-Cell Profiling of AKI in Mice Highlights Differential Immune Cellular Response Programs in Regeneration and Fibrosis

Single-Cell Profiling of AKI in Mice Highlights Differential Immune Cellular Response Programs in Regeneration and Fibrosis

Mycobacterial Control of Host Mitochondria: Bioenergetic and Metabolic Changes Shaping Cell Fate and Infection Outcome.

Mitochondria, are undoubtedly critical organelle of a eukaryotic cell, which provide energy and offer a platform for most of the cellular signaling pathways that decide cell fate. The role of mitochondria in immune-metabolism is now emerging as a crucial process governing several pathological states, including infection, cancer, and diabetes. Mitochondria have therefore been a vulnerable target for several bacterial and viral pathogens to control host machinery for their survival, replication, and dissemination. Mycobacterium tuberculosis, a highly successful human pathogen, persists inside alveolar macrophages at the primary infection site, applying several strategies to circumvent macrophage defenses, including control of host mitochondria. The infection perse and specific mycobacterial factors that enter the host mitochondrial milieu perturb mitochondrial dynamics and function by disturbing mitochondrial membrane potential, shifting bioenergetics parameters such as ATP and ROS, orienting the host cell fate and thereby infection outcome. In the present review, we attempt to integrate the available information and emerging dogmas to get a holistic view of Mycobacterium tuberculosis infection vis-a-vis mycobacterial factors that target host mitochondria and changes therein in terms of morphology, dynamics, proteomic, and bioenergetic alterations that lead to a differential cell fate and immune response determining the disease outcome. We also discuss critical host factors and processes that are overturned by Mycobacterium tuberculosis, such as cAMP-mediated signaling, redox homeostasis, and lipid droplet formation. Further, we also present alternate dogmas as well as the gaps and limitations in understanding some of the present research areas, which can be further explored by understanding some critical processes during Mycobacterium tuberculosis infection and the reasons thereof. Toward the end, we propose to have a set of guidelines for pursuing investigations to maintain uniformity in terms of early and late phase, MOI of infection, infection duration and incubation periods, the strain of mycobacteria, passage numbers, and so on, which all work as probable variables toward different readouts. Such a setup would, therefore, help in the smooth integration of information across laboratories toward a better understanding of the disease and possibilities of host-directed therapy.

Impact of aging on the immune response to traumatic brain injury (AIm:TBI) study protocol

BackgroundTraumatic brain injury (TBI) in older adults leads to considerable morbidity and mortality. Outcomes among older adults with TBI are disparately worse than in younger adults. Differences in immunological response...

Comprehensive Transcriptome of the Maize Stalk Borer, Busseola fusca, from Multiple Tissue Types, Developmental Stages, and Parasitoid Wasp Exposures.

Busseola fusca (Fuller) (Lepidoptera: Noctuidae), the maize stalk borer, is a widespread crop pest in sub-Saharan Africa that has been the focus of biological research and intensive management strategies. Here, we present a comprehensive annotated transcriptome of B. fusca (originally collected in the Western Province of Kenya) based on ten pooled libraries including a wide array of developmental stages, tissue types, and exposures to parasitoid wasps. Parasitoid wasps have been used as a form of biocontrol to try and reduce crop losses with variable success, in part due to differential infectivities and immune responses among wasps and hosts. We identified a number of loci of interest for pest management, including genes potentially involved in chemoreception, immunity, and response to insecticides. The comprehensive sampling design used expands our current understanding of the transcriptome of this species and deepens the list of potential target genes for future crop loss mitigation, in addition to highlighting candidate loci for differential expression and functional genetic analyses in this important pest species.

