The Mode and Duration of Anti-CD28 Costimulation Determine Resistance to Infection by Macrophage-Tropic Strains of Human Immunodeficiency Virus Type 1 In Vitro

Abstract

We have investigated the ability of anti-CD28 antibody costimulation to induce resistance to macrophage (M)-tropic strains of human immunodeficiency virus type 1 (HIV-1) in vitro. Our results confirm the observations of Levine et al. (15) that stimulation of CD4 T cells with anti-CD3/anti-CD28 antibodies coimmobilized on magnetic beads renders the cells resistant to infection by M-tropic strains of HIV-1. The resistance was strongest when the beads were left in the cultures throughout the experiment. In contrast, stimulation of CD4 T cells with the same antibodies immobilized on the surface of plastic culture dishes failed to induce resistance and resulted in high levels of p24 production. This was true even if the cells were passaged continuously on freshly coated plates. If the beads were removed after initial stimulation, p24 production increased over time and produced a result intermediate to the other forms of stimulation. For beads-in, beads-out, and one-time plate stimulated cultures, resistance to infection correlated with down-regulation of CCR5 expression at the cell surface and with increased production of β-chemokines. However, cultures of CD4 T cells continuously passaged on anti-CD3/anti-CD28-coated plates produced large amounts of p24 despite decreased levels of CCR5 expression and increasing production of β-chemokines. Expression of the T-cell activation markers CD25 and CD69 and production of gamma interferon further supported the differences in plate versus bead stimulation. Our results explain the apparent contradiction between the ability of anti-CD28 antibody costimulation to induce resistance to HIV infection when presented on magnetic beads and the increased ability to recover virus from the cells of HIV-positive donors who are on highly active antiretroviral therapy when cells are stimulated by anti-CD3/anti-CD28 immobilized on plastic dishes.

HIV-1 latency is established preferentially in minimally activated and non-dividing cells during productive infection of primary CD4 T cells

“…And, it is necessary for biologically relevant evaluation of how and to what extent viral tropism may affect the mechanisms of establishment and maintenance of viral latency in different CD4 T cell subsets in vivo . Because the CCR5 receptor is expressed predominantly on memory cells, and its level of expression is highly sensitive to the form of T cell activation used during in vitro culture [ 74 ], it is extremely likely that had we been able to use a CCR5-tropic HIV clone to establish infection in our model of latency, the results obtained may have reflected quite different ratios for the prevalence of latent infection in CD4 T cells with minimal activation and cell proliferation.…”

Determination of cell expansion and surface molecule expression on anti‐CD3/28 expanded CD4+ T cells

“…The in vitro expanded CD4 + T cells with anti‐CD3/28 activation were proved to be resistant to HIV‐1 infection via the reduction in frequencies and densities of CCR5 molecules . Our expanded cells also rendered a low frequency in CCR5 (<15% of CD4 + T cells) which presumably maintain at this low level because the recovery of CCR5 expression was low when activation with anti‐CD3/28‐coated beads compared to stimulation with anti‐CD3/28 immobilized on the surface of a tissue culture plate . Our anti‐CD3/28 activation protocol also rendered the expanded CD4 + T cells with twice as less CXCR4 expression than the unexpanded cells.…”

CD18 is redundant for the response to multiple vaccines: A case study

“…Except for IL-2, patient cytokine levels were approximately twofold to threefold (IL-33), fourfold to 11-fold (IL-6), and >10-fold higher (CXCL13) than controls levels (7 days post-vaccination samples from three PCV and diphtheria-tetanus booster-vaccinated healthy adult controls) (Figure 1). Three days of in vitro stimulation with a combination of anti-CD3/anti-CD28-coated beads, which in itself constitutes a very potent stimulatory modality,3 and IL-2 (10 ng/mL) showed that seven days post-vaccination patient CD4 + T cells displayed more intracellular Bcl-6 (13.9% of CD4 + T cells) than those of a vaccinated control(5.2% of CD4 + T cells, data not shown) but only marginally more intracellular CXCL13 (9.8% of CD4 + T cells) compared to the vaccinated control (7.9% of CD4 + T cells, data not shown). Under steady-state conditions and in response to anti-CD3/anti-CD28 stimulation, approximately 3% of peripheral CD4 + T cells are intracellular CXCL13 + .…”