Name: forward genetic approaches in chlamydia trachomatis
Uploaded: 2013-10-23T18:30:00
Description: Watch this Scientific Journal Video about Forward Genetic Approaches in Chlamydia trachomatis at JoVE.com

1. 화학적 돌연변이 유발 참고 : 우리는 증식하는의 RB 양식 EB 양식보다 화학적 돌연변이 유발에 더 순종 것으로 나타났습니다. 중간 사이클 (HPI 20-18 사이)에서 RBS는 사전 RB-EB 전환에 가장 큰 숫자에 있습니다. 클라미디아의 trachomatis는 의무 세포 내 병원체이기 때문에, 호스트 건강에 돌연변이의 효과는 세균의 회복을 제한 할 수 있습니다. 베로 세포는 테스트를 다른 세...

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이 유전자형과 표현형 사이의 연계를 설정으로이 방법은 유전자 분석을위한 기본 요구 사항을 충족합니다. 중요한 것은,이 재조합 DNA의 변화와 종종 비 모델 미생물의 유전자 기능의 분석 속도 제한 단계는 박테리아 유전자의 insertional 비활성화에 대한 기존의 분자 도구의 도움없이 달성된다. 하나의 중요한 단계는 패 정제 된 돌연변이 체의 클론을 보장하는 것입니다. 야생...

관련과 미국에서 연간 약 280 만 생식기 감염 (질병 통제 센터) 후유증과 같은 골반 염증성 질환, 자궁외 임신, 불임 (1)에 대한 의무 세포 내 세균 클라미디아의 trachomatis 계정. 클라미디아 균은 고유 한이 전염성하지만 비 복제 초등학교 바디 (EB) 및 비 감염성하지만, 증식하는 그물 몸 (RB) : 두 가지 형태로 구성된 이상성 개발주기 생리학. 감염 endoctyotosis (2) 다음 상피 세포에 사채의 첨부 파일이 시작됩니다. 막 바인딩 공포는 포함을라고 이내에 교환 사채는 이진 핵분열에 의해 복제 RB 형태로 분화. 중반 사이클에서, RBS 전환 당시 감염의 새로운 라운드를 시작하기 위해 세포 공간으로 추방 사채,에 때 숙주 세포 lyses (3). C. trachomatis에 있습니다이러한 세균 유전학 대부분의 연구 중심되었습니다 타겟 유전자 교체, 트랜스포존과 transducing에 파지, 표준 분자 유전 학적 도구와 일상적인 조작에 내화물, 그것은 개인의 클라미디아 유전자가 타고난 면역 회피에 기여하는 정도 불분명하다 , 영양소 수집, 개발 전환, 또는 진핵 호스트 (4) 내 병원체의 생존에 중요한 다른 프로세스. 따라서이 병원체는 임상 적 중요성에도 불구하고 저조한 특징 남아있다. 클라미디아 균의 게놈. 차세대 시퀀싱 기술을 사용하여 염기 서열 여러 종 biovars와 (5) (~ 1MB의) 상대적으로 작은 수 있습니다. WGS하여 비교 게놈 분석은 독성 요인의 잠재적 기능 (9, 10)에 관해서 몇 가지 정보를 제공하고 있습니다 클라미디아 종과 인간 (6-8)에 어느 정도에 그들의 적응의 진화에 독특한 통찰력을 제공하고 있습니다. 티임상 분리하여 표시 그는 유전 적 다양성은 유전자의 돌연변이가 쉽게에 대한 선택했을 아마도 때문에, 체계적으로 대부분의 독성 요소의 기능을 매핑하는 데 필요한 해상도를 제공하지 않습니다. 독성의 측정 결함, 조사 할 수있는 돌연변이의 스펙트럼을 확장 할 수있는 정의 된 분석과 함께 자연 선택, 돌연변이 유발 유전자 변이의 혼란 함을 주죠 효과없이. 화학 돌연변이는 특히 그들이 널, 조건, hypomorphic (감소 함수)를 생성 할 수 있습니다으로 유용하고, hypermorphic (함수의 이득) 대립 유전자이다. 강력한 차세대 게놈 시퀀싱 기술의 도착과 함께, 이러한 돌연변이 쉽게 식별 매핑 할 수 있습니다. 이러한 방식으로, 강한 협회는 앞으로 유전자 접근 방식의 적용을 가능하게하는 유전자 또는 유전 경로의 변이와 일반적인 표현형 사이에 만들 수 있습니다. 임상 균주의 게놈 시퀀스 모자이 B 밝혀etween의 혈청 형과 자주 재조합 (11)의 궤적. 재조합 경험적 증거는 두 계통에서 유전 적 기여 (12, 13)을 가지고 계시 이중 저항 재조합 자손의 두 가지 항생제 내성과 선택의 공동 감염을 통해 증명되었다. 따라서, 공동 감염 설정 야생형과 돌연변이 균주 간의 유전 적 교환은 화학적으로 유도 된 돌연변이의 분리가 관찰 된 표현형에 이르게 영향을받는 유전자를 찾아 낼 수 있습니다. 여기에서 우리는 화학 돌연변이, WGS, 감염된 세포 내에서 DNA 교환 (14) (그림 1)에 대한 시스템을 기반으로 클라미디아의 유전자 분석을 수행하는 방법을 설명합니다.