Age-Related Differences in Immunological Responses to SARS-CoV-2

There is a striking age-related disparity in the prevalence and severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced coronavirus disease 2019 infections, which might be explained by age-dependent immunological mechanisms. These include age-related physiological differences in immunological responses, cross-neutralizing antibodies, and differences in levels and binding affinity of angiotensin-converting enzyme 2, the SARS-CoV-2 target receptor; antibody-dependent enhancement in adults manifesting with an overexuberant systemic inflammation in response to infection; and the increased likelihood of comorbidities in adults and the elderly. Emerging immunological phenomena such as Pediatric Multi-System Inflammatory Disorder Temporally associated with SARS-CoV-2 or Multisystem Inflammatory Syndrome in Children are now being observed, though the underlying mechanisms are still unclear. Understanding the mechanisms through which pediatric patients are protected from severe novel coronaviruses infections will provide critical clues to the pathophysiology of coronavirus disease 2019 infection and inform future therapeutic and prophylactic interventions. Asymptomatic carriage in children may have major public health implications, which will have an impact on social and health care policies on screening and isolation practices, school reopening, and safe distancing requirements in the community.

Longitudinal changes of inflammatory parameters and their correlation with disease severity and outcomes in patients with COVID-19 from Wuhan, China

BackgroundCoronavirus disease 2019 (COVID-19) is a newly emerging infectious disease and rapidly escalating epidemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The pathogenesis of COVID-19 remains to be elucidated. We aimed to clarify correlation of systemic inflammation with disease severity and outcomes in COVID-19 patients.MethodsIn this retrospective study, baseline characteristics, laboratory findings, and treatments were compared among 317 laboratory-confirmed COVID-19 patients with moderate, severe, or critically ill form of the disease. Moreover, the longitudinal changes of serum cytokines, lactate dehydrogenase (LDH), high-sensitivity C-reactive protein (hsCRP), and hsCRP to lymphocyte count ratio (hsCRP/L) as well as their associations with disease severity and outcomes were investigated in 68 COVID-19 patients.ResultsWithin 24 h of admission, the critically ill patients showed higher concentrations of inflammatory markers including serum soluble interleukin (IL)-2 receptor, IL-6, IL-8, IL-10, tumor necrosis factor alpha (TNF-α), ferritin, procalcitonin, LDH, hsCRP, and hsCRP/L than patients with severe or moderate disease. The severe cases displayed the similar response patterns when compared with moderate cases. The longitudinal assays showed the levels of pro-inflammatory cytokines, LDH, hsCRP, and hsCRP/L gradually declined within 10 days post admission in moderate, severe cases or those who survived. However, there was no significant reduction in cytokines, LDH, hsCRP, and hsCRP/L levels in critically ill or deceased patients throughout the course of illness. Compared with female patients, male cases showed higher serum concentrations of soluble IL-2R, IL-6, ferritin, procalcitonin, LDH, and hsCRP. Multivariate logistic regression analysis revealed that IL-6 > 50 pg/mL and LDH > 400 U/L on admission were independently associated with disease severity in patients with COVID-19.ConclusionExuberant inflammatory responses within 24 h of admission in patients with COVID-19 may correlate with disease severity. SARS-CoV-2 infection appears to elicit a sex-based differential immune response. IL-6 and LDH were independent predictive parameters for assessing the severity of COVID-19. An early decline of these inflammation markers may be associated with better outcomes.

The deficiency of myelin in the mutant taiep rat induces a differential immune response related to protection from the human parasite Trichinella spiralis.

Taiep rat is a myelin mutant with a progressive motor syndrome characterized by tremor, ataxia, immobility episodes, epilepsy and paralysis of the hindlimbs. Taiep had an initial hypomyelination followed by a progressive demyelination associated with an increased expression of some interleukins and their receptors. The pathology correlated with an increase in nitric oxide activity and lipoperoxidation. In base of the above evidences taiep rat is an appropriate model to study neuroimmune interactions. The aim of this study was to analyze the immune responses in male taiep rats after acute infection with Trichinella spiralis. Our results show that there is an important decrease in the number of intestinal larvae in the taiep rat with respect to Sprague-Dawley control rats. We also found differences in the percentage of innate and adaptive immune cell profile in the mesenteric lymphatic nodes and the spleen that correlated with the demyelination process that took place on taiep subjects. Finally, a clear pro-inflammatory cytokine pattern was seen on infected taiep rats, that could be responsible of the decrement in the number of larvae number. These results sustain the theory that neuroimmune interaction is a fundamental process capable of modulating the immune response, particularly against the parasite Trichinella spiralis in an animal model of progressive demyelination due to tubulinopathy, that could be an important mechanism for the clinical course of autoimmune diseases associated with parasite infection.

