Single-cell, phosphoepitope-specific analysis demonstrates cell type- and pathway-specific dysregulation of Jak/STAT and MAPK signaling associated with in vivo human immunodeficiency virus type 1 infection.
Despite extensive evidence of cell signaling alterations induced by human immunodeficiency virus type 1 (HIV-1) in vitro, the relevance of these changes to the clinical and/or immunologic status of HIV-1-infected individuals is often unclear. As such, mapping the details of cell type-specific degradation of immune function as a consequence of changes to signaling network responses has not been readily accessible. We used a flow cytometric-based assay of signaling to determine Janus kinase/signal transducers and activators of transcription (Jak/STAT) signaling changes at the single-cell level within distinct cell subsets from the primary immune cells of HIV-1-infected donors. We identified a specific defect in granulocyte-macrophage colony-stimulating factor (GM-CSF)-driven Stat5 phosphorylation in the monocytes of HIV-1+ donors. This inhibition was statistically significant in a cohort of treated and untreated individuals. Ex vivo Stat5 phosphorylation levels varied among HIV-1+ donors but did not correlate with CD4(+) T-cell counts or HIV-1 plasma viral load. Low Stat5 activation occurred in HIV-1-infected donors despite normal GM-CSF receptor levels. Investigation of mitogen-activated protein kinase (MAPK) pathways, also stimulated by GM-CSF, led to the observation that lipopolysaccharide-stimulated extracellular signal-regulated kinase phosphorylation is enhanced in monocytes. Thus, we have identified a specific, imbalanced monocyte signaling profile, with inhibition of STAT and enhancement of MAPK signaling, associated with HIV-1 infection. This understanding of altered monocyte signaling responses that contribute to defective antigen presentation during HIV-1 infection could lead to immunotherapeutic approaches that compensate for the deficiency.
Lee
Andrew W
AW
Division of Experimental Medicine, University of California at San Francisco, 1001 Potrero Ave., Bldg. 3, UCSF Box 1234, San Francisco, CA 94143-1234, USA.
Sharp
Elizabeth R
ER
O'Mahony
Alison
A
Rosenberg
Michael G
MG
Israelski
Dennis M
DM
Nolan
Garry P
GP
Nixon
Douglas F
DF
D000293:Adolescent; D000954:Antigens, Surface / Q000032:analysis; D018791:CD4 Lymphocyte Count; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D048049:Extracellular Signal-Regulated MAP Kinases; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000276:immunology* / Q000378:metabolism; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007223:Infant; D008297:Male; D009000:Monocytes / Q000737:chemistry; D010766:Phosphorylation; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / Q000032:analysis; D050799:STAT5 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction; D019562:Viral Load
D000954:Antigens, Surface; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; D050799:STAT5 Transcription Factor; D048049:Extracellular Signal-Regulated MAP Kinases