scholarly journals Proteome-wide analysis of HIV-specific naive and memory CD4+ T cells in unexposed blood donors

2014 ◽  
Vol 211 (7) ◽  
pp. 1273-1280 ◽  
Author(s):  
Suzanne L. Campion ◽  
Tess M. Brodie ◽  
William Fischer ◽  
Bette T. Korber ◽  
Astrea Rossetti ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Peptide Mapping ◽  
Human Microbiome ◽  
Effector Memory ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Memory Cd4 T Cells ◽  
Hiv 1

The preexisting HIV-1–specific T cell repertoire must influence both the immunodominance of T cells after infection and immunogenicity of vaccines. We directly compared two methods for measuring the preexisting CD4+ T cell repertoire in healthy HIV-1–negative volunteers, the HLA-peptide tetramer enrichment and T cell library technique, and show high concordance (r = 0.989). Using the library technique, we examined whether naive, central memory, and/or effector memory CD4+ T cells specific for overlapping peptides spanning the entire HIV-1 proteome were detectable in 10 HLA diverse, HIV-1–unexposed, seronegative donors. HIV-1–specific cells were detected in all donors at a mean of 55 cells/million naive cells and 38.9 and 34.1 cells/million in central and effector memory subsets. Remarkably, peptide mapping showed most epitopes recognized by naive (88%) and memory (56%) CD4+ T cells had been previously reported in natural HIV-1 infection. Furthermore, 83% of epitopes identified in preexisting memory subsets shared epitope length matches (8–12 amino acids) with human microbiome proteins, suggestive of a possible cross-reactive mechanism. These results underline the power of a proteome-wide analysis of peptide recognition by human T cells for the identification of dominant antigens and provide a baseline for optimizing HIV-1–specific helper cell responses by vaccination.

Reconstitution of the T Cell Repertoire Following Treatment with Alemtuzumab in Patients with B-Cell Chronic Lymphocytic Leukemia (B-CLL).

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2986-2986
Author(s):  
Mohammad R. Rezvany ◽  
Mahmood J. Tehrani ◽  
Claes Karlsson ◽  
Jeanette Lundin ◽  
Hodjattallah Rabbani ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Long Term Follow Up

Abstract Background and Methods: B-cell chronic lymphocytic leukemia (B-CLL) occurs as a result of clonal accumulation of functionally abnormal B cells. Alemtuzumab is a humanized monoclonal antibody specific for the CD52 antigen, which is highly expressed on both B-CLL cells and normal lymphocytes, but not on hematopoietic (CD34) stem cells. Alemtuzumab has been shown to effectively deplete the blood and bone marrow of lymphocytes, including CD4 and CD8 T cells, which may lead to profound immunosuppression and make patients more susceptible to infections. We and others have previously shown that the CD4 T cells in B-CLL patients may be clonally distinct from the normal population in that they present a more clonal pattern of the T-cell receptor (TCR) repertoire (Rezvany et al, Blood2003;101:1063–1070). It is therefore of interest to study the T cell repertoire following alemtuzumab administration as well as factors affecting T cell reconstitution following CD52 targeted therapy. In this study, we evaluated in depth the T-cell receptor-beta-variable sequence (TCR BV) in CD4 and CD8 T cells by real-time PCR, before and repeatedly after/during long term follow-up, in 5 B-CLL patients who had received alemtuzumab as first-line therapy (Lundin et al, Blood2002;100:768–773). Also, an analysis was conducted of CDR3 length polymorphism to describe changes in the clonality pattern. Results: A decline in most of BV genes either in CD4 or CD8 T cells was observed shortly after alemtuzumab treatment, which was followed by a gradual increase in most of the BV genes during long-term follow up. CDR3 length polymorphism analysis shortly after treatment revealed an even more highly restricted pattern in CD4 T cells compared to baseline with a shift towards a monoclonal/oligoclonal pattern regardless of increased or decreased BV usage. Furthermore, in the analysis of the clonal spectrum that was expressed shortly after alemtuzumab therapy, the number of peaks was significantly reduced in CD4 (P <0.01) but not in CD8 T cells, which was followed by a gradual increase in diversity towards a polyclonal repertoire during long-term follow up. Conclusions: These results indicate that perturbations in the T cell repertoire following alemtuzumab are complex, and are not reflected by changes in CD4/CD8 T cell numbers only. The restricted CDR3 pattern present prior to therapy became even more restricted after end of treatment, followed by a normalization of CDR3 patterns in CD4 T-cells during long-term follow-up. These results further suggest a regulatory role for T cells in relation to the malignant B cell clone in patients with B-CLL.

