[Proliferative response of peripheral blood mononuclear cells to the recombinant allergen BtM of the Blomia tropicalis housedust mite].

Allergic diseases are triggered when individuals genetically predisposed to developing an allergy (atopy) are exposed to sensitizing allergens. These allergens are captured and processed by antigen-presenting cells (APC) which presents them to T lymphocytes. Some of these allergens have a significant influence on the development of this type of disease and cause most of the symptoms in allergic individuals around the world. They are found in the feces of house dust mites, which have diverse and varied origin in several species, for example the Blomia tropicalis (Bt) mite. In Cartagena (Colombia), this highly prevalent mite has been a central object of study by the Institute of Immunological Research of the University of Cartagena, where several of its allergens have been cloned, sequenced and expressed as recombinant allergens. Moreover, their capacity to bind to IgE and the frequency of this process has been studied. The aim of the present study was to analyze the lymphoproliferative response of peripheral blood mononuclear cells (PBMC) in healthy and allergic individuals to one of the recombinant allergens of B. tropicalis, BtM. This response was studied in PBMC from six patients with allergy to Bt (positive cutaneous test to Bt extract), using a cellular proliferation technique, with incorporation of 3H thymidine at days 3 and 6 days of culture, and at three different concentrations of BtM. Notable among the results was the high proliferation produced by cells from patient JF018 at 3 days of stimulus (41.7 IE), with the lowest concentration of protein (100 microg/mL). Moreover, in all the experiments this concentration was the cause of most of the cell proliferation. In addition, some response to control LAC012 against glutathione-S-transferase (GST) was induced. In conclusion, the results of the present study demonstrate that the recombinant allergen BtM is able to induce a cellular response in the PBMC of patients allergic to Bt. Moreover, it is able to induce a response similar to that produced by natural allergens, because its pattern of response is similar to that shown by cells stimulated with Bt extract. These results also show that a process of anergy can be produced in cells when excess antigen is present. In some individuals (both allergic and nonallergic), GST is able to cause a proliferative response, indicating its sensitizing potential in these individuals.