RETRO-TEK kits have been designed for the quantitative measurement of viral antigens from the retroviruses HIV-1, SIV and HTLV found in cell culture, serum, plasma or other biological fluids.

Product list:

Virus Core Antigen Detection

- Measures the p24 core protein of HIV-1
- Quantitation is performed on a standard microplate reader
- p24 Standard included

Overview: An anti-HIV p24 monoclonal coating antibody is adsorbed onto a microtiter plate. p24 antigen present in the sample or standard binds to the antibodies adsorbed on the plate; a FITC-conjugated mouse anti-p24 antibody is added and binds to p24 antigen captured by the first antibody.

Following incubation and wash steps, a HRP-conjugated mouse anti-FITC antibody is added and binds to the FITC conjugated anti-p24. Following unbound HRP-conjugated mouse anti-FITC antibody is removed during a wash step, and substrate solution reactive with HRP is added to the wells.

A colored product is formed in proportion to the amount of p24 antigen present in the sample. The reaction is terminated by addition of acid and absorbance is measured at 450 nm. A standard curve is prepared from recombinant HIV-1 p24 protein and sample p24 concentration is then determined.

Storage: Store all kit reagents at 2° - 8°C. DO NOT FREEZE. When stored properly the kit is stable until the date indicated on the box label.

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Price: 486 Euro

Untreated HIV infection destroys a person's immune system by killing infection-fighting cells, but precisely when and how HIV wreaks this destruction has been a mystery until now. New research by scientists at the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, reveals how HIV triggers a signal telling an infected immune cell to die. This finding has implications for preserving the immune systems of HIV-infected individuals.

HIV replicates inside infection-fighting human immune cells called CD4+ T cells through complex processes that include inserting its genes into cellular DNA. The scientists discovered that during this integration step, a cellular enzyme called DNA-dependent protein kinase (DNA-PK) becomes activated. DNA-PK normally coordinates the repair of simultaneous breaks in both strands of molecules that comprise DNA. As HIV integrates its genes into cellular DNA, single-stranded breaks occur where viral and cellular DNA meet. Nevertheless, the scientists discovered, the DNA breaks during HIV integration surprisingly activate DNA-PK, which then performs an unusually destructive role: eliciting a signal that causes the CD4+ T cell to die. The cells that succumb to this death signal are the very ones mobilized to fight the infection.

According to the scientists, these new findings suggest that treating HIV-infected individuals with drugs that block early steps of viral replication -- up to and including activation of DNA-PK and integration -- not only can prevent viral replication, but also may improve CD4+ T cell survival and immune function. The findings also may shed light on how reservoirs of resting HIV-infected cells develop and may aid efforts to eliminate these sites of persistent infection.

Methadone reduces the risk of HIV transmission in people who inject drugs (PWID), as reported by an international team of researchers in a paper published October 5 in the online edition of theBritish Medical Journal. This team included Dr. Julie Bruneau from the CHUM Research Centre (CRCHUM) and the Department of Family Medicine at the University of Montreal.

"There is good evidence to suggest that opiate substitution therapies (OST) reduce drug-related mortality, morbidity and some of the injection risk behaviors among PWID. However, to date there has been no quantitative estimate of the effect of OST in relation to HIV transmission. This new study provides solid evidence demonstrating the link between these treatments and a reduced risk of HIV transmission," notes Dr. Bruneau, one of the six investigators who worked with Dr. Matthew Hickman, the study's principal investigator and Professor in Public Health and Epidemiology at the University of Bristol (UK).

"These results are important given that increases in HIV incidence have been reported among PWID in a number of countries in recent years, where opiate substitution therapies are illegal or severely restricted," adds Dr. Bruneau. 

Injection drug use is a major risk factor for the transmission of HIV and AIDS. It is estimated that around 5-10% of HIV infections worldwide are due to injection drug use. Methadone and buprenorphine are the main forms of drug prescribed for addicts and are frequently prescribed as opiate substitution therapies.

The results of this study are the fruit of an international collaborative effort. Authors from the US, Canada, Italy and Australia carried out a review and pooled analysis (known as a meta-analysis) of several published and unpublished studies from multiple countries (including the USA, Canada, the UK, the Netherlands, Austria, Italy, Thailand, Puerto Rico and China) to determine the association between OST and HIV transmission among PWID. The nine selected studies looked predominantly at males between 26 and 39 years old and totalled 819 incidents of HIV infection with 23,608 person-years of follow-up.

