CN103074422A

CN103074422A - MS4A6A gene application

Info

Publication number: CN103074422A
Application number: CN2012105894444A
Authority: CN
Inventors: 陈心春; 张国良; 周伯平; 杨倩婷; 张明霞; 蔡毅
Original assignee: Third Peoples Hospital of Shenzhen
Current assignee: Third Peoples Hospital of Shenzhen
Priority date: 2012-12-29
Filing date: 2012-12-29
Publication date: 2013-05-01

Abstract

The invention provides an MS4A6A gene application, and relates to the preparation of products to distinguish latent tuberculosis infection and active tuberculosis. The preferred products include the products utilizing real-time quantitative PCR or gene chip detection to distinguish the latent tuberculosis infection and the active tuberculosis. According to the experimental results, the expression of the MS4A6A gene is obviously higher in the blood of tuberculosis patients than in healthy people or latent infection crowds, and therefore, the MS4A6A gene can serve as a special marking gene for the diagnosis of tuberculosis, so as to allow the tuberculosis diagnosis to be more accurate and quicker.

Description

The purposes of MS4A6A gene

Technical field

The present invention relates to technical field of bioengineering, particularly the purposes of MS4A6A gene.

Background technology

Tuberculosis (Tuberculosis, TB) is the chronic infection disease that is caused by m tuberculosis infection, and mycobacterium tuberculosis not only can cause pulmonary tuberculosis (85%), and can cause the tuberculosis of the outer multiple organ of lung.Although have at present effective antitubercular agent, tuberculosis remains the No.1 killer of current infectious diseases, and annual about 2,000,000 people in the whole world die from tuberculosis; The whole world about 1/3rd population infects mycobacterium tuberculosis, is called as among the crowd of tubercule bacillus latent infection (LTBI) at these, have an appointment 10% the most at last progress be active tuberculosis.

Because lack at present effective tuberculosis vaccine, prevention and control lungy mainly depend on early discovery, treatment, isolation active tuberculosis patient.Yet, there is wretched insufficiency in diagnostic activities detection technique lungy now, can not satisfy requirement clinical and tuberculosis prophylaxis control: 1) phlegm mycobacterium tuberculosis microorganism checking specificity is high, it is the phthisical gold standard of current diagnostic activities, but there is susceptibility low (less than 40%), length consuming time (tubercule bacillus was cultivated 1-2 consuming time month), the demanding shortcoming of laboratory Biosafety.2) mycobacterium tuberculosis gene test, although realized the purpose (1 day) of quick diagnosis, the gene test of directly carrying out from sputum specimen does not significantly improve aspect the susceptibility, and has false negative, false-positive problem.3) antibody test is not suitable for diagnosis lungy by World Health Organization's identification in the immunology detection; Cellular immunology detects and comprises tuberculin skin test (TST) and tubercule bacillus Interferon, rabbit release test (IGRA), can not effectively distinguish active tuberculosis patient and tubercule bacillus latent infection person, although the latter is significantly higher than other detections in the susceptibility that the active tuberculosis patient detects.

MS4A6A also is 4SPAN3,4SPAN3.2, CD20L3, CDA01.Utilize whole-genome association to find in the astroglia cell of senile dementia, the up-regulated of MS4A6A infers that it is playing the part of important effect in the neural inflammation that senile dementia causes.At present very few to the research of this gene function.At present still not about the report of MS4A6A gene as the Diagnosis of Tuberculosis mark.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of purposes of MS4A6A gene, and the MS4A6A gene can be used as the molecular marker of differentiating tuberculosis latent infection and active tuberculosis.

In order to solve the problems of the technologies described above, the present invention is achieved through the following technical solutions:

The invention provides a kind of purposes of MS4A6A gene, for the preparation of the product of differentiating tuberculosis latent infection and active tuberculosis.

The product of described differentiation tuberculosis latent infection and active tuberculosis preferably includes: the product of differentiating tuberculosis latent infection and active tuberculosis with real-time quantitative PCR or genechip detection.

