The realization of the concept of Harm Reduction in Russia

By the present moment cases of HIV infection among injecting narcotic users (INU) have been registered in more than 100 countries. To prevent HIV infection, the program "Harm Reduction" has been developed in Britain; the program states that the prevention of HIV infection must be considered more important than the prevention of the use of narcotic drugs, as this infection is a growing danger for both drug users and public health in general. Breaking drug dependence must not be the only aim of services working with drug addicts, because this will exclude persons decisively disposed to the mode of life including the prolonged use of drugs from the sphere of their activity. Active INU having no contacts with organizations which must give them treatment and assistance find themselves in dangerous situations more often than INU maintaining contacts with such organizations. Penetration into such hidden group and its education must be the primary task. Propaganda plays a decisive role in this process, as the only way to penetrate into such group is to develop work in its territory, so that drug addicts, supplied with the necessary means could change their behavior in the desired direction. In the Russian Federation work on the project "Harm Reduction" has been carried out in 50 regions. This work has contributed to conducting teaching seminars, working out teaching programs, as well as to augmenting the interest among specialists of different professions to the problem of decreasing the spread of HIV infection. The importance of information distributed by the narcological service and the probability that very responsible persons take correct decisions on the basis of their understanding the situation have increased. The rating of public organization has risen.     

On the epidemiological situation in quarantine, natural focal and other infections on the territory of the Southern Federal District

The data on the sanitary and epidemiological situation in the Southern Federal District are presented. The analysis of morbidity in tuberculosis, measles, HIV infection, viral hepatitis A, typhoid fever, cholera and quarantine infections, Crimean hemorrhagic fever, West Nile fever, rabies, malaria has been carried out. Special attention has been given to "new and newly returning infections", and among them to the spread of SARS ("atypical pneumonia"). The role of regional epidemiological safety programs, in particular such program as "The prophylaxis of quarantine and natural focal infections and the sanitary protection of the territory of the Southern Federal District of the Russian Federation from the import and spread infectious diseases in 2003-2005", has been substantiated.     

The organization of the work to determine antibodies to the human immunodeficiency virus in the Republic of Byelarus

The study revealed that the method of mass screening for the detection of antibodies to HIV antigen, carried out in the Republic till 1993, proved to be economically and diagnostically unjustified. Starting from 1993, the work on the step-by-step reduction of groups to be tested for the presence of antibodies to HIV began. At the same time from 1997 the proportion of tested donors of blood, organs and tissues, as well as persons belonging to high risk groups, increased in comparison with 1993 (from 23.3% to 40% and from 5.3% to 21% respectively). Voluntary and anonymous testing for the presence of HIV infection was organized and legally introduced. In comparison with 1991, in 1997 the number of persons who voluntarily underwent testing increased 3.7 times. The period of transition from mass screening to selective one was noted to have no effect on the detection of HIV-infected persons. Since 1995 the method of "patrol" epidemiological surveillance was also used. 2,118 persons underwent testing, the results of screening were negative. During the period of 3 years the testing of 12,547 young people called up for military service revealed 28 seropositive persons in the region where an outbreak of HIV infection had been registered among addicts using drugs intravenously.     

Human retroviral infections in The Gambia: prevalence and clinical features

The prevalence of infection with human immunodeficiency virus type 1 (HIV 1) is lower in west Africa than in other parts of Africa. Human immunodeficiency virus type 2 (HIV 2) has been isolated from west African patients and may be transmitted by heterosexual contact. The prevalence of antibodies to HIV 1 and HIV 2 was studied by enzyme linked immunosorbent assay (ELISA) among various groups of subjects in The Gambia, west Africa—namely, prostitutes, blood donors, patients with suspected infection with HIV, patients attending clinics for sexually transmitted diseases, and patients with tuberculosis. Four cases of the acquired immune deficiency syndrome (AIDS) due to infection with HIV 1 were detected, of which three had been acquired abroad. No other subject was found to be positive for antibodies to HIV 1. The prevalence of antibodies to HIV 2 among the patients attending clinics for sexually transmitted diseases was found to have increased from 0/117 in 1984 to 10/185 (5%) in the last six months of 1986. One out of 278 blood donors was positive for antibodies to HIV 2 as were 10 out of 80 patients with suspected AIDS.HIV 2 seems to be transmitted sexually, and, although it has been present for only a short time, it seems to be endemic in The Gambia and is pathogenic.     

