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Biomedical subjects

Mark A Brockman

Publications and source records attributed to Mark A Brockman.

3 recordsLinked to original sources

Macrophage-derived complement component C4 can restore humoral immunity in C4-deficient mice.

Mice with a disrupted C4 locus (C4(-/-)) have an impaired immune response to thymus-dependent Ags. To test the role of bone marrow-derived C4 in humoral immunity, we reconstituted deficient animals with wild-type bone marrow or an enriched fraction of bone marrow-derived macrophages. C4 chimeras were immunized with 4-hydroxy-3-nitrophenyl(5) conjugated to keyhole limpet hemocyanin (NP(5)- KLH) or infected with HSV-1, and the Ab response was evaluated. Wild-type bone marrow rescued the humoral immune response to both Ags, i.e., the soluble Ag and HSV-1, demonstrating that local C4 production is sufficient for humoral responses. Although the C4 chimeric animals lacked detectable C4 in their sera, C4 mRNA was identified in splenic sections by in situ hybridization, and C4 protein deposits were identified in the germinal center areas of splenic follicles by immunofluorescence staining. Macrophages derived from bone marrow produced sufficient C4 protein to restore the humoral response to NP(5)-KLH in C4-deficient animals when administered along with Ag. Cell-sorting experiments, followed by C4-specific RT-PCR, identified splenic macrophages (CD11b(+), CD11c(-)) as a cellular source for C4 synthesis within the spleen.

Adoptive Transfer↗

Herpes simplex virus.

Herpes simplex virus (HSV) commonly causes human infections in the orofacial region (HSV-1) and in the genital region (HSV-2). Productive viral infection in mucosal epithelial cells may result in clinical symptoms and is followed by a latent infection within sensory neurons. During productive infection a large number of viral gene products are expressed while during latent infection few or no viral proteins are expressed. Reactivation from latency results in recurrent infections and disease at or near the primary site of infection. Understanding the details of the two stages of the HSV life cycle is a particular focus of current research on HSV. The virus interacts with and modifies numerous host cell functions in both epithelial and neuronal cells, and studies of HSV have enhanced our knowledge of many fundamental processes in eukaryotic cells. Ongoing research continues to uncover novel effects of HSV on cells, and a complete understanding of HSV infection during both productive and latent infection should allow the design of new antiviral agents and vaccines and increased knowledge of basic cell and molecular biology. This review article is designed to provide an introduction to HSV biology and key aspects of the infection cycle.

Animals↗

Herpes simplex virus vectors elicit durable immune responses in the presence of preexisting host immunity.

Herpes simplex virus (HSV) recombinants are being developed as vaccine vectors for the expression of heterologous antigens. There is concern, however, that preexisting HSV immunity may decrease their effectiveness. We have addressed this issue in an animal model. Immunized mice were inoculated with a replication-defective HSV-1 vector that expressed the Escherichia coli beta-galactosidase protein as a model antigen. We assessed vector efficacy by analyzing the immunoglobulin G (IgG) antibody response and cellular proliferative response directed against beta-galactosidase. We report that the ability of the vector to induce antibody or proliferative responses was not diminished by preexisting immunity to HSV. Of further note, the anti-HSV and anti-beta-galactosidase IgG responses following vector administration were extremely durable in both immunized and naive mice. These results indicate that the ability of a replication-defective HSV-derived vaccine vector to elicit long-lived immune responses in mice is not impaired by prior HSV exposure.

Animals↗