PubMed Health⌕ Search

Biomedical subjects

W E Rawls

Publications and source records attributed to W E Rawls.

At least 55 records · Page 3Linked to original sources
PubMed1984

Differences in lymphocyte responsiveness to lymphokines in two inbred strains of Syrian hamster.

Two inbred strains of Syrian hamster have been shown to display differences in splenic NK cell activity both endogenously and after infection with Pichinde virus. On further investigation of these differences, it was found that the spleens and thymuses of the high NK strain, MHA, displayed greater cellularity than those of the low NK strain, LSH. Additionally, thymocytes from MHA hamsters were found to proliferate to a greater extent than those of LSH hamsters in response to Con A-induced conditioned medium plus lectin. Splenocytes from MHA hamsters showed high levels of lymphokine-activated killer cell (LAK) activity after culture in conditioned medium, in contrast to LSH splenocytes cultured under the same conditions. By limiting dilution analysis, spleens from MHA hamsters were found to contain a greater frequency of LAK precursors than those from LSH hamsters. The data suggest that the relative concentrations of lymphopoietic cells is genetically determined.

Animals↗
PubMed1983

Canalicular function during herpetic keratoconjunctivitis in rabbits.

Canalicular function during acute herpetic keratoconjunctivitis was investigated in rabbits. Evidence of partial obstruction of the duct was obtained in the infected as compared with the mock-infected eyes. Direct damage of the ductal epithelium by virus could not be demonstrated by histologic and immunofluorescent studies. Our findings suggest that canalicular dysfunction associated with viral infection may result from accompanying inflammatory changes.

Animals↗
PubMed1983

Sexual and socioeconomic factors affecting the risk of past infections with herpes simplex virus type 2.

Between November 1978 and May 1980, a cross-sectional survey of 566 females and 391 males, aged 35 to 50 years, living in metropolitan Toronto, was conducted to examine the influence of socioeconomic status and sexual behavior on the occurrence of antibodies to herpes simplex virus type 2. Antibodies to the virus were detected in 17.5% of females and 12.8% of males. Lower socioeconomic status was associated with an increased risk of herpes simplex virus type 2 seropositivity for females but not for males. An increased risk of seropositivity was associated in both sexes with young age at first intercourse, multiple sexual partners, and renting rather than owning their residence. The risk associated with each of these attributes remained when the effects of the other attributes including socioeconomic status and age at interview were controlled. The greatest risk was associated with renting. If the renting effect is real, it suggests that there is some determinant of risk not measured by this study, which is more important than socioeconomic status or sexual behavior.

Adult↗
PubMed1983

Gene mapping in Pichinde virus: assignment of viral polypeptides to genomic L and S RNAs.

Previous studies have demonstrated that Pichinde virus encodes at least three primary translation products. Using wild-type Pichinde and Munchique viruses and a reassortant between the two, designated RE-2, we were able to assign polypeptides L, GPC, and NP to viral L and S RNAs. The RE-2 virus contains the L RNA of Pichinde virus and the S RNA of Munchique virus. Two-dimensional tryptic peptide mapping of L-[35S]methionine-containing peptides demonstrated that NP and GPC were identical in Munchique and RE-2 viruses, and both differed from the corresponding Pichinde virus tryptic profiles. On the basis of this, NP and GPC must be encoded by viral S RNA. Similar comparisons for L polypeptide demonstrated that L is a virus-specific polypeptide encoded by L RNA.

Arenaviridae↗
PubMed1983

Pichinde virus-specific cell-associated suppression of primary footpad swelling in an inbred strain of Syrian hamsters.

Pichinde virus causes a lethal disease after i.p. inoculation of adult MHA hamsters; other strains of Syrian hamsters are resistant to this lethal infection. During studies of cell-mediated immune responses to Pichinde virus, it was noted that MHA hamsters survived infection when the virus was given in the footpad. However, unlike the resistant LSH and LVG strains of hamsters, the MHA hamsters did not manifest a footpad swelling response. Failure of the MHA hamster to respond to a footpad inoculation of Pichinde virus was shown to be virus-specific and appeared to be mediated by a cell-associated suppressor mechanism.

