Autoimmune manifestations in SCID due to IL7R mutations: Omenn syndrome and cytopenias.

B+NK+SCID (severe combined immunodeficiency) due to IL7Rα deficiency represents approximately 10% of American SCID cases. To better understand the spectrum of autoimmune disorders associated with IL7Rα deficiency, we describe two unrelated IL7Rα-deficient female SCID infants whose clinical picture was dominated by autoimmune manifestations: one with intrauterine Omenn syndrome (OS) and another with persistent thrombocytopenic purpura since 4months of age. The OS baby harbored a homozygous p.

IgG placental transfer in healthy and pathological pregnancies.

Placental transfer of maternal IgG antibodies to the fetus is an important mechanism that provides protection to the infant while his/her humoral response is inefficient. IgG is the only antibody class that significantly crosses the human placenta. This crossing is mediated by FcRn expressed on syncytiotrophoblast cells.

The spleen CD4+ T cell response to blood-stage Plasmodium chabaudi malaria develops in two phases characterized by different properties.

The pivotal role of spleen CD4(+) T cells in the development of both malaria pathogenesis and protective immunity makes necessary a profound comprehension of the mechanisms involved in their activation and regulation during Plasmodium infection. Herein, we examined in detail the behaviour of non-conventional and conventional splenic CD4(+) T cells during P. chabaudi malaria.

Comparative analysis of activation phenotype, proliferation, and IFN-gamma production by spleen NK1.1(+) and NK1.1(-) T cells during Plasmodium chabaudi AS malaria.

The NK1.1 molecule participates in NK, NKT, and T-cell activation, contributing to IFN-gamma production and cytotoxicity. To characterize the early immune response to Plasmodium chabaudi AS, spleen NK1.

Gradual decline in malaria-specific memory T cell responses leads to failure to maintain long-term protective immunity to Plasmodium chabaudi AS despite persistence of B cell memory and circulating antibody.

The mechanisms responsible for the generation and maintenance of immunological memory to Plasmodium are poorly understood and the reasons why protective immunity in humans is so difficult to achieve and rapidly lost remain a matter for debate. A possible explanation for the difficulty in building up an efficient immune response against this parasite is the massive T cell apoptosis resulting from exposure to high-dose parasite Ag. To determine the immunological mechanisms required for long-term protection against P.