• 생명과학회지
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• 제25권4호
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• pp.481-485
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• 2015

수백만 년 전부터 인간의 유전체에는 retrovirus의 유전자들이 삽입되기 시작하였다. 이러한 retrovirus의 유전자들은 결실 혹은 nonsense mutation등 여러 영향으로 지금은 더 이상 활동성 있는 바이러스로서의 역할을 못하는 흔적으로만 남아 있는 형태로 존재하며 이러한 내생(endogenous) retrovirus를 human endogenous retrovirus (HERV)라 부른다. HERV의 각 유전자들은 완성된 활동성을 지닌 바이러스를 만들어 내지는 못하지만 여전히 부분적으로 발현이 가능하고 심지어는 바이러스 particle 까지 만들어지는 것이 관찰되었다. 이러한 내성 retrovirus 에 반해 실질적으로 감염되고 활동하여 질병을 야기하는 외인성(exogenous) retrovirus들이 있는데 이 중 human immunodeficiency virus (HIV)는 인간의 생명을 위협하는 대표적 바이러스로 가장 많이 연구되고 있는 바이러스중의 하나이다. 최근 흔적으로만 존재하는 것으로 보고된 HERV가 실질적으로 활성화된 바이러스인 HIV의 감염에 의해 활성화되고 발현이 증가할 뿐 아니라 HIV 감염의 여러 과정에 관여하고 있다는 연구 결과가 보고되고 있다. 또한 이러한 현상을 이용하여 HIV의 백신 및 치료 방법으로 HERV를 이용하고자 하는 시도가 활발히 이루어지고 있다. 이 리뷰에서는 HIV 감염에 의한 HERV의 활성화 및 관련 상호 기작에 관한 연구를 소개하고 HERV를 이용한 HIV의 백신 및 치료제 개발을 위한 시도들을 함께 소개하고자 한다.

• Molecules and Cells
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• 제45권8호
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• pp.522-530
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• 2022

Transposable elements (TEs) account for approximately 45% of the human genome. TEs have proliferated randomly and integrated into functional genes during hominoid radiation. They appear as right-handed B-DNA double helices and slightly elongated left-handed Z-DNAs. Human endogenous retrovirus (HERV) families are widely distributed in human chromosomes at a ratio of 8%. They contain a 5'-long terminal repeat (LTR)-gag-pol-env-3'-LTR structure. LTRs contain the U3 enhancer and promoter region, transcribed R region, and U5 region. LTRs can influence host gene expression by acting as regulatory elements. In this review, we describe the alternative promoters derived from LTR elements that overlap Z-DNA by comparing Z-hunt and DeepZ data for human functional genes. We also present evidence showing the regulatory activity of LTR elements containing Z-DNA in GSDML. Taken together, the regulatory activity of LTR elements with Z-DNA allows us to understand gene function in relation to various human diseases.

• 미생물학회지
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• 제43권4호
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• pp.237-242
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• 2007

레트로바이러스(Retrovirus; RV)의 독특한 특징 중 하나는 프로바이러스의 상태로 숙주세포의 염색체에 삽입되어 숙주세포 유전자의 일부분으로서 다른 숙주세포 유전자들과 함께 다음세대로 유전된다는 것이다. 이러한 독특한 형태의 RV를 내인성 RV (endogenous RV; ERV)라고 하는데, 여러 종류의 내 외적신호에 의해 그자신의 유전자뿐만 아니라 인근한 숙주유전자의 발현에 변화가 일어난다. 사람과 쥐에서는 각각 HERV (Human ERV)와 MuERV (Murine ERV)가 세포 속에 존재하여 이들의 발현 변화가 숙주 생물체에 주로 해롭게 작용하여 질병을 일으키게 된다. 이들 ERV는 생체분자, 세포물질들이 관여하는 기작을 통해 암과 자가면역 반응과 같은 질병을 일으키는데, 이에 수반하여 많은 병리생리적 변화를 가져온다. HERV와 관련된 질병을 앓고 있는 환자들을 위해서는 이러한 질병을 이해하고, 이를 바탕으로 치료요법을 개발하기 위해 여러 단계의 대책들이 고려되어야 한다.