Animals↗
PubMed1982

Protection against lethal challenge of BALB/c mice by passive transfer of monoclonal antibodies to five glycoproteins of herpes simplex virus type 2.

Monoclonal antibodies secreted by six hybridomas and recognizing antigenic sites on glycoproteins gC, gAB, gD, gE, and gF of herpes simplex virus type 2 were examined for their ability to protect BALB/c mice from lethal infection by the virus. Administration of monoclonal antibodies to individual glycoproteins intraperitoneally 3 h before footpad challenge with 10 times the 50% lethal dose of virus protected between 35 and 75% of the mice, except for one of two monoclonal antibodies recognizing antigens on gC. The antibodies did not neutralize virus in vitro and protected A/J mice deficient in the fifth component of complement as efficiently as complement-sufficient BALB/c mice. A good correlation was found between protection and titers of monoclonal antibodies assessed by antibody-dependent cell-mediated cytolysis. The results indicate that any of the glycoproteins can serve as antigens for a protective immune response. In addition, the data are compatible with protection being mediated by an antibody-dependent cell-mediated cytolysis mechanism.

Animals↗
PubMed1982

Identification and typing of herpes simplex viruses with monoclonal antibodies.

Monoclonal antibodies which reacted with type-specific antigens of herpes simplex virus type 2 or with antigens shared by herpes simplex virus types 1 and 2 were used in an indirect immunofluorescence assay to type virus isolates and to detect viral antigens in cells obtained from herpetic lesions. Complete concordance was obtained for 42 isolates typed by endonuclease restriction analysis of viral DNA and by indirect immunofluorescence with monoclonal antibodies. Examination of a limited number of ulcerative lesions revealed that indirect immunofluorescence and virus isolation were comparable in detecting herpes simplex virus. The results indicate that monoclonal antibodies can be used to accurately identify and type isolates of herpes simplex virus.

Animals↗
PubMed1982

Synthesis of virus-specific polypeptides and genomic RNA during the replicative cycle of Pichinde virus.

A stock of plaque-purified Pichinde virus, prepared under conditions designed to limit the amounts of defective interfering virus, was used to infect BHK cells. At daily intervals after infection, cells were examined for infectious and radiolabeled virus particle production and for the synthesis of virus-specific polypeptides. Quantitative comparisons were also made of the concentrations of genomic Pichinde virus L and S RNAs in the cytoplasm of infected cells on different days after infection. Our results showed that virus particle production, rates of protein synthesis, and the intracellular levels of viral genomic RNAs all increased and decreased with similar kinetics, and that this regulation was independent of the cell growth cycle. We were unable to relate these changes in viral macromolecule and virus production to the appearance of readily identifiable defective interfering particles. Our findings suggest that regulation of virus replication early during the replicative cycle of Pichinde virus may not be dependent upon the generation of defective interfering virus.

Animals↗
PubMed1982

Glycoproteins of herpes simplex virus type 2 as defined by monoclonal antibodies.

We used monoclonal antibodies reacting with glycoproteins specified by herpes simplex virus type 2 (HSV-2) to characterize the individual antigens in terms of structure, processing, and kinetics of synthesis in BHK or Vero infected cells. Our results provided a direct demonstration of the structural identity of the gA and gB proteins of HSV-2 as well as confirmation of the existence of type-specific and type-common domains within the gD molecule. They also show that, with the exception of gC, processing of the viral glycoproteins differs to some extent in Vero and BHK infected cells, possibly as a result of different efficiency of glycosylation or different processing of underglycosylated and unglycosylated products in the two cell types. Finally, we showed that individual HSV-2 glycoproteins are synthesized at greatly different times during the infectious cycle, possibly in response to their different roles in virus replication and assembly.

