An HIV type 1 subtype B founder effect in Korea: gp160 signature patterns infer circulation of CTL-escape strains at the population level

Sequence Length of HIV-1 Subtype B Increases over Time: Analysis of a Cohort of Patients with Hemophilia over 30 Years

We aimed to investigate whether the sequence length of HIV-1 increases over time. We performed a longitudinal analysis of full-length coding region sequences (FLs) during an HIV-1 outbreak among patients with hemophilia and local controls infected with the Korean subclade B of HIV-1 (KSB). Genes were amplified by overlapping RT-PCR or nested PCR and subjected to direct sequencing. Overall, 141 FLs were sequentially determined over 30 years in 62 KSB-infected patients. Phylogenetic analysis indicated that within KSB, two FLs from plasma donors O and P comprised two clusters, together with 8 and 12 patients with hemophilia, respectively. Signature pattern analysis of the KSB of HIV-1 revealed 91 signature nucleotide residues (1.1%). In total, 48 and 43 signature nucleotides originated from clusters O and P, respectively. Six positions contained 100% specific nucleotide(s) in clusters O and P. In-depth FL analysis for over 30 years indicated that the KSB FL significantly increased over time before combination antiretroviral therapy (cART) and decreased with cART. This increase occurred due to the significant increase in env and nef genes, originating in the variable regions of both genes. The increase in sequence length of HIV-1 over time suggests an evolutionary direction.

The frequency of defective genes in vif and vpr genes in 20 hemophiliacs is associated with Korean Red Ginseng and highly active antiretroviral therapy: the impact of lethal mutations in vif and vpr genes on HIV-1 evolution

Background

We have reported that internal deletions in the nef, gag, and pol genes in HIV-1–infected patients are induced in those treated with Korean Red Ginseng (KRG). KRG delays the development of resistance mutations to antiretroviral drugs.

Methods

The vif-vpr genes over 26 years in 20 hemophiliacs infected with HIV-1 from a single source were sequenced to investigate whether vif-vpr genes were affected by KRG and KRG plus highly active antiretroviral therapy (ART) (hereafter called GCT) and compared the results with our previous data.

Results

A significantly higher number of in-frame small deletions were found in the vif-vpr genes of KRG-treated patients than at the baseline, in control patients, and in ART-alone patients (p < 0.001). These were significantly reduced in GCT patients (p < 0.05). In contrast, sequences harboring a premature stop codon (SC) were more significant in GCT patients (10.1%) than in KRG-alone patients, control (p < 0.01), and ART-alone patients (p = 0.078 for peripheral blood mononuclear cells). The proportion of SC in Vpr was similar to that in Vif, whereas the proportion of sequences revealing SC in the env-nef genes was significantly lower than that in the pol-vif-vpr genes (p < 0.01). The genetic distance was 1.8 times higher in the sequences harboring SC than in the sequences without SC (p < 0.001). Q135P in the vif gene is significantly associated with rapid progression to AIDS (p < 0.01).

Conclusion

Our data show that KRG might induce sΔ in the vif-vpr genes and that vif-vpr genes are similarly affected by lethal mutations.

Genetic Analysis of the Full-Length gag Gene from the Earliest Korean Subclade B of HIV-1: An Outbreak among Korean Hemophiliacs

We determined the earliest full-length HIV-1 gag gene sequences in 110 patients with HIV-1, including 20 hemophiliacs (HPs) and 90 local controls (LCs). The gag gene from stored sera was amplified using RT-PCR, and was subjected to direct sequencing. Phylogenetic analysis indicated that 94 and 16 sequences belonged to the Korean subclade of HIV-1 subtype B (KSB) and subtype B, respectively. A total of 12 signature pattern amino acids were found within the KSB, distinct from the worldwide consensus of subtype B. Within the KSB, the gag gene sequences from donors O and P and those from the 20 HPs comprised two subclusters. In particular, sequences from donor O strongly clustered with those of eight HPs. Moreover, signature pattern analysis indicated that 14 signature nucleotides were shared between the HPs and LCs within KSB (p < 0.01). Among the 14 nucleotides, positions 9 and 5 belonged to clusters O and P, respectively. In conclusion, signature pattern analysis for the gag gene revealed 12 signature pattern residues within the KSB and also confirmed the previous conclusion that the 20 HPs were infected with viruses due to incompletely inactivated clotting factor IX. This study is the first genetic analysis of the HIV-1 gag gene in Korea.

