title: Activated platelet-T-cell conjugates in peripheral blood of patients with HIV infection: coupling coagulation/inflammation and T cells.
abstract: BACKGROUND
  Despite successfully suppressed viremia by treatment, patients with high levels of biomarkers of coagulation/inflammation are at an increased risk of developing non-AIDS defining serious illnesses such as cardiovascular diseases. Thus, there is a relationship between persistent immune activation and coagulation/inflammation, although the mechanisms are poorly understood. Platelets play an important role in this process. Although interactions between platelets and elements of the innate immune system, such as monocytes, are well described, little is known about the interaction between platelets and the adaptive immune system.
  
  
  METHODS
  We investigated the interaction of a component of the coagulation system, platelets, and the adaptive immune system T cells.
  
  
  METHODS
  Healthy controls and combination antiretroviral therapy (cART)-treated HIV-infected patients with viral loads of less than 40 copies/ml for more than 15 months were analysed for platelet-T-cell conjugate formation.
  
  
  RESULTS
  Platelets can form conjugates with T cells and were preferentially seen in CD4 and CD8 T-cell subsets with more differentiated phenotypes [memory, memory/effector and terminal effector memory (TEM)]. Compared with healthy controls, these conjugates in patients with HIV infection were more frequent, more often composed of activated platelets (CD42bCD62P), and were significantly associated with the D-dimer serum levels.
  
  
  CONCLUSIONS
  These data support a model in which platelet-T-cell conjugates may play a critical role in the fast recruitment of antigen-experienced T cells to the place of injury. This mechanism can contribute in maintaining a state of coagulation/inflammation observed in these patients contributing to the pathology of the disease.
authors.affiliation: aCMRS/Laboratory of Immunoregulation bResearch Technology Branch, NIAID, NIH, Bethesda cElectron Microscopy Laboratory, Cancer Research Technology Program dLaboratory of Human Retrovirology, Leidos Biomedical Research, Inc. Frederick eLaboratory of Pathology, NCI, NIH fBiostatistics Research Branch, DCR, NIAID, NIH, Bethesda gAIDS Monitoring Laboratory, Leidos Biomedical Research, Inc., Frederick, Maryland, USA.
authors.forename: Samantha A
authors.initials: SA
authors.lastname: Green
authors.forename: Mindy
authors.initials: M
authors.lastname: Smith
authors.forename: Rebecca B
authors.initials: RB
authors.lastname: Hasley
authors.forename: David
authors.initials: D
authors.lastname: Stephany
authors.forename: Adam
authors.initials: A
authors.lastname: Harned
authors.forename: Kunio
authors.initials: K
authors.lastname: Nagashima
authors.forename: Shahed
authors.initials: S
authors.lastname: Abdullah
authors.forename: Stefania
authors.initials: S
authors.lastname: Pittaluga
authors.forename: Tomozumi
authors.initials: T
authors.lastname: Imamichi
authors.forename: Jing
authors.initials: J
authors.lastname: Qin
authors.forename: Adam
authors.initials: A
authors.lastname: Rupert
authors.forename: Alex
authors.initials: A
authors.lastname: Ober
authors.forename: H Clifford
authors.initials: HC
authors.lastname: Lane
authors.forename: Marta
authors.initials: M
authors.lastname: Catalfamo
mesh_terms: D015415:Biomarkers / Q000097:blood*; D001777:Blood Coagulation; D001792:Blood Platelets / Q000276:immunology*; D018791:CD4 Lymphocyte Count; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D016022:Case-Control Studies; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D015658:HIV Infections / Q000097:blood*; D006801:Humans; D007249:Inflammation / Q000276:immunology*; D008213:Lymphocyte Activation; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D019562:Viral Load; D014766:Viremia / Q000188:drug therapy
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D