Primary Humoral Immune Response Research Articles

Evaluation of immunomodulatory effect of aqueous extract of aloe vera in Wistar albino rat models

Aim of the study wasto evaluate the immunomodulatory effects of Aqueous extracts of Aloe vera in Wistar albino rats using humoral immune response (antibody titre), a cellular immune response, and a neutrophil adhesion test after oral administration. : 24 healthy Wistar albino rats of either sex were divided into 4 different groups containing 6 rats for each immunomodulatory model. Group I ,the control group received gum acacia suspended in normal saline; Group II rats were treated with dexamethasone (1 mg/kg bw)whereas Groups III & IV received AloeVera aqueous extract at a dose of 125 mg/kg and 250 mg/kg, respectively. Each rat was antigenically challenged by injecting 0.1 ml of 0.5 × 10 SRBCs (suspended in normal saline) intraperitoneally. The study of humoral immune response was seen by measurement of antibody titre obtained on 20 day (7 day of Ag challenge) and 27 day (14 day of challenge) with sRBC considered the primary and secondary humoral immune response, respectively. For the cellular immune response, foot pad edema was calculated due to a hypersensitivity reaction after injection of sRBC into the .rat hind paw. A test of neutrophil adhesion is used to evaluate immunomodulatory activity. Aloe vera aqueous extracts at 250 mg/kg significantly improved a significant increase in paw edema volume indicated increased cell-mediated immunity, and elevated Ab titre on the 20th and 27th days served as a marker of increased humoral immune response. Additionally, AVE 250 mg/kg caused an increase in neutrophil adhesion, demonstrating its immunomodulatory effects. Aloe vera aqueous extracts at a dose of 250 mg/kg demonstrated immunomodulatory activity in a model using Wistar albino rats.Aloe vera extract at a dose of 250 mg/kg significantly increased hemagglutination antibody titers compared to the control group, indicating enhanced humoral immunity. This study demonstrates the immunostimulant properties of orally administered Aloe vera aqueous extract in Wistar albino rats. The extract increased antibody production, enhanced cell-mediated immunity, and improved neutrophil function. These findings support the potential of Aloe vera as a natural immunomodulator and warrant further exploration of its therapeutic applications.

Longitudinal Characterization of a Neutralizing and Total Antibody Response in Patients with Severe COVID-19 and Fatal Outcomes.

The host immune response to SARS-CoV-2 appears to play a critical role in disease pathogenesis and clinical manifestations in severe COVID-19 cases. Until now, the importance of developing a neutralizing antibody response in the acute phase and its relationship with progression to severe disease or fatal outcome among hospitalized patients remains unclear. In this study, we aim to characterize and compare longitudinally the primary humoral immune host response in the early stages of the disease, looking for an association between neutralization, antibody titers, infective viral lineage, and the clinical outcome in hospitalized and non-hospitalized patients. A total of 111 patients admitted at INER from November 2021 to June 2022 were included. We found that patients with negative or low neutralization showed a significant reduction in survival probability compared to patients with medium or high neutralization. We observed a significant decrease in the median of neutralization in patients infected with viral variants with changes in RBD of the spike protein. Our results suggest that developing an early and robust neutralizing response against SARS-CoV-2 may increase survival probability in critical patients.