High Prevalence of Non-B HIV-1 Subtypes in Overseas Sailors and Prostitutes in Korea

There have been no studies related to groups at the highest risk for HIV-1 infection in Korea before 1993. In this study, for the first time, we report the distribution of HIV subtypes in overseas sailors (OSs) and prostitutes who worked in brothels near U.S. military bases in Korea. We retrospectively determined the sequences of nef in 131 patients using reverse transcription polymerase chain reaction (RT-PCR). These patients composed of 102 OSs, 14 OS spouses, and 15 prostitutes. Phylogenetic analysis was performed using 128 Korean OSs, OS spouses, and prostitutes. The distribution of non-B subtypes (n = 105) was as follows: 39, CRF02_AG; 15, CRF01_AE; 7, A1; 7, A2; 6, D; 2, CRF06_cpx; 3, C; 6, G; 11, untypable; and 1 each for CRF09_cpx, CRF12_BF, CRF50_A1D, A3, AFG, H, F1, F2, and A. Of the 116 OSs and OS spouses, 101 (87%), 11 (9%), and 4 (3%) subjects had non-B, Western B, and Korean subclade B (KSB) HIV-1s, respectively. Among the 15 prostitutes, 10 had Western B (67%), 4 non-B (27%), and 1 KSB (7%) HIV-1s. All 14 couples, each comprising of an OS and his spouse, had the same subtype. KSB (5%) was detected in OSs and prostitutes in 1990 and 1994, respectively. Of the 131 patients analyzed in this study, 105 (80%), 21 (16%), and 5 (4%) were infected with the non-B, Western B, and KSB subtypes of HIV, respectively. In future, these data may provide an important foundation for analysis of HIV-1 subtypes in Korea.

Signature pattern analysis for the full-length env gene of the earliest Korean subclade B of HIV-1: outbreak among Korean hemophiliacs

The epidemiological link in the hypervariable env gene between viruses infecting HIV-positive hemophiliacs (HPs) and plasma donors was not studied. We determined full-length env gene sequences in 20 HPs, 3 plasma donors whose plasma was used for domestic clotting factor (DCF) production, and 54 local controls (LCs). Env genes from viruses in frozen stored sera obtained 1-3 years after diagnosis and from samples collected several years after infection were amplified via RT-PCR and subjected to direct sequencing. Phylogenetic analysis indicated that all sequences were subtype B, including 133 sequences from 77 cases (20 HPs, 3 plasma donors, and 54 LCs) belonging to the Korean subclade B (KSB) and 6 sequences from 5 cases that did not belong to the KSB. Env gene sequences from donors O and P and those of the 20 HPs comprised 2 subclusters within the KSB, although phylogenetic analysis did not support significant bootstrap values. In contrast, signature pattern analysis indicated signature nucleotides at 43 positions between the HPs and LCs (P < 0.05). In particular, specific signature nucleotides at 4 positions were fully conserved in the HPs, but not in the LCs (P < 0.0001). Furthermore, there were 26 signature residues within the KSB and were distinct from the worldwide consensus for subtype B. In conclusion, signature pattern analysis for the hypervariable env gene revealed an epidemiological link that the 20 HPs in this study had been infected with viruses from the DCF used for treatment, consistent with our previous finding.

Molecular Epidemiology of Human Immunodeficiency Virus

During the evolution of human immunodeficiency virus (HIV), transmissions between humans and primates resulted in multiple HIV lineages in humans. This evolution has been rapid, giving rise to a complex classification and allowing for worldwide spread and intermixing of subtypes, which has consequently led to dozens of circulating recombinant forms. In the Republic of Korea, 12,522 cases of HIV infection have been reported between 1985, when AIDS was first identified, and 2015. This review focuses on the evolution of HIV infection worldwide and the molecular epidemiologic characteristics of HIV in Korea.

