ABSTRACT
BACKGROUND: An antigen is a small foreign substance, such as a microorganism structural protein, that may trigger an immune response once inside the body. Antigens are preferentially used rather than completely attenuated microorganisms to develop safe vaccines. Unfortunately, not all antigens are able to induce an immune response. Thus, new adjuvants to enhance the antigen's ability to stimulate immunity must be developed. OBJECTIVES: Therefore, this work aimed to evaluate the molecular-structure adjuvant activity of tannic acid (TA) coupled to a protein antigen in Balb/c mice. METHODS: Bovine serum albumin (BSA) was used as an antigen. The coupling of BSA and TA was mediated by carbodiimide crosslinking, and verified by SDS-PAGE. Forty-two Balb/c mice were divided into seven groups, including two controls without antigen, an antigen control, an adjuvant control, and two treatment groups. An additional group was used for macrophages isolation. A 30-day scheme was used to immunize the mice. The analysis of humoral immunity included immunoglobulin quantification, isotyping and antigen-antibody precipitation. The analysis of cell-mediated immunity included the quantification of nitric oxide from peritoneal macrophages and splenocytes' proliferation assay after treatment stimulation. RESULTS: No differences were found in the antibodies' concentration or isotypes induced with the conjugate or the pure BSA. However, an immunogenicity improvement (p < 0.05) was observed through the specific anti-BSA antibody titers in mice immunized with the conjugate. Besides, macrophage activation (p < 0.05) was detected when stimulated with the treatments containing TA. CONCLUSION: Tannic acid exhibited macrophages' activation properties. Moreover, when TA was incorporated into the structure of a protein antigen, such as BSA, an antibody specificity enhancement was observed. This was a consequence of antigen processing by activated antigen-presenting cells. These results showed the use of tannic acid as a novel candidate for vaccine molecular-structure adjuvant.
Subject(s)
Tannins , Vaccines , Mice , Animals , Antibody Specificity , Adjuvants, Immunologic/pharmacology , Immunity, Humoral , Mice, Inbred BALB C , Serum Albumin, Bovine/chemistryABSTRACT
BACKGROUND: Inhaled glucocorticoids are the most effective and potent drugs used to control the inflammatory bronchial reaction in patients with asthma. There are several research projects evaluating the use of immune modulators in the treatment of the asthma related inflammatory process. OBJECTIVE: To evaluate the effect of transfer factor in the treatment of pediatric patients with moderate persistent allergic asthma in terms of inhaled glucocorticoid dosing and time of using. PATIENTS AND METHODS: Randomized, double blind, placebo controlled pilot clinical trial in a cohort of pediatric patients (6-17 years old) with moderate persistent allergic asthma. Two groups were formed. Group one received transfer factor and group two was given placebo. Both groups received conventional therapy with inhaled budesonide and formoterol. Daily respiratory symptoms (cough during day, or at night, and wheezing episodes) were recorded in a personal diary. Spirometric evaluations were performed before enrolling patients, and at 1, 3 and 6 months after. RESULTS: Eleven patients were enrolled in each group. Patients in the transfer factor group showed a statistical significant reduction in the inhaled glucocorticoid doping since month 3, and this difference was maintained until the end of study. Patients on TF group showed also a non statistical significant improvement in spirometrical findings and also showed a better asthma control. CONCLUSIONS: Transfer factor helps to reduce inhaled glucocorticoids dose in patients with allergic rhinitis; however, studies with a larger number of patients should be done in order to obtain better results.