POS0185 BELIMUMAB DISRUPTS MEMORY B-CELL TRAFFICKING IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

BackgroundBelimumab (BEL), a recombinant human monoclonal antibody directed against B-cell activating factor (BAFF), is the first approved biological agent for patients with active systemic lupus erythematosus (SLE) and lupus nephritis (LN).1 BEL inhibits primary humoral immune responses by depleting naïve B cells that are dependent on BAFF for their survival while secondary humoral immune responses by memory B cells (MBCs) remain intact. Indeed, some studies reported an increase of circulating MBCs following neutralisation of BAFF.2-4 So far, these effects of BEL on the MBC compartment in SLE patients have not been investigated.ObjectivesThis study aimed to establish the dynamics of circulating MBCs in patients with SLE treated with BEL and to perform an in-depth analysis of the impact of BEL on the MBC compartment.MethodsFirst, a retrospective meta-analysis was performed by pooling individual patient MBC flow cytometry data from 1245 patients with SLE treated with BEL 10 mg/kg IV or placebo (PBO) from four randomised clinical trials (NCT00071487, NCT00410384 [BLISS-76],3NCT01632241 [EMBRACE],5NCT01649765 [PLUTO]6). Second, extensive B-cell subset phenotyping was performed prospectively by employing high-sensitivity flow cytometry (HSFC) based on EuroFlow protocols7 in patients with active SLE (from the BLISS-BELIEVE trial [NCT03312907])8 and with severe SLE/LN (from the SynBioSe-2 trial [NCT03747159])9 treated with BEL. Additionally, in-depth characterisation of surging MBCs in circulation was performed by single-cell RNA sequencing (scRNA-seq).ResultsBy comparing BEL-treated with PBO-treated patients with SLE, a substantial increase in circulating MBC counts was established 4 weeks after BEL initiation, gradually returning to baseline by Week 52. The increase of MBCs was most prominent in BEL-treated patients with higher SLE disease activity (SLE Disease Activity Index >9), serologically active patients (dsDNA positive and/or low complement levels) and with younger age (below 18 years). HSFC established that the increase was non-specific and observed in a broad range of MBC subclasses peaking as early as 2 weeks after BEL initiation. Subsequent scRNA-seq analysis of the emerging MBCs revealed a non-proliferating phenotype with a prominent decrease in activation status. In these circulating MBCs, a large amount of migration and adhesion genes were downregulated suggesting that the accumulation of MBCs following BEL treatment was related to their impaired cell-cell adhesion, disrupting cell-trafficking and preventing extravasation.ConclusionAfter initiation of BEL treatment, a substantial increase of circulating MBCs was firmly established and was most notable in patients with severe, serologically active SLE/LN. The surge of circulating MBCs appeared to be associated with disrupted lymphocyte trafficking of MBCs, thereby suggesting a new potential therapeutic mechanism of BEL on MBCs in SLE. These findings have important implications to our understanding and consequent improvement of B-cell targeted treatment strategies in patients with active SLE and LN, as MBC accumulation in circulation might allow for more efficient targeting of the B-cell compartment.

MO246: Belimumab Disrupts Memory B Cell Trafficking in Patients with Systemic Lupus Erythematosus

Abstract BACKGROUND AND AIMS Belimumab (BEL), a recombinant human monoclonal antibody directed against B-cell activating factor (BAFF), is the first approved biological agent for patients with systemic lupus erythematosus (SLE) and a high level of disease activity or lupus nephritis (LN). BEL inhibits primary humoral immune responses by depleting naive B-cells that are dependent on BAFF for their survival while secondary humoral immune responses by memory B cells (MBCs) remain intact. Indeed, some studies reported an increase of circulating MBCs following neutralization of BAFF [1–3]. So far these effects of BEL on the MBC compartment in SLE patients have not been investigated. This study aimed to establish the dynamics of circulating MBCs in patients with SLE treated with BEL and to perform an in-depth analysis of the impact of BEL on the MBC compartment. METHOD First, extensive B cell subset phenotyping was performed prospectively by employing high-sensitivity flow cytometry (HSFC) based on EuroFlow protocols [4] in severe SLE/LN patients treated with BEL [5]. Additionally, in-depth characterisation of surging MBCs in circulation was performed by single-cell RNA sequencing (scRNA-seq). RESULTS HSFC established that the increase in MBCs was non-specific and observed in a broad range of MBC immunoglobulin subclasses peaking as early as 2 weeks after BEL initiation. Subsequent scRNA-seq analysis of the emerging MBCs revealed a non-proliferating phenotype with a prominent decrease in activation status. In these circulating MBCs, a large amount of migration and adhesion genes were downregulated suggesting that the accumulation of MBCs by BEL initiation was related to their impaired cell–cell adhesion disrupting cell-trafficking and preventing extravasation. CONCLUSION After initiation of BEL treatment, a substantial increase of circulating MBCs was firmly established in patients with SLE/LN. The surge of circulating MBCs appeared to be associated with disrupted lymphocyte trafficking of MBCs, thereby suggesting a new potential therapeutic mechanism of BEL on MBCs in SLE. These findings have important implications to our understanding and consequent improvement of B-cell targeted treatment strategies in patients with active SLE and LN as MBC accumulation in circulation might allow for more efficient targeting of the B-cell compartment.

