Bovine antibody dependent cell-mediated cytotoxicity (ADCC) effector cells

ADCC effector cells from bovine blood were separated by centrifugation, adherence and rosetting techniques. Each enriched cell population, peripheral blood mononuclear cells (PBM), null lymphocytes, monocytes and neutrophils, was then examined for its capacity to mediate ADCC. Utilizing heterologous sensitizing antisera it was found that monocytes had approximately twice the ADCC activity of null lymphocytes and that neutrophils had essentially no activity. However, when homologous sensitizing antisera were used it was found that neutrophils possessed the greatest activity followed by monocytes and null cells. Results confirm the existence of an ADCC active null lymphocyte in the bovine.     

Morphological observation of canine natural killer cells mediated cytotoxicity.

The cytotoxic effects of canine NK cells on CL-1 target cells were examined by scanning electron microscopy (SEM). NK cell mediated cytotoxicity on CL-1 target cells was detected by 51Cr release assay. SEM showed that a canine NK cell extended projections to the CL-1 target cell. Furthermore, the surface of CL-1 target cells changed a mesh-like structure. Therefore, the cytotoxic effects of canine NK cells on CL-1 target cells were morphologically demonstrated.     

Inflammatory cytokines and antigen presenting cell activation

Immune responses are stimulated in response to threats against health. In animals, defense against infectious agents, particularly rapidly growing viruses and bacteria, requires an immediate response to limit growth and dissemination, and then stimulation of a more prolonged, specific immunity to prevent re-infection. The process by which animals meet the dual needs of an immediate response to danger and initiation of long-term protection is substantially influenced by inflammatory cytokines produced primarily by macrophages and professional antigen presenting cells (APCs). Inflammatory cytokines mobilize the immune system in response to danger and increase the efficiency of an immune response as effectors of APC function. Here we review the evidence for the involvement of inflammatory cytokines in immune induction and as mediators of APC activity, with a particular emphasis on swine and on the induction of immunity at mucosal surfaces. The vast majority of infections occur at mucosal surfaces of the enteric, respiratory and reproductive tracts, and induction of protective immunity at these sites is particularly challenging. Induction of immunity at mucosal surfaces of the small intestine is greatly facilitated by the oral adjuvant, cholera toxin (CT). CT potentiates inflammatory cytokine and costimulatory molecule expression in macrophages, and stimulates humoral and cell-mediated immune responses both locally and systemically. These observations are consistent with the hypothesis that activation of APCs is a key step in the induction of antigen-specific immunity, and that inflammatory cytokine expression is a hallmark of activated APC function. The efficacy of vaccine adjuvants, particularly in the context of mucosal immunity, may be determined by their ability to induce a controlled inflammatory response in gut-associated lymphoid tissue, characterized by the expression of various costimulatory molecules and inflammatory cytokines. Thus, elucidation of the patterns of inflammatory cytokine expression and features of APC activation will help to facilitate the rational development of more efficacious vaccines.     

Detection of Infectious Bovine Rhinotracheitis (IBR) by Immunofluorescence

Infectious bovine rhinotracheitis can be readily and accurately diagnosed by direct fluorescent antibody techniques on infected bovine embryo kidney monolayers. Non-specific fluorescence was encountered in direct observation of bovine nasal secretions and cotyledon impressions.     

Bovine superfetation by natural conception secondary to an embryo transfer pregnancy

There was only one embryo transferred to the recipient female. There was no chance for natural service to occur from 21 days prior to the transfer of the embryo to 31 days after the transfer of the 7 day old blastocyst. The surrogate female was palpated as being 38 days pregnant 31 days after the transfer of a 7 day old embryo by an experienced professional before being exposed to the natural service sire. The second fetus was of a different sex than the first and was approximately 60 days less mature. All other pregnancies within this well managed herd were accounted for and no other cows calved within the area close to that time. The remaining recipients carried pregnancies to the approximate expected calving date. Conclusion. This case report should support earlier evidence that superfetation in the bovine can and does occur.     