<table border="0" cellspacing="0" cols="4">
	<colgroup width="291">
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	<colgroup width="123">
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	<colgroup width="144">
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	<colgroup width="84">
	</colgroup>
	<tbody>
		<tr>
			<td>Dulbecco&#8217;s Modified Eagle Medium (DMEM)</td>
			<td>Life Technologies</td>
			<td>11995-073</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum (FBS)</td>
			<td>Cellgro</td>
			<td>35-010-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethyl methanesulfonate (EMS)</td>
			<td>Sigma</td>
			<td>M0880</td>
			<td></td>
		</tr>
		<tr>
			<td>Cyclohexamide</td>
			<td>Sigma</td>
			<td>C4859-1ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Gentamicin</td>
			<td>Life Technologies</td>
			<td>15750-060</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate buffered saline (PBS)</td>
			<td>Life Technologies</td>
			<td>14190-144</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate buffered saline (PBS) solution with 0.493 mM MgCl2 and 0.901 mM CaCl2 (PBS+MgCl2/CaCl2)</td>
			<td>Life Technologies</td>
			<td>14040-133</td>
			<td></td>
		</tr>
		<tr>
			<td>1 M NaOH</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>5x SPG buffer (1.25 M sucrose, 50 mM sodium phosphate, 25 mM glutamic acid)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>SPG buffer (0.25 M sucrose, 10 mM sodium phosphate, 5 mM glutamic acid)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Water (sterile, tissue culture grade)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>2x DMEM (prepared from powder, buffered with 7.4 g/L Sodium Bicarbonate</td>
			<td>Sigma</td>
			<td>D7777</td>
			<td></td>
		</tr>
		<tr>
			<td>Nonessential amino acids (NEAA)</td>
			<td>Life Technologies</td>
			<td>11140-050</td>
			<td></td>
		</tr>
		<tr>
			<td>1.2% GTG Agarose , autoclaved</td>
			<td>Lonzo</td>
			<td>50070</td>
			<td></td>
		</tr>
		<tr>
			<td>Genomic DNA purification kits</td>
			<td>Qiagen</td>
			<td>69504</td>
			<td></td>
		</tr>
		<tr>
			<td>DNAzol</td>
			<td>Life Technologies</td>
			<td>10503-027</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol (molecular biology grade)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>8 mM NaOH</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>0.1 M HEPES ( 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) buffer</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>25 cm2 tissue culture flasks (T25 flasks)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>6-well tissue culture plates</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>12-well tissue culture plates</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>96-well tissue culture plates</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Chemical safety hood</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Biological safety hood</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>&#62;Centrifuge and adaptors for spinning tissue plates</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>&#62;Dissection microscope</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorometer (Qubit)</td>
			<td>Invitrogen</td>
			<td>Q32866</td>
			<td></td>
		</tr>
		<tr>
			<td>Adaptive Focused Acoustics S220 instrument</td>
			<td>Covaris</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

