[Institutional delivery rate in minority inhabited areas of China from 1996 to 2017].

Objective: To describe the secular trends of institutional delivery (ID) rate in minority inhabited areas of China from 1996 to 2017 according to national health policies. Methods: The number of live births and IDs for each county/district in 31 provinces of China were derived from the datasets collected by the Office for National Maternal & Child Health Statistics of China. Information on health policies and ethnical areas was derived from official governmental websites. The calendar years were divided into three periods: pre-program period (1996 to 1999), program implementation period (2000 to 2008) and post-program period (2009 to 2017). Minority autonomous regions, autonomous prefectures, and autonomous counties were defined as minority inhabited areas. The ethnic that a county was classified into was determined by a principle of close proximity to the name of the county or its next higher level administrative division. A total of 700 counties in minority inhabited areas were included in the analysis. Results: A total of 45 684 265 live births including 35 098 855 delivered in institutions were analyzed. The ID rate in minority inhabited areas was 37.5% (696 221/1 856 164) in 1996 and 99.2% (2 371 209/2 390 131) in 2017, with an annual growth rate of 4.7%. During the 22-years period, the ID rates in the eastern, central and western regions increased simultaneously, with the annual growth rates of 3.1%, 4.2% and 4.9% respectively. The difference between the eastern and western regions decreased steadily from 16% in 1996 to <1% in 2017 and the difference between the urban and rural areas decreased from 32.1% in 1996 to <1% in 2017. Besides, the ID rates in Tibetan and Yi inhabited areas with lower baseline levels increased 73 and 63 percentage points respectively. The number of counties with the ID rate of <96% were substantially reduced from 589 in 1996 to 72 in 2017; the 71 counties were all located in national deep poverty-stricken areas named Three Districts and Three States, predominantly involving Tibetan (58), Yi (6), Uygur (2) and Lisu (2) ethnics. Conclusion: During the past 22 years, the ID rate in minority inhabited areas in China has dramatically increased, achieving the goal of 2 020 ahead of schedule, but there remains a few western counties where ID rates are still<96%, indicating that minority inhabited western areas should be focused in developing national policies concerning institutional delivery.

[HIV epidemic among pregnant women in China, 2016: trend and spatial analysis].

Objective: To describe the spatial distribution characteristics of the HIV prevalence among pregnant women in mainland China in 2016, providing scientific evidence for the prevention of mother-to-child transmission of HIV. Methods: Data on pregnant women and those living with HIV in 2016 for all counties in mainland China is from the National Maternal & Child Health Statistics dataset. To obtain robust estimates, 2 964 counties were merged into 344 cities. Spatial autocorrelation analysis and trend analysis were performed based on the city-level dataset to detailedly describe the characteristics of the spatial distribution. Results: A total of 14 879 082 pregnant women were included in the analysis, among whom 5 051 were diagnosed to be infected with HIV, giving an overall prevalence of 34.0 per 100 000 pregnant women. The prevalence was higher in the south than in the north, and decreased from the west (93.5/100 000) to the east(8.6/100 000 ), more specifically, the prevalence in the West region was 11 times as high as that in the East region(χ(trend)(2)=68.61, P<0.01). Stratified analysis by provinces showed that there were 6 provinces whose prevalence was >50.0 per 100 000, and they (Yunnan, Xinjiang, Sichuan, Guangxi, Guizhou and Chongqing) were all located in the West Region; pregnant women in these provinces accounted for 21% of all pregnant women, but the HIV cases accounted for 76% of all cases diagnosed in mainland China. Stratified analysis by cities showed that there were 30 cities whose prevalence was >100.0 per 100 000, and 28 of these cities were also located in the western provinces above. Furthermore, the global Moran's I (0.5, P<0.01) indeed indicated a strong clustered distribution across mainland China; 2 hot spots were observed in the Midwest of Xinjiang, and Yunnan and its bordering areas (Sichuan, Guizhou, Guangxi and Chongqing), while 1 cold spot in the central and east China. The HIV prevalence in the hot spots (183.6/100 000) was 23 times as much as that in the cold spot (8.1/100 000). Conclusion: The overall HIV prevalence for pregnant women who lived in mainland China in 2016 (34.0/100 000) ranked at low-level worldwide, but varied markedly across the whole country with 2 high-prevalence-clustered areas: the Midwest of Xinjiang Uygur Autonomous Region, and Yunnan province along with its bordering areas, indicating comprehensive intervention strategies especially targeted to the areas with high HIV prevalence should be developed.

