HTLV-III EXPRESSION IN INFECTED LYMPH-NODES AND RELEVANCE TO PATHOGENESIS OF LYMPHADENOPATHY

  • 1 December 1986
    • journal article
    • research article
    • Vol. 125  (3) , 436-442
Abstract
In situ hybridization with a 35S-labeled probe of cryosections from 14 lymph nodes of HTLV-III/LAV-seropositive individuals with lymphadenopathy showed the presence of rare cells containing HTLV-III RNA at levels consistent with virus replication. Positive cells were observed at a frequency of only 1-10 per section. In all lymph nodes studied, including those showing follicular hyperplasia or involution, most of the cells expressing viral RNA were present in the follicular areas. Only a minority of such cells were found outside the follicles. The nature of the follicular, virus-replicating cells was not evident from the processed cryosections. After prolonged autoradiography, another pattern of hybridization was observed, suggesting low levels of viral RNA diffusely distributed through-out most, but not all, follicles. This may represent extracellular virus and/or virus-antibody complexes, but was not consistent with intracellular viral RNA or phagocytosed virus particles. Comparison of hybridization levels in relation to histology suggested a decrease in both the number of HTLV-III replicating cells as well as in the diffusely distributed viral RNA with progression of follicular involution. Our observations indicate that in HTLV-III-infected subjects, lymph node follicles are an important site of virus replication and trapping, suggesting a decisive role of the virus in the characteristic reactive and cytopathogenic changes of HTLV-III-associated lymphadenopathy.