The severe fever with thrombocytopenia syndrome virus (SFTSV) is the causative pathogen of an emerging infectious disease severe fever with thrombocytopenia syndrome and a new member in the genus Phlebovirus of family Bunyaviridae. Immune responses and pathological lesions in SFTSV-infected Balb/C mice and hamsters were evaluated by inoculation of SFTSV at 105 TCID50 or 103 TCID50 per animal through four different routes of infection, including intravenous, intramuscular, intraperitoneal, and intracerebral injections. The vehicle control groups were also included. At different time points after the inoculation blood and plasma samples were collected. Blood cell counts, blood viral RNA copies, and plasma antibodies were detected by automatic blood cell counters, real-time PCR, and luminex assays, respectively. At two weeks post inoculation, the animals were sacrificed. Tissues including heart, liver, spleen, lung, kidney, intestine, muscle, and brain, were collected for pathological analyses. Results showed that the SFTSV could infect Balb/C mice and hamsters with SFTSV-specific immunoglobulin (Ig) M and IgG antibodies detected in plasma samples on day 7 post inoculation. The SFTSV-specific IgM levels peaked on day 7 post inoculation and then decreased, whereas the SFTSV-specific IgG levels started to increase on day 7 and then peaked on day 14 post inoculation. Pathological analyses indicated significant pathological lesions in liver and kidney tissues. In conclusion, SFTSV could can infect different strains of rodent animals and cause similar immunological and pathological responses.
Animals ; Antibody Specificity ; Bunyaviridae Infections ; blood ; pathology ; Cricetinae ; Immunoglobulin G ; blood ; Immunoglobulin M ; blood ; Leukocyte Count ; Mice ; Mice, Inbred BALB C ; Organ Specificity ; Phlebovirus ; immunology ; physiology

To evaluate the in vivo effect of autologous serum including antibodies to house dust mite in atopic individuals, we observed the immediate (15 mins) and late (6 hours) skin reactions (ISR, LSR) on intradermal (ID) test of serially diluted Dermatophagoides farinae antigens (DFa, Allergopharma, Germany) mixed with autologous sera (DFa-S) and diluent alone (DFa-D). We tested 34 DFa-skin reactive atopic individuals including 12 asthmatics (BA), 8 asthmatics on immunotherapy with DFa (IT), and 14 healthy atopic controls (AC). We observed complete inhibition of ISR in the lowest allergen dose of DFa-S in 7 (58.3%) of 12 BA, 3 (37.5%) of 8 IT, and 2 (14.3%) of 14 AC. In BA, the inhibition of ISR was more frequent than AC (p< 0.05). We observed larger late reactions in half of LSR positive cases on ID test by DFa-S than by DFa-D (> or = 1.5 X size; accentuation of LSR). Accentuation of LSR were shown more frequently by DFa mixed with larger amount of serum (25% in 1:1 mix; 80% in 1:3 mix, p< 0.05). But there were no differences of DFa-specific IgE and IgG subclass antibodies regardless of the inhibition of ISR or the accentuation of LSR. In conclusion, some autologous sera from DFa-sensitive individuals showed the inhibition of ISR and the accentuation of LSR on DFa-ID test.
Animal ; *Blood Physiology ; Dermatitis, Atopic/blood/*immunology ; Human ; Hypersensitivity, Delayed/*immunology ; Hypersensitivity, Immediate/*immunology ; Immunoglobulin E/metabolism ; Immunoglobulin G/metabolism ; Intradermal Tests ; Mites/*immunology ; Skin/*immunology ; Support, Non-U.S. Gov't

Although animal models with ovalbumin have been used to study chronic asthma, there are difficulties in inducing recurrence as well as in maintaining chronic inflammation in this system. Using a murine model of house dust mite (HDM)-induced bronchial asthma, we examined the airway remodeling process in response to the chronic exposure to HDM. During the seventh and twelfth weeks of study, HDM were inhaled through the nose for three consecutive days and airway responsiveness was measured. Twenty-four hours later, bronchoalveolar lavage and histological examination were performed. The degree of overproduction of mucus, subepithelial fibrosis, and the thickness of the peribronchial smooth muscle in the experimental group was clearly increased compared to the control group. In addition, HDM-exposed mice demonstrated severe airway hyperreactivity to methacholine. In the bronchoalveolar lavage fluid, the number of total cells and eosinophils was increased; during the twelfth week, the number of neutrophils increased in the experimental group. With regard to changes in cytokines, the concentrations of IL-4, IL- 13, and transforming growth factor-beta (TGF-beta) were increased in the experimental group. The data suggest that eosinophils, IL-4, IL-13, and TGF-beta might play an important role in the airway remodeling process and that neutrophils may be involved with increased exposure time.
Animals ; Asthma/*etiology/pathology ; Eosinophils/physiology ; Female ; Immunoglobulin E/blood ; Immunoglobulin G/blood ; Inflammation/*etiology ; Interleukin-13/physiology ; Interleukin-4/physiology ; Lung/*pathology ; Mice ; Mice, Inbred BALB C ; Pyroglyphidae/*immunology ; Transforming Growth Factor beta/physiology

