Eubacterium rectale detoxification mechanism increases resilience of the gut environment.

Lachnospiraceae members were highly detected in dysbiotic IL-10 KO mice that displayed similar physiological outcomes as control mice. Lachnospiraceae is a highly diverse family of microbes that have been shown to display both commensal and pathogenic characteristics in the colon environment. We investigated the impact of genetic variation in five Lachnospiraceae strains on lowering cellular inflammation and ROS levels. Cell free spent media (CFSM) from Eubacterium rectale resulted in lowered ROS, and nitric oxide levels in stressed colon cells. We demonstrated through an array of multi-omics and molecular techniques that glutathione (GSH) biosynthesized by E. rectale was able to alleviate host ROS damage. We further showed downregulation of cell stress and immune response genes by host RNA sequencing, which is evidence that E. rectale microbial products promote recovery and alleviate ROS stress.

Directional microwave ablation in spine: experimental assessment of computational modeling.

BACKGROUND: Despite the theoretical advantages of treating metastatic bone disease with microwave ablation (MWA), there are few reports characterizing microwave absorption and bioheat transfer in bone. This report describes a computational modeling-based approach to simulate directional microwave ablation (dMWA) in spine, supported by ex vivo and pilot in vivo experiments in porcine vertebral bodies. MATERIALS AND METHODS: A 3D computational model of microwave ablation within porcine vertebral bodies was developed. Ex vivo porcine vertebra experiments using a dMWA applicator measured temperatures approximately 10.1 mm radially from the applicator in the direction of MW radiation (T1) and approximately 2.4 mm in the contra-lateral direction (T2). Histologic assessment of ablated ex vivo tissue was conducted and experimental results compared to simulations. Pilot in vivo experiments in porcine vertebral bodies assessed ablation zones histologically and with CT and MRI. RESULTS: Experimental T1 and T2 temperatures were within 3-7% and 11-33% of simulated temperature values. Visible ablation zones, as indicated by grayed tissue, were smaller than those typical in other soft tissues. Posthumous MRI images of in vivo ablations showed hyperintensity. In vivo experiments illustrated the technical feasibility of creating directional microwave ablation zones in porcine vertebral body. CONCLUSION: Computational models and experimental studies illustrate the feasibility of controlled dMWA in bone tissue.

Limitation of amino acid availability by bacterial populations during enhanced colitis in IBD mouse model.

IMPORTANCE: Inflammatory bowel disease is associated with an increase in Enterobacteriaceae and Enterococcus species; however, the specific mechanisms are unclear. Previous research has reported the associations between microbiota and inflammation, here we investigate potential pathways that specific bacteria populations use to drive gut inflammation. Richie et al. show that these bacterial populations utilize an alternate sulfur metabolism and are tolerant of host-derived immune-response products. These metabolic pathways drive host gut inflammation and fuel over colonization of these pathobionts in the dysbiotic colon. Cultured isolates from dysbiotic mice indicated faster growth supplemented with L-cysteine, showing these microbes can utilize essential host nutrients.

The tumor microenvironment generated by Marek's disease virus suppresses interferon-gamma-producing gamma delta T cells.

The tumor microenvironment (TME) is generated by the cross-talk among tumor cells, immune system cells, and stromal cells. The TME generated by Marek's disease virus (MDV) is suggested to display an immunosuppressive milieu due to immune inhibitory molecules and cytokines which are possibly induced by MDV-transformed cells and regulatory T cells. Both anti-tumor and pro-tumor gamma delta (γδ) T cells are reported in human cancer. Although anti-tumor like and pro-tumor like γδ T cells are found in MDV-infected chickens at the later phase of infection, how the TME affects circulating and tissue-resident γδ T cells has not been investigated. Here, we demonstrated that the supernatant of the cultured splenocytes derived from MDV-challenegd chickens inhibited interferon (IFN)-γ production and CD25 expression by T cell receptor (TCR)γδ-stimulated tissue-resident γδ T cells, but the supernatant of the cultured MDV-transformed cell line did not affect γδ T cell activation. TCRγδ-stimulated circulating γδ T cells were influenced neither by the supernatant of the cultured splenocytes derived from MDV-challenegd chickens nor by the supernatant of the cultured MDV-transformed cell line. Taken together, activation and IFN-γ production by tissue-resident γδ T cells can be inhibited in the TME generated by MDV while tumor attracted circulating γδ T cells may not be influenced in activation and IFN-γ production by the TME generated by MDV.

