Neutral-Coating Capillary Electrophoresis Coupled with High-Resolution Mass Spectrometry for Top-Down Identification of Hemoglobin Variants

BACKGROUND

Identification of hemoglobin (Hb) variants is of significant value in the clinical diagnosis of hemoglobinopathy. However, conventional methods for identification of Hb variants in clinical laboratories can be inadequate due to the lack of structural characterization. We describe the use of neutral-coating capillary electrophoresis coupled with high-resolution mass spectrometry (CE-HR-MS) to achieve high-performance top-down identification of Hb variants.

METHODS

An Orbitrap Q-Exactive Plus mass spectrometer was coupled with an ECE-001 capillary electrophoresis (CE) unit through an EMASS-II ion source. A PS1 neutral-coating capillary was used for CE. Samples of red blood cells were lysed in water and diluted in 10 mM ammonium formate buffer for analysis. Deconvolution of raw mass spectrometry data was carried out to merge multiple charge states and isotopic peaks of an analyte to obtain its monoisotopic mass.

RESULTS

The neutral-coating CE could baseline separate individual Hb subunits dissociated from intact Hb forms, and the HR-MS could achieve both intact-protein analysis and top-down analysis of analytes. A number of patient samples that contain Hb subunit variants were analyzed, and the variants were successfully identified using the CE-HR-MS method.

CONCLUSIONS

The CE-HR-MS method has been demonstrated as a useful tool for top-down identification of Hb variants. With the ability to characterize the primary structures of Hb subunits, the CE-HR-MS method has significant advantages to complement or partially replace the conventional methods for the identification of Hb variants.

[Pediatric pancreatic lesions: a clinicopathological analysis of 42 cases]

Objective: To investigate the clinicopathological characteristics of pancreatic lesions in children. Methods: The clinicopathological data of pancreatic lesions in children were analyzed including 42 cases of pancreatic tumors diagnosed from January 2000 to May 2021 in Guangzhou Women's and Children's Medical Center, Guangzhou, China. Histological and immunohistochemical assessments were performed. Related literature was reviewed. Results: The 42 pediatric patients with pancreatic lesions aged 1 day to 12 years (mean, 4.25 years). There were 23 males and 19 females. Clinical presentations included abdominal masses, abdominal pain, vomiting and persistent hypoglycemia after birth. Ultrasound and computerized tomography examination showed space-occupying pancreatic lesions in 31 cases, but no detectable pancreatic lesions in 11 cases. Histologically, among the 42 cases, 22 cases (52.4%) were neoplastic, including 18 cases of epithelial origin. Nine cases of pancreatoblastoma showed that the epithelial tumor cells were arranged in a trabecular pattern, with squamous nests. Six cases of solid-pseudopapillary tumors revealed hemorrhagic and necrotic cysts and monomorphic epithelioid cells arranged in solid sheets, nests or pseudopapillae. Two cases of neuroendocrine tumors showed tumor cells arranged in cords or nests; one case had a mitotic count of about 3/10 high power field, and a Ki-67 index of about 5%, which was consistent with G2 neuroendocrine tumor; the other case showed tumor cells with cytological atypia, brisk mitoses, about 25/10 HPF and a Ki-67 index of about 80%, consistent with small-cell type neuroendocrine carcinoma. The case of acinar cell carcinoma showed high cellularity, tumor cells in solid, cord-like or acinar-like arrangement with little stroma, and monotonous tumor cells with single distinct nucleolus. There were 4 cases of mesenchymal tumors, including 3 cases of Kaposi's hemangioendothelioma and 1 case of inflammatory myofibroblastic tumor. Among the 20 cases (47.6%) of non-neoplastic lesions, there were 11 cases of hyperinsulinism with ATP-sensitive potassium channel abnormality (HAPCA). Severn cases of diffuse type HAPCA in which the islets scattered between the pancreatic acinar tissue, enlarged, and prominent nuclei. Three cases of focal type HAPCA showed pancreatic islet hyperplasia in the form of nested nodules (0.6-1.5 cm). One case of atypical type HAPCA had extensive islet hyperplasia in pancreatic tissue, and scattered proliferation of nest-like nodules was noted. There were also 7 cases of pseudocyst and 2 cases of congenital cyst. Immunohistochemically, pancreatoblastomas were diffusely positive for CKpan, CK8/18, and β-catenin (nuclear staining of squamous nests only). Solid-pseudopapillary tumors expressed CD10, cyclin D1, CD99, vimentin, CD56, and β-catenin (nuclear staining). Neuroendocrine tumors were positive for CK, Syn, NSE, CgA, CD56, and β-catenin (membranous staining). The acinar cell carcinoma was positive for CK8/18, trypsin, and β-catenin (membranous staining). Conclusions: Pancreatic lesions in children have a wide range of histopathological types. HAPCA is the most common lesion of newborns. Pediatric pancreatic tumors are rare and mostly malignant. It is important to recognize them and make correct pathological diagnoses.

