title: Depletion of pro-inflammatory CD161(+) double negative (CD3(+)CD4(-)CD8(-)) T cells in AIDS patients is ameliorated by expansion of the γδ T cell population.
abstract: In this present investigation, flow cytometry was utilized to evaluate 13 healthy controls and 31 HIV-1 infected patients who had advanced to the AIDS stage of infection (CD4 count below 200 cells/mm(3)), for the expression of CD161 on CD3(+) double negative (DN) (CD3(+)CD4(-)CD8(-)) T cells, CD4(+) T cells, CD8(+) T cells and γδ T cells. The observed depletion of CD161(+) T cells from peripheral circulation was due primarily to the loss of CD4(+)CD161(+) T cells; as these cells represented 8.67±0.74% of the total healthy control peripheral T cell population, while the CD4(+)CD161(+) T cells of the AIDS group represented only 3.35±0.41% (p=<0.0001) of the total peripheral T cell population. We have also shown here that the DN T cell population was more than doubled in the AIDS group, with the DN T cell population expanding from 3.29±0.45% of the healthy control peripheral T cell population to 8.64±1.16% (p=0.0001) of the AIDS group peripheral T cell population. By evaluating the expression of CD161 on the surface of the DN T cells we showed that within the healthy control group, 47.4±4.99% of the DN T cells were positive for the expression of CD161, while only 26.4±3.54% (p=0.002) of the AIDS group's DN T cells expressed CD161. Despite CD161 expression being halved on the DN T cells of the AIDS group, when we compared the total peripheral T cell percentage of CD161(+) DN T cells between the healthy control group and the AIDS group, there was no statistical difference. Even though only 26.4% DN T cells within the AIDS group were positive for CD161(+), the overall DN T cell population had expanded to such an extent that there was no statistical difference between the groups with regard to CD161(+) DN T cells as a percentage of the total peripheral T cell population. Furthermore, we showed that within the DN T cell population, there was an approximate 2:1 ratio of γδ to αβ T cells, and this ratio was maintained in both the healthy control group and the AIDS group. While evaluating γδ T cells we also discovered that CD8(+) γδ T cells were expanded from 0.62±.09% of the healthy control peripheral T cell population to 5.01±.88% (p=<0.0001) of the peripheral T cell population of the AIDS group; and that this population of CD8(+) γδ T cells underwent the same reduction in percentage of cells expressing CD161(+), further demonstrated that the phenomenon of CD161(+) percentage reduction and compensatory increase in total cell population was affecting the entire circulating γδ T cell population.
authors.affiliation: University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216, United States. wsingleterry123@gmail.com
authors.forename: Will L
authors.initials: WL
authors.lastname: Singleterry
authors.forename: Harold
authors.initials: H
authors.lastname: Henderson
authors.forename: Julius M
authors.initials: JM
authors.lastname: Cruse
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000097:blood / Q000276:immunology* / Q000821:virology; D017252:CD3 Complex / Q000276:immunology / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016827:CD8 Antigens / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D005434:Flow Cytometry; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D016130:Immunophenotyping; D008213:Lymphocyte Activation / Q000276:immunology; D018655:Lymphocyte Count; D008297:Male; D055651:NK Cell Lectin-Like Receptor Subfamily B / Q000378:metabolism*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D017252:CD3 Complex; D016827:CD8 Antigens; C527203:KLRB1 protein, human; D055651:NK Cell Lectin-Like Receptor Subfamily B; D016692:Receptors, Antigen, T-Cell, gamma-delta