Antibody Responses to SARS-CoV-2 Antigens in Humans and Animals.

To optimize the public health response to coronavirus disease 2019 (COVID-19), we must first understand the antibody response to individual proteins on the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) and the antibody’s cross reactivity to other coronaviruses. Using a panel of 37 convalescent COVID-19 human serum samples, we showed that the magnitude and specificity of responses varied across individuals, independent of their reactivity to seasonal human coronaviruses (HCoVs). These data suggest that COVID-19 vaccines will elicit primary humoral immune responses in naïve individuals and variable responses in those previously exposed to SARS-CoV-2. Unlike the limited cross-coronavirus reactivities in humans, serum samples from 96 dogs and 10 cats showed SARS-CoV-2 protein-specific responses focused on non–S1 proteins. The correlation of this response with those to other coronaviruses suggests that the antibodies are cross-reactive and generated to endemic viruses within these hosts, which must be considered in seroepidemiologic studies. We conclude that substantial variation in antibody generation against coronavirus proteins will influence interpretations of serologic data in the clinical and veterinary settings.

Effective Delivery of Nef-MPER-V3 Fusion Protein Using LDP12 Cell Penetrating Peptide for Development of Preventive/Therapeutic HIV-1 Vaccine.

There is no effective and safe preventive/therapeutics vaccine against HIV-1 worldwide. Different viral proteins such as Nef, and two regions of Env including; variable loop of gp120 (V3) and membrane proximal external region of gp41 (MPER) are particularly important for vaccine development in different strategies and they are also the primary targets of cellular and humoral immune responses. On the other side, LDP12 is a new cell-penetrating peptide (CPP) which is capable of therapeutic application and cargoes delivery across the cellular membrane. In current study, we designed and produced Nef-MPER-V3 fusion protein harboring LDP12 that has the capability of being used in future vaccine studies. The CPP-protein was expressed in E. coli Rosseta (DE3) strain and purified through Ni-NTA column. Characterization of cellular delivery and toxicity of the recombinant protein were evaluated by western blotting and MTT assay. Our results showed that the CPP-protein was successfully expressed and purified with high yield of 5 mg/L. Furthermore, non-cytotoxic effect was observed and specific band (~ 37 KDa) in western blotting indicated the capability of LDP12 to improve the rate of penetration into HEK-293T cells in comparison with a control sample. Altogether, the data indicated that LDP12 CPP could be utilized to internalize HIV-1 Nef-MPER-V3 protein into eukaryotic cell lines without any toxicity and represented a valuable potential vaccine candidate and this guarantees the further evaluation towards the assessment of its immunogenicity in mice, which is currently under process.

Selective immunoglobulin M deficiency: An underestimated immunodeficiency disorder – not so rare

Immunoglobulin M (IgM) is the first antibody to be produced during an immune response, and most of the primary humoral immune response is mediated by IgM. Selective IgM deficiency (sIgMD) is a rare immune disorder that has been reported in the association with serious infections. Patients with sIgMD may be asymptomatic; however, approximately 80% of patients present with infections with bacteria, viruses, or protozoa or with an associated allergic, malignant, or autoimmune condition. sIgMD is usually identified when evaluating a patient for recurrent or serious infections. Attempts should be made to document the infection, as well as the responsible organism, whenever possible. It is a diagnosis of exclusion, and formal diagnostic criteria have not been established. We report three adult cases that were diagnosed to have sIgMD during the evaluation for serious polymicrobial infections with bacteria, fungi, mycobacterium, and viruses. One of them was diagnosed to have associated lymphocytic leukemia. All were successfully managed with intravenous Immunoglobulin (Ig), antibiotics, antiviral, supportive treatment, and discharged. We conclude that patients presenting with polymicrobial infections with encapsulated bacteria, fungi, mycobacterium, and viruses should be evaluated for specific antibody deficiency responses, and they appear to improve clinically on Ig therapy. It appears that the disorder is underdiagnosed.

