CROI 2019 Abstract eBook

Abstract eBook

Poster Abstracts

1 National Cancer Institute, Frederick, MD, USA, 2 Stellenbosch University, Cape Town, South Africa, 3 Leidos Biomedical Research, Inc, Frederick, MD, USA, 4 University of Pittsburgh, Pittsburgh, PA, USA, 5 Tufts University, Boston, MA, USA Background: Integration site analysis has shown extensive clonal expansion of HIV-1 infected cells in adults. We know that infected clones arise early, persist for many years, and that there is selection for cells with proviruses integrated in BACH2, MKL2, and STAT5B. However, little is known about the behavior of infected cells in children treated shortly after birth. We characterized clones of infected cells in a cohort of perinatally-infected and early-treated children. Methods: PBMC samples were obtained from the Children with Early HIV Antiretroviral therapy (CHER) cohort prior to ART and after 6 to 9 years of continual suppression on ART. We determined the integration sites in samples taken at both time points and compared the data to integration site data from PBMCs infected ex-vivo and adults who initiated ART in either early or chronic infection. Results: Integration sites were obtained from 11 children who initiated ART at a median age of 5.1 months (range: 1.8-17.4 months). We obtained a median of 701 integration sites per child (range: 204-1482) pre-ART and 128 on-ART (range: 94-454). We found clones of infected cells in pre-ART samples from 8 children, including 2 who started ART before 3 months of age, and in all 11 children after 6-9 years on ART. In 6 children, some of the clones detected pre-ART persisted for at least 6 years on ART and in 1 child for 9 years on ART. We quantified the fraction of integration sites detected in clones and found no significant difference between children (24%) and adults treated either in early infection (N=14; 16%) (p=0.08) or in chronic infection (N=9; 22%) (p=0.66). We also compared the fraction of integration sites in individual genes in the on-ART samples to a library prepared from ex-vivo infected PMBCs and, as in adults, we found strong selection for proviruses integrated in BACH2 (p=2*10^- 11) and STAT5B (p=1*10^-23). Conclusion: Although the numbers of T cells and their population dynamics are different in children and adults, the timing of establishing HIV-1 infected cell clones, the frequency of infected clones, and the selection for some infected clones appears similar in children and adults, even in children who initiated ART before 3 months of age. Our findings indicate that clonal expansion of infected cells occurs very early after infection in children, as in adults, and that clonal expansion of infected cells is a major mechanism for persistence of HIV-1 despite long-term ART. 806 INTACT HIV PROVIRUSES ARE DETECTABLE 7-9 YEARS LATER WHEN ART STARTS AFTER 3 MONTHS Mary Grace K. Katusiime 1 , Michael J. Bale 2 , Imogen Wright 3 , Wei Shao 4 , Wei-Shau Hu 2 , Mark Cotton 1 , John W. Mellors 5 , Mary F. Kearney 2 , Gert U. van Zyl 1 1 Stellenbosch University, Tygerberg, South Africa, 2 National Cancer Institute, Frederick, MD, USA, 3 University of Western Cape, Cape Town, South Africa, 4 Leidos Biomedical Research, Inc, Frederick, MD, USA, 5 University of Pittsburgh, Pittsburgh, PA, USA Background: In adults starting ART in acute infection only 2-5% of proviruses are intact. However, no intact full length proviral sequences were detected in a cohort of early treated, long-term suppressed children. We sought to characterize proviral sequences in another cohort of early treated children after 6-9 years on suppressive ART. Methods: PBMC samples from perinatally infected children in the CHER study were analyzed. Single, near full length proviral amplification and sequencing (NFL-PAS) was performed at one time point after 6-9 years of suppressive ART. Amplicons with large internal deletions were excluded (<9kb on gel electrophoresis). All amplicons ≥9kb were sequenced (Sanger and Illumina) and analysed through an ‘Intactness bio-informatic pipeline’ to detect indels, frameshifts, inactivating point mutations and/or hypermutations that would render the proviruses defective. Results: In 9 children who started ART at a median age of 2.3 (range: 1.7 – 11.1) months, 738 single NFL-PAS amplicons were generated. Of these, 553 (74.9%) had large internal deletions, 175 (23.7%) had hypermutation, 3 (0.4%) had deletions in the packaging signal and major splice donor site, and 7 (1%) were intact. These 7 intact sequences were from 3 children who initiated ART after 8 months of age; of whom one had two identical and intact sequences, suggestive of a cell clone harbouring a replication-competent provirus. No intact provirus was detected in 5 children who initiated ART before 2.3 months of age.

