γδ T Cell Subpopulations Associate with Recovery of Memory Function in Indonesian HIV Patients Starting Antiretroviral Therapy.

Cognitive impairment may persist in HIV patients despite effective antiretroviral therapy (ART). However, recovery is influenced by the neurocognitive domain tested, the severity of HIV disease, and by education. In young adult patients commencing ART in Jakarta, Indonesia, we described improvements in all cognitive domains except memory after 6-12 months on ART. In this study, we address relationships between cytomegalovirus (CMV), γδ T cell profiles and neurocognitive assessments with a focus on memory. The JakCCANDO (Jakarta CMV Cardiovascular ART Neurology Dentistry Ophthalmology) project recruited patients (aged 18-48 years) beginning ART with <200 CD4+ T cells/µL. Cognitive assessments used validated tests of five domains. Flow cytometry was used to assess proportions of Vδ2- and Vδ2+ γδ T cells, and their activation (HLA-DR) and terminal differentiation (CD27-/CD45RA+). All patients carried high levels of antibodies reactive with CMV, so the detection of CMV DNA before ART was used to stratify participants into subgroups with a moderate/high or an extremely high burden of CMV. Patients had higher proportions of Vδ2- γδ T cells and fewer Vδ2+ γδ T cells than healthy controls before ART and at 6 months. Z-scores for memory function correlated with proportions of Vδ2+ γδ T cells at both time points. Linear regression analyses confirmed this association. When the detection of CMV DNA was used to stratify the cohort, the association between memory Z-scores and Vδ2+ γδ T cells or CMV antibodies was only discernible in patients with a lower CMV burden. Hence, CMV and Vδ2+ γδ T cells warrant further consideration as factors that may contribute to the poor recovery of memory on ART.

Which NK cell populations mark the high burden of CMV present in all HIV patients beginning ART in Indonesia?

BACKGROUND: Cytomegalovirus (CMV) has been linked with cardiovascular disease (CVD) in populations where some individuals are seronegative. However, effects of CMV are unclear in HIV patients who all have high levels of CMV antibodies. Other metrics of their CMV burden are needed. Amongst transplant recipients, CMV drives the expansion of NK cell populations expressing NKG2C and/or LIR1 and lacking FcRγ. METHODS: Indonesian HIV patients (n = 40) were tested before ART and after 6 months, with healthy local controls (n = 20). All patients had high CMV antibody titres. 52% started therapy with CMV DNA detectable by qPCR, providing a crude measure of CMV burden. Proportions of CD56Hi or CD56Lo NK cells expressing FcRγ, NKG2C or LIR1 were determined flow cytometrically. CVD was predicted using carotid intimal media thickness (cIMT). Values were correlated with levels of CMV antibodies on ART. RESULTS: Patients had low proportions of CD56Lo and more CD56Hi NK cells. However proportions of FcRγ- NK cells were lowest in patients with CMV DNA, and cIMT values related inversely with FcRγ- NK cells in these patients. Percentages of NKG2C+CD56Lo NK cells were similar in patients and controls, but rose in patients with CMV DNA. Proportions of NKG2C+ CD56Hi NK cells correlated with levels of CMV antibodies in CMV DNA-negative patients. CONCLUSIONS: We show that the very high burdens of CMV in this population confound systems developed to study effects of CMV in other populations. FcRγ- NK cells may be depleted by very high CMV burdens, but NKG2C and antibody levels may be informative in patients on ART.

Understanding the effects of CMV on γδ T-cell populations in HIV patients starting antiretroviral therapy.

Cytomegalovirus (CMV) affects γδ T-cell profiles in healthy individuals and transplant recipients, but the effects of HIV and CMV have not been distinguished in HIV patients. CMV-seropositive Indonesian HIV patients (n = 40) were studied before ART and after six months, alongside healthy controls (n = 20). 50% of patients started ART with detectable CMV DNA. Proportions of Vδ2- γδ T-cells were high in patients and declined on ART, whilst proportions of Vδ2+ γδ T-cells were uniformly low, and correlated inversely with levels of CMV DNA and CMV-reactive antibody. Residual Vδ2+ cells were enriched for markers of terminal differentiation, but this did not associate with CMV metrics. Patients with CMV DNA at baseline showed a direct correlation between CMV reactive-antibody and CD8+ γδ T-cells. Our data are consistent with a role for CMV in the depletion of Vδ2+ γδ T-cells in HIV patients beginning ART, with no consistent evidence of a role for CMV in γδ T-cell activation or differentiation.

A TNF Block Genotype may Influence CMV Retinitis in HIV Patients without Affecting Systemic Viral Replication.

BACKGROUND: A conserved TNF block haplotype marked by the minor alleles of rs1800629 (TNFA-308*A) and rs9281523 [BAT1(intron 10)*C] has been linked with several immunopathological conditions and with rapid progression of HIV disease. Reported associations with cytomegalovirus (CMV) retinitis in HIV patients before or during early antiretroviral therapy (ART) may therefore reflect greater replication of CMV in advanced HIV disease or an immunopathological response to CMV in the retina. OBJECTIVE: As all Indonesian HIV patients display high levels of CMV replication, we evaluated whether TNF block genotypes alter markers of their burden of CMV and/or associate with retinitis. METHODS: We assessed 79 consecutive HIV patients beginning ART, 25 HIV patients with a history of CMV-retinitis and 63 healthy adults. HIV RNA, CD4 T-cell counts, CMV-reactive antibody and CMV DNA were measured and alleles of TNFA-308, BAT1(intron 10) and TNFA-1031 (rs1799964) were determined. RESULTS: TNFA-308 and BAT1(intron 10) were in complete linkage disequilibrium. Patients carrying minor alleles at both loci had higher levels of CMV-reactive antibody after one month on ART (p=0.01), but not at other time points spanning 1 year on ART. 50% of patients had detectable CMV DNA before ART, irrespective of TNF block genotypes. However, the TNFA-308*A/- BAT1(intron 10)*C haplotype was more common in CMV-retinitis patients than other patients or healthy controls (p<0.01). CONCLUSION: The TNFA-308*A/BAT1(intron 10)*C haplotype appears to affect CMV-induced pathology rather than CMV replication.