forward genetic approaches in chlamydia trachomatis

클라미디아의 trachomatis, 성병 및 안구 감염의 병인 에이전트, 재조합 DNA와 가난 때문에 실험 변환에 해당 다루기 힘듦을 특징으로 남아있다. 우리는 C에서 유전자 분석을 수행 할 수있는 방법을 개발 분자 유전 학적 도구의 부족에도 불구의 trachomatis. 우리의 방법이 포함됩니다 : I)를 빠르게 별개의 표현형과 유전 정의 된 돌연변이의 포괄적 인 라이브러리를 생성하는 화학 돌연변이, ii)에서 전체 게놈 시퀀싱 (WGS)가 기본 유전 병변을지도하고 변이 유전자 (들) 사이의 연결을 발견하고.. 일반적인 표현형;. 돌연변이 야생형 박테리아와 포유 동물 세포의 공동 감염을 통해 재조합 균주의 III는) 생성. 따라서, 우리는 유전자형과 표현형 사이의 인과 관계를 확립 할 수 있었다. 화학적으로 유도 된 유전자 변이와 WGS의 결합은 상호 유전자형 - 표현형 협회에게 우리말을 설정하려면LD는 유전자 분석에 현재 어려운 의학 및 환경 중요한 미생물의 큰 목록에 광범위하게 적용합니다.

돌연변이에 노출 세균 세포의 죽음으로 인해 아마도, 세균없는 표시 함유로 연결됩니다. 일반적으로 혈청 형 LGV-L2 완전히 48 시간 게시물 감염에서 감염 세포를 용해되지만, 돌연변이와 치료&gt; 90 시간이 사이클을 확장 할 수 있습니다. 흠의 약 10 %를 회복 할 것으로 예상된다. 우리의 실험에서, 감염 베로 세포 치료 컨트롤에 비해 전염성 자손의 회복에 99 % 감소했다 20 MG / ML EMS로 처리. 돌연변이 ?...

Watch this Scientific Journal Video about Forward Genetic Approaches in Chlamydia trachomatis at JoVE.com

Forward Genetic Approaches in Chlamydia trachomatis

우리는 화학 돌연변이 및 전체 게놈 시퀀싱에 따라 클라미디아의 유전자 분석을 수행하는 방법을 설명합니다. 또한, 감염된 세포 내에서 DNA 교환을위한 시스템은 유전자 매핑에 사용할 수있는 설명합니다. 이 방법은 변환 시스템 및 분자 유전 학적 도구가 부족한 미생물 시스템에 광범위하게 적용 할 수있다.

앞으로 유전 접근<em&gt; 클라미디아의 trachomatis</em

Chlamydia trachomatis, the etiological agent of sexually transmitted diseases and ocular infections, remains poorly characterized due to its ...