Abstract 2232: A novel immune checkpoint regulator in the ovarian cancer microenvironment

Abstract High-grade serous ovarian cancer (HGSC) is the most lethal gynecologic malignancy, accounting for 70-80% of ovarian cancer deaths worldwide. Despite promising results with platinum-based chemotherapy and cytoreductive surgery, more than 75% of women with HGSC will relapse after completion of first-line therapy. The window of opportunity to tailor therapeutic interventions to control progressive disease is limited due to the inherent tumor heterogeneity and genomic instability of HGSC and to how these factors contribute to different immune responses. Recent studies show that biomarkers expressed by specific stromal cell types in the tumor microenvironment may have prognostic value. Our group and others has shown that CD8+ lymphocyte infiltration in the ovarian tumor epithelium is associated with prolonged survival in patients with HGSC. Nevertheless, the molecular mechanisms underlying the promotion or inhibition of CD8+ lymphocyte infiltration by stromal cells in ovarian cancer are not fully understood.By laser microdissection and transcriptome profiling of tumor tissue samples from HGSC patients, we identified stromal cancer associated fibroblasts (CAF)-specific gene signatures that are associated with the survival of patients and with the differential tumor immune response. Among the differentially expressed genes identified, validation study by qPCR, Imaging CyTOF and immunohistochemistry indicated a significant inverse correlation between stromal MFAP5 expression and intratumoral granzyme B+/CD8+ T cell density in HGSC tissue samples. MFAP5 is an extracellular matrix glycoprotein and an important component in the assembly of microfibrils. Moreover our recent studies showed that increased stromal MFAP5 expression is associated with poorer survival in HGSC patients. This led to the hypothesis that MFAP5 could acts as an immune checkpoint mediator by generating an immunosuppressive environment through suppressing CD8+ T cell activation and trafficking in the ovarian tumor tissue. To test this hypothesis, transcriptome profile was performed to identify alteration in immune related genes in ovarian cancer cells treated with rMFAP5. The results showed markedly higher expression of CD47, a novel immune checkpoint molecule that triggers “don't eat me” signals on macrophages, in rMFAP5 treated ovarian cancer cells and CD8+ T cells than control cells. Additionally, we demonstrated that rMFAP5 induced apoptosis in CD8+ T cells and reduced macrophage phagocytosis potential. These data suggest that CD47 mediates the effect of MFAP5 on inducing apoptosis in CD8+ T-cells as wells as on preventing macrophage phagocytosis of ovarian cancer cells.Overall, the identification of MFAP5 as a novel stroma-derived immunomodulatory molecule that is associated with patient survival rates and CD8+ T cell densities presents a unique opportunity for the development of new treatment strategies that may improve survival. Citation Format: Sammy Ferri Borgogno, Tsz-Lun Yeung, Cecilia S. Leung, Chi Lam Au Yeung, Ying Zhu, Stephen T. Wong, Samuel C. Mok. A novel immune checkpoint regulator in the ovarian cancer microenvironment [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2232.

Differential Viral-Host Immune Interactions Associated with Oseltamivir-Resistant H275Y and Wild-Type H1N1 A(pdm09) Influenza Virus Pathogenicity.

Oseltamivir is a common therapy against influenza A virus (IAV) infections. The acquisition of oseltamivir resistance (OR) mutations, such as H275Y, hampers viral fitness. However, OR H1N1 viruses have demonstrated the ability to spread throughout different populations. The objective of this work was to compare the fitness of two strains of OR (R6 and R7) containing the H275Y mutation, and a wild-type (F) pandemic influenza A (H1N1) 2009 (pdm09) virus both in vitro and in vivo in mice and to select one OR strain for a comparison with F in ferrets. R6 showed faster replication and pathogenicity than R7 in vitro and in mice. Subsequently, R6 was selected for the fitness comparison with the F strain in ferrets. Ferrets infected with the F virus showed more severe clinical signs, histopathological lung lesions, and viral quantification when compared to OR R6-infected animals. More importantly, differential viral kinetics correlated with differential pro-inflammatory host immune responses in the lungs of infected ferrets, where OR-infected animals developed a protective higher expression of type I IFN and Retinoid acid Inducible Gene I (RIG-I) genes early after infection, resulting in the development of milder disease. These results suggest the presence of early specific viral-host immune interactions relevant in the development of influenza-associated lung pathology.