Bovine respiratory syncytial virus (BRSV): a review

Bovine respiratory syncytial virus (BRSV) infection is the major cause of respiratory disease in calves during the first year of life. The study of the virus has been difficult because of its lability and very poor growth in cell culture. However, during the last decade, the introduction of new immunological and biotechnological techniques has facilitated a more extensive study of BRSV as illustrated by the increasing number of papers published. Despite this growing focus, many aspects of the pathogenesis, epidemiology, immunology etc. remain obscure. The course and outcome of the infection is very complex and unpredictable which makes the diagnosis and subsequent therapy very difficult. BRSV is closely related to human respiratory syncytial virus (HRSV) which is an important cause of respiratory disease in young children. In contrast to BRSV, the recent knowledge of HRSV is regularly extensively reviewed in several books and journals. The present paper contains an updated review on BRSV covering most aspects of the structure, molecular biology, pathogenesis, pathology, clinical features, epidemiology, diagnosis and immunology based on approximately 140 references from international research journals.     

Bovine leukocyte adhesion deficiency (BLAD): a review

Bovine leukocyte adhesion deficiency (BLAD) in Holstein cattle is an autosomal recessive congenital disease characterized by recurrent bacterial infections, delayed wound healing and stunted growth, and is also associated with persistent marked neutrophilia. The molecular basis of BLAD is a single point mutation (adenine to guanine) at position 383 of the CD18 gene, which caused an aspartic acid to glycine substitution at amino acid 128 (D128G) in the adhesion molecule CD18. Neutrophils from BLAD cattle have impaired expression of the beta2 integrin (CD11a,b,c/CD18) of the leukocyte adhesion molecule. Abnormalities in a wide spectrum of adherence dependent functions of leukocytes have been fully characterized. Cattle affected with BLAD have severe ulcers on oral mucous membranes, severe periodontitis, loss of teeth, chronic pneumonia and recurrent or chronic diarrhea. Affected cattle die at an early age due to the infectious complications. Holstein bulls, including carrier sires that had a mutant BLAD gene in heterozygote were controlled from dairy cattle for a decade. The control of BLAD in Holstein cattle by publishing the genotypes and avoiding the mating between BLAD carriers was found to be successful. This paper provides an overview of the genetic disease BLAD with reference to the disease in Holstein cattle.     

Bovine torovirus (Breda virus) revisited

Bovine torovirus (BoTV) is a pleomorphic virus with a spike-bearing envelope and a linear, non-segmented, positive-sense single-stranded RNA genome. This kidney-shaped virus is associated with diarrhea in calves and apparently has a worldwide distribution. This review provides details of the history and taxonomy of BoTV since its discovery in 1979. Information about virion morphology and architecture, antigenic and biological properties, viral genome, protein composition, thermal and chemical stability, and pH and proteolytic enzymes resistance is also summarized. A major focus of this review is to postulate a possible epidemiological cycle for BoTV, based on epidemiological data obtained in our studies and other published data, and progressing from the newborn calf to the adult animal. The distribution, host range, pathogenesis, disease and clinical signs (under experimental and natural exposure), pathology, diagnosis, prevention, treatment and control of BoTV infections are also described. In addition, a discussion of the zoonotic implications of torovirus-like particles detected in patients with gastroenteritis that resemble and cross-react with BoTV is presented. Hopefully, the findings described here will alert others to the existence of BoTV in cattle and its contribution to the diarrheal disease complex. This review also highlights the need for continual vigilance for potential zoonotic viruses belonging to the order Nidovirales, such as the SARS coronavirus.     

Influence of different tumour types on natural cytotoxicity (NK cell activity) and mitogen-induced lymphocyte proliferation in isolated blood lymphocytes from 110 dogs with tumours

The cell-mediated immune response of blood lymphocytes from 110 untreated dogs with different tumours was evaluated. The influence of different tumour types on the cellular immune system was examined by assessing the percentage of isolated large granular lymphocytes (LGL), in vitro natural cytotoxicity and mitogen-induced lymphocyte proliferation. Although the overall natural cytotoxicity of dogs with different tumours was decreased, the overall difference from control values was not statistically significant. However, mitogen-induced lymphocyte proliferation was significantly depressed in dogs with tumours in comparison with the controls. Dogs with mammary carcinomas showed significantly lower natural cytotoxicity than controls and dogs with myeloid neoplasms showed significantly lower mitogen-induced lymphocyte proliferation. Abnormalities exist not only in natural cytotoxicity but also in mitogen-induced lymphocyte proliferation. For the dog, this is the first study to assess the influence of different tumours using a combined evaluation of natural cytotoxicity and mitogen-induced lymphocyte proliferation in such a large number of animals.     