forward-genetic-approaches-in-chlamydia-trachomatis

Research

JoVE Journal

Immunology and Infection

Forward Genetic Approaches in Chlamydia trachomatis

A Genetic Screen to Isolate Toxoplasma gondii Host-cell Egress Mutants

The widespread, obligate intracellular, protozoan parasite Toxoplasma gondii causes opportunistic disease in immuno-compromised patients and causes birth defects upon congenital infection. The lytic replication cycle is characterized by three stages: 1. active invasion of a nucleated host cell; 2. replication inside the host cell; 3. active egress from the host cell. The mechanism of egress is increasingly being appreciated as a unique, highly regulated process, which is still poorly understood at the molecular level. The signaling pathways underlying egress have been characterized through the use of pharmacological agents acting on different aspects of the pathways1-5. As such, several independent triggers of egress have been identified which all converge on the release of intracellular Ca2+, a signal that is also critical for host cell invasion6-8. This insight informed a candidate gene approach which led to the identification of plant like calcium dependent protein kinase (CDPK) involved in egress9. In addition, several recent breakthroughs in understanding egress have been made using (chemical) genetic approaches10-12. To combine the wealth of pharmacological information with the increasing genetic accessibility of Toxoplasma we recently established a screen permitting the enrichment for parasite mutants with a defect in host cell egress13. Although chemical mutagenesis using N-ethyl-N-nitrosourea (ENU) or ethyl methanesulfonate (EMS) has been used for decades in the study of Toxoplasma biology11,14,15, only recently has genetic mapping of mutations underlying the phenotypes become routine16-18. Furthermore, by generating temperature-sensitive mutants, essential processes can be dissected and the underlying genes directly identified. These mutants behave as wild-type under the permissive temperature (35 &deg;C), but fail to proliferate at the restrictive temperature (40 &deg;C) as a result of the mutation in question. Here we illustrate a new phenotypic screening method to isolate mutants with a temperature-sensitive egress phenotype13. The challenge for egress screens is to separate egressed from non-egressed parasites, which is complicated by fast re-invasion and general stickiness of the parasites to host cells. A previously established egress screen was based on a cumbersome series of biotinylation steps to separate intracellular from extracellular parasites11. This method also did not generate conditional mutants resulting in weak phenotypes. The method described here overcomes the strong attachment of egressing parasites by including a glycan competitor, dextran sulfate (DS), that prevents parasites from sticking to the host cell19. Moreover, extracellular parasites are specifically killed off by pyrrolidine dithiocarbamate (PDTC), which leaves intracellular parasites unharmed20. Therefore, with a new phenotypic screen to specifically isolate parasite mutants with defects in induced egress, the power of genetics can now be fully deployed to unravel the molecular mechanisms underlying host cell egress.

A Genetic Screen to Isolate Toxoplasma gondii Host-cell Egress Mutants

Forward genetics is a powerful method to unravel the molecular level of how Toxoplasma egresses from its host cell. Protocols are provided to chemically mutagenize parasites, enrich for mutants with defects in induced egress, and validate the phenotype of cloned mutants.

분리하기위한 유전자 스크린 Toxoplasma gondii 호스트 세포 재현의 돌연변이

The widespread, obligate intracellular, protozoan parasite Toxoplasma gondii causes opportunistic disease in immuno-compromised patients and causes birth ...

연구

면역학 및 감염병학

Genetic Manipulation in &Delta;ku80 Strains for Functional Genomic Analysis of Toxoplasma gondii

Targeted genetic manipulation using homologous recombination is the method of choice for functional genomic analysis to obtain a detailed view of gene function and phenotype(s). The development of mutant strains with targeted gene deletions, targeted mutations, complemented gene function, and/or tagged genes provides powerful strategies to address gene function, particularly if these genetic manipulations can be efficiently targeted to the gene locus of interest using integration mediated by double cross over homologous recombination.
Due to very high rates of nonhomologous recombination, functional genomic analysis of Toxoplasma gondii has been previously limited by the absence of efficient methods for targeting gene deletions and gene replacements to specific genetic loci. Recently, we abolished the major pathway of nonhomologous recombination in type I and type II strains of T. gondii by deleting the gene encoding the KU80 protein1,2. The &Delta;ku80 strains behave normally during tachyzoite (acute) and bradyzoite (chronic) stages in vitro and in vivo and exhibit essentially a 100% frequency of homologous recombination. The &Delta;ku80 strains make functional genomic studies feasible on the single gene as well as on the genome scale1-4.
Here, we report methods for using type I and type II &Delta;ku80&Delta;hxgprt strains to advance gene targeting approaches in T. gondii. We outline efficient methods for generating gene deletions, gene replacements, and tagged genes by targeted insertion or deletion of the hypoxanthine-xanthine-guanine phosphoribosyltransferase (HXGPRT) selectable marker. The described gene targeting protocol can be used in a variety of ways in &Delta;ku80 strains to advance functional analysis of the parasite genome and to develop single strains that carry multiple targeted genetic manipulations. The application of this genetic method and subsequent phenotypic assays will reveal fundamental and unique aspects of the biology of T. gondii and related significant human pathogens that cause malaria (Plasmodium sp.) and cryptosporidiosis (Cryptosporidium).

