Human immunodeficiency virus therapeutics and pharmacogenomics.

Pharmacogenomics and pharmacogenetics are promising in development of a personalized treatment approach They are of paramount importance for basic immunology, for peptide based vaccine design (vaccinomics) drug monitoring in clinical setting and molecular pathophysiology of multifactorial diseases like cancer, tuberculosis, cardiac disorders, diabetes, asthma, HIV, etc

[Evaluation of touchdown nested PCR to circumvent spurious priming and increase specificity during HIV and GBV-C gene amplification]

Primer-Template hybridization temperature is one of the important parameters in Nested PCR optimization. Unlike instant temperature for sequence amplification in routine PCR process, Touchdown PCR is a modified form of standard PCR that employs a range of annealing temperature. This study intended to develop a Touchdown Nested PCR in order to circumvent spurious priming and enhancing specify during gene amplification. This is an experimental study conducted at Tarbiat Modarres University of Tehran during 2008-2009. Study samples were collected from Digestive Diseases Research Centre at Shariati Hospital and HIV research center-Imam Khomeini Hospital. After extracting the nucleic acid, primer designing for HIV and GBV-C and c-DNA synthesis; Nested PCR was performed on negative and positive samples using standard and touchdown protocols. The intended band was observed in all positive samples. No band was observed in any human and viral negative control samples. After electrophoresis of PCR products, non specific band were seen in HIV and GBV-C samples during standard PCR. Using the touchdown protocol, undesirable bands were omitted or significantly decreased. In the present study, despite the formation of uncalled bands in standard reaction; using the touchdown method led to omission of non-specific bands without any significant effect on the final products. As for its simplicity, cost and time saving, it seems that using this method is a rational and economical way for fast optimization of PCR reactions

Immunobiology of human imunodeficiency virus infection.

After the discovery of human immunodeficiency virus (HIV) and its role in the causation of most devastating epidemic acquired immune deficiency syndrome (AIDS), there has been an increasing trend to decipher the mechanism of infection and to understand why it cannot be controlled by our immune system. By evolution, our immune system has been empowered and enough trained to recognize, elicit immune response and remove antigens and pathogens from the body. Simultaneously, HIV has also gained enough mechanism to escape the natural immune response. On one hand, it downregulates HLA class I antigens, which may present viral antigens to specific CD8 + T cells; on the other hand, the viral genome get mutated very readily under the selection pressure of specific cytotoxic T lymphocytes. The high mutation rate and convertibility of its genotype makes it a moving target and poses a prime hurdle in vaccine development. This review explains how HIV enters into the cell, how it resists the host immune response and how HIV manages to escape from it and establish in the human body.

Prevalence of occult hepatitis B & C in HIV patients infected through sexual transmission.

BACKGROUND: Prevalence of Hepatitis B virus (HBV) and Hepatitis C virus (HCV) markers including active and occult infection has not been described in diverse cohorts among HIV-infected patients in India. Earlier studies have explained the role of HBV/HCV co-infection in cohorts of injection drug users (IDUs) but the sexual co-transmission of HBV/ HCV is not completely understood. OBJECTIVE: The objective of this study was to assess the prevalence of occult HBV & HCV infection in HIV positive sexually acquired transmission risk group. MATERIALS AND METHODS: 58 sexually acquired HIV positive patients were taken up for the study of occult HBV/HCV co-infection. Data on demographics, sexual behaviour, sexually transmitted diseases (STD), medical history, laboratory tests viz., serum ALT and CD4 count were recorded. HBV serology included HBsAg, anti HBs, IgG anti HBc and HBV DNA (PCR). HCV serology included anti HCV & HCV RNA (RT-PCR). RESULTS: Occult HBV infection (HBV DNA) was observed in 12.2% (7/58 with HBsAg -ve and IgG anti HBc +ve subjects) while an overall prevalence of HBV DNA was 13.7% (12% occult & 1.7% in HBsAg+ve patients). Out of 58 HIV positive patients 29.3% demonstrated reactivity for any marker of past or current HBV infection. (HBsAg 1.7%, anti HBs 10.3% anti HBc IgG 17.2%). 4/58 (6.8%) revealed anti HCV positivity along with HCV RNA positivity by RT-PCR while 6/58 (10.3%) individuals revealed an occult HCV infection (anti HCV negative). The overall HCV RNA prevalence was 17.2%. 2 out of 58 (3.4%) individuals were positive for occult infection of both HBV DNA & HCV RNA (Triple infection HIV/HBV/ HCV). The HBV/HCV co-infected group (n = 18) showed a significantly high ALT (114.3 + 12.3 U/I) & low CD4 count (202.5 + 33.7 cells/mm3). The percent prevalence of HBV/ HCV co-infection was higher in the illiterate group, in men less than 30 years of age, and in those who were married and exhibited polygamous activity. CONCLUSIONS: The study demonstrated that in HIV infected patients testing only serological viral markers like HBsAg, antiHBcIgG & anti HCV, fails to identify the true prevalence of co-infection with HBV & HCV. Qualitative PCR for HBV DNA & HCV RNA detects co-infection in patients who are negative for serological markers. Also, in subjects who had only a sexual risk factor for parenterally transmitted infections, HIV may enhance the sexual transmission of HBV and HCV.