CCR7 ligands CCL19 and CCL21 increase permissiveness of resting memory CD4+ T cells to HIV-1 infection: a novel model of HIV-1 latency

Blood ◽  
2007 ◽  
Vol 110 (13) ◽  
pp. 4161-4164 ◽  
Author(s):  
Suha Saleh ◽  
Ajantha Solomon ◽  
Fiona Wightman ◽  
Miranda Xhilaga ◽  
Paul U. Cameron ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Lymphocyte Migration ◽  
Major Barrier ◽  
Memory Cd4 T Cells ◽  
Novel Model ◽  
Hiv 1

Latent HIV-1 infection of resting memory CD4+ T cells represents the major barrier to HIV-1 eradication. To determine whether the CCR7 ligands involved in lymphocyte migration can alter HIV-1 infection of resting CD4+ T cells, we infected purified resting CD4+ T cells after incubation with the chemokines CCL19 and CCL21. Incubation with CCL19 or CCL21 did not alter markers of T-cell activation or proliferation. However, after HIV-1 infection of CCL19- or CCL21-treated CD4+ T-cells, we observed low-level HIV-1 production but high concentrations of integrated HIV-1 DNA, approaching that seen in mitogen-stimulated T-cell blasts. Restimulation of CCL19-treated infected CD4+ T cells resulted in virus production consistent with establishment of postintegration latency. CCR7 ligands facilitate efficient entry of HIV-1 into resting CD4+ T cells. These studies demonstrate a unique action of the chemokines CCL19 and CCL21 and provide a novel model with which to study HIV-1 latency in vitro.

scholarly journals Kynurenine Reduces Memory CD4 T-Cell Survival by Interfering with Interleukin-2 Signaling Early during HIV-1 Infection

2016 ◽  
Vol 90 (17) ◽  
pp. 7967-7979 ◽  
Author(s):  
Xavier Dagenais-Lussier ◽  
Mouna Aounallah ◽  
Vikram Mehraj ◽  
Mohamed El-Far ◽  
Cecile Tremblay ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Survival ◽  
Cd4 T Cells ◽  
Interleukin 2 ◽  
Cd4 T Cell ◽  
Tryptophan Catabolism ◽  
T Cell Survival ◽  
Memory Cd4 T Cells ◽  
Hiv 1

ABSTRACTEarly HIV-1 infection is characterized by enhanced tryptophan catabolism, which contributes to immune suppression and disease progression. However, the mechanism by which kynurenine, a tryptophan-related metabolite, induces immune suppression remains poorly understood. Herein, we show that the increased production of kynurenine correlates with defective interleukin-2 (IL-2) signaling in memory CD4 T cells from HIV-infected subjects. Defective IL-2 signaling in these subjects, which drives reduced protection from Fas-mediated apoptosis, was also associated with memory CD4 T-cell loss. Treatment of memory CD4 T cells with the concentration of kynurenine found in plasma inhibited IL-2 signaling through the production of reactive oxygen species. We further show that IL-2 signaling in memory CD4 T cells is improved by the antioxidantN-acetylcysteine. Early initiation of antiretroviral therapy restored the IL-2 response in memory CD4 T cells by reducing reactive oxygen species and kynurenine production. The study findings provide a kynurenine-dependent mechanism through IL-2 signaling for reduced CD4 T-cell survival, which can be reversed by early treatment initiation in HIV-1 infection.IMPORTANCEThe persistence of functional memory CD4 T cells represents the basis for long-lasting immune protection in individuals after exposure to HIV-1. Unfortunately, primary HIV-1 infection results in the massive loss of these cells within weeks of infection, which is mainly driven by inflammation and massive infection by the virus. These new findings show that the enhanced production of kynurenine, a metabolite related to tryptophan catabolism, also impairs memory CD4 T-cell survival and interferes with IL-2 signaling early during HIV-1 infection.

scholarly journals 343. T-cell Subsets Associated with Diabetes in Veterans with and without HIV