Co-administration of tecovirimat and ACAM2000™ in non-human primates: Effect of tecovirimat treatment on ACAM2000 immunogenicity and efficacy versus lethal monkeypox virus challenge

Naturally occurring smallpox has been eradicated but research stocks of variola virus (VARV), the causative agent of smallpox, still exist in secure laboratories. Clandestine stores of the virus or resurrection of VARV via synthetic biology are possible and have led to concerns that VARV could be used as a biological weapon. The US government has prepared for such an event by stockpiling smallpox vaccines and TPOXX®, SIGA Technologies’ smallpox antiviral drug. While vaccination is effective as a pre-exposure prophylaxis, protection is limited when administered following exposure. Safety concerns preclude general use of the vaccine unless there is a smallpox outbreak. TPOXX is approved by the FDA for use after confirmed diagnosis of smallpox disease. Tecovirimat, the active pharmaceutical ingredient in TPOXX, targets a highly conserved orthopoxviral protein, inhibiting long-range dissemination of virus. Although indications for use of the vaccine and TPOXX do not overlap, concomitant use is possible, especially if the TPOXX indication is expanded to include post-exposure prophylaxis. It is therefore important to understand how vaccine and TPOXX may interact. In studies presented here, monkeys were vaccinated with the ACAM2000TM live attenuated smallpox vaccine and concomitantly treated with tecovirimat or placebo. Immune responses to the vaccine and protective efficacy versus a lethal monkeypox virus (MPXV) challenge were evaluated. In two studies, primary and anamnestic humoral immune responses were similar regardless of tecovirimat treatment while the third study showed reduction in vaccine elicited humoral immunity. Following lethal MPXV challenge, all (12 of 12) vaccinated/placebo treated animals survived, and 12 of 13 vaccinated/tecovirimat treated animals survived. Clinical signs of disease were elevated in tecovirimat treated animals compared to placebo treated animals. This suggests that TPOXX may affect the immunogenicity of ACAM2000 if administered concomitantly. These studies may inform on how vaccine and TPOXX are used during a smallpox outbreak.

Murine Model of Maternal Immunization Demonstrates Protective Role for Antibodies That Mediate Antibody-Dependent Cellular Cytotoxicity in Protecting Neonates From Herpes Simplex Virus Type 1 and Type 2.

Neonatal herpes simplex virus (HSV) disease results in unacceptable morbidity and mortality. The primary humoral immune response to natural infection is neutralizing antibodies (Abs). However, Abs that activate Fc gama receptors (FcγRs) and mediate antibody-dependent cell-mediated cytotoxicity (ADCC) may play a dominant role in protection. In adult mice, a single-cycle HSV candidate vaccine deleted in glycoprotein-D (ΔgD-2) that induces ADCC provided complete protection against HSV disease and prevented the establishment of latency. Passive transfer studies showed that Abs were sufficient for protection. The current study tested the hypothesis that maternal immunization with ΔgD-2 would protect neonates. C57BL/6 female mice were vaccinated 3 weeks apart with ΔgD-2, and pups were challenged at different times postnatally with lethal doses of HSV-1 or HSV-2. Concentration and functionality of Abs and immune cells were assessed. Maternal ΔgD-2 immunization provided significant protection and reduced viral dissemination after lethal challenge with HSV-1 or HSV-2. Protection correlated with Abs acquired transplacentally or from breastmilk that mediated ADCC. Protection was reduced when pups were challenged on Day 1 of life, and this was associated with decreased ability of newborn cells to mediate Ab-dependent cell killing. Antibodies mediating ADCC provide significant protection against neonatal HSV.

Effect of atorvastatin on humoral immune response to 23-valent pneumococcal polysaccharide vaccination in healthy volunteers: The StatVax randomized clinical trial