Activated Chicken Gamma Delta T Cells Are Involved in Protective Immunity against Marek's Disease.

Gamma delta (γδ) T cells play a significant role in the prevention of viral infection and tumor surveillance in mammals. Although the involvement of γδ T cells in Marek's disease virus (MDV) infection has been suggested, their detailed contribution to immunity against MDV or the progression of Marek's disease (MD) remains unknown. In the current study, T cell receptor (TCR)γδ-activated peripheral blood mononuclear cells (PBMCs) were infused into recipient chickens and their effects were examined in the context of tumor formation by MDV and immunity against MDV. We demonstrated that the adoptive transfer of TCRγδ-activated PBMCs reduced virus replication in the lungs and tumor incidence in MDV-challenged chickens. Infusion of TCRγδ-activated PBMCs induced IFN-γ-producing γδ T cells at 10 days post-infection (dpi), and degranulation activity in circulating γδ T cell and CD8α+ γδ T cells at 10 and 21 dpi in MDV-challenged chickens. Additionally, the upregulation of IFN-γ and granzyme A gene expression at 10 dpi was significant in the spleen of the TCRγδ-activated PBMCs-infused and MDV-challenged group compared to the control group. Taken together, our results revealed that TCRγδ stimulation promotes the effector function of chicken γδ T cells, and these effector γδ T cells may be involved in protection against MD.

Multifocal spinal inflammatory myofibroblastic tumors in a juvenile paraparetic dog.

A 1-year-old, female English Bulldog presented with a 10-day history of progressive paraparesis. Neuroanatomical localization was consistent with T3-L3 segment myelopathy. Magnetic resonance imaging (MRI) revealed a severely compressive, mildly contrast enhancing, extradural, dorsal, broad-based mass at the level of L3-4. Similar, non-compressive, smaller nodules were present along the extradural space and dura mater of the caudal lumbar spine. Owners elected euthanasia based on these imaging findings and progressive clinical signs. Necropsy, histopathology and immunohistochemistry revealed a mesenchymal mass and nodules, admixed with numerous inflammatory cells. The diagnosis of an extradural inflammatory myofibroblastic tumor (IMT) with a multifocal presentation was made.

Investigating fecal microbial transplant as a novel therapy in dogs with inflammatory bowel disease: A preliminary study.

BACKGROUND: There are limited studies investigating the use of fecal microbial transplant (FMT) in dogs with inflammatory bowel disease (IBD). The aim of this preliminary study was to assess the feasibility of adding FMT to standard therapy (corticosteroids and a hypoallergenic diet) for dogs with IBD and to and to describe the changes in measured outcomes after 30 days of treatment. METHODS: Thirteen client-owned dogs with IBD were enrolled in this double blinded, randomized clinical trial. All dogs received corticosteroid therapy and a hypoallergenic diet; dogs were randomized to receive either placebo or FMT. Measured outcomes included the canine chronic enteropathy clinical activity index (CCECAI) at 1 week and 1 month after enrolment. Fecal microbiota were analyzed after extracting DNA from fecal samples and profiling using 16S amplicon sequencing. Dogs in the placebo group not responding to treatment after 1 month were offered FMT. RESULTS: The CCECAI significantly decreased over time in both groups (p = 0.001). There were no significant differences between the CCECAI of the placebo and FMT group at each time point (F test from ANOVA, p = 0.40). No adverse effects were reported in the 30 days following FMT. CONCLUSIONS: The addition of FMT to standard therapy for IBD was feasible. No significant differences were observed in the CCECAI between groups at each time point. Large scale clinical trials can be performed using these methods to evaluate the longer term effect of FMT on clinical signs, microbial diversity, and other outcomes.

