Pieter J. M. Leenen

Learn More
Monocytes and cells of the dendritic cell lineage circulate in blood and eventually migrate into tissue where they further mature and serve various functions, most notably in immune defense. Over recent years these cells have been characterized in detail with the use of cell surface markers and flow cytometry, and subpopulations have been described. The(More)
Blood monocytes are well-characterized precursors for macrophages and dendritic cells. Subsets of human monocytes with differential representation in various disease states are well known. In contrast, mouse monocyte subsets have been characterized minimally. In this study we identify three subpopulations of mouse monocytes that can be distinguished by(More)
Molecular markers, especially surface markers associated with type II, cytokine-dependent, alternatively activated macrophages (aaMF), remain scarce. Besides the earlier documented markers, macrophage mannose receptor and arginase 1, we demonstrated recently that murine aaMF are characterized by increased expression of found in inflammatory zone 1 (FIZZ1)(More)
The early innate response after Mycobacterium bovis bacille Calmette-Guérin (BCG) vaccination is poorly characterized but probably decisive for subsequent protective immunity against tuberculosis. Therefore, we vaccinated mice with fluorescent BCG strains in the ear dorsum, as a surrogate of intradermal vaccination in humans. During the first 3 days, we(More)
The characterization of early branch points in the differentiation of leukocytes requires identification of precursor cells in the bone marrow. Recently, we produced two monoclonal antibodies, ER-MP12 and ER-MP20, which in two-color flow-cytometric analysis divide the murine bone marrow into six defined subsets. Here we show, using fluorescence-activated(More)
This immunohistochemical study describes the infiltration pattern of monocytes-macrophages and dendritic cells during the development of insulitis and diabetes in the NOD mouse. A panel of monoclonal antibodies (MoAbs) was used to analyze pancreases of nondiabetic (glucosuria negative) male and female NOD mice at 3, 7, 10, and 17 weeks of age. BALB/c female(More)
In this review, we present and discuss a selected panel of antibody-defined markers expressed during different stages of mouse macrophage development. We distinguish four categories of markers, which are characteristic of: (1) macrophage precursors and immature macrophages (ER-MP12, ER-MP20, ER-MP54, ER-MP58); (2) mature macrophages in general (F4/80, BM8,(More)
The aim of the present study was the phenotypical analysis of early stages in macrophage (M phi) differentiation. For this purpose, we produced a panel of syngeneic rat hybridomas, which secreted antibodies (mAb) against M phi precursor antigens. As immunogens we used immortalized M phi precursors (P.J. M. Leenen et al., Eur. J. Immunol. 1990, 20: 15). We(More)
In the normal mouse spleen, two distinct populations of dendritic cells (DC) are present that differ in microanatomical location. The major population of marginal DC is found in the "marginal zone bridging channels" and extends into the red pulp. The interdigitating cells (IDC) are localized in the T cell areas in the white pulp. The aim of the present(More)
Microbes use numerous strategies to invade the central nervous system. Leukocyte-facilitated entry is one such mechanism whereby intracellular pathogens establish infection by taking advantage of leukocyte trafficking to the central nervous system. Key components of this process include peripheral infection and activation of leukocytes, activation of(More)