Assembly of a high-resolution map of the Acadian Usher syndrome region and localization of the nuclear EF-hand acidic gene

Usher syndrome type 1C (USH1C) occurs in a small population of Acadian descendants from southwestern Louisiana. Linkage and linkage disequilibrium analyses localize USH1C to chromosome 11p between markers D11S1397 and D11S1888, an interval of less than 680 kb. Here, we refine the USH1C linkage to a region less than 400 kb, between genetic markers D11S1397 and D11S1890. Using 17 genetic markers from this interval, we have isolated a contiguous set of 60 bacterial artificial chromosomes (BACs) that span the USH1C critical region. Exon trapping of BAC clones from this region resulted in the recovery of an exon of the nuclear EF-hand acidic (NEFA) gene. However, DNA sequence analysis of the NEFA cDNA from lymphocytes of affected individuals provided no evidence of mutation, making structural mutations in the NEFA protein unlikely as the cellular cause of Acadian Usher syndrome. Copyright (C) 1998 Elsevier Science B.V

CD4(+) T cell–independent DNA vaccination against opportunistic infections

Depletion or dysfunction of CD4(+) T lymphocytes profoundly perturbs host defenses and impairs immunogenicity of vaccines. Here, we show that plasmid DNA vaccination with a cassette encoding antigen (OVA) and a second cassette encoding full-length CD40 ligand (CD40L), a molecule expressed on activated CD4(+) T lymphocytes and critical for T cell helper function, can elicit significant titers of antigen-specific immunoglobulins in serum and Tc1 CD8(+) T cell responses in CD4-deficient mice. To investigate whether this approach leads to CD4(+) T cell–independent vaccine protection against a prototypic AIDS-defining infection, Pneumocystis (PC) pneumonia, we used serum from mice vaccinated with PC-pulsed, CD40L-modifed DCs to immunoprecipitate PC antigens. Kexin, a PC antigen identified by this approach, was used in a similar DNA vaccine strategy with or without CD40L. CD4-deficient mice receiving DNA vaccines encoding Kexin and CD40L showed significantly higher anti-PC IgG titers as well as opsonic killing of PC compared with those vaccinated with Kexin alone. Moreover, CD4-depleted, Kexin-vaccinated mice showed a 3-log greater protection in a PC challenge model. Adoptive transfer of CD19(+) cells or IgG to SCID mice conferred protection against PC challenge, indicating a role of humoral immunity in the protection. The results of these studies show promise for CD4-independent vaccination against HIV-related or other opportunistic pathogens