Primary Intestinal Lymphoma in Rabbits.

Neoplasms of the intestinal tract are uncommon in rabbits and primary lymphoma of the intestinal tract is rare. This case series is the first detailed description of primary intestinal lymphoma in rabbits. We reviewed four cases of primary intestinal lymphoma in rabbits aged 5-9.5 years old with an average age of 7.8 years. Neoplastic cells in three cases were large (8 µm diameter) while one case had intermediate cells (5 µm diameter). Neoplastic lymphocytes were of B-cell lineage and characterized by intense, multifocal, membranous immunoreactivity for CD79a and no immunoreactivity to CD3. Based on the Revised European-American Classification of Lymphoid Neoplasms/World Health Organization classification, three of the cases were consistent with diffuse large B-cell lymphoma and the case with intermediate-sized neoplastic cells was consistent with lymphoblastic lymphoma.

Pax5 and CD3 immunophenotyping of lymphoma in 2 central bearded dragons.

Two central bearded dragons (Pogona vitticeps), a 3-y-old male and a 5-y-old female, were diagnosed with different manifestations of lymphoma at the Kansas State Veterinary Diagnostic Laboratory between 2019 and 2020. The 3-y-old male was presented for postmortem evaluation and was in poor body condition. Microscopically, nearly all examined organs contained variable numbers of neoplastic round cells. Neoplastic cells in the stomach and liver had moderate immunoreactivity to CD3 consistent with multicentric T-cell lymphoma, and non-neoplastic lymphocytes infiltrating the stomach mass had strong immunoreactivity to Pax5. The 5-y-old female had an ulcerated oral mass located in the right lingual gingiva submitted as an excisional biopsy. Microscopically, the mass was composed of large numbers of neoplastic round cells in the epithelium and connective tissue that were strongly and diffusely positive for CD3 and frequently positive for Pax5, consistent with a dual-positive, localized, epitheliotropic T-cell lymphoma. Neoplastic and non-neoplastic lymphocytes did not stain with CD20 or CD79a. Neoplasms are increasingly reported as a cause of morbidity and mortality in reptiles. Our 2 cases illustrate various presentations of T-cell lymphoma and the effectiveness of CD3 and Pax5 immunohistochemistry in bearded dragons.

Differential activation of chicken gamma delta T cells from different tissues by Toll-like receptor 3 or 21 ligands.

Gamma delta (γδ) T cells are highly enriched in mucosal barrier sites including intestinal tissues where microbial infections and tumors often originate in mammals. Human γδ T cells recognize stress antigens and microbial signals via their T cell receptor (TCR), natural killer (NK) receptors, and pattern recognition receptors. However, little is known about antigens or ligands capable of stimulating chicken γδ T cells. The results of the present study demonstrated that polyinosinic-polycytidylic acid (poly(I:C)), a Toll-like receptor (TLR)3 ligand, significantly induced upregulation of CD8α molecules on circulating and lung γδ T cells. Moreover, poly(I:C) stimulation induced interferon (IFN)-γ production from splenic and lung CD8α+ γδ T cells while Cytosine-phosphate-Guanine oligodeoxynucleotides (CpG-ODN) 2007, a TLR21 ligand, stimulation induced IFN-γ production by circulating γδ T cells. Neither poly(I:C) nor CpG-ODN 2007 stimulation elicited degranulation of γδ T cells. Additionally, the results revealed that CpG-ODN 2007 induced IFN-γ production from TCR-stimulated γδ T cells sorted from spleen. In our experiments, isopentenyl pyrophosphate (IPP), 4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), or zoledronate (Zol) stimulation did not induce IFN-γ production or degranulation in γδ T cells. Taken together, a combination of CpG-ODN 2007 and anti-CD3ε monoclonal antibodies (mAbs) can stimulate chicken γδ T cells and induce production of IFN-γ by these cells while IFN-γ production by γδ T cells induced by stimulation of poly(I:C) needs signals from other cells. These results suggest that chicken γδ T cells can sense invading pathogens via TLRs and produce IFN-γ as a first line of defense.

