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African trypanosomiases are parasitic diseases transmitted by tse-tse flies, considered as the main sanitary obstacle to animal production development in sub-Saharan Africa. However, if trypanosomiases have dramatic consequences on zebu (Bos indicus) populations, they have a weaker impact on the western African taurine (Bos taurus), which is known to be naturally tolerant to trypanosome infection. Mechanisms governing this trypanotolerant trait are still poorly understood, but today, recent postgenomic biotechnologies, such as the SAGE technique (serial analysis of gene expression) allow us to explore the full transcriptome. Twelve SAGE libraries were constructed from two trypanotolerant animals (N'Dama and Baoulé) and one susceptible species of cattle (the Sudanese zebu) during an experimental Trypanosoma congolense infection; 43,458 different tags were obtained at several particular points during the infection (before infection, at the maximum of parasitemia, the maximum of anemia, and at the end of the experiment after value normalization). Bioinformatics analyses highlighted some interesting gene variations with respect to the trypanotolerance status of the animal.

The low-affinity Fcγ receptor IIIb (FcγRIIIb and CD16b) is constituted by a unique FCGR3B polypeptide chain that comprises two extracellular immunoglobulin-like domains, and is expressed as a glycosylphosphatidyl inositol-anchored receptor on the neutrophils. The FCGR3B chain bears allotypes that define the human neutrophil antigen-1 (HNA-1 and NA) system involved in major post-transfusional reactions. FCGR3B is highly homologous to FCGR3A, which is expressed as a transmembrane receptor on natural killer cells and monocytes/macrophages. Its transcription products were not yet fully characterized. In the present work, we sequenced FCGR3B cDNAs with complete 3′ untranslated region from purified granulocytes of HNA-1b/HNA-1b (NA2/NA2) genotyped donors. We characterized two FCGR3B cDNAs of different lengths corresponding to two polyadenylation sites. This result was corroborated by data raised by serial analysis of gene expression (SAGE). FCGR3B allele polymorphisms, from this article [FCGR3B*02 (HNA-1b, NA2)] and from the literature, are described for the first time according to the IMGT standardized nomenclature and to the IMGT unique numbering for C-LIKE-DOMAIN (http://www.imgt.cines.fr). These rules, described in the IMGT Scientific chart, are based on the IMGT-ONTOLOGY concepts. IMGT allele alignments and IMGT Collier de Perles graphical two-dimensional representations are provided for the two Ig-like domains (or C-LIKE-DOMAINs) [D1] and [D2] of FCGR3B*02. The standardized description of FCGR3B allele polymorphisms was approved by the IMGT Nomenclature Committee (IMGT-NC) and is freely available in IMGT repertoire at IMGT, http://www.imgt.cines.fr.

Vitamin D and retinoids cooperate to inhibit the proliferation and induce the differentiation of human myelomonocytic U937 leukemia cells. In the present work, we investigated the role of TGF-β as an endogenous mediator of this process. We found that the TGF-β1 precursor began to accumulate in cell culture supernatants soon after the addition of 1α,25 dihydroxyvitamin D3 (VD) and retinoids. We used neutralizing antibodies (AbTGF-β) and antisense oligonucleotide (AS Oligo) to inhibit its possible effects. Our data demonstrated that AbTGF-β partially inhibit the expression of the differentiated phenotype, as assessed by measurement of phagocytic activity, response to the chemotactic peptide fMLP, and lysozyme secretion. AS Oligo was also inhibitory, and the effects of AS Oligo and AbTGF-β were cumulative. Cell growth inhibition induced by VD and retinoids was completely reversed, and differentiation was reduced by about 75% when both inhibitors were associated. Time course experiments based on the delayed addition of AbTGF-β and AS Oligo showed that TGF-β1 was required for cell differentiation 24 h after the addition of inducers. Studies on TGF-β receptors revealed that, while the expression of type II receptor was stable, the level of type I TGF-β receptor mRNA and the expression of the protein began to decline early during the differentiation process. As a whole, these results support the notion that an autocrine TGF-β pathway, activated by VD and retinoids in U937 cells, is involved in the early steps of the process leading to cell growth arrest and differentiation. J Cell Physiol 178:109–119, 1999. © 1999 Wiley-Liss, Inc.

RA induces the differentiation of myeloid leukemic cells both from patients and cell lines . The fact that differentiated cells loose their pro-liferative capacity provides an efficient approach for the treatment of acute promyelocytic leukemia by RA. Moreover a therapeutic effect extended to other fonns of leukemia is expected by using an appropriate synergistic combination between RA and other cell differentiating agents such as the biologically active form of vitamin D, la,25-dihy-droxyvitamin D

Haptoglobin (Hp) is a glycoprotein which is found in the serum of several animals. Its characteristic property is the ability to form with hemoglobin (Hb) a stable equimolecular complex Hp-Hb which Possess a peroxidase activity; this property allows a quantitative estimation of Hp [ 1 ] . The normal level of Hp varies according to the species: from 0.05 g/l in Bovidae and Cervidae, to 1.2 g/l in human. It always rises in any inflammatory state [2]. In the sheep, Hp is composed of a series of polymeric proteins, whose electrophoretic pattern is very similar to that of human Hp 2-2 [3]. Their mol. wts. range from lo5 to 10” [3]. They are formed in the human by combination in different numbers of two polypeptidic chains called (Y and 0 [4]. We have undertaken the purification of sheep Hp in order to study its structure. We have controlled the purification by using the Hp estimation after each stage. But, as we shall establish later, sheep Hp is easily altered: below pH 4 or above pH 6.5, it looses its ability to combine with Hb. For these reasons, the preparation of this protein in the native state is very difficult. Therefore, after two successive chromatographic purifications, we have used an immunological technique as a last step of purification. The method is based on the following fact: since the Hp level in normal sheep is very low, a rabbit immune-serum anti-normal-sheep serum contains a very small quantity of y-globulins anti-haptoglobin. After insolubilisation of these rabbit antibodies, affinity chromatography retains selectively proteins