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S182-S183
Author(s):  
Samuel Bailin ◽  
Kathleen McGinnis ◽  
Wyatt J McDonnell ◽  
Kaku So-Armah ◽  
Melissa Wellons ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Immune Activation ◽  
Cd4 T Cells ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Hiv Status ◽  
Adaptive Immune ◽  
Memory Cd4 T Cells

Abstract Background Depletion of naïve CD4+ T cells and elevated adaptive immune activation are hallmarks of HIV infection. Higher proportions of memory CD4+ T cells are associated with prevalent diabetes in the general population, but few studies of persons with HIV (PWH) exist. Methods We analyzed data from 1532 PWH and 836 uninfected veterans in the longitudinal Veterans Aging Cohort Study (VACS), which archived peripheral mononuclear cells from these veterans between 2005 and 2007. We used flow cytometry to phenotype CD4+ and CD8+ T cells, including naïve, activated CD38+, senescent CD57+, total memory, and memory subsets. Prevalent diabetes (at blood collection) was identified in the VA electronic medical record using random glucose, hemoglobin A1c, ICD-9 codes, and medication. Cases were validated by two-physician chart review. We used multivariate logistic regression models adjusted for age, gender, body mass index, race/ethnicity, unhealthy alcohol use, hepatitis C, CMV status, and viral suppression stratified by HIV status to identify T-cell subsets associated with diabetes in PWH and uninfected. Results The cohort was 95% male, 68% African-American, and 22% diabetic. Higher CD4+CD45RO+ memory T cells were associated with prevalent diabetes in the uninfected and in PWH (P = 0.03 and P = 0.07, respectively; Figure A). Among subsets, diabetes was associated with higher transitional memory CD4+ T cells in the uninfected (P = 0.01), but higher central memory cells (P = 0.02) and lower effector memory cells (P = 0.04) in PWH. T effector memory RA+ cells were not associated with diabetes. Lower senescent CD4+CD57+ T cells were associated with diabetes in both PWH and uninfected (P = 0.03 and P = 0.04, respectively; Figure B), but results for naïve CD8+ T cells diverged: diabetes was associated with higher naïve CD8+cells in PWH but lower in uninfected (P = 0.01 and P < 0.01, respectively; Figure C). We assessed interaction by HIV status in a pooled model, which was only significant for the naïve CD8+ T cells (P = 0.01). Conclusion The adaptive immune profile associated with prevalent diabetes was similar by HIV status and characterized by a shift in CD4+ T cells from senescent to memory phenotypes, suggesting that chronic immune activation contributes to the higher risk of diabetes in PWH. Disclosures All authors: No reported disclosures.

scholarly journals Quantitative Analysis of the T Cell Repertoire Selected by a Single Peptide–Major Histocompatibility Complex

1998 ◽  
Vol 187 (11) ◽  
pp. 1871-1883 ◽  
Author(s):  
Laurent Gapin ◽  
Yoshinori Fukui ◽  
Jean Kanellopoulos ◽  
Tetsuro Sano ◽  
Armanda Casrouge ◽  
...  
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Mhc Class Ii ◽  
Cd4 T Cells ◽  
Class Ii ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Histocompatibility Complex ◽  
Single Peptide

The positive selection of CD4+ T cells requires the expression of major histocompatibility complex (MHC) class II molecules in the thymus, but the role of self-peptides complexed to class II molecules is still a matter of debate. Recently, it was observed that transgenic mice expressing a single peptide–MHC class II complex positively select significant numbers of diverse CD4+ T cells in the thymus. However, the number of selected T cell specificities has not been evaluated so far. Here, we have sequenced 700 junctional complementarity determining regions 3 (CDR3) from T cell receptors (TCRs) carrying Vβ11-Jβ1.1 or Vβ12-Jβ1.1 rearrangements. We found that a single peptide–MHC class II complex positively selects at least 105 different Vβ rearrangements. Our data yield a first evaluation of the size of the T cell repertoire. In addition, they provide evidence that the single Eα52-68–I-Ab complex skews the amino acid frequency in the TCR CDR3 loop of positively selected T cells. A detailed analysis of CDR3 sequences indicates that a fraction of the β chain repertoire bears the imprint of the selecting self-peptide.