Passive immunization for the treatment and prevention of HIV infection.

Passive immunization using serum or immunoglobulin preparations has been used in the prophylaxis and treatment of many bacterial and viral diseases. Preliminary attempts to use these methods to prevent HIV infection in chimpanzees have been promising. With the identification of polyclonal and monoclonal antibodies with protective activity against HIV in in vitro systems, the possibility of using these reagents in vivo takes on new relevance. The potential and problems of using passively administered anti-HIV antibodies for HIV prophylaxis and treatment are discussed, as well as the relative merits of polyclonal versus monoclonal reagents.     

The use of PCR analysis for the diagnosis of HIV infection in infants in the 1st months of life

In this review the data of contemporary studies of dynamic changes in serological and virological markers in the course of HIV infection in infants aged 0-18 months, aimed at finding out the comparative value of different tests made with a view to established exact diagnosis, are discussed. The results of the study of the sensitivity and specificity of the RNA and DNA polymerase chain reaction in the diagnostics of HIV infection in infants during the first months of life, as well as the recommended time of testing, have been analyzed in detail. On the basis of the data presented in this review the author has formulated the scheme of the algorithm for diagnosing HIV infection in infants born of HIV-infected mothers with the following variants of the diagnosis: "possible infection", "seroversion" (marking it possible to exclude the presence of the infection) and "HIV infection". The proposed scheme has the character of recommendation, but under the conditions of the rapid spread of HIV infection with the involvement of infants into the process this scheme may be useful in pediatric practice.     

Development of a sensitive quantitative focal assay for human immunodeficiency virus infectivity.

Accurate and sensitive quantitation of infectious human immunodeficiency virus (HIV) has been difficult to achieve. In this report, a quantitative focal immunoassay (FIA) for HIV was developed using human HeLa cells rendered susceptible to HIV infection by introduction of the CD4 gene via a retrovirus vector. Infected cells were identified by using human anti-HIV antibodies or mouse monoclonal antibodies specific for HIV together with secondary fluorescein- or peroxidase-conjugated antibody specific for mouse or human immunoglobulins. The assay identified cells infected with either wild-type or culture-adapted HIV isolates and was capable of detecting 1 positive cell in 10(6) cells. The FIA was also effective at detecting cell-free HIV, and in contrast to assays using A3.01, CEM, and other human leukemia cells, the FIA detected most wild-type HIV isolates. HIV neutralization could be determined by using the FIA, and two monoclonal antibodies reactive with HIV gp120 were found to neutralize only the LAV-IIIB strain of HIV. These monoclonal antibodies, as well as antibodies in serum samples from patients with acquired immune deficiency syndrome, were able to inhibit the spread of HIV infection in human lymphocyte suspension cultures but not in CD4-positive HeLa cells growing attached to plastic dishes.     

Antibody-dependent and antibody-independent complement-mediated enhancement of human immunodeficiency virus type 1 infection in a human, Epstein-Barr virus-transformed B-lymphocytic cell line.

A human Epstein-Barr virus-transformed B-cell line (IC.1) was characterized for cell surface antigen profile and permissivity to immunodeficiency virus (HIV) infection. According to cocultivation assay with MT2 cells, P24 release, and immunofluorescence assay, complement-sufficient serum enhanced in vitro infection of IC.1 cells. Enhancement occurs independently of the presence of HIV type 1-specific antibodies, although more efficiently when they are present. Blocking experiments with monoclonal antibodies demonstrated that complement receptor type 2 mediates this phenomenon and that the CD4 molecule is required for infection. Enhancement of in vitro infection on IC.1 cells appears closely related to previously described complement-mediated, antibody-dependent enhancement of HIV infection on the T-lymphoblastoid cell line MT2 (W. E. Robinson, Jr., D. C. Montefiori, and W. M. Mitchell, Lancet i:790-794, 1988).     