Animals↗
PubMed1981

Susceptibility to fatal Pichinde virus infection in the Syrian hamster.

The data presented in this paper suggest that the susceptible MHA hamster strain possesses a spleen target cell for Pichinde virus replication which is minimally expressed in the resistant strain. This target cell co-purifies with cells mediating NK activity, raising the possibility that the NK cell itself may be the additional target cell for Pichinde virus replication in the susceptible hamster strain. We hypothesize that early virus replication in the spleens of IP-inoculated hamsters leads to an overwhelming proliferation of virus. In contrast, a footpad inoculation of Pichinde virus retards virus spread into the spleen, and the host's immune response can effectively clear the relatively low amount of virus. In addition, data have been presented that show that a footpad inoculation of Pichinde virus elicits swelling in resistant hamster strains at eight days after infection, but fails to evoke a response in the susceptible MHA hamster strain. The response is controlled by a single autosomal dominant gene, and suggests that the MHA hamster strain has a defective delayed-type hypersensitivity response. The gene responsible for footpad swelling appears to be distinct from the single autosomal dominant gene that controls virus replication in the popliteal lymph nodes of footpad-injected hamsters. The phenotype of survival, then, may be the result of either limited virus replication early in infection, or an effective anti-viral cell-mediated immune response, or both.

Animals↗
PubMed1981

Production of hybrid cell lines secreting antibodies to herpes simplex virus type 2.

Following different immunization schedules we have produced 102 myeloma--spleen cell hybrid lines (30.8% of the total) secreting antibodies to HSV-2 infected cells. The highest yield of hybrids was derived from fusion of myeloma cells with spleen cells from mice sensitized by footpad injection of formalin-inactivated virus and boosted intravenously with the same antigen. To date, twelve of the antibody-producing hybrids have been cloned by limiting dilutions to generate over 100 monoclonal lines reacting specifically with HSV-infected but not with mock-infected cells. Several hybrid lines have also been injected into mice to generate tumors and high titers of anti-HSV-specific antibodies have been detected in ascitic fluids. All of the hybrids so far tested have retained the capacity to secrete anti-HSV antibodies after long-term in culture or repeated passages through mice. Antibodies reacting with cytoplasmic or nuclear antigens in infected cells as well as type-specific and type common antibodies have been detected.

Animals↗
PubMed1981

Role of natural killer cells in Pichinde virus infection of Syrian hamsters.

Pichinde virus produced a fatal infection in adult MHA hamsters but not LSH hamsters after intraperitoneal inoculation. After footpad inoculation, an 8-day swelling response was observed in LSH but not MHA hamsters; however, both strains survived infection by this route. Examination of the kinetics of viral replication in the two hamster strains inoculated by the two routes revealed a correlation between infectious centers and natural killer activity in cells obtained from spleens and popliteal lymph nodes. A subpopulation of cytolytic and infected cells which sedimented at about 3.0 to 4.5 mm/h in albumin gradients was found in greater numbers in MHA than in LSH hamsters. These data suggest that one factor contributing to the fatal outcome of Pichinde virus infection in MHA hamsters is the presence of excessive numbers of splenic target cells which possess properties of natural killer cells.

Animals↗
PubMed1981

Antibody responses in humans to individual proteins of herpes simplex viruses.

