Evidence for simian immunodeficiency virus-specific IgM and IgG response in peripheral blood mononuclear cells of serum enzyme-linked immunosorbent assay-negative nonhuman primates.
In vitro polyclonal activation of peripheral blood mononuclear cells (PBMCs) from 70% of the simian immunodeficiency virus (SIV) serum enzyme-linked, immunosorbent assay (ELISA)-negative sooty mangabeys leads to synthesis and release of low but significant and reproducible levels of SIV-reactive antibodies, as determined by ELISA and Western blot analysis. The predominant isotype of SIV-reactive antibodies in the pokeweed mitogen (PWM) supernatant fluids from serum ELISA-negative mangabeys is IgM, whereas the predominant isotype of SIV-reactive antibodies in seropositive mangabeys is IgG. Depletion of CD8+ cells led to a marked increase in the levels of SIV-reactive antibodies detected in supernatant fluids from PWM-induced cultures from the serum ELISA-negative mangabeys. No evidence for such SIV-reactive antibodies has been found, to date, in similar unfractionated or CD8+ T-cell-depleted PWM-induced PBMC cultures from uninfected macaques. Supernatant fluids from PWM cultures of PBMCs from a select group of serum ELISA-negative mangabeys, when concentrated five times, were shown to give a Western blot profile against SIV, similar to the profile seen with plasma from seropositive infected macaques and mangabeys. Evidence is presented to show that these serum ELISA-negative mangabeys are most likely latently infected with SIV. This evidence, which was obtained in samples from such ELISA-negative mangabeys, includes the detection of reverse transcriptase activity and the presence of SIV p27 in supernatant fluids of phytohemagglutinin-stimulated PBMCs in vitro. In addition, the data show the presence of CD8+ T cells that regulate SIV-specific Ig synthesis and show the detection of gag sequences by the polymerase chain reaction. Thus, the PWM assay described herein may provide a valuable additional tool for detection of lentivirus infection before or in the absence of seroconversion.
Jehuda-Cohen
T
T
Department of Pathology and Laboratory Medicine, Winship Cancer Center, Emory University School of Medicine, Atlanta, Georgia 30322.
Powell
J D
JD
Villinger
F
F
Mayne
A E
AE
Sell
K W
KW
Ansari
A A
AA
D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D000918:Antibody Specificity; D015153:Blotting, Western; D002478:Cells, Cultured; D016665:Cercocebus atys; D004797:Enzyme-Linked Immunosorbent Assay; D007074:Immunoglobulin G / Q000096:biosynthesis*; D007075:Immunoglobulin M / Q000096:biosynthesis*; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000382:microbiology*; D008253:Macaca mulatta; D016097:Simian Acquired Immunodeficiency Syndrome / Q000175:diagnosis / Q000276:immunology*; D015302:Simian Immunodeficiency Virus / Q000276:immunology* / Q000502:physiology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D017735:Virus Latency
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M