Genetic Manipulation in &lt;em&gt;&amp;Delta;ku80&lt;/em&gt; Strains for Functional Genomic Analysis of &lt;em&gt;Toxoplasma gondii&lt;/em&gt;

Here we report a method for using type I and type II &Delta;ku80 strains of Toxoplasma gondii to efficiently generate targeted gene deletions and gene replacements for functional genomic analysis.

유전 조작<em&gt; Δku80</em의 기능 게놈 분석을위한&gt; 균주<em&gt; 톡소 포자충</em

Targeted genetic manipulation using homologous recombination is the method of choice for functional genomic analysis to obtain a detailed view of gene ...

VIGS-Mediated Forward Genetics Screening for Identification of Genes Involved in Nonhost Resistance

Nonhost disease resistance of plants against bacterial pathogens is controlled by complex defense pathways. Understanding this mechanism is important for developing durable disease-resistant plants against wide range of pathogens. Virus-induced gene silencing (VIGS)-based forward genetics screening is a useful approach for identification of plant defense genes imparting nonhost resistance. Tobacco rattle virus (TRV)-based VIGS vector is the most efficient VIGS vector to date and has been efficiently used to silence endogenous target genes in Nicotiana benthamiana.

	In this manuscript, we demonstrate a forward genetics screening approach for silencing of individual clones from a cDNA library in N. benthamiana and assessing the response of gene silenced plants for compromised nonhost resistance against nonhost pathogens, Pseudomonas syringae pv. tomato T1, P. syringae pv. glycinea, and X. campestris pv. vesicatoria. These bacterial pathogens are engineered to express GFPuv protein and their green fluorescing colonies can be seen by naked eye under UV light in the nonhost pathogen inoculated plants if the silenced target gene is involved in imparting nonhost resistance. This facilitates reliable and faster identification of gene silenced plants susceptible to nonhost pathogens. Further, promising candidate gene information can be known by sequencing the plant gene insert in TRV vector. Here we demonstrate the high throughput capability of VIGS-mediated forward genetics to identify genes involved in nonhost resistance. Approximately, 100 cDNAs can be individually silenced in about two to three weeks and their relevance in nonhost resistance against several nonhost bacterial pathogens can be studied in a week thereafter. In this manuscript, we enumerate the detailed steps involved in this screening. VIGS-mediated forward genetics screening approach can be extended not only to identifying genes involved in nonhost resistance but also to studying genes imparting several biotic and abiotic stress tolerances in various plant species.

Virus-induced gene silencing is an useful tool for identifying genes involved in nonhost resistance of plants. We demonstrate the use of bacterial pathogens expressing GFPuv in identifying gene silenced plants susceptible to nonhost pathogens. This approach is easy, fast and facilitates large scale screening and similar protocol can be applied to studying various other plant-microbe interactions.

유전자의 식별을위한 VIGS - 중재 앞으로 유전학 검사는 Nonhost 저항에 참여


	Nonhost disease resistance of plants against bacterial pathogens is controlled by complex defense pathways. Understanding this mechanism is important ...

Discovery of New Intracellular Pathogens by Amoebal Coculture and Amoebal Enrichment Approaches

Intracellular pathogens such as legionella, mycobacteria and Chlamydia-like organisms are difficult to isolate because they often grow poorly or not at all on selective media that are usually used to cultivate bacteria. For this reason, many of these pathogens were discovered only recently or following important outbreaks. These pathogens are often associated with amoebae, which serve as host-cell and allow the survival and growth of the bacteria. We intend here to provide a demonstration of two techniques that allow isolation and characterization of intracellular pathogens present in clinical or environmental samples: the amoebal coculture and the amoebal enrichment. Amoebal coculture allows recovery of intracellular bacteria by inoculating the investigated sample onto an amoebal lawn that can be infected and lysed by the intracellular bacteria present in the sample. Amoebal enrichment allows recovery of amoebae present in a clinical or environmental sample. This can lead to discovery of new amoebal species but also of new intracellular bacteria growing specifically in these amoebae. Together, these two techniques help to discover new intracellular bacteria able to grow in amoebae. Because of their ability to infect amoebae and resist phagocytosis, these intracellular bacteria might also escape phagocytosis by macrophages and thus, be pathogenic for higher eukaryotes.