[Secular trends of institutional delivery rate in China from 1996 to 2015].

Objective: To describe the secular trends of institutional delivery (ID) rate in China from 1996 to 2015, and to assess the impacts of national health policies on the ID rate. Methods: Data on the number of live births and IDs for districts/counties in 31 provinces of China was annually collected by the Office for National Maternal & Child Health Statistics of China. Information concerning the relevant policies was from official governmental websites, including the programme to reduce maternal mortality and eliminate neonatal tetanus (2000 to 2008), and ID subsidy programme in rural China (2009 to present). According to the programme to reduce maternal mortality and eliminate neonatal tetanus, the calendar years were categorized into three periods: pre-programme period (1996 to 1999), programme implementation period (2000 to 2008) and post-programme period (2009 to 2015). Results: A total of 244 398 010 live births were included in the analysis, in which 211 605 727 were delivered in institutions. During the 20 years, the ID rate steadily increased from 58.7% (6 309 255/10 739 816) in 1996 to 99.7% (13 583 658/13 626 948) in 2015, with a compound annual growth rate of 2.8%. Analyses stratified by economic regions or urban-rural areas showed notably consistent increases in ID rates, and the regional and urban-rural differences became nearly disappeared by 2015. The largest regional difference between East (71.6%, 2 540 896/3 547 423) and West (44.6%, 1 675 305/3 752 873) was 27% in 1996 and <1% in 2015 (East 99.9%[5 177 865/5 180 636]and West 99.0%[3 925 766/3 964 622]). The urban-rural difference was 22.7% in 1996 (urban 73.5%[2 756 531/3 748 703], rural 50.8%[3 552 724/6 991 113]) and 0.4% in 2015(urban 99.9%[6 257 853/6 262 763], rural 99.5%[7 325 805/7 364 185]). During the programme implementation period and the post-programme period, the ID rates in rural area increased faster than those in urban area, and the corresponding compound annual growth rates in rural area were 2.4 and 2.8 times of those in urban area; the ID rates in Middle and West regions increased faster than those in East region, and the corresponding compound annual growth rates in West region were 3.6 and 6.3 times of those in East region. By 2015, the ID rates in all provinces other than Tibet (90.5%[48 445/53 505]) and Qinghai (97.2%[60 836/62 600]) reached or were close to 100%. However, there were still 112 districts/counties with ID rates <96%, of which 39 with ID rates <80%; the 39 districts/counties were all located in four western provinces (Tibet 19, Sichuan 15, Qinghai 3, and Xinjiang 2). Conclusions: During the past 20 years, the ID rate in China has steadily increased and achieved the goal of the year 2020 ahead of schedule; the regional and urban-rural inequality in ID has nearly disappeared. Given universal two-child policy, it is of significance to strengthen existing achievements, focus on complicated pregnancies and comprehensively improve the capability and quality of ID services; meanwhile, it is also of significance to develop particular policies and explore the medical-aid model for the minority-inhabited western regions with lower ID rates.

Enhanced antitumor immunotherapeutic effect of B-cell-based vaccine transduced with modified adenoviral vector containing type 35 fiber structures.

For successful clinical tumor immunotherapy outcomes, strong immune responses against tumor antigens must be generated. Cell-based vaccines compromise one strategy with which to induce appropriate strong immune responses. Previously, we established a natural killer T-cell (NKT) ligand-loaded, adenoviral vector-transduced B-cell-based anticancer cellular vaccine. To enhance tumor antigen delivery to B cells, we established a modified adenoviral vector (Ad-k35) that encoded a truncated form of the breast cancer antigen Her2/neu (Ad-k35HM) in which fiber structure was substituted with adenovirus serotype 35. We observed increased tumor antigen expression with Ad-k35HM in both human and murine B cells. In addition, an Ad-k35HM-transduced B-cell vaccine elicited strong antigen-specific cellular and humoral immune responses that were further enhanced with the additional loading of soluble NKT ligand KBC009. An Ad-k35HM-transduced, KBC009-loaded B-cell vaccine efficiently suppressed the in vivo growth of established tumors in a mouse model. Moreover, the vaccine elicited human leukocyte antigen (HLA)-A2 epitope-specific cytotoxic T-cell responses in B6.Cg (CB)-Tg (HLA-A/H2-D) 2Enge/Jat mice. These findings indicated that the Ad-k35 could be appropriate for the preclinical and clinical development of B-cell-based anticancer immunotherapies.