Described product with real-time quantitative PCR differentiation tuberculosis latent infection and active tuberculosis preferably comprises the primer of a pair of specific amplified MS4A6A gene at least.

The primer of described specific amplified MS4A6A gene is preferably:

MS4A6A-F：5’-GCTCTCTATCAATCGCCACAG-3’，

MS4A6A-R：5’-ACTGCAGTGAGGCAGGATTT-3’；

The described product of differentiating tuberculosis latent infection and active tuberculosis with genechip detection preferably includes: with the probe of the nucleic acid array hybridizing of MS4A6A gene.

Utilize test kit of the present invention, can detect the expression of patient MS4A6A gene, thereby whether the diagnosis patient suffers from active tuberculosis.

In the present invention, term " primer " refers to a kind of oligonucleotide, can be natural also can synthesizing, it can be used as the synthetic starting point of induce dna under certain condition, under conditions suitable, bring out primer extension product synthetic and the nucleic acid chains complementation, namely in the presence of four kinds of different triphosphoric acid dezyribonucleosides and a kind of polymerization agent (being archaeal dna polymerase or reversed transcriptive enzyme), in a kind of suitable damping fluid and under suitable temperature, carry out amplified reaction.Preferred primer is the sub-thread oligodeoxyribonucleotide.The appropriate length of primer depends on the designed use of this primer, but generally between 15～25 Nucleotide.

In the present invention, described probe can be DNA, RNA, DNA-RNA mosaic, PNA or other derivative.The length of described probe without limits, as long as finish specific hybrid, with purpose nucleotide sequence specific binding, any length can.

The experiment proved that the expression of MS4A6A gene of the present invention in tuberculosis patient blood be apparently higher than healthy population and latent infection crowd, so the MS4A6A gene can be used as the special marker gene of diagnosis of tuberculosis, make Diagnosis of Tuberculosis more accurately, fast.

Description of drawings

The present invention is further detailed explanation below in conjunction with the drawings and specific embodiments.

Fig. 1 is the quantitative RT-PCR figure as a result of MS4A6A gene differential expression in human peripheral blood single nucleus cell (PBMC) of the embodiment of the invention 1.

Fig. 2 is the chip results figure of MS4A6A gene differential expression in PBMC of the embodiment of the invention 2.

Embodiment

The present invention is described further below in conjunction with embodiment and accompanying drawing:

Embodiment 1

Present embodiment is divided into three groups with the crowd: tuberculosis patient, latent infection crowd and healthy population (each 20 example), the MS4A6A gene mRNA changes in every Patients with Peripheral blood mononuclear cell (PBMC) by detecting, and finds that it is obvious up-regulated expression trend in tuberculosis patient.

Present embodiment changes with the expression that quantitative RT-PCR method detects every routine MS4A6A gene.Concrete steps are as follows:

Step 1: the preparation of peripheral blood mononuclear cell (PBMC) suspension

In centrifuge tube, add lymphocyte separation medium (Fresenius Kabi NOrge As:LYS3773) 5ml; Get the above-mentioned tuberculosis patient of making a definite diagnosis, each 2ml of anticoagulant heparin venous blood of latent infection patient and healthy population and the phosphoric acid buffer (PBS) of equivalent 1M fully mixing obtain mixed solution, with pipettor mixed solution slowly is superimposed on the lymphocyte separation medium liquid level along tube wall, keep clearly interface, 2000 rev/mins centrifugal 20 minutes; The cloud and mist stratification enters the 1M PBS that then adds 5 times of volumes behind another centrifuge tube in the middle of drawing with suction pipe, 1500 rev/mins of centrifugal 10 minutes washed cells, abandon supernatant, the same terms repeated washing cell once, then add contain the calf serum volume percent be 10% RPMI1640(Thermo scientific:SH30807.01b) 1ml, re-suspended cell obtains each 20 routine PBMC suspension of three groups of crowds;

Every example is got the PBMC suspension of 20 μ l on blood counting chamber, counting cells concentration.

