Rotaviruses are important human and veterinary pathogens and are responsible for some 1-2 million human deaths per annum, worldwide. Conventional vaccine strategies for this pathogen have, on the whole been unsuccessful. Therefore, a detailed and comprehensive understanding of the immune response to rotaviruses, particularly at the cell mediated level is being sought, such that successful vaccines can be generated. A lymphocyte proliferation assay system has been developed for examining the Th cell response to the bovine rotavirus (BRV), UKtc. Splenocytes from adult BALB/c mice, orally inoculated with infectious BRV(UKtc) proliferated in response to in vitro stimulation with purified BRV(UKtc) particles. Proliferation was (i)detected at 4 days and 8 days after primary oral inoculation, (ii)not detected in uninoculated animals, (iii)specific to the priming virus and (iv)eliminated by NH4CI treatment of the spleen cells. Splenocytes from animals challenged by both oral and intra-peritoneal (i.p.) routes, were more efficiently stimulated by double-shelled BRV(UKtc) particles than single-shelled particles. Proliferation was found to be mediated by both Thy-1+,CD8−,CD4+ cells (i.e. Th cells) and Thy-1+,CD8+,CD4− cells (i.e. cytotoxic T-cells) but was dependent on Thy-1+,CD8−,CD4+ cells, when mice were inoculated by either the oral or i.p. routes. A greater proportion of the splenocyte proliferative response was found to be due to Thy-1+,CD8−,CD4+ cells when the animals were inoculated by the i.p. route. Virus replication in the intestinal tract was not required for a splenocyte proliferative response to be detected and the splenocyte response was long lived. For example, significant proliferation to both double and single-shelled forms of BRV(UKtc) was detected at 144 days (oral inoculation) and 224 days (i.p. inoculation), after a single dose of virus. BRV(UKtc) stimulated splenocytes secreted interferon-gamma, upon activation but no significant differences in titer were present between cells stimulated with double-shelled virus or single-shelled virus, in contrast to the [3H]thymidine incorporation results. Cross-challenge experiments with the porcine rotavirus OSU showed that cross-reactivity existed at the T-cell level. However, memory splenocyte proliferative responses to this strain were not long lived following oral inoculation with BRV(UKtc). The response of mesenteric lymph node cells to in vitro challenge with rotavirus was also studied at various times post oral inoculation. Of importance was the finding that proliferative responses to rotavirus were not present in mesenteric lymph node cells at 63 days post oral inoculation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:238810 |
| Date | January 1993 |
| Creators | Jones, Christopher David |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/103918/ |
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