Bronchiolitis and recurrent wheezing are distinguished by type 2 innate lymphoid cells and immune response.

BackgroundRecurrent wheezing (RW) is frequently developed in infants that have suffered bronchiolitis (BCH) during first months of life, but the immune mechanism underlying is not clear. The goal was to analyze the innate immune response that characterizes BCH and RW.MethodsNinety‐eight and seventy hospitalized infants with BCH or RW diagnosis, respectively, were included. Nasopharyngeal aspirate (NPA) was processed. Cellular pellet was employed to evaluate type 2 innate lymphoid cells (ILC2) by flow cytometry and mRNA expression assays by semi‐quantitative real‐time PCR (qRT‐PCR). In supernatant, twenty‐seven pro‐inflammatory and immunomodulatory factors, as well as lipid mediators and nitrites, were evaluated by ELISA and Luminex.ResultsBronchiolitis patients showed higher ILC2 percentage compared with RW (P < .05). Also, ST2+/ILC2 percentage was higher in the BCH group than in the RW group (P < .01). TLR3, IL33, IFNG, IL10, and FLG mRNA levels were significantly increased in BCH vs RW (P < .05). In supernatant, no significant differences were reached, observing similar levels of parameters linked to vascular damage, monocyte activation, and fibroblast growth. Prostaglandin E2 and cysteinyl leukotrienes C4 were evaluated; a significant difference was only found in their ratio.ConclusionBronchiolitis is associated with elevated nasal percentage of ILC2. This cellular population could be the key element in the differential immune response between BCH and RW which share some mechanisms such us monocyte activation, vascular damage, and fibroblast repair. Lipid mediators could play a role in the evolution of the disease later in life through innate lymphoid cells.

T cell fraction impacts oncologic outcomes in human papillomavirus associated oropharyngeal squamous cell carcinoma.

We investigated T cell clonality (TCC) and T cell fraction (TCF) in human papilloma virus associated oropharyngeal squamous cell carcinoma (HPV(+)OPSCC) progressors [cases] vs. non-progressors [controls]. This nested case-control study included patients undergoing intent-to-cure surgery±adjuvant therapy from 6/1/2007-10/3/2016. Patients experiencing local/regional/distant disease (progressors), and a consecutive sample of non-progressors were matched (2 controls: 1 case) on tumor subsite, T-stage and number of metastatic lymph nodes. We performed imunosequencing of the CDR3 regions of human TCRβ chains. 34 progressors and 65 non-progressors were included. There was no statistically significant difference in baseline TCF (range: 0.039-1.084) and TCC (range: 0.007-0.240) (p>0.05). Female sex was associated with higher TCF (p=0.03), while extranodal extension (ENE) was associated with lower TCF (p=0.01). There was a positive correlation between tumor size and clonality (R=0.34, p<0.01). The strongest predictor of progression-free survival (PFS) was TCF (HR 0.80, 95%CI 0.66-0.96, p=0.02). The strongest predictors of cancer specific survival (CSS) were TCF (HR0.69, 95%CI 0.47-1.00, p<0.05) and Adult Comorbidity Evaluation-27 (ACE-27) score (p<0.05). Similarly, the strongest predictors of overall survival (OS) were TCF (HR 0.62, 95%CI 0.43-0.91, p=0.01) and ACE-27 score (p=0.03). On multivariable modeling, TCF≥0.4 was independently associated with PFS (HR 0.34, 95%CI 0.14-0.85, p=0.02) while an ACE-27 score of≥2 independently predicted CSS (HR 3.85, 95%CI 1.07-13.85, p=0.04) and OS (HR 3.51, 95%CI 1.10-11.20, p=0.03). In patients with HPV(+)OPSCC, TCF was higher in female patients and those without ENE, suggesting differential immune responses. Lower TCF was significantly and independently associated with disease progression. Better ACE-27 scores appear to predict improved oncologic control.