[Gonadal neoplastic related lesions in children with disorders of sexual development: a clinicopathological study of twelve cases]

Objective: To investigate the clinicopathological features of gonadal neoplastic related lesions in children with disorders of sexual development (DsD). Methods: The clinical manifestations, chromosomal karyotype, histology and immunophenotype of 12 cases of neoplastic related lesions from Guangzhou Women and Children's Medical Center, Guangzhou were analyzed during Jan 2015 to May 2020. Results: Twelve cases of neoplastic related lesions were screened in 205 cases of DsD, and 6 patients with gonadal germ cell neoplasia aged 3-13 years with an average age of 8.3 years. There were 2 males and 4 females. Clinical features showed malformation of external genitalia in 2 cases, short stature in 2 cases, clitoral enlargement in 1 case, lower abdominal pain and a huge pelvic mass in 1 case. Chromosomal karyotyping of peripheral blood showed 2 cases of 46XY and 4 cases of 45X/46XY. Fourteen gonadal specimens were examined. Microscopically, 1 case showed dysgerminoma in left ovary, and malignant mixed germ cell tumors in right ovary, as well as gonadoblastoma (GB) and undifferentiated gonadal tissue (UGT). The remaining 5 cases were all precursor lesions of germ cell tumor. Six specimens showed GB, 3 of UGT, and 3 specimens showed germ cell neoplasia in situ (GCNIS), one of which was accompanied by intratubular seminoma and 1 was GB with GCNIS. The other 6 patients with DsD were aged from 8 months to 2 years and 5 months, including 5 males and 1 females. Clinical manifestations showed 5 cases of hypospadias and 1 case of bilateral indirect inguinal hernia. Microscopically, 6 cases showed maturation delay of gonocytes in seminiferous tubules. Immunohistochemically, the primordial germ cells/gonocytes expressed OCT3/4, PLAP and c-KIT in the 12 cases. Conclusion: Gonadal neoplasia in children with DsD is mainly precursor lesions of germ cell tumor and improved understanding of these lesions is of great significance.

[Pathologic features on gonadal changes of sexual developmental disorders in children]