BackgroundThe immunomodulatory effects of statins on vaccine response remain uncertain. Therefore, the objective of this study was to determine if atorvastatin enhances pneumococcal-specific antibody titer following 23-valent pneumococcal polysaccharide vaccination. MethodsDouble-blind, placebo-controlled, single-center randomized clinical trial entitled StatVax. Subjects were enrolled between June and July 2014 and followed up through September 2014. 33 healthy volunteers signed informed consent after volunteer sampling. 11 participants were excluded; 22 healthy volunteers without prior pneumococcal vaccination were enrolled and completed the study. Participants were randomized to receive a 28-day course of 40 mg atorvastatin (n = 12) or matching lactose placebo (n = 10). On day 7 of treatment, Pneumovax 23 was administered intramuscularly. The primary outcome was fold change in total pneumococcal-specific antibody titer determined by a ratio of post-vaccination titer over baseline titer. Secondary outcomes included serotype-specific pneumococcal antibody titer, seroconversion, complete blood counts (CBC), erythrocyte sedimentation rate (ESR), and serum cytokine analysis. ResultsOf the 22 randomized patients (mean age, 23.86; SD, 4.121; 11 women [50%]), 22 completed the trial. Total anti-pneumococcal antibody titer in the atorvastatin group went from a baseline mean of 32.58 (SD, 15.96) to 147.7 (SD, 71.52) μg/mL at 21 days post-vaccination while titer in the placebo group went from a mean of 30.81 (SD, 13.04) to 104.4 (SD, 45) μg/mL. When comparing fold change between treatment groups, there was a significant increase in fold change of total anti-pneumococcal antibody titer in the atorvastatin group compared to the placebo group (2-way ANOVA, p = .0177). ConclusionsAtorvastatin enhances antigen-specific primary humoral immune response to a T cell-independent pneumonia vaccination. Pending confirmation by larger cohort studies of target populations, peri-vaccination conventional doses of statins can become a novel adjuvant for poorly-immunogenic polysaccharide-based vaccines.Trial Registration: clinicaltrials.gov Identifier: NCT02097589

Measurement of the IgM and IgG Autoantibody Immune Responses in Human Serum has High Predictive Value for the Presence of Colorectal Cancer

IntroductionColorectal cancer is a major public health issue, with incidences continuing to rise owing to the growing and aging world population. Current screening strategies for colorectal cancer diagnosis suffer from various limitations, including invasiveness and poor uptake. Consequently, there is an unmet clinical need for a minimally invasive, sensitive, and specific method for detecting the presence of colorectal cancer and pre-malignant lesions. Patients and MethodsAn indirect enzyme-linked immunosorbent assay was used to measure the primary (IgM) and secondary (IgG) adaptive humoral immune responses to a panel of previously identified cancer antigens in the sera of normal and adenoma samples, and sera from patients with colorectal cancer. ResultsAn optimal panel of 7 biomarkers capable of identifying patients with colorectal cancer as distinct from both normal and adenoma samples is identified. The cumulative sensitivity and specificity of the assay are 70.8% and 86.5%, respectively. The positive and negative predictive values of the cohort are 77.3% and 82.1%. This assay was not able to accurately discriminate between normal and adenoma samples. Patients whose serum was positive for the presence of anti-ICLN IgM autoantibodies had a significantly poorer 5-year survival than patients whose serum was negative (P = .004). ConclusionThis study describes a novel minimally invasive enzyme-linked immunosorbent assay-based method, capable of identifying patients with colorectal cancer as distinct from both normal and adenoma samples. Patients are likely to be far more amenable to a blood-based test such as the one described herein, rather than a fecal-based test, likely leading to increased patient uptake.

INVESTIGATION OF IMMUNOTOXICITY AND ALLERGENIC PROPERTIES OF DRY EXTRACT OF POTENTILLA ALBA L

The comprehensive study of allergenicity and immunotoxicity of dry extract of Potentilla alba L. has shown that the extract has no sensitizing effect in tests of the general systemic anaphylaxis (anaphylactic shock) and active skin anaphylaxis conducted on Guinea pigs albinos, as well as in the reaction of delayed hypersensitivity in mice. In the study of immunotoxic properties, it has been found that the extract has a stimulating effect on the primary humoral immune response at a therapeutic dose of 3 mg / kg and has no influence on the effectors of the cellular immunity of experimental animals.

Comparison of growth performance and immune responses of broiler chicks reared under heat stress, cold stress and thermoneutral conditions