Phenotypic characterization of gamma delta (γδ) T cells in chickens infected with or vaccinated against Marek's disease virus.

Marek's disease (MD) vaccines reduce the incidence of MD but cannot control virus shedding. To develop new vaccines, it is essential to elucidate mechanisms of immunity to Marek's disease virus (MDV) infection. In this regard, gamma delta (γδ) T cells may play a significant role in prevention of viral spread and tumor surveillance. Here we demonstrated that MDV vaccination induced interferon (IFN)-γ+CD8α+ γδ T cells and transforming growth factor (TGF)-ß+ γδ T cells in lungs. γδ T cells from MDV-infected chickens exhibited cytotoxic activity. Importantly, γδ T cells from the vaccinated/challenged group exhibited maximum cytotoxic activity following ex vivo stimulation. These results suggest that MDV vaccines activate effector γδ T cells which may be involved in the development of protective immune responses against MD. Further, it was demonstrated that MDV infection increases the frequency of a subpopulation of γδ T cells expressing membrane-bound TGF-ß in MDV-infected birds.

Inoculation of Weaned Pigs by Feed, Water, and Airborne Transmission of Salmonella enterica Serotype 4,[5],12:i:.

ABSTRACT: Salmonella enterica serotype 4,[5],12:i:- (STM) has become an increasing problem for food safety and has been often detected in swine products. Weanling pigs were exposed to STM-contaminated feed, water, or air to determine possible STM transmission routes. A control group of pigs was included. STM was monitored daily in feces and rectal and nasal swabs. STM colonization was most prevalent in tissues from tonsil, lower intestine, and mesenteric lymph nodes. No differences in lesion severity were observed between inoculated and control pigs. Contaminated feed, water, and aerosolized particles caused infection in weaned pigs; however, no STM colonization was observed in skeletal muscle destined for human consumption. Based on the results from this study, STM contamination in pork products most likely results from cross-contamination of meat by digesta or lymph node tissue during processing.

Strategic reconstruction of macrophage-derived extracellular vesicles as a magnetic resonance imaging contrast agent.

A contrast agent (CA) in magnetic resonance imaging (MRI) is now an essential add-on to obtain high-quality contrast-enhanced anatomical images for disease diagnosis and monitoring the treatment response. However, the rapid elimination of CAs by the immune system and excretion by the renal route has limited its application. As a result, the CA dose for effective contrast is ever-increasing, resulting in toxic side effects such as gadolinium (Gd) related nephrogenic systemic fibrosis (NSF) toxicity. Considering the widespread application of Gd-based CAs, it is now very important to revisit their formulation in order to improve their local concentration and minimize their dose while achieving clinical goals. Therefore, we have adapted a unique strategy to maximize Gd delivery to the target site using macrophage cell-derived extracellular vesicles (EVs) reconstructed with a Gd-conjugated liposomal system herein called gadolinium infused hybrid EVs (Gd-HEVs). We hypothesize that Gd-HEVs, owing to the presence of immune cell-derived EV protein cargo, can effectively disguise themselves as a biological entity, prolong the retention time for contrast enhancement, and show tumor specificity. Incorporation of Gd into nanoformulations can enhance the longitudinal relaxivity r1 by reducing the tumbling rate of paramagnetic metal complexes. Here, Gd-HEVs showed a higher r1 relaxivity of 9.86 mM-1 s-1 compared to 3.98 mM-1 s-1 of Magnevist® at an equivalent Gd concentration, when measured by clinical 3T MRI. This will allow us to reduce the clinically used Gd concentration about three-fold while maintaining contrast in the clinical window thereby supporting our hypothesis. Furthermore, Gd-HEVs showed a preferential cellular interaction and accumulation towards cancer cells compared to non-cancer cells, both in vitro and in vivo. More importantly, Gd-HEVs showed excellent contrast enhancement in the blood vasculature with a higher retention time compared to its counterpart, Magnevist®. Our study successfully showed that the incorporation of Gd in the EV framework can help to enhance the contrast ability, and therefore it can be a platform technology for the development of safer MRI contrast agents.