Immunoglobulin with complementary paratope and idiotope.

A hybridoma antibody (11E7-1) was isolated from a myeloma fusion with nu/nu BALB/c immunized against the T15 idiotype. This IgM antibody exhibited a dual specificity, binding both to PC and to anti-PC antibodies from two idiotype families. Binding to PC and anti-PC antibodies are completely inhibited by PC analogs. Furthermore, the hybridoma antibody binds to itself. Self-binding is also inhibited by PC analogs. From these data, we suggest that 11E7-1 hybridoma antibody has a PC-specific paratope site, and at same time expresses the internal PC antigen idiotope. The term autobody is proposed to signify its self-binding and potential role in autoimmunity. Autobodies may have a unique role in the network of immune system. Furthermore, it may be a model for designing idiotype vaccines.

Idiotypic self binding of a dominant germline idiotype (T15). Autobody activity is affected by antibody valency.

We have previously described (1-3) an IgM antibody that binds to PC, expresses the T15 idiotype, and binds also to itself or T15 if insolubilized. Because of the simultaneous presence of complementary idiotopes and paratopes this type of antibody has been termed autobody. The self binding involves the antigen-binding site because the F(ab')2 fragment of T15, PC, and no other haptens inhibit the self binding. DNA sequence analysis of 11E7-1 using primer extension cDNA sequencing showed that the variable sequences of H and L chains of 11E7-1 are identical to the germline sequence of the prototype T15 idiotype. Furthermore, monomeric and dimeric T15 IgA were shown to bind to insolubilized T15 and other T15+ antibodies including 11E7-1. Thus, the self-binding activity is an inherent property of the T15 germline sequence. The self binding is highly dependent on the polymeric state of the binding antibody since the IgM pentamer of 11E7-1 is about three fold more effective than the T15 dimer and 50 times more than the T15 monomer. These data suggest that the self-binding activity of a germline-encoded idiotype may play an important role in the biology of its expression, and more specifically, may be responsible for the establishment of its dominant expression.

Anti-allergic effects of PG102, a water-soluble extract prepared from Actinidia arguta, in a murine ovalbumin-induced asthma model.

BACKGROUND: Asthma is a chronic inflammatory disease of the lung and its incidence has been increasing around the world. We previously reported that oral administration of a water-soluble extract prepared from Actinidia arguta, code-named PG102, could modulate the level of Th1 and Th2 cytokines and suppress the production of immunoglobulin E (IgE) in the ovalbumin (OVA)-immunized murine model as well as in the in vitro cell culture system, and furthermore could significantly improve dermatitis conditions in the NC/Nga murine model. These data suggested that PG102 might have therapeutic effects in a broad range of allergic diseases. OBJECTIVE: To assess the possible anti-allergic effects of PG102 in the OVA-induced murine asthma model. METHODS: The quality of PG102 was standardized, using its effects on the production of IgE, IL-5, and IL-13, in in vitro cell culture systems. To test effects on asthma, BALB/c mice were orally administrated with PG102, followed by OVA sensitization and challenge to induce asthmatic symptoms. Airway hyperresponsiveness (AHR), bronchoalveolar lavage fluid, serum, and lung tissue were analysed by using various methods. RESULTS: PG102 could decrease the level of IgE, IL-5, and IL-13 in in vitro cell culture systems with IC(50) being 1.12-1.43 mg/mL. PG102 could ameliorate asthmatic symptoms, including AHR and eosinophilia in the lungs. Such improvement of asthmatic symptoms by PG102 was accompanied by the down-regulation of IL-5 and IgE. In PG102-treated mice, high level expression of heme oxygenase-1, a potent anti-inflammatory enzyme, was observed in alveolar inflammatory cells, while the mRNA levels of foxp3, TGF-beta1, and IL-10, important markers for regulatory T cells, were also up-regulated in the lung tissue. CONCLUSIONS: PG102 may have potential as a safe and effective reagent for the prevention or treatment of asthma.

Inhibition of self-binding antibodies (autobodies) by a VH-derived peptide.

