Specific Migratory Dendritic Cells Rapidly Transport Antigen from the Airways to the Thoracic Lymph Nodes

Antigen transport from the airway mucosa to the thoracic lymph nodes (TLNs) was studied in vivo by intratracheal instillation of fluorescein isothiocyanate (FITC)-conjugated macromolecules. After instillation, FITC+ cells with stellate morphology were found deep in the TLN T cell area. Using flow cytometry, an FITC signal was exclusively detected in CD11cmed-hi/major histocompatibility complex class II (MHCII)hi cells, representing migratory airway-derived lymph node dendritic cells (AW-LNDCs). No FITC signal accumulated in lymphocytes and in a CD11chiMHCIImed DC group containing a CD8αhi subset (non–airway-derived [NAW]-LNDCs). Sorted AW-LNDCs showed long MHCIIbright cytoplasmic processes and intracytoplasmatic FITC+ granules. The fraction of FITC+ AW-LNDCs peaked after 24 h and had reached baseline by day 7. AW-LNDCs were depleted by 7 d of ganciclovir treatment in thymidine kinase transgenic mice, resulting in a strong reduction of FITC-macromolecule transport into the TLNs. Compared with intrapulmonary DCs, AW-LNDCs had a mature phenotype and upregulated levels of MHCII, B7-2, CD40, and intracellular adhesion molecule (ICAM)-1. In addition, sorted AW-LNDCs from FITC-ovalbumin (OVA)–instilled animals strongly presented OVA to OVA-TCR transgenic T cells. These results validate the unique sentinel role of airway DCs, picking up antigen in the airways and delivering it in an immunogenic form to the T cells in the TLNs

Allergen-induced changes in bone-marrow progenitor and airway dendritic cells in sensitized rats

Eosinophilic airway inflammation is orchestrated by T-helper (Th)-2 lymphocytes. We have previously demonstrated that dendritic cells (DC) are essential for the presentation of antigen to these Th2 cells leading to airway inflammation. Here, we have examined the presence of DC in the lungs, the kinetics of appearance, and the possible involvement of the bone-marrow progenitor for DC in a rat model of ovalbumin (OVA)-induced airway inflammation. Sensitized rats were exposed to 0, 1, 3, or 7 consecutive daily OVA aerosols. Control rats were sham sensitized and/or exposed to phosphate-buffered saline (PBS), and bronchoalveolar lavage (BAL) was performed 24 h after the last challenge. DC were identified in BAL fluid as low-density, low-autofluorescence, CD3 � , CD45RA � , OX62 � , OX6 � cells that had long surface extensions and strong costimulatory activity. Low but detectable amounts of BAL DC were seen in sensitized, unexposed animals. After three OVA exposures, the inflammatory infiltrate consisted of CD4 �-activated T cells, eosinophils, and monocytes. The number of BAL DC was significantly increased in OVA-sensitized/OVA-exposed animals compared with sham-sensitized or PBS-exposed animals. The kinetics of DC increase closely parallelled those in other inflammatory cells. Bone-marrow cells taken from the OVAsensitized and-exposed group were grown in the DC growth factor granulocyte macrophage colony-stimulating factor for 6 d and the yield of OX62 � OX6 � DC was 60 % higher compared with PBS-exposed o

Cytoplasmatische expressie van het humaan DNase I in eukaryote cellijnen /

Afstudeerwerk ingediend tot het behalen van de graad van gediplomeerde in de gespecialiseerde studie van de biomedische en klinische ingenieurstechnieke

Endogenously produced substance P contributes to lymphocyte proliferation induced by dendritic cells and direct TCR ligation

Substance P (SP) is an immunoregulatory tachykinin which augments antigen- and mitogen-induced lymphocyte proliferation via signaling through the neurokinin-1 receptor (NK1-R). Non-neuronal cells of the immune system such as monocytes, T lymphocytes and eosinophils can be a source of SP. We have investigated if antigen-presenting dendritic cells (DC) produce SP. DC were grown from bone marrow precursors using a cocktail of GM-CSF, IL-4 and Flt-3 ligand. Reverse transcriptase-PCR amplification using primers for the mouse preprotachykinin-A gene and direct DNA sequencing of amplified products from purified DC demonstrated the presence of the γ-transcript of the gene, coding for SP and neurokinin A. At the protein level, mouse DC expressed SP as determined by an enzyme immunoassay and confirmed by immunostaining. The functional role of endogenous SP release was determined. During the interaction with syngeneic or allogeneic DC, the addition of a specific NK1-R antagonist partly reduced proliferation in responding T lymphocytes. This was confirmed by using responders derived from NK1-R-deficient mice. In the absence of DC, proliferation of T cells induced by direct TCR ligation and soluble CD28 was partly dependent on signaling through NK1-R, revealing an autocrine effect of SP production by T cells. In conclusion, these results demonstrate that endogenously produced SP contributes to T cell proliferation induced by DC or TCR / CD28 stimulation.This work was sup-ported in part by the Concerted Research Initiative of theUniversity of Ghent (Project no. GOA 98-6) and by a grantfrom Zeneca, Belgium. B.N.L. and P.R.G. are recipients of ascholarship of the Fund for Scientific Research Vlaanderen.E.G.E. is supported by the Concerted Research Initiative ofthe University of Ghent. I.C.M. is supported by the FlandersInstitute for the Advancement of Scientific Research inIndustry (I.W.T.).Peer reviewe