The ongoing pandemic of Coronavirus disease 19 (COVID-19) is caused by a newly discovered β Coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). How long the adaptive immunity triggered by SARS-CoV-2 can last is of critical clinical relevance in assessing the probability of second infection and efficacy of vaccination. Here we examined, using ELISA, the IgG antibodies in serum specimens collected from 17 COVID-19 patients at 6-7 months after diagnosis and the results were compared to those from cases investigated 2 weeks to 2 months post-infection. All samples were positive for IgGs against the S- and N-proteins of SARS-CoV-2. Notably, 14 samples available at 6-7 months post-infection all showed significant neutralizing activities in a pseudovirus assay, with no difference in blocking the cell-entry of the 614D and 614G variants of SARS-CoV-2. Furthermore, in 10 blood samples from cases at 6-7 months post-infection used for memory T-cell tests, we found that interferon γ-producing CD4
Adaptive Immunity/physiology* ; Adult ; Aged ; Antibodies, Neutralizing/blood* ; COVID-19/immunology* ; Cohort Studies ; Female ; Humans ; Immunoglobulin G/blood* ; Male ; Middle Aged ; SARS-CoV-2/immunology* ; T-Lymphocytes/physiology* ; Time Factors ; Viral Proteins/immunology*

Toxoplasma gondii is an obligate intracellular protozoan that is distributed worldwide. Recently, several tests for avidity of Toxoplasma IgG antibodies have been introduced to help discriminate between recently acquired and distant infections. The study was conducted in Jawaharlal Nehru Medical College and Hospital, India from February 2011 to September 2012. Serum specimens were subjected to Toxoplasma IgM ELISA and IgG avidity ELISA test. Out of 48 patients with abortions, 17 (35.4%) were positive for IgM ELISA, and 8 (16.6%) had low IgG avidity antibodies. Out of 48 patients with other obstetric problems, 23 (47.9%) were positive for IgM ELISA, and 17 (35.4%) had low IgG avidity antibodies. Combining both groups on avidity test, only 25 of 40 (62.5%) IgM-positive women had low-avidity IgG antibodies suggesting a recent T. gondii infection in these women. More importantly, 15 (37.5%) of the IgM-positive women had high-avidity antibodies suggesting that the infection was acquired before gestation The relation of IgM seropositivity with the following risk factors was not found to be statistically significant; contact with cats (0.13), non-vegetarian food habits (0.05), and low socio-economic status (0.49). While, for IgG avidity ELISA, only contact with cats (0.01) was significantly associated with seropositivity. All other risk factors have P-values of >0.05 (not significant). IgG avidity test when used in combination with IgM test was a valuable assay for diagnosis of ongoing or recently acquired T. gondii infection in India.
Abortion, Spontaneous/immunology ; Adolescent ; Adult ; Animals ; Antibodies, Protozoan/*immunology ; *Antibody Affinity ; Cats ; Enzyme-Linked Immunosorbent Assay ; Female ; Food Contamination ; Humans ; Immunoglobulin G/blood/immunology/*physiology ; Immunoglobulin M/blood ; India/epidemiology ; Risk Factors ; Seroepidemiologic Studies ; Toxoplasma/*immunology ; Toxoplasmosis/epidemiology/*immunology ; Young Adult

OBJECTIVETo study the prophylactic effects of nasal tolerance with a dual analogue, Lys262-Ala207, on the mouse model of experimental autoimmune myasthenia gravis (EAMG) and the underlying mechanism.

METHODSMouse model of EAMG was induced by intraperitoneal injection of mAb35. Lys262-Ala207 or PBS was given nasally before 10 days (study group A and control group A) or on the day (study group B and control group B) of immunization for 10 days. Clinical syndromes were evaluated after immunization. Serum level of acetylcholine receptor antibody (AChR-Ab) IgG was detected using ELISA. The number of monouclear cells expressing CD4+ and CD4+ CD25+T from spleen was measured using flow cytometry.

