Aitken, Ruth Mary

2018-05-14T10:20:28Z

2018-05-14T10:20:28Z

1972

The immunoglobulins of the chicken have been studied with particular reference to their synthesis and function.

Since information on the physico-chemical properties of normal immunoglobulins in the fowl was limited, the initial part of the work was concerned with the production of specific anti IgG and anti IgM antisera and further characterisation studies of these proteins including gel filtration and DEAE cellulose chromatography. Attempts were made to isolate other immunoglobulin classes and a third component - referred to as 7S α1 - was studied and some of its physico-chemical properties noted. It was not possible either by radioimmunoelectrophoresis or antiglobulin studies to demonstrate antibody activity in this serum component. Later, analyses of sera from bursectomised chickens where normal amounts of 7S α1 were present also indicated that this was not an immunoglobulin.

The experimental procedure of bursectomy was used to study immunoglobulin synthesis and function. A method for the surgical removal of the bursa of Fabricius in ovo was developed and is described in detail.

Serum IgG and IgM levels in normal birds and birds bursectomised as 17> 18 or 19 day old embryos were measured from hatching to adulthood and three distinct patterns of development were noted in the bursectomised birds - they were either deficient in both immunoglobulins, deficient in IgG with higher than normal levels of IgM or produced substantial amounts of both Ig types. IgG and IgM levels at 3 months of age were compared for birds bursectomised at 17» 18 or 19 days and a significant difference was noted in the numbers of birds deficient in IgM in the 17 day group as compared with the others. All groups showed marked inhibition in the development of IgG synthesis. These results are discussed in the light of current theories of the mechanism of development of immunocompetence

A long-term study of serum immunoglobulins in bursectomised birds showed an eventual decline to agammaglobulinaemia even in those birds with normal initial immunoglobulin levels.

The survival rates of bursectomised birds are compared with controls and studied in relation to immunoglobulin status. Possible reasons for differences noted in survival are suggested.

Specific antibody responses of normal and bursectomised birds to bovine serum albumin, sheep erythrocytes and live Salmonella gallinarum were measured and related to immunoglobulin synthesis.

The receptor function of immunoglobulin molecules on the surfaces of lymphocytes has been investigated. Immunoglobulin determinants have been demonstrated on the surface of bursa dependent lymphocytes but not thymus dependent lymphocytes by the mixed antiglobulin method. These results indicate that the surface receptors of "T" lymphocytes may not be immunoglobulin in nature, and possible methods for the detection and characterisation of these receptors are suggested, and initial attempts to do so described.

The literature on avian immune responses is reviewed and the most important findings in the present work discussed* Suggestions are made for further research in various areas of the work.

http://hdl.handle.net/1842/30070

The University of Edinburgh

Annexe Thesis Digitisation Project 2018 Block 18

Already catalogued

Studies on the synthesis and functions of immunoglobulins in the fowl

Thesis or Dissertation

Doctoral

PhD Doctor of Philosophy