This study was conducted to compare the effects of thermal stress on growth performance and some immunity variables of broiler chickens. Birds were randomly assigned to one of three thermal treatments as follows: cold stress (CS, 12±1°C), (b) heat stress (HS, 33±3 °C) and (c) thermoneutral (TN, 24±2 °C). Body weight gain (BWG), feed intake (FI), water intake (WI) and feed conversion ratio (FCR) were recorded. In order to evaluate the primary and secondary humoral immune responses, two birds per replicate were intravenously administrated with a suspension of 7% sheep red blood cell (SRBC) at 28 and 35 days. The heat-stressed broiler chickens had lower FI (-14.90%), BWG (-25.71%) and higher FCR (+13.06%) in comparison to broiler chickens reared under TN condition (p<0.001) from 1 to 42 days of age. The cold-stressed broiler chickens showed lower FI (-22.05%), BWG (-38.32%) and higher FCR (+22.47%) in comparison to birds reared under TN conditions (p<0.001). Stressed birds (CS and HS) showed decreased antibody titer against SRBC, lymphocyte count and the relative weights of lymphoid organs and increased heterophil count, heterophil to lymphocyte ratio and the serum concentration of corticosterone, in comparison to birds in TN group (p<0.001). In conclusion, HS and CS conditions have similar negative effects on performance and immunity of broiler chickens.

Low-Dose Methotrexate Prevents Primary and Secondary Humoral Immune Responses and Induces Immune Tolerance to a Recombinant Immunotoxin.

Recombinant immunotoxins (RITs) are chimeric proteins being developed for cancer treatment. They are composed of an Ab fragment that targets a cancer Ag and a cytotoxic portion of Pseudomonas exotoxin A. They are effective for patients with hematologic malignancies with defective immunity, but their efficacy against solid tumors is limited by anti-drug Ab (ADA) responses in immune-competent patients. Pre-existing Abs or immune memory owing to previous toxin exposure represent additional hurdles because they induce rapid and strong ADA responses. Here, we evaluated the efficacy of methotrexate (MTX) to prevent ADA formation against the mesothelin-targeting RIT LMB-100 in naive mice and in mice with pre-existing Abs. We found that low-dose MTX combined with LMB-100 completely suppressed the formation of ADAs in a dose- and frequency-dependent manner. Suppression of the immune response restored blood levels of LMB-100 and prevented its neutralization. Furthermore, combination of MTX with LMB-100 did not compromise the immune response against a second Ag given after stopping MTX, indicating specific immune tolerance. Adoptive transfer of splenocytes suppressed Ab responses to LMB-100 in recipient mice, indicating a durable immune tolerance. We conclude that combination of MTX and LMB-100 is effective at preventing immune responses in a durable, Ag-specific manner. We propose combining low-dose MTX in immune-competent cancer patients receiving RIT therapy to prevent immunogenicity. This approach could be applied to other immunogenic therapeutic agents and to proteins for which there is pre-existing immunity.

Immunomodulatory activity of curcumin-entrapped poly d,l-lactic-co-glycolic acid nanoparticles in mice

BackgroundStudies have shown that curcumin from Curcuma longa has a wide range of medicinal and immunomodulatory properties. These activities have, however, been hindered by its low bioavailability. Meanwhile, incorporation of nanoparticles has been shown to increase bioavailability of certain drugs. This study was, therefore, conducted to comparatively evaluate the immunomodulatory activity of free and nanoparticulate curcumin in mice. MethodsHealthy albino mice were sensitized with sheep red blood cells (SRBCs) and thereafter free and nanoparticulate curcumin were administered orally at doses of 5mg/kg/day and 10mg/kg/day for 10 days to the mice. The assessment of the immunomodulatory activity was carried out by determining the humoral and cell-mediated immune responses using hemagglutination and delayed-type hypersensitivity assays, respectively. Hematological components and some lymphoid organs of treated mice were further evaluated. ResultsThe study showed that nanoparticulate curcumin stimulated higher early cell-mediated immune response at 5mg/kg and 10mg/kg when compared to control. While nanoparticulate curcumin significantly stimulated primary humoral immune response with 9.00±1.00 antibody titre (p<0.05), the free curcumin suppressed the immunity with 3.33±0.67 antibody titre when compared to control. Similar result was observed with secondary humoral antibody titres. Production of white blood cells and weight of the lymphoid organs were also enhanced in the groups that received 10mg/kg nanocurcumin. ConclusionThis work showed that poly d,l-lactic-co-glycolic acid entrapped curcumin nanoparticle could increase bioavailability of curcumin for improved immunity.

Bortezomib decreases the magnitude of a primary humoral immune response to transfused red blood cells in a murine model.

