T and B lymphocytes in the brains of dogs with concomitant seropositivity to three pathogenic protozoans: Leishmania chagasi, Toxoplasma gondii and Neospora caninum

Background: Visceral leishmaniasis is a disease with great variability regarding the clinical manifestations in humans and dogs. Chronically infected dogs may develop neurological disorders, however, there are few reports that characterize the lesions and make clear the pathogenesis of the canine cerebral leishmaniasis. Concomitant with Leishmania chagasi, dogs may be infected by opportunistic pathogens, such as Toxoplasma gondii and Neospora caninum, which may contribute to the occurrence of lesions in the central nervous system. Hence, we aimed to compare the T and B lymphocytes population in the brains of infected dogs with seropositivity to L. chagasi, T. gondii and N. caninum concurrently (n = 24), seropositivity only to L. chagasi (n = 31), and seropositivity to T. gondii and N. caninum (n = 16). Uninfected dogs were used as control (n = 10). Results: Inflammatory lesions, characterised by mononuclear cell accumulation, composed mainly of CD3+ T lymphocytes predominated in several encephalic regions of the dogs from all the three infected groups, with no difference among them (P = 0.0004), whereas CD79α+ B lymphocytes were detected in very small intensity and presented no difference among groups (P = 0.5313). Furthermore, no association among diseases was detected at the serological enquire. Conclusions: We demonstrate that the peripheral infection by L. chagasi per se can promote the influx of lymphocytes within the nervous milieu as occurs during Toxoplasma and Neospora infections, and the concomitant seropositivity against these pathogens does not exacerbate the inflammatory brain lesions. Therefore, these findings give additional support that the brain should be included in the list of organs affected by visceral leishmaniasis and that even asymptomatic infected dogs may develop brain lesions. © 2013 Sakamoto et al.; licensee BioMed Central Ltd.

B lymphocyte involvement in ankylosing spondylitis: the heavy chain variable segment gene repertoire of B lymphocytes from germinal center-like foci in the synovial membrane indicates antigen selection

The synovial membrane (SM) of affected joints in ankylosing spondylitis (AS) is infiltrated by germinal center-like aggregates (foci) of lymphocytes similar to rheumatoid arthritis (RA). We characterized the rearranged heavy chain variable segment (VH) genes in the SM for gene usage and the mutational pattern to elucidate the B lymphocyte involvement in AS.

Étude de la migration des populations de lymphocytes B du sang de patients infectés par le virus d’immunodéficience humaine (VIH)

La dérégulation du compartiment de cellules B est une conséquence importante de l’infection par le virus de l’immunodéficience humaine (VIH-1). On observe notamment une diminution des nombres de lymphocytes B sanguins ainsi qu’une variation des fréquences relatives des différentes populations de lymphocytes B chez les individus infectés par rapport aux contrôles sains. Notre laboratoire a précédemment démontré l’implication des cellules dendritiques dans la dérégulation des lymphocytes B via la roduction excessive de BLyS/BAFF, un stimulateur des cellules B. De plus, lors l’études menées chez la souris transgénique présentant une maladie semblable au SIDA, et chez la souris BLyS/BAFF transgénique, l’infection au VIH-1 fut associée à une expansion de la zone marginale (MZ) de la rate. De façon intéressante, nous observons chez les contrôleurs élites une diminution de la population B ‘mature’ de la MZ. Il s’agit du seul changement important chez les contrôleurs élites et reflète possiblement un recrutement de ces cellules vers la périphérie ainsi qu’une implication dans des mécanismes de contrôle de l’infection. Pour tenter d’expliquer et de mieux comprendre ces variations dans les fréquences des populations B, nous avons analysé les axes chimiotactiques CXCL13-CXCR5, CXCL12-CXCR4/CXCR7, CCL20-CCR6 et CCL25-CCR9. L’étude longitudinale de cohortes de patients avec différents types de progression clinique ou de contrôle de l’infection démontre une modulation des niveaux plasmatiques de la majorité des chimiokines analysées chez les progresseurs rapides et classiques. Au contraire, les contrôleurs élites conservent des niveaux normaux de chimiokines, démontrant leur capacité à maintenir l’homéostasie. La migration des populations de cellules B semble être modulée selon la progression ou le contrôle de l’infection. Les contrôleurs élites présentent une diminution de la population B ‘mature’ de la MZ et une augmentation de la fréquence d’expression du récepteur CXCR7 associé à la MZ chez la souris, suggérant un rôle important des cellules de la MZ dans le contrôle de l’infection au VIH-1. De façon générale, les résultats dans cette étude viennent enrichir nos connaissances du compartiment de cellules B dans le contexte de l’infection au VIH-1 et pourront contribuer à élaborer des stratégies préventives et thérapeutiques contre ce virus.