Periocular sarcoid with bone invasion in a Thoroughbred mare.

A periocular nodular sarcoid was diagnosed on the right upper eyelid and medial canthus of a 12-year-old Thoroughbred mare. Enucleation was performed and during the procedure the mass was noted to be firmly adhered to the underlying frontal bone. Partial ostectomy of the dorsal orbital rim was performed. Histopathology revealed invasion of the cortical lamellar bone and the bone marrow by neoplastic spindle cells and extension of these cells to multiple surgical margins. Recurrence at the level of the surgical site and its surroundings occurred 3 months after the procedure. The horse was euthanized 12 months later. Key clinical message: Invasion of the underlying bone occurs in some cases of equine periocular sarcoids. The case highlights how this bone invasion might affect the surgical planning and shows potential aggressiveness of this type of tumor.

Sarcoïde péri-oculaire avec invasion osseuse chez une jument Thoroughbred. Un sarcoïde nodulaire péri-oculaire fut diagnostiqué sur la paupière supérieure droite et le canthus médial d'une jument Thoroughbred âgée de 12 ans. L'énucléation fut effectuée et durant la procédure il fut noté que la masse était fermement adhérée à l'os frontal sous-jacent. Une ostectomie partielle de la bordure orbitale dorsale fut effectuée. L'examen histopathologique révéla l'invasion de l'os lamellaire cortical et de la moelle osseuse par des cellules fusiformes néoplasiques et l'extension de ces cellules à de multiples bordures chirurgicales. Une récurrence au site chirurgical et son entourage s'est produit 3 mois après la procédure. Le cheval fut euthanasié 12 mois plus tard.Message clinique clé:Ce cas démontre que l'invasion de l'os sous-jacent se produit dans certains cas de sarcoïdes péri-oculaires équins. Ce cas souligne comment cette invasion osseuse peut affecter la planification chirurgicale et montre le potentiel agressif de ce type de tumeur.(Traduit par Dr Serge Messier).

WC1+ and WC1neg γδ T lymphocytes in intestinal mucosa of healthy and Mycobacterium avium subspecies paratuberculosis-infected calves.

Mucosal surfaces such as the gastrointestinal tract, and skin are the front line of host defence and immunity against many pathogens. Gamma delta (γδ) T lymphocytes preferentially localize to the mucosal surfaces in several species including cattle, and are thought to play crucial roles in immunosurveillance and host defence, particularly against mycobacteria. Many γδ T cells are present in young calves, which is the period when calves are thought to be initially exposed to Mycobacterium avium subspecies paratuberculosis (Map). The role of mucosal γδ T cells in cattle, especially during host-pathogen interactions during early pre-clinical phases of infectious disease remains unclear. The purposes of this study were to investigate and characterize WC1+ and WC1neg γδ  T cell subsets in various segments of the gastrointestinal (GI) tract of young calves, and then to examine γδ  T cell subsets in the distal small intestine of calves after experimental intestinal Map infection by direct Peyer's patch inoculation. We show that in healthy calves, the relative proportion of γδ T cells is constant throughout the GI mucosa, though the ileum has significantly more γδ T cells. In the distal intestine, γδ T cells are mainly WC1neg and primarily located within the lamina propria of the jejunum and ileum. In Map-infected intestine, there are higher numbers of γδ T cells in the lamina propria and a greater proportion of WC1+ cells within the epithelial layer compared to control calves. While WC1neg γδ T cells preferentially localize to the distal small intestine of healthy calves, WC1+ γδ T cells are increased in the intestinal mucosa during Map infection, which is suggestive of effector cell function. Further, spectral microscopy and flow cytometry in tandem will lead to improved understanding of the functions of these cells during health and disease.

