Fatal Disseminated Mouse Adenovirus Type 1 Infection in Mice Lacking B Cells or Bruton's Tyrosine Kinase

Abstract

Human adenoviruses are associated with self-limiting respiratory, conjunctival, and gastrointestinal disease. In immunocompromised people, human adenovirus infection can result in pneumonia, hepatitis, encephalitis, pancreatitis, gastroenteritis, or disseminated disease involving multiple organs (8, 43). Disseminated human adenovirus infection usually results in death. The incidence of disseminated human adenovirus disease is increasing with the increased number of immunocompromised children, and pediatric bone marrow transplant recipients are most at risk (5,12,13,16).Due to species specificity, human adenovirus pathogenesis is poorly understood. Study of mouse adenovirus type 1 (MAV-1) permits the analysis of a replicating adenovirus in vivo. The outcome of infection depends on the virus dose and mouse strain (15,26,33,40). In outbred and C57BL/6 (B6) mouse strains, MAV-1 infects cells of the monocyte-macrophage lineage and endothelial cells (10,20,33). The highest levels of virus are found in the spleen and brain (20,26,39). MAV-1-specific cytotoxic T cells peak at 10 days postinfection (d.p.i.) and then decline (18). T cells cause acute immunopathology and are required for survival 9 to 16 weeks postinfection in MAV-1-induced encephalomyelitis (33). Inbred mouse strains susceptible and resistant to MAV-1 are available, and sublethal irradiation of resistant mice renders them susceptible (40). Mice with a severe combined immunodeficiency (SCID) mutation are susceptible to MAV-1 (10, 35).Here we report findings that survival of acute MAV-1 infection is B-cell dependent and T-cell independent. We postulated that Bruton's tyrosine kinase (Btk) plays a role in protection from MAV-1. Loss of Btk in mice results in the X-linked immunodeficiency (Xid) phenotype (22). Btk Ϫ/Ϫ mice have reductions in serum immunoglobulin (natural antibody), conventional B cells, and peritoneal B-1 cells relative to control mice (22). Here we demonstrate that Btk is required for survival of MAV-1 infection. We present data indicating that early T-cell-independent antiviral immunoglobulin M (IgM) plays a pivotal role in protection against disseminated MAV-1 infection. MATERIALS AND METHODSVirus and mice. Wild-type MAV-1 was propagated and titrated in 3T6 cells (9). The mice used are indicated in Table 1 (11,14,23,24,(29)(30)(31). A ␤ bϪ/Ϫ and Jh mice were purchased from Taconic. C57BL/6NCr (B6) and BALB/CAnNCr mice were purchased from the National Cancer Institute. All other mice were purchased from Jackson Laboratory. The 50% lethal dose (LD 50 ) was determined as described previously (37). Sera were heat inactivated at 57°C for 45 min before passive transfer.Quantitation of virus. Organ homogenates were prepared as described previously (40) or in phosphate-buffered saline (PBS) with 1-mm glass beads (BioSpec Products, Bartlesville, Okla.) in 2 ml/well 96-well plates (Axygen, Union City, Calif.) with a Mini Beadbeater (BioSpec) and the manufacturer's protocol. Virus was titrated by plaque assay as described previously (9). The means of...

Intracellular antibody receptor TRIM21 prevents fatal viral infection

“…Survival from acute infection is highly dependent on the humoral immune response. Antibody-deficient mouse strains such as btk −/− , Jh, and μMT are particularly susceptible to disease, having increased viral loads in the brain and other organs and increased mortality (7). Passive transfer of neutralizing antibodies is sufficient to protect btk −/− mice and reduce viremia in a RAG −/− strain (7).…”

Adenovirus-Specific CD4+ T Cell Clones Recognizing Endogenous Antigen Inhibit Viral Replication In Vitro through Cognate Interaction

“…Murine models using HAdV provide only limited information because HAdV does not produce a permissive infection in murine cells. Studies in mice using murine adenovirus reveal that B cells are involved in protection from early disease, whereas T cells, either CD4 ϩ or CD8 ϩ , are responsible for late viral clearance, even in the absence of perforin (51,52). However, there are significant differences with adenovirus infections in humans; the main target cells in mice are endothelial cells vs EC in humans, T cells can cause immunopathology, and the course of infection is dependent on the genetic background of the mice (52).…”

“…Target cells were infected with HAdV5 (infectious or MBinactivated) at an MOI of 100 as described above or loaded with peptide at 5 g/ml and cultured for 16 h unless otherwise indicated. Target cells were labeled with 51 Cr for 1.5 h at 37°C and washed three times with RPMI 1640 medium. Various numbers of effector cells were cocultured with 2.5 ϫ 10 3 B-LCL or 2.5 ϫ 10 3 MJS per well for 4 h at 37°C and 5% CO 2 , and 51 Cr release was determined in the supernatant.…”

“…Target cells were labeled with 51 Cr for 1.5 h at 37°C and washed three times with RPMI 1640 medium. Various numbers of effector cells were cocultured with 2.5 ϫ 10 3 B-LCL or 2.5 ϫ 10 3 MJS per well for 4 h at 37°C and 5% CO 2 , and 51 Cr release was determined in the supernatant. Maximal release was determined by the addition of 2 N HCl to target cells, and spontaneous release was obtained by the addition of medium alone.…”

“…Then, the two cell populations were separated by FACS sorting based on eGFP expression, incubated with peptide or medium during labeling with 51 Cr, and used as target cells.…”