Amoebal coculture is a cell culture system using adherent amoebae to selectively grow intracellular pathogens able to resist phagocytic cells such as amoebae and macrophages. It thus represents a key tool to discover new infectious agents. Amoebal enrichment allows discovery of new amoebal species and of their specific intracellular bacteria.

Amoebal 공 배양 및 Amoebal 심화 접근에 의한 새로운 세포 내 병원균의 발견

Intracellular pathogens such as legionella, mycobacteria and Chlamydia-like organisms are difficult to isolate because they often grow poorly or not at ...

Using Fluorescent Proteins to Visualize and Quantitate Chlamydia Vacuole Growth Dynamics in Living Cells

The obligate intracellular bacterium Chlamydia elicits a great burden on global public health. C.&#160;trachomatis is the leading bacterial cause of sexually transmitted infection and also the primary cause of preventable blindness in the world. An essential determinant for successful infection of host cells by Chlamydia is the bacterium's ability to manipulate host cell signaling from within a novel, vacuolar compartment called the inclusion. From within the inclusion, Chlamydia acquire nutrients required for their 2-3 day developmental growth, and they additionally secrete a panel of effector proteins onto the cytosolic face of the vacuole membrane and into the host cytosol. Gaps in our understanding of Chlamydia biology, however, present significant challenges for visualizing and analyzing this intracellular compartment. Recently, a reverse-imaging strategy for visualizing the inclusion using GFP expressing host cells was described. This approach rationally exploits the intrinsic impermeability of the inclusion membrane to large molecules such as GFP. In this work, we describe how GFP- or mCherry-expressing host cells are generated for subsequent visualization of chlamydial inclusions. Furthermore, this method is shown to effectively substitute for costly antibody-based enumeration methods, can be used in tandem with other fluorescent labels, such as GFP-expressing Chlamydia, and can be exploited to derive key quantitative data about inclusion membrane growth from a range of Chlamydia species and strains.

Using Fluorescent Proteins to Visualize and Quantitate Chlamydia Vacuole Growth Dynamics in Living Cells

A live cell fluorescent protein based method for illuminating cellular vacuoles (inclusions) containing Chlamydia is described. This strategy enables rapid, automated determination of Chlamydia infectivity in samples and can be used to quantitatively investigate inclusion growth dynamics.

시각화 및 정량하기 위해 형광 단백질을 사용하여<em&gt; 클라미디아</em&gt; 액포 성장 역학 살아있는 세포에서

The obligate intracellular bacterium Chlamydia elicits a great burden on global public health. C.&#160;trachomatis is the leading bacterial cause of ...

Forward Genetics Screens Using Macrophages to Identify Toxoplasma gondii Genes Important for Resistance to IFN-&#947;-Dependent Cell Autonomous Immunity

Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular protozoan pathogen. The parasite invades and replicates within virtually any warm blooded vertebrate cell type. During parasite invasion of a host cell, the parasite creates a parasitophorous vacuole (PV) that originates from the host cell membrane independent of phagocytosis within which the parasite replicates. While IFN-dependent-innate and cell mediated immunity is important for eventual control of infection, innate immune cells, including neutrophils, monocytes and dendritic cells, can also serve as vehicles for systemic dissemination of the parasite early in infection. An approach is described that utilizes the host innate immune response, in this case macrophages, in a forward genetic screen to identify parasite mutants with a fitness defect in infected macrophages following activation but normal invasion and replication in na&#239;ve macrophages. Thus, the screen isolates parasite mutants that have a specific defect in their ability to resist the effects of macrophage activation. The paper describes two broad phenotypes of mutant parasites following activation of infected macrophages: parasite stasis versus parasite degradation, often in amorphous vacuoles. The parasite mutants are then analyzed to identify the responsible parasite genes specifically important for resistance to induced mediators of cell autonomous immunity. The paper presents a general approach for the forward genetics screen that, in theory, can be modified to target parasite genes important for resistance to specific antimicrobial mediators. It also describes an approach to evaluate the specific macrophage antimicrobial mediators to which the parasite mutant is susceptible. Activation of infected macrophages can also promote parasite differentiation from the tachyzoite to bradyzoite stage that maintains chronic infection. Therefore, methodology is presented to evaluate the importance of the identified parasite gene to establishment of chronic infection.