Step 2: RNA extracting

The RNeasy Mini Kit(article No. 74106 of employing Qiagene company) each 20 routine PBMC suspension of three groups of crowds obtained above carried out the RNA extracting.Concrete operations are: get and above-mentionedly contain 1 * 10 ⁶The PBMC suspension of individual cell in the centrifuge tube that removes DNA enzyme and RNA enzyme, 3000 rev/mins centrifugal 10 minutes, abandon supernatant; In cell precipitation, add 350 μ l Buffer RLT, fully mixing cracking; Add 250 μ l dehydrated alcohols, mixing moves on to liquid rotating in the RNeasy pillar, and centrifugal 30 seconds of 8,000g abandons waste liquid; Add 350 μ l Buffer RW1 with 8,000g centrifugal 30 seconds, abandon waste liquid; Add 80 μ l DNase solution (10 μ l DNase+70 μ l Buffer RDD), digest 15min on the post, centrifugal 30 seconds of 8,000g abandons waste liquid; Add 350 μ l Buffer RW1, centrifugal 30 seconds of 8,000g abandons waste liquid; Add 500 μ l Buffer RPE, centrifugal 30 seconds of 8,000g abandons waste liquid; Sky gets rid of, centrifugal 1 minute of 8,000g; Posts transfer to a 1.5ml centrifuge tube that removes DNA enzyme and RNA enzyme, is added 40 μ l without the ddH of RNase ₂O, centrifugal 1 minute of 10,000g, collect three groups of crowds each 20 example RNA in-80 ° of C preserve, stand-by.

Step 3: reverse transcription

Adopt the reverse transcription test kit (DRR047) of TAKARA company, get the RNA0.5 μ g that step 2 obtains and carry out reverse transcription, this test kit has increased the step of removing genomic dna than classical inverse transcript reagent box, can guarantee to the full extent the purity of RNA and the specificity of amplification.Substep is as follows:

(1) removal of genomic dna reaction

Table 1

Reagent

Usage quantity

[0035]?

5 * gDNAEraser damping fluid	2μl
		gDNA?Eraser	1μl
Total RNA	0.5μg
		Rnase?Free?ddH ₂O	Benefit to 10 μ l

After preparing reaction system according to table 1, bathe 2min 42 ℃ of temperature, in 4 ℃ of lower preservations.

(2) reverse transcription reaction

The reaction system preparation is all carried out on ice, and concrete system is as follows:

Table 2

Reagent	Usage quantity
		5 * Prime Script damping fluid 2	4μl
PrimeScript RT enzyme mixture I	1μl
		The RT primer mixture	1μl
Remove the RNA reaction solution of genomic dna	10μg
		Rnase?Free?ddH ₂O	Benefit to 20 μ l

After preparing reaction system according to table 2, bathe 15min 37 ℃ of temperature, placed 5 seconds, and reacted and put 4 ℃ of preservations for 85 ℃.

Step 4: quantitative fluorescent PCR reaction

Template: above-mentioned reverse transcription product is as the template of quantitative fluorescent PCR reaction, and the template consumption is 1 μ l.Utilize MS4A6A gene (NM_145201.4) and GADPH gene (NM_002046.4) sequence, with two pairs of primers of Primer Premier5 software design.

Primer: (Shanghai) trade Co., Ltd is synthetic by the prompt base in the English Weihe River, designs as follows:

Table 3

The system of PCR reaction:

TAKARA company is adopted in the PCR reaction

Premix Ex TaqTMII(article No.: DRR081D), this product can suppress nonspecific reaction, carries out quantitative more accurately in the scope of broadness.Hot Start method after this Buffer and the improvement is used in combination with archaeal dna polymerase TaKaRa Ex Taq HS, can carry out good, the with a high credibility Real Time PCR of reproducibility and resolve.