TNF-Block Genotypes Influence Susceptibility to HIV-Associated Sensory Neuropathy in Indonesians and South Africans.

HIV-associated sensory neuropathy (HIV-SN) is a disabling complication of HIV disease and antiretroviral therapies (ART). Since stavudine was removed from recommended treatment schedules, the prevalence of HIV-SN has declined and associated risk factors have changed. With stavudine, rs1799964*C (TNF-1031) associated with HIV-SN in Caucasians and Indonesians but not in South Africans. Here, we investigate associations between HIV-SN and rs1799964*C and 12 other polymorphisms spanning TNF and seven neighboring genes (the TNF-block) in Indonesians (n = 202; 34/168 cases) and South Africans (n = 75; 29/75 cases) treated without stavudine. Haplotypes were derived using fastPHASE and haplotype networks built with PopART. There were no associations with rs1799964*C in either population. However, rs9281523*C in intron 10 of BAT1 (alternatively DDX39B) independently associated with HIV-SN in Indonesians after correcting for lower CD4 T-cell counts and >500 copies of HIV RNA/mL (model p = 0.0011, Pseudo R2 = 0.09). rs4947324*T (between NFKBIL1 and LTA) independently associated with reduced risk of HIV-SN and African haplotype 1 (containing no minor alleles) associated with increased risk of HIV-SN after correcting for greater body weight, a history of tuberculosis and nadir CD4 T-cell counts (model: p = 0.0003, Pseudo R2 = 0.23). These results confirm TNF-block genotypes influence susceptibility of HIV-SN. However, critical genotypes differ between ethnicities and with stavudine use.

Characterization of Natural Killer Cells in HIV Patients Beginning Therapy with a High Burden of Cytomegalovirus.

BACKGROUND: Active infections with cytomegalovirus (CMV) increase NK cell expression of the inhibitory receptor LIR-1 and the activating receptor NKG2C in transplant recipients. However, the effects of CMV on NK cells are different in HIV patients stable on antiretroviral therapy (ART) and have not been analyzed in young HIV patients beginning ART. METHODOLOGY: We followed a cohort of 78 Indonesian HIV patients beginning ART. CMV antibodies were measured in plasma before ART (baseline), and after 1, 3, 6, and 12 months. CMV DNA was sought in blood granulocytes at baseline by quantitative PCR assay and a deletion in the NKG2C gene was identified by PCR. NK cell profiles were monitored by flow cytometry in 19 patients stratified by the presence of CMV DNA. Healthy controls (n = 17) were assessed once. RESULTS: All 78 patients were CMV seropositive and 41 had detectable CMV DNA. CMV DNA+ patients had higher proportions of total NK cells and CD16+ NK cells at baseline, but similar expression of LIR-1 and NKp30 on NK cells on ART. However, levels of CMV antibody were inversely related to median LIR-1 expression on NK cells. A dramatic elevation in cells expressing NKG2C was restricted to CMV DNA+ patients heterozygous for the NKG2C deletion. Patients with High NKG2C expression had lower levels of CMV antibodies. CONCLUSION: A subpopulation of NK cells expressing NKG2C was induced by CMV replication in HIV patients heterozygous for a deletion in this gene. Individuals with an abundant NKG2C+ and LIR-1+ NK cells displayed lower levels of CMV reactive antibody.

Active and Persistent Cytomegalovirus Infections Affect T Cells in Young Adult HIV Patients Commencing Antiretroviral Therapy.

Altered T cell profiles have been linked with metrics of persistent cytomegalovirus (CMV) infections in healthy aging and older HIV patients stable on antiretroviral therapy (ART). In this study, we use CMV DNA to identify active infections, and levels of CMV-reactive antibody to assess the persistent burden of CMV in a longitudinal study of 78 young adult patients beginning ART in Jakarta, Indonesia, with <200 CD4 T cells/µL. CMV antibodies, inflammatory markers (C-reactive protein [CRP], soluble interferon-α/ß receptor) and T cell phenotypes were assessed before ART (V0) and after 1, 3, 6, and 12 months (V1-V12). CMV DNA was detected in 41 patients (52%) at V0, irrespective of CD4 T cell counts, gender, age, or plasma HIV RNA. CMV DNA+ patients had higher levels of antibody reactive with CMV Immediate Early 1 (IE-1) at V0 and V12 (p = 0.04), and with CMV lysate at V12 (p = 0.01). Detectable CMV DNA did not align with inflammatory markers, but associated with lower CD4/CD8 ratios until V3. CMV antibody levels correlated inversely with proportions of naive CD4 and CD8 T cells, and directly with proportions of CD57+ and activated memory T cells (CD3+ CD45RA-) after 3-12 months on ART. Overall, active CMV replication is common in HIV patients beginning ART in Indonesia and associates with low CD4/CD8 ratios. Elevated levels of CMV-reactive antibody measured on ART also mark a depletion of naive T cells, accumulation of memory T cells, and may be a stable metric of the burden of CMV.