After analysing these studies, authors found that OST was associated with a 54% reduction in risk of HIV infection among PWID. There were differences between the studies, including different background rates of HIV infection, making it impossible to calculate an "absolute risk reduction" for HIV infection that would translate to all settings. And not all studies reported adjustments to the intervention to take account of other factors that might influence the association between OST and HIV infection. But the impact of OST on HIV was strong and consistent in further analyses in the paper. There was weak evidence to suggest that longer duration of OST exposure may be associated with greater benefit.

For Dr. Bruneau, the results of this study favour the promotion of opiate substitution therapies: "These therapies can reduce HIV transmission among PWID not only in countries in which there is a high incidence of this disease, but also in Quebec where there has been an increase in the use of illicit opiates intravenously, particularly among youths, and where access to OST is problematic."

Two patients have been taken off their HIV drugs after bone-marrow transplants seemed to clear the virus from their bodies, doctors report.

One of the patients has spent nearly four months without taking medication with no sign of the virus returning.

The team at Brigham and Women's Hospital, in the US, caution that it is far too soon to talk about a cure as the virus could return at any point. The findings were presented at the International Aids Society Conference.

It is difficult to get rid of an HIV infection because it hides inside human DNA, forming untouchable "reservoirs" in body. Anti-retroviral drugs keep the virus in check within the bloodstream - but when the drugs stop, the virus comes back.

The two men, who have not been identified, had lived with HIV for about 30 years. They both developed a cancer, lymphoma, which required a bone-marrow transplant.

Bone marrow is where new blood cells are made and it is thought to be a major reservoir for HIV. After the transplant, there was no detectable HIV in the blood for two years in one patient and four in the other.

It is far too early to call this a cure for HIV. And even if it was a cure, it wouldn't be a very good one.

It is very expensive and often leads to "graft-v-host" disease. There is a 15-20% mortality rate within the first few years after the transplant.

This occurs when new immune cells produced by the graft treat the rest of the body as foreign and attack it.

The two patients in this study have replaced their regimen of anti-retroviral drugs, with those to suppress the immune system.

The procedure was carried out in these patients only because they had cancer that needed to be treated. The real value of this research for the majority of people with HIV will come from a deeper understanding of the virus and HIV reservoirs. The pair came off their anti-retroviral drugs earlier this year.

One has gone 15 weeks, and the other seven, since stopping treatment, and no signs of the virus have been detected so far.

Dr Timothy Henrich told the BBC the results were exciting. But he added: "We have not demonstrated cure, we're going to need longer follow-up.

"What we can say is if the virus does stay away for a year or even two years after we stopped the treatment, that the chances of the virus rebounding are going to be extremely low. "It's much too early at this point to use the C-word [cure]."

It is thought that the transplanted bone marrow was initially protected from infection by the course of anti-retrovirals. Meanwhile the transplant also attacked the remaining bone marrow, which was harbouring the virus.

However Dr Henrich cautioned that the virus could be still be hiding inside brain tissue or the gastrointestinal track.

"If the virus does return, it would suggest that these other sites are an important reservoir of infectious virus and new approaches to measuring the reservoir at relevant sites will be needed to guide the development of HIV curative strategies," he said.

The two US cases both received bone marrow from normal donors. There was also a report of an HIV cure in a baby born in Mississippi, US. She was treated with anti-retroviral drugs at birth so it is thought the virus was cleared from the body before reservoirs were established.

Dr Michael Brady, the medical director of the Terrence Higgins Trust, said: "It is too early to know whether HIV has been eradicated from these men's bodies or whether it might return.

Doctors say it is far too soon to talk about a cure for HIV, as James Gallagher reports "However, the case suggests that what happened to Timothy Brown, the Berlin Patient was perhaps not a one-off.

"A bone marrow transplant is a complex and expensive procedure, which comes with significant risks. "For most people with HIV, it would be more dangerous to undergo a transplant than to continue managing the virus with daily medication.

"So while this is by no means a workable cure, it does give researchers another signpost in the direction of one."

The head of the Foundation for AIDS Research, Kevin Frost, said: "These findings clearly provide important new information that might well alter the current thinking about HIV and gene therapy.

"While stem-cell transplantation is not a viable option for people with HIV on a broad scale because of its costs and complexity, these new cases could lead us to new approaches to treating, and ultimately even eradicating, HIV."