Non-coding transcript in T cells (NTT): Antisense transcript activates PKR and NF-kappa B in human lymphocytes

T cell activation is a complex process involving many steps and the role played by the non-protein-coding RNAs (ncRNAs) in this phenomenon is still unclear. The non-coding T cells transcript (NTT) is differentially expressed during human T cells activation, but its function is unknown. Here, we detected a 426 m NTT transcript by RT-PCR using RNA of human lymphocytes activated with a synthetic peptide of HIV-1. After cloning, the sense and antisense 426 nt NTT transcripts were obtained by in vitro transcription and were sequenced. We found that both transcripts are highly structured and are able to activate PKR. A striking observation was that the antisense 426 nt NTT transcript is significantly more effective in activating PKR than the corresponding sense transcript. The transcription factor NF-kappa B is activated by PKR through phosphorylation and subsequent degradation of its inhibitor I-kappa B beta. We also found that the antisense 426 nt NTT transcript induces more efficiently the degradation Of I-kappa B beta than the sense transcript. Thus, this study suggests that the role played by NTT in the activation of lymphocytes can be mediated by PKR through NF-kappa B activation. However, the physiological significance of the activity of the antisense 426 nt NTT transcript remains unknown. (c) 2007 Elsevier Inc. All rights reserved.

A soluble form of CD83 is released from activated dendritic cells and B lymphocytes, and is detectable in normal human sera

CD83 is an inducible glycoprotein expressed predominantly by dendritic cells (DC) and B lymphocytes. Expression of membrane CD83 (mCD83) is widely used as a marker of differentiated/ activated DC but its function and ligand(s) are presently unknown. We report the existence of a soluble form of CD83 (sCD83). Using both a sCD83-specific ELISA and Western blotting, we could demonstrate the release of sCD83 by mCD83(+) B cell and Hodgkin's disease-derived cell lines, but not mCD83(-) cells. Inhibition of de novo protein synthesis did not affect the release of sCD83 during short-term (2 h) culture of cell lines although mCD83 expression was significantly reduced, suggesting sCD83 is generated by the release of mCD83. Isolated tonsillar B lymphocytes and monocyte-derived DC, which are mCD83(low), released only low levels of sCD83 during culture. However, the differentiation/activation of these populations both up-regulated mCD83 and increased sCD83 release significantly. Analysis of sera from normal donors demonstrated the presence of low levels (121 +/- 3.6 pg/ml) of circulating sCD83. Further studies utilizing purified sCD83 and the analysis of sCD83 levels in disease may provide clues to the function and ligand(s) of CD83.

Suidés et tayassuidés du burdigalien V-a et du langhien V-b de lisbonne

Teeth and astragali were used for a biometrical study concerning suids from V-a (upper Burdigalian) and V-b (Langhian) divisions from Lisbon's Miocene series. The Hyotherium (V-b) are identical to those from french localities, hence they all belong in the same species H. soemmeringi. Bunolistriodon populations from V-a and V-b are homogenous; no significant difference between them has been found, inspite of different geological age. Both may be ascribed to B. lockharti. No evolutive trend was detected. The presence of another form close to the north african B. massai could not be confirmed either. French localities' Bunolistriodon populations also seem homogenous and conspecific with those from Lisbon. Notwithstanding its essentially homogenous character, there can be distinguished two sets in both V-a and V-b populations according to M3 size; this remains to be explained, since the last molars are the most likely to show a broad range of variation and are not unequivocally related to sexual dimorphism. Classification of the rare Tayassuidae has been confirmed. All known taxa are shown (see tableau I).

Manual de plantas de Costa Rica /B.E. Hammel ... [et al.] editores ; Silvia Troyo, ilustraciones.

v.1 (2004) [ser. v.97]

Manual de plantas de Costa Rica /B.E. Hammel ... [et al.] editores ; Silvia Troyo, ilustraciones.

v.2 (2003) [ser. v.92]

Manual de plantas de Costa Rica /B.E. Hammel ... [et al.] editores ; Silvia Troyo, ilustraciones.

v.3 (2003) [ser. v.93]

Spécies général et iconographie des coquilles vivantes comprenant la collection du Muséum d'histoire naturelle de Paris : la collection Lamarck, celle du prince Masséna (appartenant maintenant a M.B. Delessert) et les découvertes récentes des voyageurs / par L.C. Kiener ... continué par .. P. Fischer.

2

Icones plantarum formosanarum nec non et contributiones ad floram formosanam : or, Icones of the plants of Formosa, and materials for a flora of the island, based on a study of the collections of the Botanical survey of the Government of Formosa / By B. Hayata ...

8

Icones plantarum formosanarum nec non et contributiones ad floram formosanam : or, Icones of the plants of Formosa, and materials for a flora of the island, based on a study of the collections of the Botanical survey of the Government of Formosa / By B. Hayata ...

7

Icones plantarum formosanarum nec non et contributiones ad floram formosanam : or, Icones of the plants of Formosa, and materials for a flora of the island, based on a study of the collections of the Botanical survey of the Government of Formosa / By B. Hayata ...

1

Icones plantarum formosanarum nec non et contributiones ad floram formosanam : or, Icones of the plants of Formosa, and materials for a flora of the island, based on a study of the collections of the Botanical survey of the Government of Formosa / By B. Hayata ...

3

Icones plantarum formosanarum nec non et contributiones ad floram formosanam : or, Icones of the plants of Formosa, and materials for a flora of the island, based on a study of the collections of the Botanical survey of the Government of Formosa / By B. Hayata ...

4