Objective: To investigate the pathologic features of gonadal tissues of disorders of sexual development (DSD) in children. Methods: Fifty-three cases of gonadal developmental disorders were collected from July 2015 to August 2017 at Guangzhou Women and Children's Medical Center. Clinical manifestations, karyotypes, sex hormone levels, ultrasound imaging, histology and immunophenotype of gonadal tissues were analyzed. Results: The age of patients ranged from 7 months to 17 years with an average of (50.7 ± 47.1) months. Social genders of the patients included 32 males and 21 females. Forty-eight patients had abnormal sex hormone levels. Clinical presentations included: toward female genitalia in 25 cases, male genitalia tendency in 17 cases and ambiguous external genitalia in 11 cases. Hypospadias was seen in 31 cases and short stature was seen in 8 cases. Chromosomal karyotyping of peripheral blood revealed 23 cases of sex chromosome disorders, 22 cases of 46 XY disorders, of which 3 cases were 5α-reductase deficiency and 8 cases of 46 XX disorders. Ultrasound examination showed cryptorchidism in 30 cases, including 16 cases of unilateral, 14 cases of bilateral and 1 case presenting a huge pelvic tumor. A total of 97 gonadal tissues from 53 cases of DSD were examined, including 9 cases of unilateral and 44 cases of bilateral gonads. Microscopically, 55 gonads (56.7%) showed dysplastic testes including 17 unilateral and 19 bilateral gonads. Fourteen were streak gonads (14.4%) including 8 unilateral and 3 bilateral gonadal tissues. Nine streak gonad with epithelial cord-like structures (9.3%) were found, of which 5 were unilateral and 2 were bilateral lesions. Seven gonads were ovotestis (7.2%), unilateral in 5 cases (the other side of the gonads of ovary in 4 cases, 1 case of dysplastic testes) and bilateral in 1 case. Seven gonads showed follicular-rich ovarian tissue (7.2%). One case showed bilateral dysplastic testes with gonadoblastoma and ectopic adrenal cortex. One case of streak gonad showed epithelial cord-like structures and undifferentiated glandular tissue embedded in malignant mixed germ cell tumors (mixed gonadoblastoma, dysgerminoma, mature teratoma and yolk sac tumor). One case had testicular microlithiasis. Uterus and fallopian tube structures were found in 11 cases. Immunohistochemical stains were performed in 15 cases. D2-40, PLAP and CKIT were expressed in germ cells and Calretinin, WT1 and inhibin were positive in Setoli cells. SALL4 and OCT3/4 were positive in 3 cases. Inhibin highlighted interstitial Leydig cells in 2 cases. GPC3 was positive in yolk sac tumor component. Conclusions: Gonadal dysgenesis presents a broad spectrum of gonadal phenotypes with variable degrees of differentiation. The development of bilateral gonadal tissues has certain variability. Chromosomal karyotypes have no correlation with gonadal phenotypes. Accurate histopathologic diagnosis of gonadal dysgenesis plays an important role in the treatment and prognosis of the patient.

Effects of different sources of protein on the growth performance, blood chemistry and polypeptide profiles in the gastrointestinal tract digesta of newly weaned piglets

To determine the effects of different sources of protein on the growth performance of newly weaned piglets, 72 newly weaned piglets were randomly assigned to three groups fed different diets (soya bean, casein and dried distillers' grain with solubles (DDGS) feeds). Casein and DDGS feeds consisted of soya bean feed in which 5% of the CP was replaced with casein- or DDGS-derived CP respectively. Blood and chyme samples were collected from each piglet 2 h post-feeding on days 0 and 28 of the feeding period. The DDGS feed decreased DMI (p = 0.024) and increased FCR (p = 0.025) due to lower nitrogen utilization (p = 0.078) than those of other feeds. Total amino acid content in chyme demonstrated that casein feed digested rapidly in the duodenum (p = 0.005), whereas DDGS feed was digested primarily in the distal jejunum (p = 0.003) and ileocecum (p = 0.002). However, polypeptide profiles in chyme exhibited a pattern different from those of amino acids. There were no differences in the polypeptide profiles in the stomachs of piglets fed soya bean or casein feeds (p > 0.05), but soya bean group had greater amounts of small polypeptides (mass under m/z 3000 Da) in the duodenum (p = 0.052) than other groups. In contrast, the DDGS feed group had more large polypeptides (m/z 3000-4000 Da) in the stomach than the other groups (p < 0.001). In addition, 10 pairs of polypeptides with matching masses were identified in the plasma and digesta, indicating that polypeptides may have been transported across the intestinal epithelial cells and into the blood. Taken together, substitution of 5% of the CP in soya bean meal-based feed with DDGS-derived CP decreased the growth performance of newly weaned piglets due to poor digestibility and N utilization of DDGS feed, as well as untimely digestion of casein feed.

[Clinicopathologic study of pediatric vascular anomalies: a report of 117 cases]

OBJECTIVE

To study the clinicopathologic features of pediatric vascular anomalies and application of ISSVA classification.

METHODS

The clinical features, histopathologic findings and immunohistochemical results were analyzed in 117 cases of pediatric vascular anomalies encountered during the period from May 2014 to May 2015.