A new report suggests that the concentration of one human cytokine, interleukin 7 (IL-7), in the semen of HIV-1-infected men may be a key determinant of the efficiency of HIV-1 transmission to an uninfected female partner. In their study published February 7 in the Open Access journal PLOS Pathogens, a research group from the Eunice Kennedy-Shriver National Institute of Child Health and Human Development (NICHD) led by Leonid Margolis report that the increased IL-7 concentration in semen facilitates HIV transmission to cervical tissue ex vivo.

Semen is a complex biological fluid containing not only spermatozoa but also cytokines, a group of extracellular proteins that modulate immune responses. As a result of HIV infection, the concentrations of various cytokines in semen is profoundly modified, in particular the concentration of interleukin 7 (IL-7) is greatly increased. Despite this evidence of strikingly elevated IL-7 levels in seminal plasma, there was limited knowledge about any effects this cytokine might have on HIV-1 sexual transmission.

To investigate the question about the effects of this increased IL-17 on HIV-1 sexual transmission, Andrea Introini and colleagues from the Margolis lab developed a system of explants of cervico-vaginal tissue that can be maintained outside of the body in culture for up to two weeks while preserving the cytoarchitecture of the tissue. In this system, HIV transmission can be simulated and studied under controlled laboratory conditions. When researchers added IL-7 in concentrations comparable to that found in the semen of HIV-1 infected men, HIV was transmitted more efficiently and replicated to a higher level than without IL-7. Normally, HIV-1-infected cells quickly die as the result of apoptosis, a programmed death triggered by HIV infection. IL-7 inhibits apoptosis of infected cells, allowing them to produce more virus and thus increasing the chances of the incoming virus to disseminate through the tissue. Also, IL-7 stimulates T cell proliferation, thereby also providing to HIV even more potential targets to infect.

The authors speculate that IL-7, together with other cytokines, may determine sexual transmission rates of HIV-1 and that changes in the seminal cytokine load may explain differences in HIV transmission from different individuals. However, whether the effect of IL-7 that has been demonstrated ex vivo occurs also for sexual partners in vivo, is a subject for future research. If this increase does occur in vivo, then it should be investigated whether HIV-1 infected individuals that have been treated systemically with IL-7 in order to increase their T cell counts may have also resulted in the unintended increase of their seminal IL-7 levels. Finally, this study suggests that seminal cytokines may become new targets for HIV-preventive strategies.

Two men with HIV may have been cured after they received stem-cell transplants to treat the blood cancer lymphoma, their doctors announced today at the International AIDS Society Conference in Kuala Lumpur.

One of the men received stem-cell transplants to replace his blood-cell-producing bone marrow about three years ago, and the other five years ago. Their regimens were similar to one used on Timothy Ray Brown, the 'Berlin patient' who has been living HIV-free for six years and is the only adult to have been declared cured of HIV. Last July, doctors announced that the two men — the ‘Boston patients’ — appeared to be living without detectable levels of HIV in their blood, but they were still taking antiretroviral medications at that time.

Timothy Henrich, an HIV specialist at Brigham and Women’s Hospital in Boston, Massachusetts, who helped to treat the men, says that they have now stopped their antiretroviral treatments with no ill effects. One has been off medication for 15 weeks and the other for seven. Neither has any trace of HIV DNA or RNA in his blood, Henrich says.

If the men stay healthy, they would be the third and fourth patients ever to be cured of HIV, after Brown and a baby in Mississippi who received antiretroviral therapy soon after birth.

But Henrich and Daniel Kuritzkes, a colleague at Brigham who also worked with the men, caution that it is still too early know whether or not the Boston patients have been cured. For that, doctors will need to follow the men closely for at least a year, because the virus may be hiding out in 'reservoirs' — parts of the men’s bodies, such as their brain or gut, that can harbour the virus for decades.

“We’re being very careful not to say that these patients are cured,” Kuritzkes says. “But the findings to date are very encouraging.”

HIV researcher Steven Deeks of the University of California, San Francisco, says that doctors might need to wait at least two years before declaring that a cure has been achieved. “Any evidence that we might be able to cure HIV infection remains a major advance,” Deeks says. But, he adds, “there have been cases of patients who took many weeks off therapy before the virus took off”.

Exciting news

Still, researchers and doctors are excited about the news, especially because the Boston patients’ treatment differed from the Berlin patient’s regimen in one key way. Brown was given stem cells that were predisposed to resist HIV infection, because the donor happened to have a mutated version of a key protein — CCR5 — that is needed for HIV to infect cells. So Brown’s transplant was akin to gene therapy with HIV-resistant cells.