Distinct Molecular Mechanisms of Host Immune Response Modulation by Arenavirus NP and Z Proteins.

Endemic to West Africa and South America, mammalian arenaviruses can cross the species barrier from their natural rodent hosts to humans, resulting in illnesses ranging from mild flu-like syndromes to severe and fatal haemorrhagic zoonoses. The increased frequency of outbreaks and associated high fatality rates of the most prevalent arenavirus, Lassa, in West African countries, highlights the significant risk to public health and to the socio-economic development of affected countries. The devastating impact of these viruses is further exacerbated by the lack of approved vaccines and effective treatments. Differential immune responses to arenavirus infections that can lead to either clearance or rapid, widespread and uncontrolled viral dissemination are modulated by the arenavirus multifunctional proteins, NP and Z. These two proteins control the antiviral response to infection by targeting multiple cellular pathways; and thus, represent attractive targets for antiviral development to counteract infection. The interplay between the host immune responses and viral replication is a key determinant of virus pathogenicity and disease outcome. In this review, we examine the current understanding of host immune defenses against arenavirus infections and summarise the host protein interactions of NP and Z and the mechanisms that govern immune evasion strategies.

Comparative effects of Novirhabdovirus genes on modulating constitutive transcription and innate antiviral responses, in different teleost host cell types

BackgroundInfectious hematopoietic necrosis virus (IHNV) and viral hemorrhagic septicemia virus (VHSV) are highly contagious, pathogenic Novirhabdoviruses affecting fish and are thusly notifiable diseases with the World Organization for Animal Health. This study assessed the relative capacities of IHNV and VHSV genes to modulate host general transcription and explores the abilities of specific IHNV genes to interfere with the interferon pathway in heterogenous teleost cell-lines.MethodsOptimized protocols allowed for efficient transient transfections in EPC, BF-2, RTG-2 and RTgill-W1 cell lines of plasmids encoding IHNV (M genogroup) and VHSV (-IVb genotype) genes, including N, P, M, G and NV. Their impact on general cellular transcription was measured 48 hours post transfection (hpt) with luciferase constructs driven by a modified β-Actin promoter (pCAG). Their modulation of the innate antiviral immune response was characterized 72 hpt, using luciferase constructs measuring rainbow trout Type I IFN or MX-1 promoter augmentation, upon MAVS co-transfection.ResultsM was generally confirmed as the strongest constitutive transcriptional suppressor while IHNV P, but not VHSV P, augmented constitutive transcription in fibroblastic cell types. Cell-specific effects were observed for viral G gene, with VHSV G exhibiting suppression of basal transcription in EPC and BF-2 but not in trout cells; while IHNV G was stimulatory in RTG-2, but inhibitory in RTgill-W1. NV consistently stimulated constitutive transcription, with higher augmentation patterns seen in fibroblastic compared to epithelial cells, and for IHNV NV compared to VHSV NV. The innate antiviral immune response, focusing on the IFN pathway, was silenced by IHNV M in all cell lines tested. IHNV N showed a dose-dependent suppression of type I IFN, but with minor effects on MX-1. IHNV P and G played minor IFN-inhibitory roles, consistent and dose-dependent only for G in rainbow trout cells. IHNV NV mediated a consistent stimulatory effect on either Type I IFN or MX-1, but much less pronounced in RTgill-W1.ConclusionsThis study extends our understanding of Novirhabdoviruses-host interaction, showing differential innate immune responses in heterogenous cell types. Viral regulators of innate immune signaling are identified, either as dose-dependent suppressors (such as M and N) or stimulators (mainly NV), indicating novel targets for the design of more efficient vaccination strategies.