HIV-1 subtype B: Traces of a pandemic

Human migration is a major process that shaped the origin and dissemination of HIV. Within HIV-1, subtype B (HIV-1B) is the most disseminated variant and it is assumed to be the causative agent in approximately 11% of all cases of HIV worldwide. Phylogenetic studies have revealed that HIV-1B emerged in Kinshasa (Africa) and was introduced into the Caribbean region via Haiti in or around 1966 by human migration. After localized dispersion, the virus was brought to the United States of America via homosexual/bisexual contact around 1969. Inside USA, the incidence of HIV-1B infection increased exponentially and it became established in the population, affecting not only homosexual individuals but also heterosexual individuals and injecting drug users. Soon after, the virus was disseminated and became established in other regions, including Europe, Asia, Latin America, and Australia. Recent studies suggest that, in addition to this pandemic clade, several lineages have emerged from Haiti and reached other Caribbean and Latin American countries via short-distance dissemination. Different subtype B genetic variants have also been detected in these epidemics. Four genetic variants have been described to date: subtype B', which mainly circulates in Thailand and other Asian countries; a specific variant mainly found in Trinidad and Tobago; the GPGS variant, which is primarily detected in Korea; and the GWGR variant, which is mainly detected in Brazil. This paper reviews the evolution of HIV-1B and its impact on the human population.

Significantly longer envelope V2 loops are characteristic of heterosexually transmitted subtype B HIV-1 in Trinidad

Background

In Trinidad and the wider Caribbean, subtype B Human Immunodeficiency Virus-type 1 (HIV-1B) overwhelmingly accounts for HIV infection among heterosexuals; this contrasts with the association of HIV-1B with homosexual transmission and injecting drug use globally. The HIV envelope contains genetic determinants of cell tropism and evasion from immune attack. In this study we investigate the genetic properties of the env V1-C4 of HIV-1B soon after transmission to Trinidadian heterosexuals. This will reveal distinctive genetic features of the strains that cause the HIV-1B epidemic in Trinidad and generate insights to better understand their properties.

Methodology/Principal Findings

Quasispecies sampling was performed on the env V1-C4 of HIV-1B strains soon after transmission to heterosexual Trinidadians in a cohort of seroconverters. Phylogenetic relationships were determined for these quasispecies and the length and number of asparagine (N) linked glycosylation sites (NLGS) in their variable loops compared to that for HIV-1B globally. Signature amino acids within the constant domains of the env V1-C4 were identified for heterosexually transmitted HIV-1B from Trinidad relative to HIV-1B globally. HIV-1B obtained from Trinidadian heterosexuals soon after seroconversion had significantly longer V2 loops with one more glycosylation site, shorter V3 loops and no significant difference in V1 or V4 when compared to HIV-1B obtained soon after seroconversion from infected individuals in the rest of the world. HIV-1B soon after seroconversion and during chronic infection of Trinidadians was not significantly different, suggesting that distinctly long V2 loops are characteristic of HIV-1B in Trinidad. A threonine deletion at position 319 (T319-) along with the substitutions R315K and S440R were found to be distinctly associated with HIV-1B from Trinidad compared to HIV-1B globally.

Conclusions

This finding of distinctive genetic features that are characteristic of HIV-1B strains from Trinidad is consistent with the Trinidad epidemic being established by a founder strain or closely related founder strains of HIV-1B.