• Journal of Microbiology and Biotechnology
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• 제21권4호
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• pp.387-390
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• 2011

Nude mice (BALB/c) were grafted with human 293 cells and PERV (porcine endogenous retrovirus)-IRES-EGFP (a packageable retroviral vector plasmid containing an internal ribosome entry site-enhanced green fluorescent protein)-producing pig PK15 cells in order to determine whether the pig cells could transmit PERV-IRES-EGFP to mice and human 293 cells in vivo. None of the transplanted human 293 cell lines were infected by PERV, but PCR analysis identified PERV-B provirus integration into both the heart and salivary gland of the inoculated nude mice. Our data indicate that hearts and salivary glands can be used to identify PERV-B receptors.

• BMB Reports
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• 제54권7호
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• pp.368-373
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• 2021

The vertebrate genome contains an endogenous retrovirus that has been inherited from the past millions of years. Although approximately 8% of human chromosomal DNA consists of sequences derived from human endogenous retrovirus (HERV) fragments, most of the HERVs are currently inactive and noninfectious due to recombination, deletions, and mutations after insertion into the host genome. Several studies suggested that Human endogenous retroviruses (HERVs) factors are significantly related to certain cancers. However, only limited studies have been conducted to analyze the expression of HERV derived elements at protein levels in certain cancers. Herein, we analyzed the expression profiles of HERV-K envelope (Env) and HERV-R Env proteins in eleven different kinds of cancer tissues. Furthermore, the expression patterns of both protein and correlation with various clinical data in each tissue were analyzed. The expressions of both HERV-K Env and HERV-R Env protein were identified to be significantly high in most of the tumors compared with normal surrounding tissues. Correlations between HERV Env expressions and clinical investigations varied depending on the HERV types and cancers. Overall expression patterns of HERV-K Env and HERV-R Env proteins were different in every individual but a similar pattern of expressions was observed in the same individual. These results demonstrate the expression profiles of HERV-K and HERV-R Env proteins in various cancer tissues and provide a good reference for the association of endogenous retroviral Env proteins in the progression of various cancers. Furthermore, the results elucidate the relationship between HERV-Env expression and the clinical significance of certain cancers.

• Animal cells and systems
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• 제6권1호
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• pp.81-84
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• 2002

SINE-R retroposons have been derived from human endogenous retrovirus HERV-K family and found to be hominoid specific. Both SINE-R retroposons and HERV_K family are potentially capable of affecting the expression of closely located genes. Using the genomic DNA from patients with schizophrenia, we identified 26 SINE-R retroposons and analyzed them with the sequences derived from the hominoid primates. The SINE-R retroposons from schizophrenia showed 89.7-96.6％ sequence similarities with the sequence of the schizo-cDNA clone that derived from postmortem tissue from the frontal cortex of an individual suffering from schizophrenial. Phylogenetic analysis using the neighbor-joining method revealed that the new SINE-R retroposons in schizophrenia have proliferated independently during hominid evolution. Such retroposons have great relevance to genomic change connected to human diseases. The data suggest that new SINE-R retroposons identified in schizophrenia deserve further investigation as potential leads on the understanding of neuropsychiatric diseases.

• Animal cells and systems
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• 제5권2호
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• pp.133-137
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• 2001

Long terminal repeats (LTRs) of the human endogenous retrovirus K family (HERV-K) have been found to be coexpressed with sequences of genes closely located nearby. We examined transcribed HERV-K LTR elements in human brain tissue. Using cDNA synthesized from mRNA of the human brain, we performed PCR amplification and identified ten HERV-K LTR elements. These LTR elements showed a high degree of sequence similarity (92.4-99.7%) with the human-specific LTR elements. A phylogenetic tree obtained by the neighbor-joining method revealed that HERV-K LTR elements could be divided into two groups through evolutionary divergence. Some HERV-K LTR elements (HKL-B7, HKL-B8, HKL-B10) belonging to the group II from human brain cDNA were closely related to the human-specific HERV-K LTR elements. Our data suggest that HERV-K LTR element are active in the human brain; they could conceivably play a pathogenic role in human diseases such as psychosis.