RESULTS

A total of 117 cases of vascular anomalies were studied. The age of patients ranged from 18 hours after birth to 11 years (mean age =34 months and median age =27 months). There were 73 male patients and 44 female patients, with the male-to-female ratio being 1.7∶1.0. Congenital skin lesions were found in 37 cases (31.6%). The common sites of involvement included head and neck region (46 cases, 39.3%), trunk (28 cases, 23.9%), extremities (14 cases, 12.0%) and internal viscera (31 cases, 26.5%). According to the new ISSVA classification, there were 74 cases of vascular malformations and 43 cases of vascular neoplasms (ratio=1.7∶1.0). The commonest vascular tumor encountered was infantile hemangioma (21 cases, 48.8%), including 17 cases in proliferative phase and 4 cases in involutive phase. Thirteen cases (23.3%) of congenital hemangioma were found, with 8 cases of rapidly involuting congenital hemangioma and 5 cases of non-involutive congenital hemangioma. Three of the congenital hemangioma occurred in liver. There were 5 cases (11.6%) of pyogenic granuloma, 3 cases (7.0%) of tufted angioma and 1 case (2.3%) of Kaposiform hemangioendothelioma. Amongst the 74 cases of vascular malformations encountered, lymphatic malformation was found in 47 cases (63.5%), venous malformation in 15 cases (20.2%), lymphatic-venous malformation in 11 cases (14.9%) and arteriovenous malformation in 1 case (1.4%). All cases of vascular anomalies were all positive for CD31 on immunostaining. Glut1 and CD15 were positive both in proliferative and involutive phases of the 21 cases of infantile hemangioma, while other vascular tumors and vascular malformations were negative. Forty-seven cases of lymphatic malformation and 11 cases of lymphatic-venous malformation showed D2-40 expression. Focal positivity for D2-40 was demonstrated in 3 cases of tufted angioma and 1 case of Kaposiform hemangioendothelioma.

CONCLUSIONS

Vascular anomalies affecting infants and children include tumors and malformations. Accurate histopathologic diagnosis and ISSVA classification of the various types of vascular anomalies play an important role in clinical management.

Purified recombinant A. fumigatus allergens induce different responses in mice

Aspergillus fumigatus an opportunistic fungus is associated with a number of diseases in humans. Allergy resulting from exposure to the A. fumigatus allergens has been recognized frequently. The damage caused by the disease is very striking in patients with atopy and those with cystic fibrosis. Avoidance to exposure is not feasible because A. fumigatus spores are ubiquitously distributed in the environment. Hence, immunotherapeutic regimens in severe forms of A. fumigatus allergy may have a high potential. However, before such forms of therapy can be envisaged, it is essential to understand the immunopathogenesis. In the present study, we investigated the role of purified A. fumigatus allergens in the development of allergic asthma in mice. We have used four major recombinant A. fumigatus allergens in the murine model. Mice exposed to Asp f 1, f 3, and f 4 showed inflammatory changes in the lungs and airway hyperreactivity. The immune responses, including elevated serum IgE, enhanced eosinophils, recruitment in the peripheral blood and lungs, and expression of regulatory cytokines, are characteristic of a Th2 response. Asp f 6 demonstrated only a reduced response in these animals. The results suggest that the pathology induced by crude A. fumigatus extract results from the cumulative effects of the allergens and the individual responses varied considerably with different purified antigens.

Regional Population Diversity of Pyricularia grisea in Arkansas and the Influence of Host Selection