Table 4

According to the reaction solution of upper table preparation fluorescent quantitation, and use instrument to carry out the real-time quantitative PCR reaction as ABI7500 real-time fluorescence quantitative PCR instrument.

Two-step approach PCR is adopted in real-time quantitative PCR reaction, the amplification standard program: 95 ℃ 30 seconds; 95 ℃ 5 seconds, 60 ℃ 40 seconds, 40 circulations.

According to the result of real-time quantitative PCR, with ABI7500software v2.0.6 the result is carried out Treatment Analysis, take the GADPH gene as reference gene, utilize 2 ^{-Δ Δ CT}Method calculate tubercular and latent infection crowd with respect to the expression amount of healthy population, the result as shown in Figure 1, wherein X-coordinate represents different crowds, ordinate zou represents relative expression quantity, ordinate zou is larger to show that its expression level is higher, the result shows, the expression level of MS4A6A in tuberculosis patient be apparently higher than the expression level (see figure 1) of latent infection and healthy population, significant difference (P＜0.05).In Fig. 1, " TB " refers to active tuberculosis the infected, and " LTBI " refers to latent tuberculosis the infected, and " HC " refers to normal healthy controls.

According to above-mentioned experimental result, can pass through quantitative RT-PCR diagnosis of tuberculosis latent infection and active tuberculosis: the PCR primer of design MS4A6A gene, detect the expression amount of MS4A6A gene in the tuberculosis tissue, if the expression amount of MS4A6A significantly raises, illustrate that then tuberculate possibility is high, otherwise then low, with better differentiation active tuberculosis the infected and latent tuberculosis the infected.

Embodiment 2

Present embodiment is divided into three groups with the crowd: tuberculosis patient 9 examples, equal 6 examples of latent infection crowd and healthy population, change by MS4A6A gene mRNA in the every Patients with Peripheral blood mononuclear cell of genechip detection (PBMC), find that it is obvious up-regulated expression trend in tuberculosis patient.

The present embodiment difference of MS4A6A gene gene expression dose in TB, LTBI and HC in the genechip detection tuberculosis sample comprises following four steps:

Step 1: chip preparation

At present the preparation chip mainly take sheet glass or silicon chip as carrier, is arranged in target gene on the carrier as probe by the point sample method in order, and target gene can be divided into genomic dna, cDNA(or artificial-synthetic DNA).

Step 2: sample preparation

The extraction steps of total RNA is as follows in the testing sample: the PBMC that separates respectively tuberculosis patient, latent infection person and healthy population, extract test kit with Qiagene RNA again and extract its concrete grammar of total RNA(with reference to embodiment 1), the total RNA that extracts is further used for the preparation of sample cDNA probe, its process comprises preparation (cDNA the first chain mark), the purifying and quantitative of fluorescence Cy3 and Cy5 probe, Cy3 quantitatively and the probe of Cy5 mark suck back to the 1.5ml centrifuge tube, heating is drained, be stored in-20 ℃, wait to hybridize.

Described after quantitatively Cy3 and the probe of Cy5 mark can be DNA, RNA, DNA-RNA mosaic, PNA or other derivative, the length of probe without limits, as long as finish specific hybrid, with purpose nucleotide sequence specific binding, any length can.

Step 3: chip hybridization

1) prepare: (1) washboard slide, cover glass is put into ddH successively ₂O, 95% ethanol, ddH ₂O, each 3min puts into 1000 rev/mins of dry 50ml centrifuge tubes at last, and centrifugal 3min removes residual water stainly, places stand-by; (2) the PBS solution of preparation 0.1M; (3) the balance hybrid heater is calibrated hybrid heater with water level gauge, the maintenance level; (4) be formulated as follows the liquid of developing a film: 20 * SSC solution, 10%(M/V) SDS of SDS solution, washing lotion I(2 * SSC/0.5%(M/V)), the SDS of washing lotion II(1 * SSC/0.1%(M/V)), the solution III (0.1 * SSC) of developing a film.