Cell surface markers of the canine natural killer (NK) cell

Studies were performed to determine which of several cell surface markers are expressed on canine peripheral blood leukocyte (PBL) natural killer (NK) cells. Chromium-51 release assays showed a decrease in NK activity after depletion of PBL by carbonyl iron ingestion and adherence to IgG-antibody-coated ovine erythrocytes (EA gamma) and to IgM-antibody-complement-coated ovine erythrocytes (EA mu C). Effector cell adherence to and subsequent lysis of canine thyroid adenocarcinoma (CTAC) target cell monolayers provided direct visual identification of the putative canine NK cell. These surface immunoglobulin-negative cells, individually identified by their physical adherence to dead CTAC target cells, failed to form nonimmune rosettes with guinea pig erythrocytes or rosettes with EA mu or EA mu C. However, 39.0 +/- 4.2% of these adherent cells formed rosettes with EA gamma and 73.3 +/- 0.8% expressed the canine T-lymphocyte marker, Thy-1.     

Bovine interleukin 2 (IL-2) production and activity on bovine and murine cell lines

Long-term growth of T cell cultures requires addition of Interleukin 2 (IL-2). In order to maintain bovine cultures, optimal conditions for bovine IL-2 production were defined using peripheral blood mononuclear cells (PBM). Irradiation and preculture enhanced IL-2 production possibly by reducing suppressor activity. IL-2 activity was also detected in Bovine Herpesvirus Type 1-stimulated cultures. Unlike mitogen-stimulated cultures, a wide variation in IL-2 activity was seen between supernatants produced by virus-stimulated cells from different animals indicating the clonal nature of antigen specific cells from individuals. Bovine IL-2-dependent cells used to quantitate IL-2 activity were characterized as: PNA, esterase negative, H4+ (anti Ia-like), B29+ (anti-pan T cell), and C5- (anti-monocyte). The observations that bovine IL-2 can maintain activated murine cells, CTLL-20 and HT-2, could lead to the replacement of rat IL-2 with bovine IL-2 in long-term murine cultures. Conditions described here result in large volumes of active medium.     

牛海绵状脑病

牛海绵状脑病（ｂｏｖｉｎｅ　ｓｐｏｎｇｉ－ｆｏｒｍ　ｅｎｃｅｐｈａｌｏｐａｔｈｙ， ＢＳＥ），又称“疯牛病”，是一种成年牛致命性神经系统性疾病，是根据当时病畜特殊的变性病变而命名的（ＢＳＥ），它是由一种非常规致病因子引起的一种亚急性海绵状脑病。该病的主要特生是牛脑发生海绵状病变，并伴随大脑功能退化，临床表现为神经质、运动失调、痴呆和死亡。能够表现这种症状的疾病还有羊的痒病、人的库鲁氏病和人的克雅氏病（ＣＪＤ）等。 该病于１９８５年４月在英国阿什福特农场首次发现，１９８６年开始命名为ＢＳＥ。当１９９…     

Bovine herpesvirus type 4: a special herpesvirus (review article)

This paper summarizes the history of and information on bovine herpesvirus type 4 (BoHV-4) from the first isolation to the most recent results. For almost twenty years BoHV-4 has been considered a typical herpes 'orphan' virus, which infects several species but causes no illness. The latest experiments revealed the close relationship of this virus with the immune system and other tissues. The virus was even considered as a possible candidate for a vector vaccine. BoHV-4 as a strange herpesvirus has several features which are not characteristic of other herpesviruses, such as several latency sites, persistence in serum, dividing cells necessary for virus replication, and the wide host range. In addition to describing the main features of the virion, replication, clinical signs, nomenclature problems, this review intends to concentrate on the new and strange results coming out from several laboratories worldwide. It is also suggested that because the virus combines several properties of various herpesvirus subfamilies and because of its close relationship with the immune system, it may deserve further attention as a representative of a potentially new genus within the Gammaherpesvirinae subfamily.