Characterization of a polypeptide present in herpes simplex virus type 2-transformed and -infected hamster embryo cells

Analysis of complex mutations induced in cells by herpes simplex virus type-1

The shuttle vector plasmid pZ189 was used as a target for mutagenesis in COS-1 cells. Complex mutations were analyzed in 5 plasmids that were recovered from noninfected cells and 15 plasmids that were recovered from cells that were infected with herpes simplex virus type-1 (HSV-1). Complex mutations in noninfected cells consisted of duplications and rearrangements of plasmid DNA, while those from cells that were infected with HSV-1 included 8 that were enlarged due to insertion of other DNA sequences. Plasmids that contained inserted DNA showed an increase in size of from 118 bp up to around 4500 bp. Maps were constructed based on restriction enzyme digestion, and some or all of each plasmid was examined by DNA sequencing. The inserted DNA was not derived from HSV-1 in any case, since it did not hybridize to DNA from HSV-1 and showed no sequence similarities to the virus. Instead, inserted DNA was found to hybridize to HindIII-digested cellular DNA as a single or double band in 5 plasmids and contained multiple repeat sequences such as alpha satellite, Alu or Kpn repeats in 4 plasmids. In four enlarged plasmids the identity of the inserted sequences could not be determined. The junctions between the shuttle vector and the inserted DNA did not show features of transposable elements and no homology was detected between inserted sequences and the sequence at the insertion site. No preferred site for recombination was detected. Although no similarities were found among the inserted sequences, it is possible that the cellular sequences represent cellular targets for virus-mediated rearrangement. It appears that HSV-1 stimulates nonhomologous recombination between DNA sequences in virus-infected cells.

Lymph node primary immunization of mice for the production of polyclonal and monoclonal antibodies

Primary immunization of mice by lymph node injection of bovine serum albumin (BSA) in doses as low as 1 ng followed by a secondary immunization with 1 microgram each for intraperiteonal and intravenous injections was sufficient to elicit the production of circulating antibodies. The lowest efficient dose tested was the injection of 100 ng of BSA in the lymph nodes and booster injections of 1 ng each. This method was extended to the production of monoclonal antibodies using less than 20 micrograms of a 35 kDa polypeptide purified from hamster cells transformed by Herpes simplex type 2 viruses.

Organization of the left-hand end of the herpes simplex virus type 2 BglII N fragment

We have determined the complete nucleotide sequence surrounding the region coding for a 38,000-dalton protein of herpes simplex virus type 2 strain 333 that is encoded between map coordinates 0.58 to 0.595 on the viral genome. The sequence data have revealed an open translational reading frame of 1,011 nucleotides encoding a protein of 337 amino acids. Upstream of those sequences, transcriptional regulatory signals could be identified that overlap another open reading frame of 489 nucleotides, which presumably encodes the carboxy-terminal 163 amino acids of a 140,000-dalton protein. Downstream of the gene encoding the 38,000-dalton protein a polyadenylation signal was found as well as one further along on the other strand near a termination codon that presumably punctuates the gene specifying a 61,000-dalton protein. The DNA sequence data were compared with the amended sequence of the herpes simplex virus type 1 strain KOS 40,000-dalton protein (K. G. Draper, R. F. Frink, and E. K. Wagner, J. Virol. 43:1123-1128, 1982) and with the 5' end of the same gene from herpes simplex virus type 1 strain 17 (J. McLaughlan and J. B. Clements, J. Gen. Virol. 64:997-1006, 1983) to assess the degree of inter- and intratypic variation. The comparison of the sequences has provided a basis for the type specifity of this viral protein and for different mechanisms giving rise to the diversity between herpes simplex virus types 1 and 2.

The oncogenic potential of herpes simplex viruses: evidence for a 'hit-and-run' mechanism

Experiments to determine the mechanism of transformation of herpes simplex virus (HSV) have identified fragments of viral DNA which are able to initiate transformation. No set of viral genes seems to be consistently retained or expressed in the transformed cells or in human cervical tumours, suggesting that viral DNA is not needed to maintain the transformed phenotype. In fact there is no conclusive evidence that initiation of neoplasia is mediated by a viral protein. Here we revisit the 'hit-and-run' hypothesis and its implications for HSV-induced tumorigenicity.