Studies of immune tolerance in mice breast-fed by antigen-exposed lactating mothers

We obtained data on immune tolerance in mice breast-fed by antigen-exposed lactating mothers.

We have previously generated a monoclonal antibody, 2C44, that reacted to a peptide derived from the Leishmania LACK protein bound to I-Ad MHC class II molecules. We have successfully used the 2C44 mAb to visualize LACK-presenting DCs in mice infected with the L. major. In 2007, we have attempted to identify the APCs that are responsible for the development of immune tolerance in mice that have been breast-fed by antigen-exposed lactating mothers. Recent experiments performed in our laboratory have shown that the exposure of a mother to an airborne antigen during lactation impacts asthma development in their progeny. We found that airborne allergens were efficiently transferred from the mother to the neonate through the milk and that this transfer resulted in the development of antigen-specific tolerance. Breastfeeding-induced tolerance did not require the transfer of immunoglobulins, relied on the presence of TGF-beta during lactation and was mediated by regulatory CD4+ T lymphocytes. Adoptive transfer experiments of LACK-specific TCR transgenic T cells into newborn mice breastfed by LACK-exposed mothers demonstrated that LACK was readily processed and presented to T cells in the neonate.

We then investigated whether the immune status of the mother has an effect on the development of tolerance in the breast-fed mouse. We found that mice breastfed on allergen exposed allergic mothers were more resistant to allergic airway inflammation as compared to those breastfed on non allergic mothers. This phenomenon was demonstrated to be dependent on the presence of allergen-specific Immunoglobulins (Ig) in the breastmilk of allergic mothers and on the transfer of immunecomplexes across the intestinal barrier of the newborn. In order to identify the APCs that were responsible for the development of this state of immune tolerance, we aimed to generate a transgenic mouse that express a recombinant fluorescent protein in the mammary glands, an approach that should result in high levels of expression of the fluorescent protein in the milk. We thus should be able to detect the cells that capture, degrade and present this antigen to T cells. Since we had previously generated a monoclonal antibody, 2C44, that reacts to a peptide derived from the Leishmania LACK protein bound to I-Ad MHC class II molecules, we chose to use LACK as a model antigen in these experiments. We have thus prepared two plasmids coding for LACK linked to either eGFP or mCherry fluorescent proteins, under the control of the beta-casein promoter. These constructs have been injected into fertilized eggs and transgenic animals are expected for march 2009. The characterization of antigen presenting cells will be performed using FACS analysis or confocal microscopy.

• organism type
• Mus musculus,
• Leishmania major

• molecule type
• peptide,
• Major histocompatibility complex class II,
• Leishmania LACK protein,
• 2C44,
• T cell receptor,
• CD4

• cell type
• T cell

• experimental design type
• in vivo design experiment

created over 15 years ago (2 March 2009)    last modified over 13 years ago (28 September 2011)   [ RDF ]   [ RelFinder ]