Sera from 231 women were used to examine their frequency of precipitation of various herpes simplex virus type 1 and 2 (HSV-1 and HSV-2) proteins and to determine if there was a rank order of immune responsiveness of humans to these HSV antigens. Radiolabeled viral proteins were reacted with serum and immune complexes isolated with staphylococcal protein A. Individual antigens were resolved by polyacrylamide gel electrophoresis and visualized by fluorography. As a group, these sera precipitated 31 HSV-1 and 27 HSV-2 proteins. HSV-1 polypeptides with molecular weights of 133,000, 99,000, and 82,000, as well as HSV-2 polypeptides with molecular weights of 131,000 and 101,000, were precipitated by essentially all sera that contained antibodies to HSV-1 and HSV-2. When attempts were made to order the viral proteins by constructing precipitation profiles ranking the antigens in patterns according to their frequency of precipitation, it was observed that the antigens were generally not ordered. Demographic analysis of the sera suggested that the differences in the number of proteins precipitated were associated with differences in age, education, age at first marriage, and income, which collectively may reflect the frequency of exposure to the virus.

Adult↗
PubMed1981

Pichinde virus L and S RNAs contain unique sequences.

Using oligodeoxyribonucleotides produced by limited DNase I digestion of calf thymus DNA as a primer, we synthesized complementary DNA (cDNA) from the L and the S RNAs of Pichinde virus. The reaction conditions for in vitro cDNA synthesis were optimized to allow transcription of about 90% of either L or S RNA. No significant hybridization was observed when the L cDNA was hybridized to the S RNA, or when the S cDNA was hybridized to the L RNA. The results indicate that the L and S RNAs of Pichinde virus contain unique nucleotide sequences.

Arenaviridae↗
PubMed1981

Characterization of polypeptides immunoprecipitable from Pichinde virus-infected BHK-21 cells.

Using hamster anti-Pichinde virus serum, we immunoprecipitated polypeptides from BHK-21 cells infected with Pichinde virus. Seven immunoprecipitable polypeptides exhibited a time- and multiplicity of infection-dependent appearance when the cultures were pulse-labeled with L-[35S]methionine for 1 h. The predominant polypeptide was a nucleoprotein (NP) of 64,000 daltons. Components of 48,000, 38,000, and 28,000 daltons, when analyzed by two-dimensional tryptic peptide mapping, were found to be derived from NP. After a 3-h chase period, polypeptides of 17,000, 16,500, and 14,000 daltons were evident, and peptide mapping revealed that these three polypeptides were also related to NP. During a series of pulse-chase experiments, a 79,000-dalton glycoprotein (GPC) was cleaved to glycoproteins of 52,000 and 36,000 daltons. Radiolabel in a polypeptide of approximately 200,000 daltons (L) did not chase into smaller cleavage products. L, GPC, and NP were found to be unique by two-dimensional tryptic peptide mapping. Comparison of polypeptides immunoprecipitated from infected cells with structural components of purified virus revealed that L protein was evident in both. This is the first report of a high-molecular-weight polypeptide in Pichinde virus particles and infected cells.

Animals↗
PubMed1981

Monoclonal antibodies to two glycoproteins of herpes simplex virus type 2.

Monoclonal antibodies to herpes simplex virus type 2 were found to precipitate different numbers of radiolabeled polypeptides from lysates of virus-infected cells. Antibodies directed against two viral glycoproteins were characterized. Antibodies from hybridoma 17 alpha A2 precipitated a 60,000-molecular-weight polypeptide which chased into a 66,000- and 79,000-molecular-weight polypeptide. All three polypeptides labeled in the presence of [3H]glucosamine and had similar tryptic digest maps. The 60,000-molecular-weight polypeptide also chased into a 31,000-molecular-weight species which did not label with [3H]glucosamine. Antibodies from hybridoma 17 beta C2 precipitated a 50,000-molecular-weight polypeptide which chased into a 56,000- and 80,000-molecular weight polypeptide. These polypeptides also shared a similar tryptic digest map and labeled with [3H]glucosamine. Both monoclonal antibodies were herpes simplex virus type 2 specific. The viral proteins precipitated by 17 alpha A2 antibodies had characteristics similar to those reported for glycoprotein E, whereas the proteins precipitated by 17 beta C2 antibodies appeared to represent a glycoprotein not previously described. This glycoprotein should be tentatively designated glycoprotein F.

Antibodies, Monoclonal↗