HIV中和抗体疫苗研究进展

由于HIV具有与其它微生物极为不同的生物学特点,HIV疫苗的研究面临着前所未有的困难和挑战。二十多年来,艾滋病疫苗研究主要采用了诱发中和抗体为主或细胞免疫为主两种策略,然而至今尚无实质性突破。诱发有效中和抗体一直是传统疫苗研发的重要策略,但HIV的高变异、多亚型等特点,使该策略在HIV疫苗研发中的应用成效甚微。近年来,一些具有广谱中和活性的HIV单抗的发现及其相应抗原表位的阐明,给HIV中和抗体疫苗的研究带来了新的希望。综合分析与评述这些进展,对于重新思考艾滋病疫苗和采用更好的策略进行艾滋病疫苗研究会有所帮助。     

＂Unconventional＂ Neutralizing Activity of Antibodies Against HIV

Neutralizing antibodies are recognized to be one of the essential elements of the adaptive immune response that must be induced by an effective vaccine against HIV. However,only a limited number of antibodies have been identified to neutralize a broad range of primary isolates of HIV-1 and attempts to induce such antibodies by immunization were unsuccessful. The difficulties to generate such antibodies are mainly due to intrinsic properties of HIV-1 envelope spikes,such as high sequence diversity,heavy glycosylation,and inducible and transient nature of certain epitopes. In vitro neutralizing antibodies are identified using "conventional" neutralization assay which uses phytohe-magglutinin (PHA)-stimulated human PBMCs as target cells. Thus,in essence the assay evaluates HIV-1 replication in CD4 T cells. Recently,several laboratories including us demonstrated that some monoclonal antibodies and HIV-1-specific polyclonal IgG purified from patient sera,although they do not have neutralizing activity when tested by the "conventional" neutralization assay,do exhibit potent and broad neutralizing activity in "unconventional" ways. The neutralizing activity of these antibodies and IgG fractions is acquired through post-translational modifications,through opsonization of virus particles into macrophages and immature dendritic cells (iDCs),or through expression of antibodies on the surface of HIV-1-susceptible cells. This review will focus on recent findings of this area and point out their potential applications in the development of preventive strategies against HIV.     

"Unconventional" Neutralizing Activity of Antibodies Against HIV

Neutralizing antibodies are recognized to be one of the essential elements of the adaptive immune response that must be induced by an effective vaccine against HIV. However, only a limited number of antibodies have been identified to neutralize a broad range of primary isolates of HIV-1 and attempts to induce such antibodies by immunization were unsuccessful. The difficulties to generate such antibodies are mainly due to intrinsic properties of HIV-1 envelope spikes, such as high sequence diversity, heavy glycosylation, and inducible and transient nature of certain epitopes. In vitro neutralizing antibodies are identified using "conventional" neutralization assay which uses phytohemagglutinin (PHA)-stimulated human PBMCs as target cells. Thus, in essence the assay evaluates HIV-1 replication in CD4+ T cells. Recently, several laboratories including us demonstrated that some monoclonal antibodies and HIV-1-specific polyclonal IgG purified from patient sera, although they do not have neutralizing activity when tested by the "conventional" neutralization assay, do exhibit potent and broad neutralizing activity in "unconventional" ways. The neutralizing activity of these antibodies and IgG fractions is acquired through post-translational modifications, through opsonization of virus particles into macrophages and immature dendritic cells (iDCs), or through expression of antibodies on the surface of HIV-1-susceptible cells. This review will focus on recent findings of this area and point out their potential applications in the development of preventive strategies against HIV.     

The use of biotin-streptavidin systems for enhancing the parameters of immunometric analysis

The possibility of improving analytical parameters of the immunometric assay with the use of biotinylated antibodies and biotin-streptavidin complexes in comparison with the commonly known approach of direct antibody modification with 125I has been studied. Experiments have been carried out with the use of low-affinity antibodies (Kass approximately 10(9) M-1) to ferritin. The signal-to-noise ratio in the immunometric increases 2.3 times when streptavidin labeled with horse-radish peroxidase is used and 4.3 times when the preformed streptavidin + biotin-peroxidase complex is used in comparison with assay systems based on 125I-labeled antibodies. The improvement of assay parameters of immunochemical systems by means of biotin-streptavidin complexes has been found to permit the use of low-affinity antibodies as assay reagents, thus ensuring analytical parameters attaining or close to those of immunoradiometric assay systems based on high-affinity 125I-labeled antibodies (Kass approximately 10(10) M-1). As shown in this study, the following factors ensure the signal enhancement in biotin-streptoavidin systems: (a) the biotin modification of several lysin residues per IgG molecule, the optimum extent of modification being 3-4 residues per molecule; (b) mild procedure for biotinylation. In contrast to oxidative iodination, the modification of NH2 groups with biotin esters does not significantly affect their antigen-binding properties.     