MGR586 DNA fingerprinting has been widely used to characterize population diversity of the rice blast pathogen, Pyricularia grisea. However, the frequency and distribution of particular haplotypes (individuals) within MGR-delimited lineages has not been examined in the United States. MGR586 DNA fingerprinting, mitochondrial DNA (mtDNA) restriction fragment length polymorphism (RFLPs), and virulence phenotyping were used to examine genetic diversity of P. grisea in Arkansas. A total of 470 monoconidial isolates were recovered from eight rice cultivars in 18 commercial fields in nine counties in Arkansas. All isolates were examined for nuclear DNA RFLPs with the MGR586 DNA fingerprint probe, and both the MGR lineage (isolates with >80% similarity) and the haplotype frequencies were determined. Four distinct MGR586 DNA fingerprint lineages (designated A, B, C, and D) were identified among the 470 field isolates. All four lineages were found in 9 of the 18 locations. Three lineages were found in four locations, two lineages in three locations, and only a single lineage was found at two locations. In all, 10, 19, 16, and 13 haplotypes (isolates which had MGR586 DNA fingerprints which differed by 1 to 20%) were identified within lineages A, B, C, and D, respectively, among the 470 isolates examined. Within each lineage, a single haplotype (clone) predominated, representing 51 to 71% of the isolates collected for each of the four lineages. Overall, 60% of the 470 isolates belonged to one of only four haplotypes (A1, B1, C1, and D1) and these four predominant haplotypes were recovered from between 7 and 14 of the 18 locations sampled, indicating a widespread distribution of these four clones. These data indicate an exceptionally low level of genetic diversity in the regional rice blast pathogen population in Arkansas relative to several other populations of P. grisea examined from tropical environments. In addition, no mtDNA RFLPs were detected among representative haplotypes within each of the lineages, indicating a single mtDNA haplotype was present in the population. Examination of virulence indicated that two races predominated in the regional collection. All 30 isolates in lineages A and C tested had an IB-49 virulence phenotype. Out of 30 isolates in lineages B and D, 29 had an IC-17 virulence phenotype. One isolate in lineage B, isolated from a highly susceptible cultivar (L201), had an IG-1 virulence phenotype. The frequencies of the four lineages varied among the locations sampled and may have been due, in part, to the cultivar from which isolates were recovered. A single lineage was recovered from two cultivars, Mars and Millie. Although only a single field of each of these cultivars was sampled, the data indicate that certain cultivars grown in Arkansas may serve as a "bottleneck", selecting out specific lineages in the regional population. To test this hypothesis, an additional 283 isolates were recovered from replicated plots of cvs. M204 and Mars located within commercial rice fields at two locations during two seasons. All four MGR586 lineages were recovered from each location. However, there was a strong bias for lineage B on cv. M204 (79% of all isolates) and a strong bias for lineage A on cv. Mars (95% of all isolates), indicating some cultivars were effective in excluding certain lineages.

Immune responses to Aspergillus antigen in IL-4-/-mice and the effect of eosinophil ablation

BACKGROUND

Exposure to Aspergillus fumigatus allergens results in enhanced total serum IgE and peripheral blood eosinophils in mice. The associated pulmonary inflammation and immunologic responses are comparable to those detected in human allergic bronchopulmonary aspergillosis. Allergen-induced cytokines are thought to regulate the inflammatory and immune responses in these animals.

METHODS

In the present study, we exposed C57BL/6 and BALB/c mice to A. fumigatus antigen. Both wild-type and IL-4 knockout phenotypes of animals of both strains were used. Some animals were also treated with anti-IL-5 or anti-IFN-gamma. Total serum IgE, Aspergillus species IgG subclass, peripheral blood eosinophils, and lung histology were studied.

RESULTS

The results demonstrate similar lung inflammation in all wild-type and IL-4-/- animals exposed to A. fumigatus antigen. Similarly, in spite of the diverse immune response produced by the anticytokine treatment, no major differences were detected among any of the animal groups studied.

CONCLUSIONS

It can be concluded that A. fumigatus exposure in an immunologically unaltered host is predominantly of a Th2 type, and that depletion of the Th2 cytokine leads to a similar lung inflammation but with a characteristic Th1 response, suggesting that the pathogenesis of allergic aspergillosis is the result of multiple induction pathways.