804 IMMUNO-VIROLOGICAL IMPACT OF EARLY VS LATE ART INITIATION IN CHILDREN AND ADOLESCENTS Pierre Frange 1 , Veronique Avettand-Fenoel 1 , Jérôme Le Chenadec 2 , Catherine Dollfus 3 , Thomas Montange 4 , Stephane Blanche 1 , Albert Faye 5 , Martine Levine 5 , Valérie Marcou 6 , Damien Batalie 4 , Marine Fillion 1 , Laura Nailler 2 , Josiane Warszawski 2 , Florence Buseyne 4 , for the ANRS-EP59-CLEAC Study Group 1 Necker Hospital, Paris, France, 2 INSERM, Le Kremlin-Bicetre, France, 3 Trousseau Hospital, Paris, France, 4 Institut Pasteur, Paris, France, 5 Robert–Debre Hospital, Paris, France, 6 Cochin Hospital, Paris, France Background: Few data are available on the long-term benefit of early cART initiation for children and adolescents. The ANRS-EP59-CLEAC study aimed to assess the immunological and virological characteristics of HIV-1-infected children and adolescents who achieved initial virological suppression, according to the age at cART initiation (<6 months vs ≥24 months of age). Methods: Patient recruitment was conducted in the Paris area in 2016 - 2018. PBMC-associated total HIV-1 DNA was quantified using ultrasensitive qPCR (adapted from Biocentric, France). CD4 and CD8 CD45RA+CCR7+ naive T lymphocytes were quantified in fresh blood by flow cytometry. Parameters of early- (E-Ch)/late- (L-Ch) treated children (5-12 years) and early- (E-ado)/ late- (L-ch) treated adolescents (13-17 years) were compared with Wilcoxon test. Results: We prospectively enrolled in the early-cART group 27 children and 9 adolescents, and in the late-cART group, 19 children and 21 adolescents. At the time of the study, all patients were receiving ART, 83% had plasma HIV-RNA <50 copies/mL, and the median CD4 T-cell count was 856 [IQR: 676 - 1236] cells/ µl. In multivariate analysis, early cART and longer duration of viremia <50 cp/ mL during the 2 previous years were strongly associated with lower HIV-DNA levels (respectively, p<0.0001 and p=0.0067). Restricting the analysis to the 63 patients with current viral suppression, early cART was associated with lower HIV-1 DNA levels (p<0.0001). Aviremic E-ado had very low HIV-DNA levels (median 1.42 [IQR: 1.08-2.25] log cp/10e6 PBMC). E-Ch had higher median percentages of naïve CD8 T lymphocytes than L-Ch (49 versus 31%; p<0.0007). Conversely, in adolescents, early cART was associated with lower percentage of naïve CD4 T lymphocytes (39 versus 52%, p=0.05), even when restricting the analysis to patients with current viral suppression. Conclusion: An immunological benefit of early cART initiation on naïve T lymphocytes was suggested in children. Further investigations are pending to explore if the high levels of thymic activity observed in adolescents may compensate for the deleterious effects of long duration of HIV replication. Early cART initiation during infancy is associated with lower short- and long-term total HIV-DNA levels, as targeted in HIV-1 remission strategies. Interestingly, aviremic E-Ado had HIV-DNA levels comparable to those observed in adults with spontaneous or post-treatment HIV control. 805 LONG-TERM PERSISTENCE OF HIV-INFECTED CELL CLONES IN CHILDREN TREATED EARLY Michael J. Bale 1 , Mary Grace K. Katusiime 2 , David Wells 3 , Xiaolin Wu 3 , Jonathan Spindler 1 , Elias K. Halvas 4 , Joshua C. Cyktor 4 , Ann Wiegand 1 , Wei Shao 3 , John M. Coffin 5 , Mark Cotton 2 , Stephen H. Hughes 1 , John W. Mellors 4 , Gert U. van Zyl 2 , Mary F. Kearney 1

Poster Abstracts

CROI 2019 313