Characterizaton of gamma delta T cells in Marek's disease virus (Gallid herpesvirus 2) infection of chickens.

Immunity against Marek's disease (MD), caused by Gallid herpesvirus 2 (GaHV-2), in chickens is mediated by both innate and adaptive responses. The present study evaluated the effects of GaHV-2 infection on distribution and frequency of γδ T cells in tissues, as well as their expression of cytokines. We found that the infected chickens had significantly higher number of γδ T cells in their spleens by 10 and 21 days post-infection (d.p.i.) and nearly 100% of these γδ T cells were CD8+ at 21 d.p.i. Conversely, the number of γδ T cells in the cecal tonsils of GaHV-2-infected birds decreased compared to uninfected birds. Splenic γδ T cells had up-regulated expression of interferon-γ early in infection followed by simultaneous gene expression of interleukin-10 during the later phases. In conclusion, these results suggest a potential role for γδ T cells in host response to GaHV-2 and further elucidate the underlying immunological mechanisms of interactions between this virus and its host.

Resilience to infection by Mycobacterium avium subspecies paratuberculosis following direct intestinal inoculation in calves.

Mycobacterium avium subspecies paratuberculosis (Map) is the cause of Johne's disease, a chronic enteritis of cattle. A significant knowledge gap is how persistence of Map within the intestinal tract after infection contributes to progression of disease. To address this, we exposed calves to Map by direct ileocecal Peyer's patch injection. Our objective was to characterize the persistence of Map in tissues, associated intestinal lesions, fecal Map shedding, and serum antibody responses, through the first 28-weeks post-inoculation (wpi). Previous work using this model showed 100% rate of Map infection in intestine and lymph node by 12 wpi. We hypothesized that direct inoculation of Map into the distal small intestine would induce intestinal Map infection with local persistence and progression towards clinical disease. However, our data show decreased persistence of Map in the distal small intestine and draining lymph nodes. We identified Map in multiple sections of distal ileum and draining lymph node of all calves at 4 and 12 wpi, but then we observed reduced Map in distal ileum at 20 wpi, and by 28 wpi we found that 50% of animals had no detectable Map in intestine or the lymph node. This provides evidence of resilience to Map infection following direct intestinal Map inoculation. Further work examining the immune responses and host-pathogen interactions associated with this infection model are needed to help elicit the mechanisms underlying resilience to Map infection.

Cyclooxygenase-2 expression in the eyes of cats with and without uveitis.

OBJECTIVE To characterize the distribution and intensity of cyclooxygenase (COX)-2 expression in the eyes of cats with and without uveitis and to determine whether COX-2 expression is correlated with severity of inflammation. SAMPLES Archived ocular tissue specimens from 51 cats with and 10 cats without ocular disease. PROCEDURES Specimens from only 1 eye were evaluated for each cat. Specimens were stained with H&E stain or immunohistochemical stain for detection of COX-2 and reviewed. For each eye, the type, severity, and distribution of inflammation and the distribution and intensity of COX-2 expression were determined for the uvea and other ocular tissues. Correlation between COX-2 expression and inflammation severity was also assessed. RESULTS COX-2 was not expressed in any nondiseased eye. Of the 51 diseased eyes, 20 had histologic evidence of lymphocytic-plasmacytic uveitis, 13 had neutrophilic uveitis, 11 had diffuse iris melanoma with uveitis, and 7 had diffuse iris melanoma without uveitis. Of the 44 eyes with uveitis, COX-2 was detected in the uvea of 16, including 11 eyes with lymphocytic-plasmacytic uveitis, 4 with neutrophilic uveitis, and 1 with diffuse iris melanoma-induced uveitis. Inflammation was severe, moderate, or mild in 10, 5, and 1 of those eyes, respectively. Cyclooxygenase-2 was detected in the cornea of 21 eyes with uveitis and 1 eye with diffuse iris melanoma without uveitis. Uveitis severity was positively correlated with COX-2 expression in both the uvea and cornea. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that COX-2 is an inflammatory mediator in feline uveitis but not diffuse iris melanoma.

