Related Experiment Videos
Cell-mediated cytotoxicity against murine cells infected with 6/94 virus, a parainfluenza type 1 isolate from
Abstract:
Maximum cytotoxicity to parainfluenza type 1 viral determinants occurs on day 5 post-immunization in mice with and without preexisting anti-6/94 virus antibody. Animals with preexisting anti-6/94 serum antibody, however, exhibited a markedly higher cytotoxic response. Syngeneic, allogeneic, and xenogeneic virus-infected cells induce virus-specific cytotoxicity, but only infected cells histocompatible with the effector cells can serve as susceptible target cells. The effector cell is a T cell, and hence cytotoxicity is thymus dependent. Coincident with the maximum cytotoxic activity on day 5 is the occurrence of pathological lesions, the sites of which are dependent on the route of inoculation.
Insights
Maximum immune cell activity against parainfluenza virus type 1 occurs 5 days post-immunization. Pre-existing antibodies significantly boost this cytotoxic response in mice.
Area of Science:
- Immunology
- Virology
- Cellular Biology
Background:
- Parainfluenza virus type 1 infections can cause significant illness.
- Understanding the host immune response is crucial for developing effective treatments.
- Cytotoxicity plays a key role in controlling viral infections.
Purpose of the Study:
- To investigate the kinetics of cytotoxic T lymphocyte (CTL) response to parainfluenza virus type 1.
- To determine the role of pre-existing antibodies in modulating the CTL response.
- To identify the characteristics of target cells susceptible to virus-specific cytotoxicity.
Main Methods:
- Immunization of mice with parainfluenza virus type 1.
- Assessment of cytotoxic activity at various time points post-immunization.
- Evaluation of the effect of pre-existing anti-6/94 virus antibody.
- Testing cytotoxicity against syngeneic, allogeneic, and xenogeneic infected cells.
- Characterization of effector cells and their dependence on thymus.
Main Results:
- Maximum cytotoxic activity against parainfluenza virus type 1 determinants was observed on day 5 post-immunization.
- Mice with pre-existing anti-6/94 virus antibody demonstrated a significantly enhanced cytotoxic response.
- Virus-specific cytotoxicity was induced by syngeneic, allogeneic, and xenogeneic infected cells.
- Only histocompatible infected cells served as susceptible targets for effector cells.
- The effector cell mediating cytotoxicity was identified as a T cell, indicating thymus dependence.
- Pathological lesions occurred concurrently with maximum cytotoxic activity, with sites dependent on inoculation route.
Conclusions:
- The T cell-mediated cytotoxic immune response to parainfluenza virus type 1 peaks at 5 days post-immunization.
- Pre-existing antibodies markedly enhance the virus-specific cytotoxic response.
- Histocompatibility between effector and target cells is essential for effective viral clearance.
- The development of cytotoxic activity is thymus-dependent, highlighting the role of T cells in viral immunity.