A metabolizable adjuvant: clinical trial of grass pollen‐tyrosine adsorbate

The low molecular weight dialyzable fraction (D) prepared from the aqueous extract of Kentucky Blue Grass pollen was shown to suppress the formation of IgE antibodies in rats immunized with the nondialyzable fraction (R). In an attempt to establish the nature of the constituents responsible for this suppression, D was fractionated by gel filtration through Sephadex G-25. The first fraction eluted (D_I) elicited skin reactions in rats sensitized with a rat reaginic serum to R and also gave a precipitate with a rabbit antiserum to R. A later fraction (D_III) was devoid of these two properties. To investigate the effects of these fractions on the antibody response, rats received either D_I or D_III, administered in saline, prior to their immunization with R in presence of aluminum hydroxide. Pretreatment with D_I resulted in a reduction of IgE antibody levels as compared with the IgE antibody response in control animals which had received pretreatment only with saline; however, pretreatment with D_I did not affect the anti-R-hemagglutinating titers. In contrast, pretreatment with D_III enhanced both the IgE and the hemagglutinating antibodies. Hence, it is concluded that the composite fraction D contains one group of constituents capable of suppressing and another of enhancing the IgE antibody response.

Section: Introductionmentioning

confidence: 99%

Modulation of the IgE Antibody Response in Rats to Kentucky Blue Grass Pollen Allergens

Ekramoddoullah¹,

Kisil²,

Sehon³

1977

“…Attention has been directed in this laboratory for some time to the development of L-tyrosine as an ad juvant [I, 2,6,7], This amino acid is a normal consti tuent of blood, occurring at a concentration of ap proximately 10 mg/1. A useful property of tyrosine is its low solubility (450 mg/1) in aqueous solution at neutral pH values.…”

Section: Introductionmentioning

confidence: 99%

<i>L</i>-Tyrosine as an Immunological Adjuvant

Wheeler¹,

Moran²,

Robins³

et al. 1982

A series of experiments has been carried out to investigate the adjuvant properties of the amino acid L-tyrosine in laboratory animals. Adsorption of various allergenic materials to L-tyrosine was found to enhance the induction of IgG antibodies, but no unusual propensity to stimulate IgE antibody or delayed hypersensitivity was observed. Administration of the amino acid at a site remote from the allergen was found not to augment antibody production. This, together with evidence of reduced bioavailability of the tyrosine-adsorbed allergen, suggested that the adjuvant activity observed resulted from a short-term depot effect.

“…Glutaraldehyde-treated grass pollen extracts have themselves been able to satisfy these two requirements, though to increase the safety mar gin in therapy and to give some adjuvant activity, they have been incor porated into a metabolisable adjuvant, the amino acid L-tyrosine [14,15,19].…”

Section: Discussionmentioning

confidence: 99%

Chemical Modification of Crude Timothy Grass Pollen Extract

Aw¹,

Pm²,

Dm³

1976

The effects have been studied of three different chemical modifications of timothy grass pollen extract on various immunological properties. The ability to induce IgG antibody with specificity for native antigen was least affected by glutaraldehyde treatment; IgE antibody production was reduced to a similar extent by all three modifications; there was no increase in IgM production; delayed reactions were reduced. New antigenic determinants were introduced by all the modifications, but the effect was minimal following glutaraldehyde treatment. The significance of these results and the potential application of modified allergen in hyposen-sitisation therapy are discussed.