Few therapeutic options currently exist to prevent or to mitigate transfusion-associated red blood cell (RBC) alloimmunization. We hypothesized that bortezomib, a proteasome inhibitor currently being utilized for HLA alloantibody and ADAMTS13 autoantibody reduction, may be beneficial in a transfusion setting. Herein, we utilized a reductionist murine model to test our hypothesis that bortezomib would decrease RBC alloimmune responses. Wild-type mice were treated with bortezomib or saline and transfused with murine RBCs expressing the human KEL glycoprotein. Levels of anti-KEL immunoglobulins in transfusion recipients were measured by flow cytometry. The impact of bortezomib treatment on recipient plasma cells (PCs) and other immune cells was also assessed by flow cytometry and immunofluorescence. After bortezomib treatment, mice had a 50% reduction in splenic white blood cells and a targeted reduction in marrow PCs. Mice treated with bortezomib before the transfusion of KEL RBCs became alloimmunized in three of three experiments, although their serum anti-KEL IgG levels were 2.6-fold lower than those in untreated mice. Once a primary antibody response was established, bortezomib treatment did not prevent an anamnestic response from occurring. To the extent that these findings are generalizable to other RBC antigens and to humans, bortezomib monotherapy is unlikely to be of significant clinical benefit in a transfusion setting where complete prevention of alloimmunization is desirable. Given the impact on PCs, however, it remains plausible that bortezomib therapy may be beneficial for RBC alloimmunization prevention or mitigation if used in combination with other immunomodulatory therapies.

Effects of two-stage weaning with nose flap devices applied to calves on cow body condition, calf performance, and calf humoral immune response.

The effects of nose flap devices in calves before dam separation on cow BCS, pre- and postseparation calf performance, and humoral immune response were compared with traditional weaning. Primiparous and multiparous Angus and Hereford cows ( = 113) and their Angus, Hereford, and Angus × Hereford calves (179.4 ± 3.92 kg and 161 ± 22.7 d of age) were used. Cow-calf pairs were allocated to 1 of 2 treatments in a completely randomized design: 1) nose flap for 21 d before separation from the dam (NF) or 2) no nose flap for 21 d before separation from the dam (CON). Calves were separated from dams on d 0, and calves were placed in group feed-yard pens for 28 d. A subset ( = 75) of weaned calves were placed into 1 of 8 pens to evaluate DMI. Cow BCS was measured on d -21 and 56, and calves were given modified live vaccinations (d -21 and 1), challenged with ovalbumin (OVA; d 1), and weighed (d -21, 1, 7, 14, 21, and 28). In addition, blood samples were collected (d -21, 1, 14, and 28) to measure primary humoral immune response. Control calves tended to have greater BW on d 14 ( = 0.09) and 21 ( = 0.07) than NF calves, and CON calves had greater ( < 0.05) ADG from d -21 to 1 vs. NF calves. Treatments did not differ ( ≥ 0.27) for postweaning DMI, G:F, or morbidity. Serum neutralization tests for bovine viral diarrhea virus type 1 (BVDV-1) and bovine herpesvirus type 1 (BHV-1) were used to measure humoral response to a viral vaccination. Serum antibody titers to BVDV-1 for CON calves tended ( = 0.08) to be greater on d 1 and were greater ( < 0.05) by d 28 vs. NF calves. By d 28, a greater percentage ( < 0.05) of CON calves seroconverted for BVDV-1 than NF calves (82.1 vs. 66.7%, respectively). Serum antibody titers for BHV-1 were greater ( < 0.05) on d 1 and 28 for CON vs. NF calves. Humoral immune response to OVA during the 28-d postseparation period from the dam was evaluated in a subset ( = 57) of calves. There was no difference ( = 0.92) in OVA-specific IgG between treatments on d 14 or 28 ( = 0.76); however, OVA-specific IgM was greater ( < 0.05) in CON vs. NF calves on d 28. Results indicate that nose flap devices did not influence feed intake, feed efficiency, or morbidity during the initial postseparation period from the dam. However, preweaning ADG, serum BVDV-1 and BHV-1 titers, and humoral immune response to OVA were decreased in calves that received the nose flap treatment.