A retrospective study of the expediency of performing the immunoblot in conducting expert diagnosis at a center for the prevention and control of AIDS

In view of the fact that Russian immunoblot assay systems yield indefinite results, thus making it necessary to carry out prolonged dispensary observations of patients and their multiple examinations, the scheme of the expert diagnostics of HIV infection on the basis of EIA results is proposed. 51 sera which had yielded indefinite results in the immunoblot assay (antibodies to gagl, envl, poll) were handed over for verification to the Regional Center in 1996-1997. Patients from whom the sera had been taken were placed under dispensary observation in the Center for 6-12 months. After the retrospective analysis of these serum samples with the use of the EIA systems 40 samples proved to be negative and 11 samples gave the positive reaction.     

Accessing the human repertoire for broadly neutralizing HIV antibodies

The human antibody response has special significance in the ongoing efforts to develop a protective HIV vaccine. The observation that a subset of HIV infected individuals, who do not develop AIDS, have a broadly neutralizing antibody response has drawn attention to deciphering the nature of this response. It is hoped that an understanding of these protective antibodies, developed over time in response to the ongoing accumulation of mutations in the infecting virus, will facilitate the development of a vaccine that can elicit a similar response. This strategy will be greatly aided by the identification of broadly neutralizing monoclonal HIV antibodies from infected individuals. Several methods have been utilized to isolate and characterize individual antibodies from the human repertoire and each of these methods has been applied to the generation of broadly neutralizing HIV antibodies, albeit with differing rates of success. This review describes several of these methods including human hybridoma; EBV transformation; nonimmortalized B cell culture; clonal sorting; and combinatorial display. Key considerations used in the comparison of different methods includes: efficiency of interrogation of an individual’s entire repertoire; assay formats that can be used to screen for antibodies of interest (i.e., binding versus biological assays); and the ability to recover native antibody heavy and light chain pairs.Key words: HIV, antibody, neutralizing, B cell, repertoire     

The diagnostic value of different test systems for the screening determination of antibodies to the human immunodeficiency virus]

Evaluation of the quality of enzyme immunoassay (EIA) systems by their sensitivity and specificity is inadequate, mainly due to the impossibility of detecting early or latent HIV infection in humans as it manifests by seroconversion only to a few HIV proteins. The additional evaluation criterion (confirmation rate) has been introduced, and an original method for the integral evaluation of the quality of assay systems intended for the diagnosis of HIV infection by EIA techniques has been proposed.     

The introduction of projects to prevent HIV infection among people using injection narcotics and women in the sex business in the city of Simferopol'

The work on the realization of the Project on the Prevention of HIV infection, carried out by the Charity Fund "Hope and Salvation" in 1998-1999 in the Crimea is described. As shown by the analysis of the results of behavioral reactions, the forms of behavior used by drug-dependent persons contribute to the spread of HIV infection. Since November 1999 the realization of the pilot project on the reduction of HIV infection among injecting drug users has been started in Simferopol (with the financial support to the Pasteur Institute and the advisory support of the UN Representation in the Ukraine). The necessity of the development of the Project "Decrease of Spread of HIV and Sexually Transmitted Diseases among Female Sex Workers in Simferopol" is substantiated.     

Antibody-dependent cellular cytotoxicity-inducing antibodies against human immunodeficiency virus. Presence at different clinical stages

The presence of antibodies mediating antibody-dependent cellular cytotoxicity (ADCC) against human immunodeficiency virus (HIV)-infected target cells was investigated with 170 sera from patients with varying severity of HIV infection. Approximately 40% of sera from individuals representing all stages of infection were ADCC-positive when tested against HTLV-IIIB infected 0937 clone 2 target cells. The positive sera had higher HIV antibody titers as measured by enzyme-linked immunosorbent assay compared with ADCC-negative sera. ADCC titers were lower in patients with acquired immune deficiency syndrome than in asymptomatic carriers. This decline in ADCC titer was not correlated with a general decrease of HIV antibodies. No correlation between the CD4:CD8 lymphocyte ratio and ADCC activity was found. The possible beneficial effect of ADCC-inducing antibodies early in infection is discussed in relation to the effect of ADCC-inducing antibodies in other retrovirus systems and to the nature of lentivirus infections.     

