Expansion of a CD8+CD28- cell population in the blood and lung of HIV-positive patients

J Acquir Immune Defic Syndr (1988). 1993 Nov;6(11):1194-204.


CD8+ cytotoxic T lymphocytes (CTLs) in human immunodeficiency virus (HIV) patients have defects in cytolytic ability and proliferative potential. The surface receptor CD28 is important in regulating antigen-specific responses to T cells. We hypothesized that activated CD8+ CTLs in HIV patients would have altered expression of CD28. We examined surface expression of D44, a CD8+ CTL marker, and of CD28 on T cells from blood and bronchoalveolar lavage from HIV+ patients and normal volunteers. We found no significant difference between normal volunteers and HIV+ individuals in percentage of CD8+D44+ CTLs in blood or the lung. In contrast, CD8+CD28- T cells in the blood of HIV patients constituted 74% of CD8+ cells compared to 25% in normal subjects (p = 0.001), findings exaggerated in both normal and HIV+ lung. CD4+CD28- blood T cells were significantly increased in HIV+ patients compared to normal subjects (24 vs. 1.5%, p = 0.004). The HIV infection itself did not directly downmodulate CD28 expression, demonstrated in the CD28+ SUPT1 cell line. Increased numbers of CD28- T cells may be the result of immunologic activation or of expansion of a preexisting CD28- subset. These findings have immunologic consequences for the antigen-specific response of T cells in HIV+ patients.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Bronchoalveolar Lavage Fluid / cytology
  • Bronchoalveolar Lavage Fluid / immunology
  • CD28 Antigens / analysis*
  • CD28 Antigens / blood
  • CD8 Antigens / analysis*
  • CD8 Antigens / blood
  • Flow Cytometry
  • HIV Infections / immunology*
  • Humans
  • Leukocyte Count
  • Lung / immunology*
  • Middle Aged
  • T-Lymphocyte Subsets


  • CD28 Antigens
  • CD8 Antigens