title: An immunohistologic study of granulomatous inflammation in SIV-infected rhesus monkeys.
abstract: We studied granulomatous inflammation in simian AIDS using histologic, immunohistologic, and in situ hybridization techniques. Complete Freund's adjuvant was used to induce granulomas in two control animals and two macaques infected with simian immunodeficiency virus (SIV) and having low peripheral CD4+ T cell counts. Control animals developed large (> 2 cm diameter) epithelioid granulomas containing CD68+ macrophages (m phi s), epithelioid m phi s and multinucleated giant cells (MNGCs), CD4+ and CD8+ T cells, and small perivascular collections of CD20+ B cells. Lymphocytes rarely expressed proliferating cell nuclear antigen (Ki-67), and only rare endothelial cells expressed vascular cell adhesion molecule 1 (VCAM-1). In contrast, SIV+ animals had smaller (< 0.5 cm diameter) epithelioid granulomas characterized by numerous large, dense CD8+, CD20+ lymphocyte aggregates with prominent local division (Ki-67+). Despite low blood CD4+ T cell numbers, there was a substantial CD4+ T cell infiltrate, accompanied by enhanced endothelial VCAM-1 expression. These granulomas contained no detectable SIV antigen or RNA. Thus, in simian AIDS, experimentally induced granulomatous responses are grossly attenuated, yet associated with increased local endothelial-leukocyte signaling and lymphocyte division.
authors.affiliation: Division of Comparative Pathology, Harvard Medical School, New England Regional Primate Research Center, Southborough, MA 01772-9102.
authors.forename: C J
authors.initials: CJ
authors.lastname: Horvath
authors.forename: R D
authors.initials: RD
authors.lastname: Hunt
authors.forename: M A
authors.initials: MA
authors.lastname: Simon
authors.forename: P K
authors.initials: PK
authors.lastname: Sehgal
authors.forename: D J
authors.initials: DJ
authors.lastname: Ringler
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000032:analysis; D018951:Antigens, CD20; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D015815:Cell Adhesion Molecules / Q000032:analysis; D002452:Cell Count; D002455:Cell Division; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D005620:Freund's Adjuvant; D006099:Granuloma / Q000378:metabolism / Q000382:microbiology / Q000473:pathology*; D007150:Immunohistochemistry; D016130:Immunophenotyping; D017403:In Situ Hybridization; D008199:Lymphadenitis / Q000209:etiology / Q000473:pathology; D008253:Macaca mulatta; D016097:Simian Acquired Immunodeficiency Syndrome / Q000378:metabolism / Q000473:pathology*; D015302:Simian Immunodeficiency Virus / Q000302:isolation & purification* / Q000378:metabolism / Q000502:physiology; D013601:T-Lymphocytes / Q000276:immunology / Q000473:pathology; D019010:Vascular Cell Adhesion Molecule-1
chemical_list: D015703:Antigens, CD; D018951:Antigens, CD20; D000944:Antigens, Differentiation, B-Lymphocyte; D015704:CD4 Antigens; D016827:CD8 Antigens; D015815:Cell Adhesion Molecules; D004279:DNA, Viral; D019010:Vascular Cell Adhesion Molecule-1; D005620:Freund's Adjuvant