RESUMO
Antigens of the nematode Nippostrongylus brasiliensis were fractionated by SDS-PAGE under reducing conditions, transferred electrophoretically onto nitrocellulose and converted to antigen-bound nitrocellulose particles for use in in vitro proliferation assays. Mesenteric lymph node cells from infected rats were analyzed for reactivity against the fractionated antigens, revealing a range of different molecular weight antigens. In addition, when supernatants from these cultures were assayed for IL3, further reactive antigens were detected. The results demonstrated that these approaches are useful for the identification of T-cell reactive components of a complex mixture of parasite antigens in helminth infections, where the cellular nature of protection is not well defined.
Assuntos
Antígenos de Helmintos/imunologia , Infecções por Nematoides/imunologia , Nippostrongylus/imunologia , Linfócitos T/imunologia , Animais , Immunoblotting , Ativação Linfocitária , Ratos , Ratos EndogâmicosRESUMO
Antigens of the nematode Nippostrongylus brasiliensis were fractionated by SDS-PAGE under reducing conditions, transferred electrophoretically onto nitrocelluose and converted to antigen-bound nitrocellulose particles for use in vitro proliferation assays. Mesenteric lymph node cells from unfected rats were analyzed for reactivity against the fractionated antigens, revealing a range of different molecular weight antigens. Ian addition, when supernatants from these cultures were assyed for IL3, further reactive antigens wee detected. The results demonstrated that these approaches are useful for the identification of T-cell reactive components of a complex mixture of parasite antigens in helminth infections, where the cellular nature of protection is not well defined
Assuntos
Ratos , Animais , Antígenos de Helmintos/imunologia , Técnicas In Vitro , Infecções por Nematoides/imunologia , Nippostrongylus/imunologia , Linfócitos T/fisiologia , Immunoblotting , Linfonodos/citologia , Ratos WistarRESUMO
We have previously shown that mast cells with the morphological and biochemical properties of mucosal mast cells (MMC) proliferate and mature in rat bone marrow cultures stimulated with factors from antigen or mitogen-activated T lymphocytes. Here we have used this system to explore the MMC hyperplasia which occurs in infections with gastrointestinal nematode parasites. Lymphocytes producing MMC-growth factor were present from day 10 onwards in N. brasiliensis-infected rats and mesenteric lymph nodes (MLN) were the major source of activated lymphocytes. When different tissues of normal rats were cultured in the presence of conditioned medium by far the greatest proliferation of MMC occurred in bone marrow, indicating an origin of MMC from haemopoietic precursors. Cultures of infected rat bone marrow yielded considerably greater numbers of MMC than cultures of normal rat bone marrow and experiments using semisolid culture media indicated that N. brasiliensis infection causes an increase in the frequency of MMC progenitors in the bone marrow. A scheme is put forward for the sequence of events occurring in vivo based on the results of these and other published experiments. The reasons for the restricted in vivo localization of MMC to the mucous membranes and associated lymph nodes is discussed. Finally we give the results of microspectrophotometric analysis which has shown that the cultured mast cell contain a non-heparin proteoglycan, thus adding a further feature to the list of MMC-like properties of these cells.
Assuntos
Mastócitos/patologia , Infecções por Nematoides/patologia , Animais , Medula Óssea/patologia , Diferenciação Celular , Divisão Celular , Técnicas de Cultura , Heparina/análise , Interleucina-2/biossíntese , Linfonodos/imunologia , Mastócitos/análise , Mastócitos/imunologia , Infecções por Nematoides/imunologia , Infecções por Nematoides/metabolismo , Nippostrongylus , Ratos , Baço/imunologiaRESUMO
A/SN mice infected with N. Brasiliensis showed depressed anti-DNP antibody responses following immunization with DNP-Asc in alum. The immunosuppression was only observed when infection preceded immunization by between 2 and 7 days, and was not achieved when the interval was extended to 10 days. The suppression lasted at least 50 days, and affected IgE levels more than IgG1 or IgG agglutinating anti-DNP antibodies. A high dose of infective larvae (500-1000 per mouse) was necessary to induce suppression. Use of low dose irradiation indicated a parasite-induced radiosensitive component of the mouse immune system which negatively regulated the anti-DNP IgE response. These results suggested that the parasite could induce suppression in an analogous manner to sequential antigen-induced suppression (AIS).
Assuntos
Tolerância Imunológica , Infecções por Nematoides/imunologia , Nippostrongylus/imunologia , Animais , Formação de Anticorpos , Dinitrofenóis/imunologia , Feminino , Imunização , Imunoglobulina E/biossíntese , Imunoglobulina G/biossíntese , Masculino , Camundongos , Camundongos EndogâmicosRESUMO
We present here a study of the relationship in time between the elevation of total serum IgE, the parasite-specific IgE response, and the potentiated IgE response to unrelated antigen which occurs in rats following infection with the worm parasite N. brasiliensis. During a first infection the potentiated IgE response (to egg albumin) and elevation of total IgE occur synchronously rising to a peak on days 12-14 after infection, with the fastest rate of increase occurring between days 8 and 10. N. brasiliensis-specific IgE rises to a peak some 2-3 weeks later when both total IgE and the potentiated response have largely declined. A strain difference is shown in that Wistar rats produce far lower levels of total and parasite-specific IgE than Hooded Listers. Events following reinfection differ in that total IgE rises more rapidly, very high levels being reached 6 days after reinfected together with a secondary specific IgE response to N. brasiliensis. The total IgE level, however, rises by a far greater factor than parasite-specific IgE and declines rapidly while the parasite-specific response declines slowly over many weeks. The egg albumin response is not repotentiated. It is proposed that the total IgE response and the potentiated IgE response which forms a small component of it results from the release of a non-specific IgE-stimulating factor produced by N. brasiliensis-specific T cells. In this scheme the same or similar cells are involved in the production of N. brasiliensis-specific IgE through a separate specific helper function.