The self-binding properties of a dominant idiotypic antibody (T15) and a minor idiotypic antibody (M603), both specific for phosphorylcholine, were examined as models of self-binding antibodies (autobodies). Observed differences in the self-binding affinity of T15 and M603 relate to variable sequence differences in their respective heavy and light chains. A molecular recognition theory based on the translation of coding and noncoding DNA strands was used to identify complementary amino acid sequences responsible for self-binding. The second hypervariable region of the heavy chain domain, extending into the third framework region, was predicted as the primary self-binding locus. Among peptides synthesized with different variable heavy and light chain regions, a 24-residue peptide spanning the second hypervariable and third framework regions of the heavy chain of T15 was nearly as effective as phosphorycholine in inhibiting the self-binding complexes.

Immunogenicity and safety profiles of genetic vaccines against human Her-2/neu in cynomolgus monkeys.

Her-2/neu is a well-characterized tumor-associated antigen, the overexpression of which in human carcinomas correlates with a poor prognosis. Here, we evaluated Her-2/neu-specific humoral and cellular immune responses in immunized monkeys after immunization with nonreplicating adenovirus (AdHM) expressing the extracellular and transmembrane domain of human Her-2/neu (HM) and/or naked DNA vaccine (pHM-hGM-CSF) expressing human granulocyte-macrophage colony-stimulating factor together with HM. Priming of monkeys with AdHM generated Her-2/neu-specific long-lasting antibody production. Furthermore, these Her-2/neu-specific antibodies produced by AdHM immunization, some of which shared epitope specificity with Herceptin, were able to induce antibody-dependent cellular cytotoxicity against Her-2-expressing target cells. Cellular immune responses were elicited in all monkeys immunized with Her-2/neu-expressing vaccine; interferon-gamma was secreted when these splenocytes were restimulated with Her-2/neu-expressing autologous cells, and immunization with AdHM induced Her-2/neu-specific lymphoproliferative responses. Further, immunization with pHM-hGM-CSF before AdHM immunization noticeably enhanced cytotoxic T-lymphocyte activity. In addition, we observed no abnormalities that would indicate that the genetic vaccines had toxic effects in the immunized monkeys. Thus, we can conclude that our genetic vaccines efficiently elicited Her-2/neu-specific humoral and cellular immune responses without causing severe adverse effects in nonhuman primates and that as such they warrant further clinical investigation.

Mapping of the functional domains of the v-rel oncogene.

Previously, the v-rel oncogene was shown to code for a protein of 503 amino acids. The protein product of v-rel was identified as a 59 kDa protein (pp59v-rel), phosphorylated predominantly on serine residues. Although the signal required for the nuclear localization of pp59v-rel in chicken embryo fibroblasts was identified, the regions of v-rel important for transformation have not been mapped. In this study, 12 linker insertion mutants of v-rel were constructed and tested for transforming activity. Seven linker insertion mutants which mapped between amino acid residues 29 and 275 abolished transformation. The remaining 5 mutants which contained linker insertion mutations between amino acid residues 332 and 459 transformed at wild type levels. The results of this analysis localize the functional domains of the v-rel oncogene to the N-terminus. Earlier reports have shown that pp59v-rel resides in a high molecular weight complex with several other cellular proteins. The transforming mutants co-precipitated the same set of cellular proteins when immunoprecipitated with v-rel antiserum. This indicates that all transforming mutants retained the ability to bind within the reported complex.

A model for the hapten-induced enhancement of monoclonal antibody binding in ELISA.

The unusual binding properties of three anti-phosphocholine (PC) monoclonal antibodies (MAbs) in ELISA has been reported [Hall T. J. (1987) Molec. Immun. 24, 773-777]. These MAbs gave reproducible 2-4 fold increases in binding to PC-protein coated plates in the presence of PC (approximately 2 mM), nitrophenyl PC (approximately 10 micron) and other PC analogues. A model is proposed here in which the complementary and opposite binding of hapten and PC-protein in the combining sites of these MAbs explains the hapten enhanceable binding in ELISA.

Antibodies of different specificities are self-binding: implication for antibody diversity.

Antibodies of the S107/T15 germline family possess variable region structures which allow them to form specific complexes. We extended the investigation of the immunochemical properties of self-binding antibodies (autobodies) to mutant antibodies: U4, which binds DNA, and U10, which has no identified antigenic specificity. U4 differs from the germline S107/TEPC15 autobody by one substitution in the variable heavy chain, which results in a loss of phosphorylcholine binding. Like TEPC15, U4 and U10 are also self-binding. While self-binding of the wild-type TEPC15 antibody is inhibited by free hapten phosphorylcholine self-binding of the anti-DNA antibody U4 is inhibited by DNA and by free nucleotides. The self-binding locus of U4 and U10 was further investigated using peptides derived from the variable region. A 22 residue peptide from the CDR2/FR3 variable heavy chain sequence of the TEPC15 germline structure specifically inhibits self-binding in solid-phase assays. Peptides from unrelated antibodies have no effect on self-binding. The finding of antibodies with identical specificities which are self-binding or not self-binding demonstrates the existence of a novel kind of antibody repertoire diversity controlled by variable sequence structures.

