CXCR4-tropism and the preferential establishment of an HIV-reservoir in

naïve CD4+ T-cells among HIV-infected Ugandan children

Theodore Ruel1, Jane Achan2, Wei Huang3, Maudi Killian1, Elizabeth Sinclair1, Edwin Charlebois1, Peilin Li1, Huyen Cao1, Leigh Anne Eller4,

Moses Kamya2, Diane Havlir1, Joseph Wong1 1 University of California, San Francisco, U.S.A.; 2 Makerere University, Kampala, Uganda; 3 Monogram Biosciences, South San Francisco, CA, U.S.A.; 4US Military HIV Research Program, Bethesda, MD, U.S.A.

THPDA0205

CXCR4-tropism and the preferential establishment of an HIV-reservoir in naïve CD4+ T-cells among HIV-infected Ugandan children

Table 1. Subject Characteristics*

DM R5

Number 4 8

Age (years) 4.9 ( 4.1-6.2) 5.1 (3.7-7.9)

CD4% 23 (21-24) 28 (23-30)

CD4 (cells/μl) 655 (581–837)834 (555-

1049)

HIV RNA Level all <400 c/ml all <400 c/ml

Duration of ART (days)

98 (96-113) 99 (95-150)

HIV subtype 2 A, 2 D 4 A, 4 D

* Values are number or median (interquartile range)

Background: • Children have large populations of naive CD4+ T-cells that express high levels of CXCR4

• HYPOTHESIS: HIV-infected Ugandan children infected with CXCR4-tropic virus would exhibit larger HIV-DNA reservoirs in naïve CD4+ T-cells, compared to children infected with CCR5-tropic virus.

• HIV-DNA: real time Taqman PCR assay using a lock nucleotide (LNA™) - based probe in HIV gag p24 region (HXB2, 1400–1412).

• Lymphocyte DNA: commercial TERT-assay.

• Calculated number of HIV copies per 106

copies of cellular DNA in the naïve and memory lymphocyte subsets for each child.

• Non-parametric Kruskal-wallis testing

Methods:• Banked specimens from a cohort of 300 HIV-infected Ugandan children.

• Selected 4 dual-mixed (CXCR4- and CCR5-tropic, DM) and 8 pure CCR5-tropic (R5) virus infected children (Trofile Assay); all children on antiretroviral therapy (ART).

• Naïve and memory CD4+ T-cell separation: Cryopreserved peripheral blood mononuclear cells were sorted into naïve (CD27+CD45RA+) and

memory (CD27-CD45+ and CD45-CD27±) CD3+CD4+ lymphocytes.

Ruel et. al., THPDA0205

Ruel et. al., THPDA0205

CXCR4-tropism and the preferential establishment of an HIV-reservoir in naïve CD4+ T-cells among HIV-infected Ugandan children

DM DM DM DM R5 R5 R5 R5 R5 R5 R5 R50%

20%

40%

60%

80%

100%

NaïveMemory

Ratio of HIV-infection frequency in Naïve : Memory CD4+ T-Cells*

DM 8.9 (6.6-13.0)

R5 0.7 (0.2-4.3)

*Median (IQR); p=0.04

Proportion of circulating HIV-infected CD4+ T-cells that are naive

Conclusions

• In contrast to adults, a significant portion of the HIV-reservoir is located among naïve CD4+ T lymphocytes among ART-treated children.

• Infection with DM virus was associated with preferential infection of naïve CD4+ T-cells

• In developing strategies to eradicate HIV, it will be important to take into account the high levels of naïve T-cell infection in children, particularly among those with with DM virus.

DM 92% (88%-95%)

R5 53% (25%-80%)

*Median (IQR); P=0.07