Variation of Neisseria gonorrhoeae lipooligosaccharide directs dendritic cell-induced T helper responses.

Gonorrhea is one of the most prevalent sexually transmitted diseases in the world. A naturally occurring variation of the terminal carbohydrates on the lipooligosaccharide (LOS) molecule correlates with altered disease states. Here, we investigated the interaction of different stable gonoccocal LOS phenotypes with human dendritic cells and demonstrate that each variant targets a different set of receptors on the dendritic cell, including the C-type lectins MGL and DC-SIGN. Neisseria gonorrhoeae LOS phenotype C constitutes the first bacterial ligand to be described for the human C-type lectin receptor MGL. Both MGL and DC-SIGN are locally expressed at the male and female genital area, the primary site of N. gonorrhoeae infection. We show that targeting of different C-type lectins with the N. gonorrhoeae LOS variants results in alterations in dendritic cell cytokine secretion profiles and the induction of distinct adaptive CD4(+) T helper responses. Whereas N. gonorrhoeae variant A with a terminal N-acetylglucosamine on its LOS was recognized by DC-SIGN and induced significantly more IL-10 production, phenotype C, carrying a terminal N-acetylgalactosamine, primarily interacted with MGL and skewed immunity towards the T helper 2 lineage. Together, our results indicate that N. gonorrhoeae LOS variation allows for selective manipulation of dendritic cell function, thereby shifting subsequent immune responses in favor of bacterial survival.

Plasmodium Falciparum malaria and perinatally acquired human immunodeficiency virus type 1 infection in Kinshasa, Zaire. A prospective, longitudinal cohort study of 587 children.

BACKGROUND: It is uncertain whether Plasmodium falciparum malaria is more frequent or more severe in children with perinatally acquired human immunodeficiency virus type 1 (HIV-1) infection and whether P. falciparum infection accelerates the progression of HIV-related disease. METHODS: We conducted a prospective, longitudinal cohort study in Kinshasa, Zaire. Two hundred sixty children 5 to 9 months of age who had been born to HIV-1-seropositive mothers and 327 children of the same age who had been born to seronegative mothers were monitored intensively for malaria over a 13-month period. All episodes of fever were evaluated with blood smears for malaria, and children found to be infected with P. falciparum were treated with a standard regimen of oral quinine. RESULTS: A total of 2899 fevers were evaluated, with 271 cases of malaria identified. No statistically significant differences were found in the incidence, severity, or response to therapy of malaria among four well-defined groups of children: those with the acquired immunodeficiency syndrome (AIDS), those who were HIV-1-seropositive throughout the study, those who were born to HIV-1-seropositive mothers but reverted to seronegative, and those who were seronegative throughout the study. During the 13-month period the incidence of malaria in the 36 children with HIV infection in whom AIDS developed was lower, although not significantly so, than in the 37 in whom AIDS did not. CONCLUSIONS: In this study malaria was not more frequent or more severe in children with progressive HIV-1 infection and malaria did not appear to accelerate the rate of progression of HIV-1 disease.

[Anomalies of enamel structure: description of a clinical case]. / Anomalie di struttura dello smalto: descrizione di un caso clinico.

The anomalies of dental structure are quite common in pediatric dentistry; these anomalies can involve separately or in the same time enamel, dentin or cementum and they are due to many factors acting during odontogenesis and istogenesis. The Authors analyse these abnormalities and describe a personal case.