• Journal of Life Science
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• 제10권2호
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• pp.45-49
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• 2000

Long terminal repeat (LTR) of human endogenous retrovirus K family (HERV-K) has been found to be coexpressed with sequences of closely located genes. We examined the transcribed HERV-K LTR elements in human liver and kidney tissues. Using the cDNA synthesized from mRNA of human liver and kidney, we performed PCR amplification and identified six HERV-K LTR elements. Those LTR elements showed a high degree of sequence similarity (93.3∼96.6%) with human-specific LTR. A phylogenetic tree obtained by the neighbor-joining method revealed that HERV-K LTR elements (Liv-1, 2, 3 and Kid-1, 2, 3) were belonged to group I. Our data suggests that HERV-K LTR elements are active on human liver and kidney tissues and may represent a source of genetic variation connected to human disease.

• Journal of Life Science
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• 제11권2호
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• pp.83-86
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• 2001

The long terminal repeat (LTR) elements of human endogenous retrovirus (HERV) have been found to be coexpressed with genes located nearby. It has been suggested that the LTR elements have contributed to the genetic variation of human genome connected to various diseases. Recently, HERV-W family was identified in the cerebrospinal fluids and brains of individuals with schizophrenia. Using genomic DNAs derived from schizophrenia, we performed PCR amplification and identified six HERV-W LTR elements. Those LTR elements showed a high degree of sequence similarity (87.7-99.5%) with HERV-W LTR (AF072500). Sequence analysis of the HERV-W LTR elements revealed that clone W-sch1 showed identical sequence with the AC003014 (PAC clone RP1-290B4) derived from human Xq23. Clone W-sch2 was closely related to the AC0072442 derived from human Y chromosome by phylogenetic analysis. Our data suggest that new HERV-W LTR elements in schizophrenia may be very useful for further studies to understand neuropsychiatric diseases.

• 생명과학회지
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• 제31권8호
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• pp.771-777
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• 2021

인간 내생 레트로바이러스(Human Endogenous Restrovirus, HERV)는 수백만년전 인간의 유전체에 삽입되었으며 이후 오랜 세월을 거치며 재조합, 결실 및 돌연변이 등 여러 원인에 의해 더 이상 활성화된 바이러스로 역할을 하지 못하고 감염되지 않는다. 하지만 HERV는 최근 연구들은 HERV 유래 인자들이 실제 생리현상 및 암을 비롯한 특정 질환에 관여 하고 있다는 것을 보여 주었다. HERV와 관련된 여러가지 생리 현상 중 염증반응에 초점을 맞추어 고찰해 볼 필요가 있다. HERV는 류마티스, 다발성 경화증, 근위축성 측삭경화증, 쇼그렌 증후군 같은 자가면역질환을 비롯한 여러 염증질환에 직접적으로 관여하는 것으로 보고 되고 있다. HERV의 염증 조절 기작으로는 HERV 유래 인자들이 비특이적 선천성 면역과정을 유발할 가능성과 HERV 유래의 RNA와 단백질이 특정 수용체를 통해 선택적 신호전달기작을 유발할 가능성을 고려 할 수 있다. 하지만 어떠한 방식으로 잠재되어 있던 HERV가 염증반응에서 활성화 되는지 또한 HERV와 관여된 인자들과 신호기작들이 어떠한 것들이 있는지 등 HERV의 인자들이 염증반응을 조절하는 기작에는 아직 많은 것들이 밝혀지지 않아 질병 발병에 대한 연구에 어려움이 있는 실정이다. 본 리뷰에서는 HERV 관련 자가 면역질환을 소개하고 염증반응 조절 기작에 관한 HERV의 분자수준에서의 작용 메커니즘을 제안 하고자 한다.