Bovine WC1+ and WC1neg γδ T Lymphocytes Influence Monocyte Differentiation and Monocyte-Derived Dendritic Cell Maturation during In Vitro Mycobacterium avium Subspecies paratuberculosis Infection.

During early Mycobacterium avium subspecies paratuberculosis (Map) infection, complex interactions occur between the bacteria, cells from the mononuclear phagocyte system (MPS) including both resident (macrophages and dendritic cells) and recruited (monocytes) cells, and other mucosal sentinel cells such as γδ T lymphocytes. Though the details of early host-pathogen interactions in cattle remain largely underexplored, our hypothesis is that these significantly influence development of host immunity and ultimate success or failure of the host to respond to Map infection. The aims of the present study were to first characterize monocyte-derived MPS cells from young calves with respect to their immunophenotype and function. Then, we set out to investigate the effects of WC1+ and WC1neg γδ T lymphocytes on (1) the differentiation of autologous monocytes and (2) the maturation of autologous monocyte-derived dendritic cells (MDDCs). To achieve this, peripheral blood WC1+ or WC1neg γδ T lymphocytes were cocultured with either autologous freshly isolated peripheral blood-derived monocytes or autologous immature MDDCs (iMDDCs). We began by measuring several markers of interest on MPS cells. Useful markers to distinguish monocyte-derived macrophages (MDMs) from MDDCs include CD11b, CD163, and CD172a, which are expressed significantly higher on MDMs compared with MDDCs. Function, but not phenotype, was influenced by WC1neg γδ T lymphocytes: viability of Map harvested from monocytes differentiated in the presence of WC1neg γδ T lymphocytes (dMonWC1neg) was significantly lower compared to MDMs and MDDCs. With respect to DC maturation, we first showed that mature MDDCs (mMDDCs) have significantly higher expression of CD11c, CD80, and CD86 compared with iMDDCs, and the phagocytic capacity of mMDDCs is significantly reduced compared to iMDDCs. We then showed that γδ T lymphocyte subsets induce functional (reduced phagocytosis) but not phenotypic (surface marker expression) iMDDC maturation. These data collectively show that γδ T lymphocytes influence differentiation, maturation, and ultimately the function of monocytes during Map infection, which has significant implications on survival of Map and success of host defense during early Map infection.

Bovine peripheral blood WC1+ and WC1neg γδ T lymphocytes modulate monocyte-derived macrophage effector functions during in vitro Mycobacterium avium subspecies paratuberculosis infection.

The importance of bovine γδ T lymphocytes during anti-mycobacterial immunity is recognized; however, the role of major subsets of γδ T lymphocytes (WC1+ and WC1neg) in this process remains unclear. We investigated how WC1+ and WC1neg γδ T lymphocyte subsets of calves modulate monocyte-derived macrophage (MDM) functions during Map infection in vitro. To achieve this, Map-infected or uninfected MDMs from young calves were co-cultured with autologous WC1+ or WC1neg γδ T lymphocytes. Our data indicate that WC1+ and WC1neg γδ T lymphocytes of young calves modulate effector functions of MDMs with respect to Map killing, CD11b and MHC-II expression. We observed differences in IFN-γ production and CD25 expression on γδ T lymphocyte subsets, as well as MDM expression of CD1b when in contact with WC1neg γδ T lymphocytes.