An in-house HIV DNA PCR assay for early diagnosis of HIV infection in children in Thailand.

Eighty-five venous blood specimens were collected at 4, 6 or 9 months of age from asymptomatic human immunodeficiency virus (HIV)-exposed infants and from symptomatic HIV-infected infants on admission to the hospital. The specimens were tested by in-house HIV deoxyribonucleic acid (DNA) nested polymerase chain reaction (PCR) and the commercial Amplicor HIV-1 DNA test. In order to determine the accuracy of the tests, the results were compared with the HIV infection status of the children. In-house HIV DNA PCR and the commercial Amplicor HIV-1 DNA test had overall sensitivity of 95.2 per cent and 100 per cent and an overall specificity of 100 per cent and 98.4 per cent, respectively. In the analysis of 62 HIV-exposed infants who received perinatal HIV prevention intervention, in-house HIV DNA PCR yielded 100 per cent sensitivity, specificity, positive predictive value and negative predictive value. The authors concluded that in-house HIV DNA PCR has comparable sensitivity and specificity to the Amplicor HIV-1 DNA test in detecting the HIV infection status of children born to HIV-infected mothers. The in-house HIV DNA PCR, which costs US $10 per test, should be considered in developing countries for the early diagnosis of HIV-1 infection in children.

Biología molecular del virus de la inmunodeficiencia humana y los recientes progresos en el tratamiento del SIDA / Molecular biology of HIV and recent progress in the treatment of AIDS

El virus de inmunodeficiencia humana (VIH), causante del síndrome de inmunodeficiencia adquirida (SIDA), ha constituido desde su emergencia hace 2 décadas, un enorme desafío a la investigación biomédica. Utilizando una amplia gama de recursos para interferir y evadir la respuesta inmune normal, infecta las células CD4+, ingresa a ellas a través de sus receptores de superficie, y expresa una alta frecuencia de mutación lo que le permite cambiar repetidamente sus determinantes antígenos. Los VIH tipo 1 y 2 corresponden a lentivirus, los cuales, junto a los oncornavirus y espumavirus integran la familia de retrovirus RNA humanos. En este artíulo se revisan los conocimientos actuales de la biología molecular del virus, se comentan modernas técnicas de diagnóstico como la reacción de transcriptasa reversa y polimerasa en cadena, usadas actualmente para medir la replicación del virus en la sangre del huésped infectado, y se discuten las actuales líneas de tratamiento exploradas, las que básicamente se dirigen a blancos moleculares susceptibles de intervención farmacológica que no afecten la funcionalidad celular, como son la interacción virus-receptor celular, , transcripción reversa del RNA viral, integración del provirus, procesamiento proteolítico del precursor gag-pol, y la regulación transcripcional virus específica por los productos tat y rev. Finalmente se comentan aspectos relacionados a la investigación en el campo de la inmunización VIH, desafío pendiente para la primera década de este nuevo siglo

Mother-to-Child HIV-1 transmission: state of the art and implications for public policy

During the past five years there have been significant advances in the knowledge of the factors that affect mother-to-infant HIV-1 transmission. Diverse interventions have been designed and proven effective in reducing the risk of such transmission. In reviewing the pivotal literature in such respect implications for public policy are also analyzed. Because of the constant evolution of the interventions, the public policies also need constant revisions. The impact of viral load assessment during pregnancy and its relationship to transmission risks is discussed, as well as the effectiveness of elective Caesarean delivery. The latter has both positive and negative aspects which merit consideration. Newer approaches, such as highly active anti retroviral therapies (HAART), which have shown to decrease the AIDS mortality, have also shown zero transmission in small cohorts. Shorter and cheaper interventions are also somewhat effective and are good alternatives to resource poor countries.

Aspectos biomoleculares de la infección por el virus de la inmunodeficiencia humana / Biomolecular aspects of the human immunodeficiency virus infection

El presente artículo de revisión se centra en las consideraciones fundamentales sobre la biología molecular del virus de la inmunodeficiencia humana, el principal de los retrovirus que infectan a los hombres, destacando sus aspectos constitutivos así como genéticos y las alteraciones con la célula huésped. Se presenta además los aspectos morfofuncionales básicos de los linfocitos T CD4 y las interacciones que a nivel de membrana se producen para favorecer la infección por el virus y que explican su fisiopatología. Finalmente, se destacan los eventos intracelulares que conducen a la replicación y ensamblaje viral que producen la muerte celular y explican la inmunosupresión del huésped