CROI 2018 Abstract eBook

Abstract eBook

Poster Abstracts

387 IMMUNE ACTIVATION CORRELATES WITH EXPRESSION OF CD32 ON CD4+ T CELLS OF HIV PATIENTS Melanie Wittner , Gabor Dunay, Johanna Eberhard, Julian Schulze zur Wiesch University Hospital Hamburg–Eppendorf, Hamburg, Germany Background: Recently, CD32, a low-affinity receptor for the IgG Fc fragment with no previously reported expression on T cells, has been described as specific surface marker of latently HIV infected CD4+ T cells. As most of the current findings are based on in vitro experiments and little is known about the frequency and distribution, we studied the CD32 expression on CD4+ T cell naïve and memory populations in blood and lymph nodes of HIV patients and healthy individuals. Methods: We analyzed peripheral blood samples of 36 HIV-1 infected patients (n=23 viremics/13=ART treated) and healthy individuals (n=14) using a multi- parametric flow cytometry determining surface expression of CD3, CD8, CD4, CD45RA, CCR7, CD27, CD25, CD127, CCR5, CCR6, CXCR4. Additionally, cells from 8 lymph nodes of HIV patients and uninfected individuals were examined. Results: Overall, expression of CD32 differed only slightly on total peripheral CD4+ T cells between viremic HIV patients, ART-treated and healthy individuals. The highest expression was found in peripheral memory CD4+ T cell sub populations of viremic patients. CD32+ CD4+ T cells showed higher immune activation and higher expression of CCR5+. Furthermore, expression of CD32 on total CD4+ T cells and memory T cell populations of viremic patients correlated with general cellular immune activation and integrated viral DNA. Compared to blood, CD32 expression was generally lower in lymph nodal CD4+ T cells. Conclusion: In line with previous reports on the nature of reservoir cells, effector memory cells expressed CD32 with a higher frequency. However, we hypothesize that the relationship between CD32 and the reservoirs of latently infected T cells is more complex as other host factors and immune activation seem to influence CD32 expression. Follow-up studies will have to re-evaluate CD32 as definite marker of latently HIV-infected CD4+ T cells.