Aspergillus fumigatus antigen exposure results in pulmonary airway resistance in wild-type but not in IL-4 knockout mice

Inhalation of Aspergillus fumigatus, a ubiquitous fungus, results in the development of allergic bronchopulmonary aspergillosis, a disabling allergic lung disease. For better patient management early diagnosis is essential, and understanding of the immune mechanism is important in achieving this goal. Although animal model studies have contributed to the understanding of the disease mechanism, details on the immunopathogenesis are still lacking. In the present study, we have developed an allergic aspergillosis model in wild-type and IL-4 knockout mice and studied the immune and airway responses. The results indicate that the immune response, pulmonary pathology, and airway reactivity comparable to allergic bronchopulmonary aspergillosis are reproducible in wild mice. IL-4 knockout mice showed similar pulmonary pathology, but no increase in airway resistance, suggesting that IgE and hence IL-4 may be important in eliciting the airway response, while other factors may be involved in the inflammatory process.

A murine model of latex allergy-induced airway hyperreactivity

Sensitization to latex proteins can cause immediate IgE mast cell-mediated reactions. Health care workers have been found to be particularly at risk because of high exposure. Latex allergy can be produced in mice as demonstrated by IgE and eosinophil responses. Thus the mouse is a potential animal model for studying this disease, but the airway response to latex sensitization in mice has not been evaluated previously. In the present study, we immunized BALB/c mice intranasally with nonammoniated latex proteins. Animals were anesthetized, and lung mechanics were evaluated plethysmographically. Changes in pulmonary conductance (GL) and compliance (Cdyn) were measured in response to a nonspecific challenge with methacholine or to a direct challenge with intravenous latex antigen. Latex sensitization resulted in elevated levels of IgE and latex-specific IgG1 as well as interstitial infiltrates consistent with an allergic response. The methacholine dose-response ED50 for GL was 116.4 microg for the control mice and fell significantly to 20.9 microg for latex-sensitized mice. The ED50 calculated for Cdyn was also significantly lower after latex sensitization. The GL in latex-sensitized mice challenged with latex antigen fell significantly from a prechallenge value of 1.87 +/- 0.41 (S.E.) to 0. 198 +/- 0.03 ml x s-1 x cmH2O after latex antigen challenge. The results indicate that latex-sensitized mice did exhibit increased airway reactivity in the methacholine challenge test. The latex allergic response in mice is unique in that direct challenge with latex antigen itself also resulted in a significant airway response.

Immune response and airway reactivity in wild and IL-4 knockout mice exposed to latex allergens

BACKGROUND

Natural rubber latex has been reported as a major cause of allergy and asthma in a number of individuals. One of the occupational groups most affected by latex allergy are the health care workers who are frequently exposed to natural rubber latex products in their patient care activities. The immunopathogenesis of latex allergy is not well understood. In order to understand the immune mechanism in latex allergy, we have developed a mouse model of latex allergy.

METHODS

Both wild-type and IL-4 knockout BALB/c mice were challenged intranasally with latex proteins and their immune responses, lung pathology, and airway reactivity were evaluated.

RESULTS

The total serum IgE and latex specific IgE, IgG1, and peripheral blood and lung eosinophil levels in wild type BALB/c mice were enhanced by the latex exposure, while no IgE or eosinophil were detected in IL-4 knockout mice. Latex-specific IgG1 levels in the sera were lower in IL-4 knockout animals compared to wild mice. However, latex-specific IgG2a antibody was higher in all the IL-4 knockout mice compared to wild type mice. Both the wild type and IL-4 knockout animals developed increased airway resistance after antigen challenge when compared to control animals, although the airway resistance response of IL-4 knockout animals was attenuated compared to the wild-type animals. The histology of the lungs of these two groups of animals was similar.

CONCLUSION

In spite of the differences in the immune responses in the two groups of mice, there were comparable lung inflammatory responses, suggesting a multifactorial pathogenetic mechanism.