Expression analysis of MHC class II DRB3 gene in mastitis affected indicus and crossbred cattle

Expression analysis of immune response genes in the mammary gland tissues of both healthy and infected animals help to explain the genetic basis of differential immune response. This study was conducted to analyze the differential expression of MHC class II DRB3 gene, in mastitis-affected and healthy animals of indicus (Sahiwal) and crossbred (Karan Fries) cattle. Real-time PCR was performed on the cDNA synthesized from the RNA isolated from PBMCs of the mastitis and healthy animals. However, no significant difference was observed in the expression of DRB3 in the two populations. The results point towards polymorphism supposed to be playing major role in differential immune response, rather than the expression of DRB3 gene as far as state of udder health is concerned.

Heterologous Chimeric Construct Comprising a Modified Bacterial Superantigen and a Cruzipain Domain Confers Protection Against Trypanosoma cruzi Infection.

Chagas disease is an endemic chronic parasitosis in Latin America affecting more than 7 million people. Around 100 million people are currently at risk of acquiring the infection; however, no effective vaccine has been developed yet. Trypanosoma cruzi is the etiological agent of this parasitosis and as an intracellular protozoan it can reside within different tissues, mainly muscle cells, evading host immunity and allowing progression towards the chronic stage of the disease. Considering this intracellular parasitism triggers strong cellular immunity that, besides being necessary to limit infection, is not sufficient to eradicate the parasite from tissues, a differential immune response is required and new strategies for vaccines against Chagas disease need to be explored. In this work, we designed, cloned and expressed a chimeric molecule, named NCz-SEGN24A, comprising a parasite antigen, the N-terminal domain of the major cysteine protease of T. cruzi, cruzipain (Nt-Cz), and a non-toxic form of the staphylococcal superantigen (SAg) G, SEG, with the residue Asn24 mutated to Ala (N24A). The mutant SAg SEGN24A, retains its ability to trigger classical activation of macrophages without inducing T cell apoptosis. To evaluate, as a proof of concept, the immunogenicity and efficacy of the chimeric immunogen vs. its individual antigens, C3H mice were immunized intramuscularly with NCz-SEGN24A co-adjuvanted with CpG-ODN, or the recombinant proteins Nt-Cz plus SEGN24A with the same adjuvant. Vaccinated mice significantly produced Nt-Cz-specific IgG titers after immunization and developed higher IgG2a than IgG1 titers. Specific cell-mediated immunity was assessed by in-vivo DTH and significant responses were obtained. To assess protection, mice were challenged with trypomastigotes of T. cruzi. Both schemes reduced the parasite load throughout the acute phase, but only mice immunized with NCz-SEGN24A showed significant differences against control; moreover, these mice maintained 100% survival. These results encourage testing mutated superantigens fused to specific antigens as immune modulators against pathogens.

Host permissiveness to baculovirus influences time-dependent immune responses and fitness costs.

Insects possess specific immune responses to protect themselves from different types of pathogens. Activation of immune cascades can inflict significant developmental costs on the surviving host. To characterize infection kinetics in a surviving host that experiences baculovirus inoculation, it is crucial to determine the timing of immune responses. Here, we investigated time-dependent immune responses and developmental costs elicited by inoculations from each of two wild-type baculoviruses, Autographa californica multiple nucleopolyhedrovirus (AcMNPV) and Helicoverpa zea single nucleopolyhedrovirus (HzSNPV), in their common host H. zea. As H. zea is a semi-permissive host of AcMNPV and fully permissive to HzSNPV, we hypothesized there are differential immune responses and fitness costs associated with resisting infection by each virus species. Newly molted 4th-instar larvae that were inoculated with a low dose (LD15 ) of either virus showed significantly higher hemolymph FAD-glucose dehydrogenase (GLD) activities compared to the corresponding control larvae. Hemolymph phenoloxidase (PO) activity, protein concentration and total hemocyte numbers were not increased, but instead were lower than in control larvae at some time points post-inoculation. Larvae that survived either virus inoculation exhibited reduced pupal weight; survivors inoculated with AcMNPV grew slower than the control larvae, while survivors of HzSNPV pupated earlier than control larvae. Our results highlight the complexity of immune responses and fitness costs associated with combating different baculoviruses.