Typing of Hantaviruses from five continents by polymerase chain reaction.

Hantavirus, a genus in the family Bunyaviridae, is comprised of at least four serologically distinct types: Hantaan, Seoul, Puumala and Prospect Hill. The present communication reports the use of polymerase chain reaction (PCR) for typing 27 independently isolated Hantaviruses from 5 different continents. Total cellular RNA was extracted from virus-infected Vero E6 cell monolayers by the acid guanidium thiocyanate-phenol-chloroform method. We have utilized 5 different sets of oligonucleotide primers ranging from 18 to 22 nucleotides in length; one set was specific for a conserved region of the S genomic segment and used as genus-specific primers, the other 4 sets of primers were designed from unique sequences of the M genomic segment such that each primer set was specific to only one serological type of Hantavirus. The PCR products were analyzed by restriction endonuclease digestion for further confirmation. We typed 10, 12, 3 and 1 isolates into Hantaan, Seoul, Puumala and Prospect Hill respectively. The results of PCR were 100% agreeable with that of serological typing, and thus, PCR can be used as an adjunct test with serological method(s) or an independent test for diagnosis and for typing of new isolates of Hantaviruses.

Viral RNA and protein synthesis in two LLC-MK2 cell lines persistently infected with human parainfluenza virus 3.

Two lines of LLC-MK2 cells persistently infected with human parainfluenza virus 3 (HPIV-3) have been maintained in culture for approximately 3 years. Subgenomic RNAs (putative defective interfering particle genomes) were detected in virions released from both persistently infected cultures. In one of the persistently infected cell lines cyclic variation in the production of virions containing standard virus genomic-size (50S) RNA and subgenomic RNA was observed. The molar ratio of subgenomic RNA to 50S RNA ranged from less than 0.1/1 to 8.7/1. Northern blot analyses revealed that the patterns of viral mRNA synthesis in persistently infected cells from both cultures were similar to those of standard virus infected cells. Furthermore, the intracellular viral-specific proteins had electrophoretic mobilities similar to the corresponding proteins in standard virus-infected cells. Nucleotide sequence analysis of cloned M gene from virus after 29 months of persistence (147 passages) revealed only one variable conservative amino acid change in two clones analyzed from each cell line, indicating that the M protein is not likely to be involved in the maintenance of the persistent infections. The possible mechanisms by which the persistent state is maintained are discussed.

Nucleotide sequence and coding capacity of the large (L) genomic RNA segment of Seoul 80-39 virus, a member of the hantavirus genus.

The nucleotide sequence of the large (L) genomic RNA segment of Seoul 80-39 virus was determined from overlapping cDNA clones. The virion L RNA segment is 6530 nucleotides long. The 3' and 5' terminal sequences are inversely complementary for 15 bases. The viral complementary-sense RNA contains a single open reading frame from an AUG codon at nucleotide position 37-39 to a UAA stop codon at nucleotide position 6490-6492. This ORF could encode a polypeptide of 2151 amino acids (246,662 kDa) which likely corresponds to the L protein detected in purified viral particles (Elliott et al., 1984) and is assumed to be an RNA-dependent RNA polymerase molecule (Schmaljohn and Dalrymple, 1983). Comparison of the L protein of the Seoul 80-39 virus with the polymerase proteins encoded by other negative-stranded RNA viruses revealed 44% similarity only with the part of the Bunyamwera virus L protein (Elliott, 1989) and a very weak homology with the PB1 protein of influenza virus.

Molecular characterization of the M genomic segment of the Seoul 80-39 virus; nucleotide and amino acid sequence comparisons with other hantaviruses reveal the evolutionary pathway.