HIV-1 infection on CD32 expression was determined in FACS-sorted CD4+ T lymphocytes stimulated with or without IL-2 (16 U/ml) and PHA (4 µg/ml) and/ or infected with an HIV-1 NL4-3-GFP virus modified to express Vpx (NL4-3*GFP- Vpx). Contribution of CD32+ cells to the viral reservoir was determined in sorted CD4+ T cells from healthy donors infected in vitro or from HIV+ patients by qPCR of integrated HIV-1 DNA. Results: Stimulation of CD4+ T cells with IL-2/PHA induced the expression of CD32 concomitant to the activation markers CD69 and HLA-DR. Infection with HIV-1 NL4-3*GFP-Vpx of non-stimulated or activated CD4 T cells increased CD32 expression that was strongly associated to HLA-DR or CD69 expression. Addition of the NNRTI efavirenz inhibited CD32 expression, indicating a virus replication induced effect. CD32 expression in CD4+ T cells from HIV+ individuals (n:12) under antiretroviral treatment indicated that a mean of 85% (70-94) of cells were CD32+/HLA-DR+. We found higher proviral DNA copies/cell in resting CD4+/CD32- T cells (n:5) infected in vitro with HIV-1 NL4-3*GFP-Vpx, except in one donor with significantly higher basal CD4 T cell activation (HLA-DR+/ CD69+ cells). There were no statistically significant (p:0.76, n:6) differences in the mean viral DNA copies/cell in CD32+ or CD32- CD4+ T cells from HIV+ individuals under therapy but 3 of 6 patients showed higher DNA copies/cell in CD32+ cells. However, total DNA copies were higher in the CD32- compartment in all patients (mean 18-fold). Conclusion: CD32 expression is a marker of CD4+ T cell activation in healthy donors and HIV+ patients. The viral reservoir lay outside the CD32+ component as the majority of HIV DNA copies are harbored in CD32- cells. HIV-1 latency may not be preferentially associated to CD32+ cells. Maria Salgado 1 , Victoria González 2 , Belén Rivaya 2 , Cristina Gálvez 1 , Mi Kwon 3 , Jon Badiola 4 , Alessandra Bandera 5 , Björn Jensen 6 , Linos Vandekerckhove 7 , Kavita Raj 8 , Monique Nijhuis 9 , Jose Luis Diez 3 , Annemarie Wensing 9 , Javier Martinez- Picado 1 1 IrsiCaixa Institute for AIDS Research, Badalona, Spain, 2 Hospital Germans Trias i Pujol, Barcelona, Spain, 3 University Hospital Gregorio Marañon, Madrid, Spain, 4 University Hospital Virgen de las Nieves, Granada, Spain, 5 San Gerardo Hospital, Monza, Italy, 6 Heinrich Heine University Hospital, Düsseldorf, Germany, 7 HIV Cure Research Center, Ghent University, Ghent, Belgium, 8 King’s College Hospital, London, UK, 9 University Medical Center Utrecht, Utrecht, Netherlands Background: Allogeneic stem cell transplantation (allo-SCT) in HIV-infected subjects with severe hematological malignancies is the only described strategy capable to dramatically reduce HIV latent reservoir. Whether this putative eradication strategy is associated with seroreversion has not been established yet. Within the IciStem Consortium, we explored the longitudinal serostatus of HIV+ individuals after allo SCT. Methods: Longitudinal plasma samples from 13 HIV+ allo-transplanted patients under cART were analyzed. HIV-1 serostatus was tested in a qualitative western blot assay (New Lav Blot I, Biorad). For 7 subjects with longer follow up (>2years) additional analysis was done using the standard and low-sensitive (LS) versions of the VITROS anti- HIV-1 assay (Ortho-Clinical Diagnostics) and the LAg avidity assay. Results: Evolution of the HIV-specific antibodies in plasma was studied for 13 allo-SCT patients, all of them under cART. We observed that p24 and/or p31 disappeared in 9/13 patients, sometimes only three months after allo-SCT. gp140, gp160, and gp120 bands persisted in most individuals. Surprisingly, in two cases we found an undetermined (Pt#19 and Pt#28) western blot. LAg avidity assay was negative in 6/7 individuals with longer follow. LS-VITROS detuned assay showed that transplanted patients presented lower antibody levels than viremic and successfully suppressed HIV+ controls. These levels started to decrease directly after allo-SCT. Remarkably Pt#19 and Pt#28 presented antibody levels close to HIV negative donors. Conclusion: We conclude that allo-SCT not only remarkably decreased the HIV latent reservoir, but also reduced the level of HIV antibodies in presence of cART. We have observed evidence of seroreversion a few years after allo-SCT. Future cART discontinuation will unravel the role of the antibodies dynamics in the HIV cure.

Poster Abstracts

386 HIV-SEROREVERSION DYNAMICS AFTER ALLOGENEIC STEM CELL TRANSPLANTATION

388 THE HIV RESERVOIR RESIDES MAINLY IN CD32A– /CD4+ T CELLS IN PERINATAL INFECTION Adit Dhummakupt 1 , Lilly V. Siems 1 , Dolly Singh 1 , Ya Hui Chen 1 , Thuy Anderson 1 , Aleisha Collinson-Streng 1 , Purvish Patel 2 , Hao Zhang 1 , Allison Agwu 1 , Douglas Watson 3 , Deborah Persaud 1 1 The Johns Hopkins University, Baltimore, MD, USA, 2 Quanterix Corporation, Lexington, MA, USA, 3 University of Maryland, Baltimore County, Baltimore, MD, USA Background: CD32a uniquely marks the latent HIV reservoir in CD4+ T cells in infected adults, with up to a 3,000-fold increase in inducible replication- competent proviruses compared with CD32a–/CD4+ T cells. The generalizability of these findings to perinatal infection is unknown. We undertook a cross- sectional study in virally suppressed, perinatally-infected youth to determine CD32a CD4+ T cell expression and the size of this reservoir. Methods: Peripheral blood mononuclear cells were assessed by FACS (N=7) for CD32a+ and CD32a–/CD4+ T cells in perinatally-infected youth on ART. In 4 participants with sufficient cells, total CD4+ T cells were sorted into CD32a+

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