Inference of surface membrane factors of HIV-1 infection through functional interaction networks

Background

HIV infection affects the populations of T helper cells, dendritic cells and macrophages. Moreover, it has a serious impact on the central nervous system. It is yet not clear whether this list is complete and why specifically those cell types are affected. To address this question, we have developed a method to identify cellular surface proteins that permit, mediate or enhance HIV infection in different cell/tissue types in HIV-infected individuals. Receptors associated with HIV infection share common functions and domains and are involved in similar cellular processes. These properties are exploited by bioinformatics techniques to predict novel cell surface proteins that potentially interact with HIV.

Methodology/Principal Findings

We compiled a set of surface membrane proteins (SMP) that are known to interact with HIV. This set is extended by proteins that have direct interaction and share functional similarity. This resulted in a comprehensive network around the initial SMP set. Using network centrality analysis we predict novel surface membrane factors from the annotated network. We identify 21 surface membrane factors, among which three have confirmed functions in HIV infection, seven have been identified by at least two other studies, and eleven are novel predictions and thus excellent targets for experimental investigation.

Conclusions

Determining to what extent HIV can interact with human SMPs is an important step towards understanding patient specific disease progression. Using various bioinformatics techniques, we generate a set of surface membrane factors that constitutes a well-founded starting point for experimental testing of cell/tissue susceptibility of different HIV strains as well as for cohort studies evaluating patient specific disease progression.     

HIV antigen and antibody detection: variable responses to infection in the Edinburgh haemophiliac cohort

Sequential serum samples from 18 haemophiliac patients exposed simultaneously to human immunodeficiency virus type 1 (HIV 1) in early 1984 were tested retrospectively for serological markers of infection. Assay for total antibodies to HIV established that the time to seroconversion might be as long as 110 days after exposure to contaminated factor VIII; serum samples were also tested by Western blotting, by enzyme linked immunosorbent assay (ELISA) for specific antibodies to envelope and core proteins, and for p24 antigen by two assay systems during the two years after infection. The studies showed that five of the 12 patients for whom serum samples obtained between exposure and seroconversion were available had transient p24 antigenaemia. Although amounts of total antibody to HIV and of antibodies to envelope proteins rose continuously during the two years of the study, amounts of antibody to the core protein were variable and tended to decline in patients who became symptomatic. Two patients had persistent p24 antigenaemia that began four months after seroconversion; these patients remained asymptomatic. One patient who developed the acquired immune deficiency syndrome (AIDS) had transient antigenaemia at the time of seroconversion but failed to show any antigen for the rest of the study; progression to AIDS was accompanied by an increase in antibodies to envelope proteins.Much of the variability in the course of infection with HIV must represent the differences in the susceptibility of the patients to infection.     

Anaemia in acute HIV-1 subtype C infection

Background

The high prevalence of anaemia and the increased morbidity and mortality associated with anaemia during AIDS has been well described yet there has been little information about anaemia and changes in haemoglobin levels during acute and early HIV-1 infection.

Methods

HIV-negative women (n = 245) were enrolled into an observational cohort as part of the Centre for the AIDS Programme of Research in South Africa (CAPRISA) Acute Infection Study. Acute infection was diagnosed following a positive HIV RNA PCR in the absence of antibodies, or detection of HIV-1 antibodies within 3 months of a previously negative antibody test. Haemotologic parameters were assessed before infection and at regular intervals in the first twelve months of HIV infection.

Results

Fifty-seven participants with acute HIV infection were identified at a median of 14.5 days post-infection (range 10–81) and were enrolled in the CAPRISA Acute Infection cohort at a median of 41 days post-infection (range 15–104). Mean haemoglobin prior to HIV-1 infection was 12.7 g/dL, with a mean decline of 0.46 g/dL following infection. The prevalence of anaemia increased from 25.0% prior to HIV-1 infection to 52.6% at 3 months post-infection, 61.1% at 6 months post-infection, and 51.4% at 12 months post-infection.

Conclusions

Haematologic derangements and anaemia with a trend towards iron deficiency are common with acute HIV-1 subtype C infection in this small cohort. The negative impact of anaemia concurrent with established HIV infection upon morbidity and mortality has been well documented but the prognostic potential and long-term effects of anaemia during acute HIV-1 infection remain unknown.