A Sensitive ELISA for Pythium ultimum Using Polyclonal and Species-Specific Monoclonal Antibodies

A double-antibody sandwich indirect enzyme-linked immunosorbent assay (ELISA) was developed for the detection and quantification of Pythium ultimum. A polyclonal antibody produced to cell walls of P. ultimum was used as the capture antibody, while a P. ultimum-specific mono-clonal antibody (MAb E5) was used for recognition of the fungus. In the ELISA, culture extracts of 7 isolates of P. ultimum exhibited strong positive reactions, whereas none of the 37 isolates of other Pythium spp. and fungal genera had positive reactions. P. ultimum was detected by ELISA in roots of bean, cabbage, and sugar beet seedlings grown in pathogen-infested soil. ELISA optical density readings for infected bean and sugar beet root samples were highly correlated (r > 0.9) with infection levels determined by culturing the samples on water agar. The correlation between the two methods of testing cabbage roots was low, but all cabbage roots in which P. ultimum was detected by culturing were strongly positive in the ELISA. Samples of roots infected with P. irregulare and those with no Pythium infection did not react in the ELISA. The ELISA was highly sensitive; the fungus was detected in culture extracts diluted 1:5,000,000 and in roots with less than 1 infection per 100 cm root.

Detection of bovine herpesvirus 1 in the semen of experimentally infected bulls by dot-blot hybridisation, polymerase chain reaction and virus isolation

Two 18-month-old bovine herpesvirus 1 (BHV1)-seronegative bulls were inoculated experimentally with BHV1 via their prepuces. Semen collected at intervals was examined by optimised virus isolation, dot-blot hybridisation and the polymerase chain reaction (PCR) for detection of BHV1, and the infection was monitored serologically by using a virus neutralisation test. Antibodies were first detected 10 days after inoculation and were still present 40 days after inoculation. Semen collected from four to 40 days after inoculation was positive by PCR with Southern blot hybridisation whereas only the semen collected on day 4 was positive by dot-blot hybridisation, virus isolation and PCR with ethidium bromide staining. These results indicate that the bulls started to shed the virus in semen before they developed any detectable antibody. PCR with Southern blot hybridisation was the most sensitive of the three methods and detected virus for the longest period.

Comparison of dot blot hybridization, polymerase chain reaction, and virus isolation for detection of bovine herpesvirus-1 (BHV-1) in artificially infected bovine semen

Bovine semen samples spiked with bovine herpesvirus 1 (BHV-1) were used to compare dot blot hybridization, polymerase chain reaction (PCR), and virus isolation for detection of BHV-1 in bovine semen. The PCR amplification used primers targeting the BHV-1 thymidine kinase gene and a nucleic acid releasing cocktail (GeneReleaser); the PCR product was used as the DNA probe in dot blot hybridization; virus isolation was done in primary bovine fetal testis (BFT) cell cultures. Semen diluted 1:20 in tissue culture medium had the least cytotoxicity and inhibition of viral cytopathic effects in BFT cells, allowing detection of 1 TCID50/100 microL of BHV-1 suspension by virus isolation. The presence of foreign DNA such as bovine sperm DNA or salmon sperm DNA increased the sensitivity of dot blot hybridization in detecting BHV-1, allowing detection of 20,000 TCID50/100 microL of neat semen. The inhibition of PCR amplification of BHV-1 DNA in bovine semen was eliminated by diluting the samples 1:20 in tissue culture medium. The best PCR amplification was obtained when semen was diluted 1:20 and when a reaction buffer of pH 9.0, with 1.0 mM MgCl2 was used. Under these conditions, the PCR followed by ethidium bromide staining of agarose gels could detect 1 TCID20/100 microL of sample, whereas PCR followed by Southern blot hybridization could detect 0.01 TCID50/100 microL of sample.(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin-3 and encephalitogenic activity of SJL/J myelin basic protein-specific T cell lines