An introduction to a novel population genetic approach for HIV characterization

The rapid evolution of the HIV genome is influenced in part by host selection pressure, which may cause parallel evolution among strains under shared selection pressures. To understand the mechanisms behind HIV-host immune escape across host populations, researchers have compared signatures of positive selection pressure on HIV codons across HIV subtypes and across phylogenetic groups of isolates within major subtypes, all relying on a criterion of phylogenetic separation. The HIV codon sites that retain diversity, evolve convergently among sets of hosts (cohorts) and diverge between cohorts may be phylogenetically undiagnostic (reveal little information about the relationship of the strains) and thus undetectable on a tree. We propose a new approach to characterizing genetic divergence among isolates using existing population genetic methods to better understand HIV response to host selection pressures. The approach combines population genetic statistical methods with codon analysis to identify putative amino acid sites evolving convergently. To illustrate the approach, we compared the C2-V3-C3 region of the envelope protein of HIV-1 clade B isolates between Haiti and USA hosts. This region showed no phylogenetic separation between host populations. Still, we identified codon sites in the C2-V3-C3 HIV-1 region that may have evolved differently between the two host populations. The sites are localized in human leukocyte antigen (HLA) class I binding epitopes, N-glycosylation motifs or both and are limited to the C2 and C3 regions. Our method provides a potential means to reveal candidate sites actively involved in HIV-1 immune escape that would otherwise be missed if a requisite for phylogenetic distinctiveness was made a priori. This strategy may prove to be a helpful way to characterize HIV genetic variation among hosts with suspected selection pressure differences, like progressors versus non-progressors.

Molecular epidemiological tracing of HIV-1 outbreaks in Hainan island of southern China

OBJECTIVES

To determine the prevalence of HIV in Hainan island and the molecular epidemiological linkages related to risk factors of viral transmission.

METHODS

A governmental HIV/AIDS surveillance program, HIV serological study was conducted in volunteers from several high-risk groups between 1991 and 2006 in Hainan province. By phylogenetic reconstruction, we performed a molecular epidemiological tracing in a representative subset of the HIV-1-seropositive individuals diagnosed during this survey.

RESULTS

Of 499 752 volunteers, 523 (0.1%) accumulated cases of HIV-1 infection (69.2% needle-sharing drug users, 19.3% heterosexually acquired adults, 3.3% receivers of blood transfusion, 0.8% children born from HIV-1-infected mothers, and 7.7% remained unknown) were diagnosed. Among 83 patient samples examined (70 were infected with HIV-1 subtypes CRF01_AE and eight, two, one, one, and one were B', C, CRF08_BC, B, and a new CRF01_AE/B' recombinant, respectively), 66 (79.5%) were segregated into one large cluster (59 sequences) (founder effect) and one small cluster (three sequences) of CRF01_AE, one small cluster (two sequences) of B', and one small cluster (two sequences) of C. Phylogenetic and epidemiological linkages confirmed four heterosexual transmission events and rejected two potential heterosexual transmission suggested by contact tracing. Only two cases of CRF01_AE showed mutations conferring resistance to nucleoside and nonnucleoside reverse transcriptase inhibitors.

CONCLUSION

The reconstruction of current HIV-1 outbreaks by molecular epidemiological tracing is helpful for identifying epidemic sources and for defining prevention strategies.

National survey of prevalent HIV strains: limited genetic variation of Korean HIV-1 clade B within the population of Korean men who have sex with men

The evolution of HIV is the result of an explosive combination of factors-a high rate of mutation, replication dynamics, frequent recombination, and natural selection. To understand the evolution of the distinctive Korean HIV-1 B clade, we investigated the characteristics of the genetic variation of the HIV-1 subtype B env gene within the group of Korean men who have sex with men (MSM). From 1985 to 2005, 700 HIV-1-infected Koreans were sequenced at the V1 to V5 region of the HIV-1 env gene. In the phylogenetic analysis, 560 isolates were identified as HIV-1 subtype B, and 489 of the 560 isolates were HIV-1 Korean clade B. Based on epidemiologic investigation, 249 of 700 HIV-1-infected patients were HIV-1 subtype B-infected MSM. Interestingly, the proportion of the GPGS motif in MSM infected by Koreans was 1.6 times higher than in MSM infected by foreigners, and the genetic expansions of diversity and divergence for HIV-1 subtype B in Korean MSM were 2.1% and 2.5%, respectively. This was much lower than those observed in other countries. Therefore, our findings imply that the HIV strains in this group were closely related. This result may be helpful for understanding the evolution of the distinct HIV-1 Korean B clade.

