An Investigation of the Allergens of Ascaris lumbricoides Using a Radioallergosorbent Test (Rast) and Sera of Naturally Infected Humans: Comparison With an Allergen for Mice Identified by a Passive Cutaneous Anaphylaxis Test

Abstract

The identification of those components of Ascaris lumbricoides (var. suum) body fluid (ABF) which are IgE-inducing antigens (allergens) was found to depend on the type of assay used. By use of the radioallergosorbent test and sera from humans naturally infected with A. lumbricoides, it was found that ABF contains a range of allergens with a variety of isoelectric points and molecular weights.Some cross-reactions were demonstrated between the allergens of A. lumbricoides and Toxocara canis. On the other hand, when a passive cutaneous anaphylaxis assay was used with sera from mice sensitized by nasal inhalation of ABF plus Bordetella pertussis vaccine, it was found that only one relatively pure fraction of ABF was involved. This consisted of some of the largest protein molecules in ABF: it had a molecular weight of approximately 360000 (subunits 140000 and 220000), an isoelectric region of 8·0-8·4, and was clearly very different from the allergens isolated from ABF by other workers.ABF and its fractions need to be freshly prepared and to be kept in the presence of reducing agents to avoid rapid deterioration and irreproducibility of some results.The relatively pure allergen fraction of ABF, isolated after identification by the passive cutaneous anaphylaxis assay and tested in mice, was found to be T cell-stimulating but was non-mitogenic. Access to the circulation after intranasal administration appeared to be highly restricted.

Isolation of <i>Ascaris suum</i> Components Which Suppress IgE Antibody Responses

“…It should be mentioned, however, that some high-MW (360,000) allergens have also been identified in man, using sera from naturally infected individuals [34,35]. At the present, it is not known why these components fail to trig ger a more prominent IgE response in animal models.…”

Attempts to induce resistance in mice to Schistosoma japonicum and Schistosoma mansoni by exposure to crude schistosome antigens plus cloned glutathione‐S‐transferases

“…(and also s.c.) together with BPV. With other antigens, this manipulation in appropriately anaesthetized mice results virtually in a quantitative deposition of antigens into the lungs (at least transiently) and induction of immunogiobulin E (IgE) antibodies (7). It can be seen from Table 6 that no resistance to infection was demonstrated in mice repeatedly exposed intranasally to crude antigens and BPV.…”

Allergenicity of Concanavalin A in Mice

“…BPV increased the potency of low doses of Con A given i.n. and this may in part result from the fact that BPV appears to increase the access of allergen to inflamed [17] lung tissues [27].…”

“…No in vitro mitogenicity was observed. However, the known persistence of Con A in subcuta neous injection sites [35], and the highly re stricted systemic dissemination of an A. suum allergen after intranasal administra tion [27], hint at the possibility that induc tion by relatively fixed antigen in subcuta neous and submucosal sites is important in promoting reagin responses. In this paper we present data on the striking effects of route of injection of Con A on anti-Con A reagin responses, the T cell dependence of the response, mouse strain variations, and induction of antihapten reagin responses to haptenated Con A injected without the wi dely-used adjuvants, Bordetella pertussis and aluminium hydroxide.…”