Efecto de la Inmunización Intranasal con Toxina de Cólera y Extracto Total de Naegleria fowleri en la Activación de Células Dendríticas y Macrófagos en el Modelo de la Meningitis en Ratones BALB/c.

Abstract

The nose-associated lymphoid tissue (NALT) and cervical lymph nodes (CN) constitute organized lymphoid tissue; whereas the nasal passages (NP) (wall, side walls, turbinate and the roof of the nose) are the lymphoid tissue diffuse and both types of tissue provide protection to the nasal mucosa against infection by pathogens. It has been shown that cholera toxin used as an adjuvant enhances the protective immune response when administered with an antigen. In this work, we determined whether immunization with lysates of N. fowleri plus CT and subsequent challenge of are capable of activating macrophages and dendritic cells of the nasal epithelium of mice in the model of Primary amoebic Meningoencephalitis. By FACS we observed in immunized and control mice the expression of costimulatory molecules CD80 and CD86; these molecules increase significantly the expression in macrophages and DC of immunized mice with respect at the control, in NALT, CN and PN. Indirectly these results reflect a high uptake, processing and presentation of antigens of N. fowleri and CT to T cells; because of in others works we found activate T-CD4 lymphocytes by the detection of the activation molecules like CD-69 and CD-25. This is related directly with the high levels of antibodies IgG and IgA either local or systemic sites, reported for the same immunization protocol in others works. The macrophages participate as APC, however its role on the elimination of the antigen is very important for this reason we analyzed by immunohistochemistry some factors that indicate the activation of these cells such as MPO, MIF, TLR2 and TLR4. First when we incubated the slices of the nasal cavity with anti-MPO, a great number of trophozoites and inflammatory cells were positive for this antibody, principally in the lumen of the superior turbinate. N. fowleri have a protein like-MPO strongly expressed. The inflammatory cells were observed also strongly activated around of the trophozoites. For MIF we observed some positive cells in the lamina propria in the medium turbinate. Regard TLR-2 and TLR- 4, only few numbers of cells were localized in the lamina propria of the turbinates superior for TLR-2 and the lamina propria of the septum for TLR-4. The MPO enzyme is expressed when macrophages and PMN are activated and as is showed in the control was not observed inflammatory cells neither lamina propria nor lumen of the nasal cavity. MIF is a chemotactic factor for the macrophage and the positive stain for this cytokine could be indicating the migration of macrophages toward the lumen of the turbinates for the possible elimination of the trophozoites. With respect TLR-2 and TLR-4 is known that the function on macrophage is to recognize diacyl-lipopeptide and LPS respectively, when these receptors binds to the ligands, induce an inflammation state in the macrophages, although the label of this molecules is very low probably these cells are participating in the elimination of N. fowleri once they have reached the inflammation site. On the other hand, the macrophage when are activated by the immunization could be participating either presentation of antigen and elimination of this. Are necessary complementary studies to explain the immunomodulator effect of the immunization with CT and lysates of N. fowleri in the nasal cavity of the mice