Forward Genetics Screens Using Macrophages to Identify Toxoplasma gondii Genes Important for Resistance to IFN-&amp;#947;-Dependent Cell Autonomous Immunity

Forward genetics is a powerful approach to identify genes in intracellular pathogens important for resistance to cell autonomous immunity. The current approach uses innate immune cells, specifically macrophages, to identify novel Toxoplasma gondii genes important for immune evasion.

앞으로 유전학 식별하는 대 식세포를 사용하여 화면<em&gt; 톡소 포자충</em&gt; 유전자 중요 저항이하는 IFN-γ 의존 세포 자치 내성

Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular protozoan pathogen. The parasite invades and replicates within ...

Utilizing the Antigen Capsid-Incorporation Strategy for the Development of Adenovirus Serotype 5-Vectored Vaccine Approaches

Adenovirus serotype 5 (Ad5) has been extensively modified with traditional transgene methods for the vaccine development. The reduced efficacies of these traditionally modified Ad5 vectors in clinical trials could be primarily correlated with Ad5 pre-existing immunity (PEI) among the majority of the population. To promote Ad5-vectored vaccine development by solving the concern of Ad5 PEI, the innovative Antigen Capsid-Incorporation strategy has been employed. By merit of this strategy, Ad5-vectored we first constructed the hexon shuttle plasmid HVR1-KWAS-HVR5-His6/pH5S by subcloning the hypervariable region (HVR) 1 of hexon into a previously constructed shuttle plasmid HVR5-His6/pH5S, which had His6 tag incorporated into the HVR5. This HVR1 DNA fragment containing a HIV epitope ELDKWAS was synthesized. HVR1-KWAS-HVR5-His6/pH5S was then linearized and co-transformed with linearized backbone plasmid pAd5/&#8710;H5 (GL) , for homologous recombination. This recombined plasmid pAd5/H5-HVR1-KWAS-HVR5-His6 was transfected into cells to generate the viral vector Ad5/H5-HVR1-KWAS-HVR5-His6. This vector was validated to have qualitative fitness indicated by viral physical titer (VP/ml), infectious titer (IP/ml) and corresponding VP/IP ratio. Both the HIV epitope and His6 tag were surface-exposed on the Ad5 capsid, and retained epitope-specific antigenicity of their own. A neutralization assay indicated the ability of this divalent vector to circumvent neutralization by Ad5-positive sera in vitro. Mice immunization demonstrated the generation of robust humoral immunity specific to the HIV epitope and His6. This proof-of-principle study suggested that the protocol associated with the Antigen Capsid-Incorporation strategy could be feasibly utilized for the generation of Ad5-vectored vaccines by modifying different capsid proteins. This protocol could even be further modified for the generation of rare-serotype adenovirus-vectored vaccines.

Here, we present a protocol to generate a proof-of-principle divalent adenovirus type 5 (Ad5) vector Ad5/H5-HVR1-KWAS-HVR5-His6 by utilizing the Antigen Capsid-Incorporation strategy. This vector was demonstrated to exhibit qualitative fitness, the capability to escape Ad5-positive sera in vitro, and the antigenicity as well as immunogenicity to the incorporated antigens.

