[Induction of EIAV-specific cellular immune response by attenuated EIAV vaccine].

The study observed the effects of an attenuated Equine Infectious Anemia Virus (EIAV) vaccine injected into horses to evaluate the cellular immune protective mechanism of the virus. It was found that the vaccine induced an EIAV-specific cellular immune response which potentially contributes to the immunity against EIAV virus infection.

Methodology of the Study

• The researchers selected six horses for the study, four of which were immunized with an attenuated EIAV (DLV) via subcutaneous injection. Two horses were given 0.85% sodium chloride, serving as the negative control.
• To observe the immediate reactions of the injections, the horses’ rectal temperatures and clinical features were recorded daily. Additionally, whole blood samples were collected and peripheral blood mononuclear cells (PBMC) were separated from these for further experimentation.

Testing and Results

• These PBMCs were then used for assays to evaluate the extent of cytotoxic T lymphocyte (CTL) activity and lymphocyte proliferation.
• The target cells used in the experiment were activated by PWM (Pokeweed mitogen, a protein used to stimulate cell division) and treated with DLV or recombinant vaccinia vectors expressing DLV and LN Gag or Env separately.
• The researchers observed that in the negative control group, the percentage of EIAV-specific CTL lysis was under 5%. In stark contrast, the percentage varied from 20% to 30% in the group of horses immunized with the DLV, indicating an enhanced immune response.
• The stimulation index (SI) was found to be 3 in the group immunized with the DLV vaccine, suggesting its potential applicability in stimulating immune response.

Conclusions

• This study concluded that EIAV-specific cellular immune responses could be induced by DLV immunization, which may contribute to the protective effect against EIAV virus infection.
• However, the results should be interpreted with caution since they are based on a small sample size of horses. Further studies may be needed to validate the findings.