Myelin basic protein (MBP)-specific SJL/J T cells were cultured in normal growth medium or growth medium supplemented with 10% culture supernatant from WEHI-3 cells, a source of interleukin-3 (IL-3), or with recombinant IL-3. T cell lines cultured with IL-3 supplementation were more encephalitogenic compared to parallel lines cultured without this supplement. There was little difference in antigen-specific proliferative response or expression of cell surface markers CD3, CD4, CD8, IL-2R, or alpha/beta TCR in the parallel lines. Supernatant fluids from antigen-stimulated T cells from each cycle were tested for the presence of IL-2, IL-3, IL-4, granulocyte macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF alpha/beta) and transforming growth factor-beta (TGF beta). No significant difference in IL-2, IL-4, GM-CSF, TNF alpha/beta, or TGF beta levels were seen when supplemented and unsupplemented cultures were compared. Supernatant culture fluids contained an activity that was highly stimulatory for the IL-3-dependent mouse mast cell line, MC/9. This activity was attributable to a combination of at least three factors that varied in relative concentrations throughout the course of the experiments. Based on neutralization by monoclonal antibodies, MC/9 stimulating activity in early passage lines was attributable entirely to IL-3 and GM-CSF. The fraction of the MC/9 stimulatory activity that could be neutralized by monoclonal antibody to IL-3 decreased with increasing stimulation cycle while the fraction neutralized by anti-GM-CSF antibodies remained relatively constant. At the time that the lines lost encephalitogenicity, the activity neutralizable by anti-IL-3 had dropped to low levels in the culture supernatants; however, MC/9 stimulatory activity remained present in the supernatants. This was due to GM-CSF and a third unidentified factor.

Epitope specificity and TCR V beta gene utilization in the encephalitogenic response of B10.RIII(71NS)/SnJ mice

A high proportion of peptide 1-11 specific T cells from H-2u (V beta 8+, H-2u) mice express the V beta 8 TCR chain. Peptide 89-101 is immunodominant for B10.RIII (V beta 8+, H-2r) mice; thus, it was of interest to determine whether V beta 8 TCR would be over-represented in a population of peptide 89-101-specific T cells of this strain. Second, it was asked whether MBP peptides other than 89-101 would induce EAE in these mice. Of 70 B10.RIII(71NS)/SnJ mice immunized with mouse myelin basic protein (MBP), 32 of 41 males (78%) and 11 of 29 females (38%) showed clinical signs of experimental allergic encephalomyelitis (EAE). All mice immunized with peptide 89-101 showed clinical signs. One of six mice immunized with peptide 91-103 showed clinical signs, and 9 of 16 mice, all males, responded with EAE when immunized with peptide 38-88. No clinical EAE was observed in mice immunized with peptide 43-67, 68-88, 55-74, 1-37 or 1-20. A peptide 89-101-specific T cell line was established. At the initial stimulation the line was 29% V beta 8+ versus 21% in normal controls, and the line did not transfer EAE adoptively. After five in vitro stimulations, the percentage of V beta 8+ T cells had increased to 54%, and the line was encephalitogenic. Encephalitogenicity was partially blocked by anti-V beta 8 monoclonal antibody. Thus, over-representation of V beta 8+ TCR by encephalitogenic peptide-specific T cells is not limited to peptide 1-11-specific T cells from H-2u mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental allergic encephalomyelitis in susceptible and resistant strains of mice after adoptive transfer of T cells activated by antibodies to the T cell receptor complex

Lymphoid cells from normal and myelin basic protein (MBP)-immune PL/J, SJL/J and (SJL x PL)F1 hybrid mice were activated by in vitro culture with monoclonal antibodies specific for CD3 or specific T cell receptor (TCR) V beta chains. Lymphoid cells activated in this manner from MBP-immune animals did not readily transfer experimental acute encephalomyelitis (EAE) to naive syngeneic recipients in contrast to lymphoid cells from the same source cultured with concanavalin A (ConA) or myelin basic protein (MBP). However, recipients of anti-TCR antibody-activated MBP-specific blasts showed accelerated onset and increased severity of EAE following immunization with MBP as compared to unmanipulated control animals. Anti-TCR activated cells incorporated [3H]-thymidine at a level comparable to ConA or antigen-stimulated cells and secreted interleukin (IL)-2 at comparable levels Anti-TCR activated blasts were greater than 90% positive for CD3 and alpha/beta TCR, 60% CD4+ and 30% CD8+. PL/J or (SJL x PL)F1 recipients of anti-TCR-activated spleen cells from syngeneic normal mice also had more severe EAE than control mice following immunization with MBP. Non-responder C57BL/10SnJ mice could be converted to responders by infusion of anti-CD3 or anti-V beta 8 monoclonal antibody-treated syngeneic spleen cells taken from normal syngeneic unimmunized mice.