RESULTSCompared with the corresponding control groups, the clinical syndromes were improved (P<0.01) in mice from the study groups A and B. The positive rate of the repetitive nerve stimulation (RNS) test in the study groups A and B was significantly lower than that in the corresponding control groups (P<0.01). The study group A showed lower positive rate of RNS than the study group B (P<0.05). The serum levels of AChR-Ab IgG in the study groups A and B (15.01+/-1.09 and 19.23+/-1.31 microg/mL) decreased compared with that in the corresponding control groups (28.12+/-1.28 and 29.35+/-1.28 microg/mL) (P<0.01). The study group A mice had lower serum AChR-Ab IgG levels than the study group B (P<0.01). The number of CD4+ CD25+T cells in the study groups A (4.516+/-0.598%) and B (3.671+/-0.300%) increased significantly compared with that in the corresponding control groups (2.661+/-0.411% and 2.412+/-0.500%) (P<0.01) and more CD4+ CD25+T cells were found in the study group A than in the study group B (P<0.01).

CONCLUSIONSNasal administration with dual analogues may ameliorate clinical syndromes in EAMG rats, which may be associated with decreased serum AChR-Ab IgG levels and increased number of CD4+ CD25+T cells from spleen.

Administration, Intranasal ; Animals ; Female ; Immune Tolerance ; drug effects ; Immunoglobulin G ; blood ; Mice ; Mice, Inbred C57BL ; Myasthenia Gravis, Autoimmune, Experimental ; immunology ; prevention & control ; Receptors, Cholinergic ; immunology ; T-Lymphocytes, Regulatory ; physiology

A few members of coronavirus group I which includes porcine epidemic diarrhea virus (PEDV) use porcine aminopeptidase N (pAPN) as a cellular receptor. Cellular receptors play an important role in virus attachment and entry. However, the low permissiveness of PEDV to APN-expressing porcine cell lines has made it difficult to elucidate the role of pAPN in vitro. The purpose of this study was to prove whether the treatment of soluble pAPN could enhance the antibody production against PEDV in guinea pigs, rabbits and sows. The animals (20 guinea pigs, 8 rabbits and 20 sows) were divided into 4 groups. Group A was injected intramuscularly (IM) with soluble pAPN at one hour before intramuscular infection of PEDV on the same site, group B for IM simultaneous injection of pAPN and PEDV, and group C for IM injection of PEDV only. Group D served as a control of pAPN treatment or PEDV infection. Antibody production against PEDV was compared among groups at regular intervals. The results suggested that pAPN could enhance the antibody production against PEDV in guinea pigs and rabbits which are free of pAPN, however, the effect of pAPN treatment in sows was not clearly elucidated.
Animals ; Antibodies, Viral/*blood ; Antibody Formation ; Antigens, CD13/*administration&dosage ; Cercopithecus aethiops ; Coronavirus/*immunology/physiology ; Coronavirus Infections/immunology/*veterinary ; Enzyme-Linked Immunosorbent Assay/veterinary ; Female ; Guinea Pigs ; Immunoglobulin G/*blood ; Immunoglobulin Isotypes ; Injections, Intramuscular ; Pregnancy ; Rabbits ; Solubility ; Swine ; Swine Diseases/*immunology ; Vero Cells/virology

OBJECTIVETo observe effect of Xue Hanjing oral fluid on mice immunological function.

METHODThe weight of thymus gland and spleen and the function of abdominal cavity macrophage were measured. Production of the hemolysin antibody, the immunoglobulin of blood serum and complement and the proliferation of T lymphocytes were observed respectively by means of microblood, immune-turbidimetry and MTT staining.

RESULTXue Hanjing oral fluid could enhance index of the thymus gland and spleen and the phago-percent of abdominal cavity macrophage, increase the immunoglobulin of blood serum(IgG and IgM), and accelerate production of the hemolysin antibody and the proliferation of T lymphocytes.

CONCLUSIONSXue Hanjing oral can reinforce immunological function in mice.

Adjuvants, Immunologic ; pharmacology ; Administration, Oral ; Animals ; Antibody Formation ; Cell Division ; drug effects ; Drugs, Chinese Herbal ; administration & dosage ; isolation & purification ; pharmacology ; Female ; Hemolysin Proteins ; immunology ; Immunoglobulin G ; blood ; Immunoglobulin M ; blood ; Macrophages, Peritoneal ; physiology ; Male ; Mice ; Organ Size ; drug effects ; Phagocytosis ; drug effects ; Plants, Medicinal ; chemistry ; Poaceae ; chemistry ; Random Allocation ; T-Lymphocytes ; cytology