Lymphocyte transformation test in veterinary clinical immunology

Lymphocyte transformation test is a powerful tool in laboratory testing of immunologic competence of animals. The impaired function of the lymphocytes or presence of mitogenesis suppressing factors in the patient serum were detected by comparing lymphocyte transformation (expressed as thymidine incorporation) obtained in media containing either autologous, homologous, or fetal calf serum additions. Most valuable results were obtained by using at least two, preferably three, different phytomitogens: concanavlin A (Con A), pokeweed mitogen (PWM), and pl ytohemagglutinin (PHA) at optimal concentrations (Con A, 15 μg/ml, PWM and PHA, 5 μg/ml) and decreased concentrations (Con A, 5 μg/ml, PWM and PHA, 1 μg/ml). Mitogenesis induced by lipopolysaccharide was considerably smaller and not used routinely. With 2 × 10⁵ lymphocytes/well, the background count of unstimulated lymphocytes in autologous serum in healthy dogs was usually between 100 and 400 counts/min (CPM), in clinically healthy cattle and horses from 200 to over 2000 CPM. Higher CPM were rarely detected without clinical disease. Increased background counts were often associated with viral infections, leukemias and lymphoreticular hyperplasias, decreased background counts were associated with various diseases. The stimulation indexes (SI) of healthy animals in autologous serum with Con A, (5 μg/ml) or PWM or PHA (1 μg/ml) were in the range from 100 to 1000 in the dogs, in the tens for Con A and in hundreds for PWM and PHA in horses and cattle. Increased SI were present during the incubation period of various diseases. Decreased SI were associated with numerous infectious and lymphoreticular diseases and were caused by any of the following: (1) the presence of serum immunosuppressive factor(s) in the patient serum, (2) the decreased response of lymphocytes to mitogens, or (3) increased mitogenicity of lymphocytes due to unidentified serum factors in absence of phytomitogens.     

兽医微生物学与免疫学实验综合教学体系的构建

设计性和开放式的实验教学模式是各农业高校在建立独立的实验教学体系改革中的一种探索。为了满足高素质兽医人才的培养需求,本文在整合和优化兽医微生物学与免疫学实验内容的基础上,对如何改变验证性的传统教学模式,构建研究设计性综合实验教学体系进行了探讨。     

Mucosal immunology: overview and potential in the veterinary species

A large part of the immune system is dedicated to protection from infection at mucosal surfaces. The concept of the common mucosal immune system has been investigated in several veterinary species where traffic of mucosally activated lymphocytes from induction to effector sites has been demonstrated. The dominant isotype found in secretions of the upper respiratory tract and gut of normal healthy and diseased animals is IgA. B lymphocytes have a relatively short half-life and there is continuous production of IgA at these sites, which is achieved by constant secretion from T helper and epithelial cells of cytokines that are critical for B cell maturation and IgA secretion. Specific stimulation of mucosal immune responses using intranasal presentation of live and inactivated antigens (with adjuvants active at mucosal surfaces) has shown great promise for inducing protective immunity to respiratory pathogens.     

Laboratory techniques of veterinary clinical immunology: a review

Laboratory tests currently used or easily applicable in veterinary clinical immunology were reviewed in the following three categories: (1) tests detecting disorders in humoral immune response: serum protein screening tests, gammaglobulin estimation and complement testing; (2) tests detecting disorders in cellular immune response: phagocyte function tests and lymphocyte function tests; (3) tests detecting autoimmune disorders: detection of antinuclear antibodies, rheumatoid factor, autoimmune hemolytic diseases, and autoimmune organ and tissue disorders. The principles of the tests and the interpretations of the results are presented with the appropriate references.     

Transfection of genes encoding lymphocyte differentiation antigens: applications in veterinary immunology

The work conducted so far in this laboratory has demonstrated the application of the use of genes encoding lymphocyte differentiation molecules, in the isolation of homologous genes from other mammalian species, by the technique of cross-species DNA hybridization. The studies have also highlighted the use of transfection as a means of obtaining expression of genes, either from total genomic DNA or cloned in plasmids, which encode lymphocyte antigens. Preliminary work presented in this paper demonstrates the application of these technologies in the isolation and expression of genes for lymphocyte antigens from species in which the gene products have not been fully defined. We favour this approach because it may allow isolation and definition of important immunological molecules independently of the existence of specific antibodies. It therefore seems the most direct way to avoid the frustrating randomness in production of anti lymphocyte subset-specific monoclonal antibodies, and to shorten the time and effort needed to define the specificities of such reagents. Furthermore, the cDNA clones isolated from alternate species (in this case the bovine) have a use in classical immunological studies apart from the application of antibodies made to their products in veterinary immunology. That is, comparisons of the DNA sequences of lymphocyte differentiation antigens from different species provide much important information about structural or functional elements of evolutionarily conserved proteins involved in generation of immune responses.