Influence of timing of growth implant administration on performance and health of newly received beef cattle ,

ABSTRACT A total of 442 Angus and crossbred steers (initial BW = 243 ± 13.1 kg) were used in a randomized complete block design to evaluate the effect of implant timing on performance and health of newly received steers. Treatments included administration of a growth implant (Revalor-XS; Merck Animal Health, Summit, NJ) on d 0 of the experiment (ARR) or d 28 (DEL). On d 0, 5 steers from each pen were injected with ovalbumin (OVA) to evaluate a primary humoral immune response. On d 28, the same 5 steers received a secondary OVA injection, and 5 additional steers from each pen received a single OVA injection. Final BW ( P = 0.02) and ADG d 0 through slaughter ( P = 0.03) were greater for DEL compared with ARR (BW: 636 vs. 627 ± 8.3 kg; ADG: 1.78 vs. 1.74 kg ± 0.029, respectively). Steers implanted on arrival had greater DMI ( P ≤ 0.02) d 0 to 28, d 29 to 56, and d 57 to 112 and lower ( P ≤ 0.03) G:F d 57 to 112, d 113 to 169, d 170 to slaughter, and d 0 to slaughter (0.175 vs. 0.186 ± 0.003) when compared with DEL steers. On a pen mean basis, BW at d 28 and ADG d 0 to 28 were numerically higher ( P = 0.25) for ARR steers as compared with DEL steers (294 vs. 291 ± 1.8 kg and 1.80 vs. 1.71 ± kg, respectively). Hot carcass weight was numerically greater ( P = 0.16) for DEL compared with ARR steers (383 vs. 378 ± 3.6 kg, respectively). Steers implanted on arrival tended ( P

Effects of in Ovo Injection and Inclusion a Blend of Essential Oils and Organic Acids in High NSPs Diets of Broiler Breeders on Performance of Them and Their Offspring.

Two factorial completely randomized design trials 2×2 and 2×2×2 were conducted to evaluate the effect of a blend of essential oils and organic acids (Biacid™) in broiler breeder diets at two levels, two dietary non-starch polysaccharides (NSPs) levels and in ovo injection of Biacid™ on their progenies performance, respectively. 240 broiler breeders of Ross 308 strain were fed from the age of week 44th for 12 weeks in four groups. 120 produced eggs from each group were divided in two groups of 60 eggs for injecting by 0.5 ml of Biacid™ or distilled water. Injection was done during transferring from setter to hatcher in day 18th of incubation. Twenty-five cockerels from each of 8 treatments were housed into separate pens. Using Biacid™ and high NSPs in broiler breeders' ration affected hatchability, embryo mortality, weight of day old chicks and progenies' carcass yield significantly (p<0.05) whereas in ovo injection of Biacid™ did not show significant effects in this regards (p≥0.05). Offspring's abdominal fat was neither affected by broiler breeders' rations nor in ovo injection of Biacid™ (p≥0.05). Biacid™ and high NSPs content in broiler breeders' ration affected all primary and secondary humoral immune responses of progenies against sheep red blood cells (p<0.05). In ovo injection of Biacid™ increased the primary IgG, primary IgT and secondary IgG responses (p<0.05). The interaction of the effects of Biacid™ and high NSPs in broiler breeders' ration and also in ovo injection of Biacid™ affected progenies' weight gain, feed intake, feed conversion ratio and European production index significantly (p<0.05). It seems that using Biacid™ in broiler breeders' diet can modify the undesirable effects of high NSPs content of breeders' ration on performance of their offspring.

Cognate interaction with iNKT cells expands IL-10–producing B regulatory cells

Successful induction of B-cell activation and memory depends on help from CD4+ T cells. Invariant natural killer T (iNKT) cells (glycolipid-specific, CD1d-restricted innate lymphocytes) provide both cognate (direct) and noncognate (indirect) helper signals to enhance B-cell responses. Both forms of iNKT-cell help induce primary humoral immune responses, but only noncognate iNKT-cell help drives humoral memory and plasma cells. Here, we show that iNKT cognate help for B cells is fundamentally different from the help provided by conventional CD4+ T cells. Cognate iNKT-cell help drives an early, unsustained germinal center B-cell expansion, less reduction of T follicular regulatory cells, an expansion of marginal zone B cells, and early increases in regulatory IL-10-producing B-cell numbers compared with noncognate activation. These results are consistent with a mechanism whereby iNKT cells preferentially provide an innate form of help that does not generate humoral memory and has important implications for the application of glycolipid molecules as vaccine adjuvants.