scholarly journals Inducible colitis-associated glycome capable of stimulating the proliferation of memory CD4+ T cells

2012 ◽  
Vol 209 (13) ◽  
pp. 2383-2394 ◽  
Author(s):  
Atsushi Nishida ◽  
Kiyotaka Nagahama ◽  
Hirotsugu Imaeda ◽  
Atsuhiro Ogawa ◽  
Cindy W. Lau ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Cell Expansion ◽  
Intestinal Inflammation ◽  
Cd4 T Cell ◽  
Effector Memory ◽  
Glycan Structure ◽  
T Cell Expansion ◽  
Memory Cd4 T Cells

Immune responses are modified by a diverse and abundant repertoire of carbohydrate structures on the cell surface, which is known as the glycome. In this study, we propose that a unique glycome that can be identified through the binding of galectin-4 is created on local, but not systemic, memory CD4+ T cells under diverse intestinal inflammatory conditions, but not in the healthy state. The colitis-associated glycome (CAG) represents an immature core 1–expressing O-glycan. Development of CAG may be mediated by down-regulation of the expression of core-2 β1,6-N-acetylglucosaminyltransferase (C2GnT) 1, a key enzyme responsible for the production of core-2 O-glycan branch through addition of N-acetylglucosamine (GlcNAc) to a core-1 O-glycan structure. Mechanistically, the CAG seems to contribute to super raft formation associated with the immunological synapse on colonic memory CD4+ T cells and to the consequent stabilization of protein kinase C θ activation, resulting in the stimulation of memory CD4+ T cell expansion in the inflamed intestine. Functionally, CAG-mediated CD4+ T cell expansion contributes to the exacerbation of T cell–mediated experimental intestinal inflammations. Therefore, the CAG may be an attractive therapeutic target to specifically suppress the expansion of effector memory CD4+ T cells in intestinal inflammation such as that seen in inflammatory bowel disease.

Reconstitution of the T-Cell Compartment After Bone Marrow Transplantation: Restoration of the Repertoire by Thymic Emigrants

Blood ◽  
1998 ◽  
Vol 92 (11) ◽  
pp. 4464-4471 ◽  
Author(s):  
Florence Dumont-Girard ◽  
Etienne Roux ◽  
René A. van Lier ◽  
Geoff Hale ◽  
Claudine Helg ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Bone Marrow Transplantation ◽  
T Cell ◽  
Cd4 T Cells ◽  
Marrow Transplantation ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Cell Compartment ◽  
Gvhd Prophylaxis

We have studied the reconstitution of the T-cell compartment after bone marrow transplantation (BMT) in five patients who received a graft-versus-host disease (GVHD) prophylaxis consisting of methotrexate, cyclosporin, and 10 daily injections (day −4 to day +5) of Campath-1G. This treatment eliminated virtually all T cells (7 ± 8 T cells/μL at day 14) which facilitated the analysis of the thymus-dependent and independent pathways of T-cell regeneration. During the first 6 months, the peripheral T-cell pool was repopulated exclusively through expansion of residual T cells with all CD4+ T cells expressing the CD45RO-memory marker. In two patients, the expansion was extensive and within 2 months, the total number of T cells (CD8>>CD4) exceeded 1,000/μL. In the other three patients, T cells remained low (87 ± 64 T cells/μL at 6 months) and remained below normal values during the 2 years of the study. In all patients, the first CD4+CD45RA+RO− T cells appeared after 6 months and accumulated thereafter. In the youngest patient (age 13), the increase was relatively fast and naive CD4+ T cells reached normal levels (600 T cells/μL) 1 year later. In the four adult patients (age 25 ± 5), the levels reached at that time-point were significantly lower (71 ± 50 T cells/μL). In all patients, the T-cell repertoire that had been very limited, diversified with the advent of the CD4+CD45RA+RO− T cells. Cell sorting experiments showed that this could be attributed to the complexity of the T-cell repertoire of the CD4+CD45RA+RO− T cells that was comparable to that of a normal individual and that, therefore, it is likely that these cells are thymic emigrants. We conclude that after BMT, the thymus is essential for the restoration of the T-cell repertoire. Because the thymic activity is restored with a lag time of approximately 6 months, this might explain why, in particular in recipients of a T-cell–depleted graft, immune recovery is delayed.

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