2) prehybridization preparation prehybridization solution 30 μ l(are by 20 * SSPE damping fluid of 9 μ l, 50 * Denhandts damping fluid and the 18 μ l ddH of 3 μ l ₂O forms), take out chip, 30 μ l prehybridization solutions are dripped on chip, then covered puts into chip the hybridizing box that is added with 0.1M PBS, places 42 ℃ of hybrid heater prehybridizations 1 hour, takes out chip ddH after prehybridization is finished ₂O embathes a moment, and it is centrifugal chip to be put into dry centrifuge tube after cover glass comes off, and removes residual water stainly, namely obtains the chip of prehybridization.

3) probe 1～5 μ l through quantitative Cy3 and Cy5 mark is taken out in hybridization, respectively with 9～15 μ l ddH ₂O fully dissolves and is mixed in the 1.5ml centrifuge tube, then continues to add the hybridization solution of Cy3/Cy5 fluorescence labeling probe (by 20 * SSPE damping fluid of 9 μ l, 50 * Denhandts damping fluid and the 18 μ l ddH of 3 μ l at this centrifuge tube ₂O forms) obtain hybrid mixed liquid, then get on the chip that the hybrid mixed drop is added in prehybridization, and covered obtains hybridization hybrid chip, at last this hybridization hybrid chip is put into the hybridizing box that is added with 0.1M PBS, place 42 ℃ of hybridization casees to hybridize 12～20 hours.

Step 4: signal detection

After the chip hybridization reaction finishes, carry out the chip washing, scan by scanner such as laser confocal scanning instrument again, after the scanning image is converted into the numerary signal based on fluorescence intensity, read chip data with GenPix pro6.0 software, GenePix pro6.0 calibrates the light intensity value of each point, and light intensity of each hybridization point is converted into data value by the light intensity analysis of background noise and the hybridization point of chip.

In order to study the changing conditions of MS4A6A in three different crowds, we have taked the analytical procedure of one way ANOVA in conjunction with the Bonferroni relation conefficient, threshold value setting is p＜0.05, finally by analysis, by the differential expression of MS4A6A gene in the genechip detection tuberculosis, the result red represent the genetic expression rise as shown in Figure 2, the green down regulation of gene expression that represents (identifies A and represents redness, identify B and represent green among Fig. 2; " TB " refers to active tuberculosis the infected, and " LTBI " refers to latent tuberculosis the infected, and " HC " refers to normal healthy controls).The result is presented in the tuberculosis patient MS4A6A genetic expression and significantly raises, and in LTBI and HC, the expression amount of MS4A6A is all reduced.

Claims

1. the purposes of a MS4A6A gene is characterized in that, for the preparation of the product of differentiating tuberculosis latent infection and active tuberculosis.

2. the purposes of MS4A6A gene according to claim 1 is characterized in that, the product of described differentiation tuberculosis latent infection and active tuberculosis comprises: the product of differentiating tuberculosis latent infection and active tuberculosis with real-time quantitative PCR or genechip detection.

3. the purposes of MS4A6A gene according to claim 2 is characterized in that, described product with real-time quantitative PCR differentiation tuberculosis latent infection and active tuberculosis comprises the primer of a pair of specific amplified MS4A6A gene at least.

4. the purposes of MS4A6A gene according to claim 3 is characterized in that,

The primer of described specific amplified MS4A6A gene, for:

MS4A6A-F：5’-GCTCTCTATCAATCGCCACAG-3’，

MS4A6A-R：5’-ACTGCAGTGAGGCAGGATTT-3’。

5. the purposes of MS4A6A gene according to claim 2 is characterized in that, the described product of differentiating tuberculosis latent infection and active tuberculosis with genechip detection comprises: with the probe of the nucleic acid array hybridizing of MS4A6A gene.