아데노 바이러스 혈청 형 5 된 벡터 백신 접근 방법의 개발을위한 항원 캡시드-설립 전략을 활용

Adenovirus serotype 5 (Ad5) has been extensively modified with traditional transgene methods for the vaccine development. The reduced efficacies of these ...

Phage Phenomics: Physiological Approaches to Characterize Novel Viral Proteins

Current investigations into phage-host interactions are dependent on extrapolating knowledge from (meta)genomes. Interestingly, 60 - 95% of all phage sequences share no homology to current annotated proteins. As a result, a large proportion of phage genes are annotated as hypothetical. This reality heavily affects the annotation of both structural and auxiliary metabolic genes. Here we present phenomic methods designed to capture the physiological response(s) of a selected host during expression of one of these unknown phage genes. Multi-phenotype Assay Plates (MAPs) are used to monitor the diversity of host substrate utilization and subsequent biomass formation, while metabolomics provides bi-product analysis by monitoring metabolite abundance and diversity. Both tools are used simultaneously to provide a phenotypic profile associated with expression of a single putative phage open reading frame (ORF). Representative results for both methods are compared, highlighting the phenotypic profile differences of a host carrying either putative structural or metabolic phage genes. In addition, the visualization techniques and high throughput computational pipelines that facilitated experimental analysis are presented.

Here, we present phenomic approaches for the functional characterization of putative phage genes. Techniques include a developed assay capable of monitoring host anabolic metabolism, the Multi-phenotype Assay Plates (MAPs), in addition to the established method of metabolomics, capable of measuring effects to catabolic metabolism.

파지 Phenomics : 생리 학적 접근 방법은 소설 바이러스 성 단백질의 특성을

Current investigations into phage-host interactions are dependent on extrapolating knowledge from (meta)genomes. Interestingly, 60 - 95% of all phage ...

A Simple Red Blood Cell Lysis Method for the Establishment of B Lymphoblastoid Cell Lines

A number of methods exist for the transformation of B lymphocytes by the Epstein Barr virus in vitro into immortalized cell lines. We have developed a new method with a powerful and simple strategy for the establishment of B-LCLs, the red blood cell lysis method. This method simplified the PBMC separation procedure with red blood cell removal, and used as little as 0.5 mL of whole blood for establishing EBV-immortalized cell lines, which can proliferate to large cell numbers in a relatively short amount time with a 100% success rate. The method is simple, reliable, time saving, and applicable to treating a large number of the clinical samples.

A simple red blood cell lysis method for establishing B-LCLs was developed with high immortalization efficiency, requiring a small amount of blood and saving time from initiation to cryopreservation.

B 임파 세포 라인의 설립에 대한 간단한 적혈구 용해 방법

A number of methods exist for the transformation of B lymphocytes by the Epstein Barr virus in vitro into immortalized cell lines. We have developed a new ...

An Efficient and Simple Method to Establish NK and T Cell Lines from Patients with Chronic Active Epstein-Barr Virus Infection

A number of methods have been described to establish NK/T cell lines from patients with lymphoma or lymphoproliferative syndrome. These methods employed feeder cells, purified NK or T cells with as much as 10 mL of blood, or a high-dose of IL-2. This study presents a new method with a powerful and simple strategy to establish NK and T cell lines by culturing the peripheral blood mononuclear cells (PBMC) with the addition of recombinant human IL-2 (rhIL-2), and uses as little as 2 mL of whole blood. The cells can proliferate quickly in two weeks and be maintained for more than 3 months. With this method, 7 NK or T cell lines have been established with a high success rate. This method is simple, reliable, and applicable to establishing cell lines from more cases of CAEBV or NK/T cell lymphoma.

A simple method for obtaining NK and T cell clones from CAEBV patients was developed with high efficiency, a small amount of peripheral blood, and a low-dose of IL-2.

NK과 만성 활성 엡 스타인-바 바이러스 감염을 가진 환자에서 T 셀 라인을 설정 하는 효율적이 고 간단한 방법

A number of methods have been described to establish NK/T cell lines from patients with lymphoma or lymphoproliferative syndrome. These methods employed ...