Expression of adhesion molecules and CD28 on T lymphocytes during human immunodeficiency virus infection

Abstract

Adhesion molecules, which play a major role in lymphocyte circulation, have not been well characterized in human immunodeficiency virus (HIV) infection. T-lymphocyte populations, including CD3, CD4, CD28, and adhesion molecules (L selectin, LFA-1, VLA-4, and ICAM-1) were measured by flow cytometry in a cross-sectional study of 100 HIV-infected and 49 HIV-seronegative adults. HIV-infected adults had lower numbers of CD3+ lymphocytes expressing L selectin (P < 0.0001) and VLA-4 (P < 0.01) and higher numbers of CD3+ lymphocytes expressing LFA-1bright (P < 0.002) than did HIV-negative adults. By CD4+-lymphocyte count category (>500, 200 to 500, or <200 cells/microl), HIV-infected adults with more advanced disease had lower percentages of CD3+ lymphocytes expressing L selectin and VLA-4 and higher percentages of CD3+ lymphocytes expressing LFA-1. The percentages of CD3+ CD28+ lymphocytes and of CD3+ L selectin+ lymphocytes were positively correlated (Spearman coefficient = 0.86; P < 0.0001), and the percentage of CD3+ CD28+ lymphocytes and the CD3+ LFA-1bright lymphocyte/CD3+ LFA-1dim lymphocyte ratio were negatively correlated (Spearman coefficient = -0.92; P < 0.00001). The results of this study suggest that HIV infection is associated with altered expression of adhesion molecules.

FIG. 1

Representative immunofluorescence histograms of adhesion molecules and CD3 expression on lymphocytes from HIV-seronegative and HIV-seropositive individuals. Quadrant settings for the four regions were established such that <2% of positive events in the isotype control sample fell in any positive region.

FIG. 2

Expression of L selectin, VLA-4, and LFA-1 on CD3⁺ lymphocytes by HIV status and CD4⁺-lymphocyte count category. SN, seronegative; HIV SP, HIV seropositive. The bars represent the medians (horizontal) and the 25th and 75th percentiles (vertical).

FIG. 3

Expression of CD28⁺ on CD3⁺-, CD4⁺-, and CD8⁺-lymphocyte subsets by HIV status and CD4⁺-lymphocyte count category. SN, seronegative; HIV SP, HIV seropositive. The bars represent the medians (horizontal) and the 25th and 75th percentiles (vertical).

FIG. 4

(a) Percentage of CD3⁺ CD28⁺ lymphocytes expressing L selectin (Spearman correlation coefficient = 0.86; P < 0.0001). (b) Percentage of CD3⁺ CD28⁺ lymphocytes versus LFA-1^bright/LFA-1^dim ratio (Spearman correlation coefficient = 0.92; P < 0.00001).