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Neutralization of Mason-Pfizer virus by sera from patients treated for renal disease
Abstract:
Sera from 67 patients treated for renal diseases were assayed by as many as three different tests for activities against Mason-Pfizer virus (M-P V) antigens. Firstly, in patients studied before kidney transplantation, neutralizing activity against syncytium-forming units of M-P V was found in 50% of 24 cases of chronic glomerulonephritis but in only 10% of 20 cases with other diseases (P less than 0.01). These proportions were higher after treatments accompanying transplantation since, of the 19 patients without antibodies before graft, 53% showed a sero-conversion after this treatment. The incidence of M-P V antibodies did not correlate with the number of transfusions received by the patients. Neither did these antibodies correlate with the presence of antibodies to antigens associated with baboon endogenous virus or simian sarcoma virus; antibodies to the latter two viruses were found in 6 to 21% of the sera, with no specific distribution among the sera. Secondly, pseudotypes of vesicular stomatitis virus with M-P V antigens in their envelope were prepared; they were inactivated by 90% of the sera which neutralized M-P V syncytium forming units and by none of the negative sera. Thirdly, specific complement-dependent cytotoxic antibodies to HeLa cells producing M-P V were also found in 61% of the sera with neutralizing activity to M-P V and only in 12% of the sera which did not neutralize M-P V. Absorption experiments indicated that the serum activities against M-P V associated antigens were not due to anticellular antibodies directed against normal constituents of human cells. However, no evidence has been provided that the M-P V associated antigens reacting with the human sera were virus coded.
Insights
Patients with renal diseases, particularly chronic glomerulonephritis, often develop antibodies against Mason-Pfizer virus (M-P V) antigens, especially after kidney transplantation. These antibodies were detected using various assays, suggesting a potential link between renal disease and M-P V antigen exposure.
Area of Science:
- Virology
- Immunology
- Nephrology
Background:
- Mason-Pfizer virus (M-P V) is a simian retrovirus.
- Renal diseases and treatments like kidney transplantation may alter immune responses.
- The presence of M-P V antibodies in patients with renal diseases is not well-characterized.
Purpose of the Study:
- To investigate the prevalence of antibodies against Mason-Pfizer virus (M-P V) antigens in patients with renal diseases.
- To explore the relationship between M-P V antibodies and kidney transplantation.
- To characterize the nature of these antibodies and their targets.
Main Methods:
- Sera from 67 renal disease patients were tested for M-P V antibody activity using three assays: neutralization of syncytium-forming units, inactivation of M-P V pseudotypes, and complement-dependent cytotoxicity against M-P V-producing cells.
- Patients were studied before and after kidney transplantation.
- Absorption experiments were performed to rule out anticellular antibodies.
Main Results:
- 50% of chronic glomerulonephritis patients (24 cases) and 10% of other renal disease patients (20 cases) showed M-P V neutralizing activity before transplantation (P<0.01).
- Post-transplantation, 53% of 19 patients seroconverted.
- Antibody presence did not correlate with transfusions or antibodies to baboon endogenous virus or simian sarcoma virus.
- Neutralizing antibodies correlated with inactivation of M-P V pseudotypes and complement-dependent cytotoxicity.
- Absorption studies excluded anticellular antibodies against normal human cells.
Conclusions:
- A significant proportion of renal disease patients, especially those with chronic glomerulonephritis, possess antibodies reactive with Mason-Pfizer virus (M-P V) antigens.
- Kidney transplantation and associated treatments appear to enhance the seroconversion rate for M-P V antibodies.
- While these antibodies are not directed against normal human cells, the viral origin of the reacting M-P V antigens remains unconfirmed.