The emergence of HIV/AIDS in the Americas and beyond

HIV-1 group M subtype B was the first HIV discovered and is the predominant variant of AIDS virus in most countries outside of sub-Saharan Africa. However, the circumstances of its origin and emergence remain unresolved. Here we propose a geographic sequence and time line for the origin of subtype B and the emergence of pandemic HIV/AIDS out of Africa. Using HIV-1 gene sequences recovered from archival samples from some of the earliest known Haitian AIDS patients, we find that subtype B likely moved from Africa to Haiti in or around 1966 (1962-1970) and then spread there for some years before successfully dispersing elsewhere. A "pandemic" clade, encompassing the vast majority of non-Haitian subtype B infections in the United States and elsewhere around the world, subsequently emerged after a single migration of the virus out of Haiti in or around 1969 (1966-1972). Haiti appears to have the oldest HIV/AIDS epidemic outside sub-Saharan Africa and the most genetically diverse subtype B epidemic, which might present challenges for HIV-1 vaccine design and testing. The emergence of the pandemic variant of subtype B was an important turning point in the history of AIDS, but its spread was likely driven by ecological rather than evolutionary factors. Our results suggest that HIV-1 circulated cryptically in the United States for approximately 12 years before the recognition of AIDS in 1981.

Introduction of HIV type 1 into an isolated population: molecular epidemiologic study from Greenland

Introduction of HIV-1 into a population may not always give rise to a subsequent epidemic. Greenland is an isolated and sparsely populated island in The Danish Kingdom. We aimed to estimate the number of introductions of HIV-1 into Greenland, the number of subsequent epidemics, and the countries from which the virus was introduced. Phylogenetic analyses were performed on three regions of HIV-1 (gag, pol, and env) in samples from 70 Greenlandic patients. Furthermore, we included gene sequences from contemporary Danish HIV-1-infected patients and sequences from the Los Alamos HIV Sequence Database. All Greenlandic sequences were subtype B except one sequence found to be a recombinant (probably CRF13). Sequence clusters in the phylogenetic trees indicated that there had been at least nine introductions of HIV-1 into Greenland. One cluster, supported by bootstrap values of 81, 76, and 96% for gag, pol, and env, corresponding to one introduction, contained 53 (76%) of the Greenland patients. The patients in the cluster differed from other Greenlandic patients in epidemiological parameters. Two distinct subgroups within the main cluster were concentrated around the two largest Greenlandic towns. Although HIV-1 has been introduced into Greenland at least nine times, only one introduction gave rise to an epidemic. The phylogeny did not indicate from where the main Greenland cluster had been introduced as no database sequence from outside Greenland was genetically close to this cluster. The large diversity between the main Greenland cluster and the rest of the sequences is most likely due to a founder effect.

Full sequence of HIV type 1 Korean subtype B in an AIDS case with atypical seroconversion: TAAAA at TATA box

A patient who presented with late stage HIV-associated diseases could not be diagnosed by commercial ELISA tests and a Western blot. However, we could amplify proviral DNA of HIV-1. We found a novel GPGGMI motif in the V3 loop, a novel insertion of a proline in the C3 region, and persistent deletion of two amino acids in the vif gene. The patient had been treated with HAART after diagnosis. Forty months after the first amplification of HIV-1 DNA, anti-HIV-1 antibody was confirmed by ELISA and Western blot and, thus, we amplified and sequenced HIV-1 full sequences. Interestingly, the sequence at the TATAA box was TAAAA, although full sequences were not CRF01_AE. The major differences in the level of the HIV-1 gene between the seronegative and seropositive states were changes at the glycosylation site (NXT) next to the inserted proline and many resistance mutations including M184V to antiretroviral drugs occurred. This is the first report on HIV-1 full sequences isolated from seronegative AIDS patients infected with subtype B in Korea.