Antigenic stimulation of T lymphocytes in chronic nononcogenic retrovirus infection: equine infectious anemia

Abstract

Equine infectious anemia is a chronic disease of horses caused by a nononcogenic retrovirus. Studies were undertaken to determine the types of cells involved in the in vitro lymphoproliferative response to viral antigens and the dynamics of this reaction. It was observed that reactive lymphocytes were present at unpredictable times in the peripheral blood of infected horses. This reaction was shown to be specific for the interaction of equine infectious anemia virus and T lymphocytes. Enriched B-lymphocyte populations did not divide when exposed to equine infectious anemia virus. Macrophages were depleted from the reaction by two methods: adherence to Sephadex and a combination of binding to Sephadex and adherence to complement-coated erythrocytes. Both methods reduced the number of monocytes, but only the combination of Sephadex and complement-coated cells removed the accessory cells needed for lymphocyte proliferation. We conclude that during the chronic stages of equine infectious anemia the number of antigen-reactive T lymphocytes fluctuates within the peripheral blood and that these cells require a complement-binding cell for reaction. The relationship of these cells to the lymphoproliferative stages of this disease is discussed.

Efficacy of inactivated whole-virus and subunit vaccines in preventing infection and disease caused by equine infectious anemia virus

“…It has been proposed that cell-mediated immune responses may be important in limiting EIAV infection (34). Cellmediated immune responses have been shown to follow EIAV infection, though the significance of these responses in controlling virus replication and disease remains unclear (6,18,39). We report here that vaccination with either an inactivated whole-virus or a glycoprotein-enriched subunit vaccine stimulates T cells capable of mediating an EIAVspecific lymphoproliferative response.…”

“…Cell-mediated immune responses to HIV have been detected following both infection and vaccination (29, 42). Likewise, lymphoproliferative and cytotoxic responses against EIAV have been shown to follow EIAV infection, although the significance of these responses in controlling virus replication and disease remains unclear (6,18,39).…”

The immunopathogenesis of equine infectious anemia virus

“…Cell-mediated immune responses to EIAV have been less well characterized than antibody responses. T-lymphocytes which proliferate in the presence of EIAV antigen are present in the peripheral blood of infected horses 143, and may be involved in the lymphoproliferative lesions seen in the liver, lymph nodes and spleen (Shively et al, 1982). Evaluation of horses with persistent EIAV infection found no defect in B-and T-lymphocytes numbers or ability to proliferate in response to in vitro stimuli (Banks et al, 1973).…”

Pronounced production of polyclonal immunoglobulin G1 in the synovial fluid of goats with caprine arthritis-encephalitis virus infection

“…The synovial fluid IgGl concentrations in goats varied above the serum values in a transient recurrent pattern and were above levels which could be explained by leakage of serum constituents into the inflamed joints. This pattern suggests recurrent local antibody synthesis in the inoculated joints and resembles the varying antiviral lymphocyte stimulation indices in animals infected by this and other lentiviruses (1,16,17,27,28). In these diseases, less pronounced fluctuations of neutralizing antibody occur in serum, but burst production of such antibodies might be concealed by the serum halflives of the immunoglobulins.…”