But the Boston patients received stem cells without the protective mutation. The transplanted cells must therefore have been protected from infection by the antiretroviral drugs taken during cancer treatment. Their doctors think that an immune response called graft-versus-host disease — a post-transplant reaction in which donated cells kill off a patient’s own cells — may have then wiped out the patients’ HIV reservoirs, potentially curing the men.

Transplant specialist Christine Durand of Johns Hopkins University School of Medicine in Baltimore, Maryland, says that the case of the Boston patients may show that current antiretroviral drugs are powerful enough, on their own, to protect the transplanted cells. “If cure has been achieved in the Boston patients, then it was the antiretroviral therapy, not gene therapy, that protected the donor cells,” she says.

The finding is very important for people with HIV who also need blood-cell transplants, but the treatment is unlikely to be used more generally because the risks from transplants are high. Durand says that Johns Hopkins is now revising its transplant procedures to keep people with both cancer and HIV on antiretroviral drugs during the transplant regimen.

Separately, the International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) Group, based in Silver Spring, Maryland, is trying to replicate the Berlin patient’s cure by giving CCR5-mutated HIV-resistant blood from umbilical cords to children and adults with HIV and cancer. 

Everyone with HIV could benefit from this work, researchers say, because it could yield valuable information about how to eliminate the HIV reservoir.

“We are still a long way off from a viable cure option for most patients,” Durand says. “But every step counts, and these cases can teach us important lessons.”

Image of an HIV-infected H9 T cell, colorized in blue, turqoise, and yellow set against a dark background.

PRODUCT DESCRIPTION:
NATtrol™ CT.NG Panel (NATCT.NGP-C) is formulated with purified, intact bacterial particles that have been chemically modified to render them non-infectious and refrigerator stable*. NATCT.NGP-C panel contains 17 x 1.2 mL vials each containing the bacterial NATtrol™ targets listed in the Expected Results. These controls are  supplied in a purified protein matrix that mimics the composition of a true clinical specimen. *NATtrol™ Patents Pending

INTENDED USE:
- NATtrol™ CT.NG Panel is designed to evaluate the performance of nucleic acid tests for determination of the presence bacterial DNA. NATCT.NGP-C can also be used for verification of clinical assays, development of diagnostic tests and training of laboratory personnel.
- NATCT.NGP-C contains intact organisms and should be run in a manner identical to that used
for clinical specimens.

ETIOLOGIC STATUS/BIOHAZARD TESTING:
- NATtrol™ inactivation was carried out on each member in the panel. The inactivation was verified by the absence of bacterial growth in a validated growth protocol.
- The purified protein matrix was manufactured from materials that were screened and found to be negative for HIV 1&2 Ab, HBsAg, HTLV I&II Ab, HCV Ab, HIV RNA, HBV DNA and HCV RNA using FDA cleared kits at the single donor level.

Catalog #: NATCT.NGP-C

For more information download PDF file

PRODUCT DESCRIPTION:
NATtrol™ BC.GP Panel (NATBC.GP-NNS) is formulated with purified, intact bacterial particles that have been chemically modified to render them non-infectious and refrigerator stable*. NATBC.GP-NNS contains 11 x 0.75 mL vials of bacterial NATtrol™ targets listed in Table 1. These panels are supplied in a purified protein matrix that mimics the composition of a true clinical specimen. *NATtrol™ Patents Pending

INTENDED USE:
- NATtrol™ BC.GP Panel is designed to evaluate the performance of nucleic acid tests for determination of the presence of bacterial nucleic acids. NATBC.GP-NNS can also be used for verification of clinical assays, development of diagnostic tests and training of laboratory personnel.
- NATBC.GP-NNS contains intact organisms and should be run in a manner identical to that used for clinical specimens.

ETIOLOGIC STATUS/BIOHAZARD TESTING:
- NATtrol™ inactivation was carried out on the bacterial stock used to formulate panel members. The inactivation was verified by the absence of bacterial growth in a validated growth protocol.
- The purified protein matrix was manufactured from materials that were screened and found to be negative for HIV 1&2 Ab, HBsAg, HTLV I&II Ab, HCV Ab, HIV RNA, HBV DNA and HCV RNA using FDA cleared kits at the single donor level.

PRECAUTIONS:
- Although NATBC.GP-NNS contains inactivated organisms, it should be handled as if potentially infectious.
- Use Universal Precautions when handling this product.
- To avoid cross-contamination, use separate pipette tips for all reagents.

Catalog #: NATBC.GP-NNS 

For more information donwload PDF file