The genomic M segment of Seoul 80-39 virus was characterized by cloning and nucleotide sequence analysis. The virion M RNA segment is 3651 nucleotides long with the 3' and 5' terminal sequences inversely complementary for 20 bases. A single open reading frame was detected in the viral complementary-sense RNA which can encode a polypeptide of 1133 amino acids. The Seoul 80-39 virus M segment was compared with the M segments of related viruses, Hantaan 76-118, Hallnas B1 and Sapporo Rat (SR-11) virus. Our results demonstrate a significant similarity between M RNA segments of the Seoul 80-39, Hantaan 76-118, Hallnas B1 and SR-11 viruses. The degree of conservation of both nucleic acid and protein sequences between these viruses reveals a close evolutionary relationship. Furthermore, it is evident that the serotypic profile of hantaviruses is determined by the rodent host species from which the virus was isolated and not by the geographical area.

Evolution of the fusion protein gene of human parainfluenza virus 3.

The nucleotide sequences of the fusion (F) gene of 15 clinical strains of human parainfluenza virus 3 (HPIV3) isolated between 1959 and 1987 were compared with the F gene sequence of the prototype strain, Wash/47885/57. Nucleotide sequence diversity was greatest in the noncoding regions of the F gene; however, regions believed to function as transcriptional signals were completely conserved. Amino acid sequences were highly conserved and all but a few amino acid substitutions were conservative in nature. Sequence comparisons indicate heterogeneity in HPIV3 F genes; however, a significant proportion of nucleotide changes are maintained after they first appear and seem to be accumulating with time. Phylogenetic analysis suggests that there are 2 lineages of HPIV3 in North America. The two lineages can be distinguished by specific amino acid differences in the F protein, which correlate with differences in antigenic properties and neutralization patterns of HPIV3. The pattern of HPIV3 evolution, based on the analysis of F gene sequences, most closely resembles that of influenza virus B, vesicular stomatitis virus and Newcastle disease virus.

Comparison of nucleotide sequences among hantaviruses belonging to the same serotype: an analysis of amplified DNA by thermal cycle sequencing.

The hantavirus genus, belonging to the bunyaviridae family, is comprised of at least four serologically distinct types: Hantaan, Seoul, Puumala and Prospect Hill. Previously, we reported the use of the polymerase chain reaction (PCR) for grouping hantavirus isolates by using four sets of primers specific to each serotype. Our PCR typing results agreed with those of serological typing. The present study makes use of thermal cycle sequencing to sequence PCR-amplified DNA products in order to determine the level of similarity among members of the same serotype. We show that members of Hantaan and Seoul serotypes are over 92% homologous, irrespective of their host and geographical origin. Puumala sequences show a degree of homology ranging from 80 to 98%. Despite the variation in sequence at the nucleotide level, amino acids show an even higher level of conservation.

Comparison of the deduced gene products of the L, M and S genome segments of hantaviruses.

The amino acid sequences deduced from all currently available nucleotide sequences of hantaviruses are compared. Comparisons of three large (L), eight medium (M) and five small (S) genome segments are included. A consensus sequence is provided, allowing easy identification of conserved and unique gene regions. The viruses included in this report represent four serologically distinct hantaviruses which are capable of causing severe, moderate, mild or no human disease.

Analysis of B cell repertoire specific to the neutralizing epitopes of glycoprotein 120 in HIV-infected individuals.

This study describes the clonotypic analysis of neutralizing anti-gp120 antibodies elicited in HIV-infected individuals by a panel of anti-idiotype monoclonal antibodies (anti-Id MAbs). Sera from 80 HIV-infected individuals at various clinical stages of HIV-infection were tested for reactivity to 19 anti-Id MAbs in ELISA. Anti-idiotype MAbs reacted with between 0 and 26% of sera. Among the 13 idiotypes specific for anti-CD4 site antibodies, 4 were expressed in 15 to 20% of individuals, whereas 2 of 4 idiotypes specific for anti-V3 antibodies were expressed in 15 to 26% of the cases. These data suggest that each HIV-infected individuals has a diverse B cell repertoire to a given neutralizing epitope cluster and that certain clonotypes are more prevalent than others. To correlate the binding activity in ELISA with anti-gp120 specificity, the idiotype-positive antibodies (Id+ Abs) from representative serum samples were isolated by anti-Id MAb-Sepharose affinity columns. In most cases, the epitope specificity and the neutralizing properties of the isolated Id+ Abs correlated with that of anti-gp120 antibodies used for the generation of anti-Id MAbs. We propose that these anti-Id MAbs may be used to identify and measure neutralizing anti-gp120 antibodies of defined specificity in the sera of HIV-infected individuals, HIV-vaccinated individuals, and in HIV-infected mother-infant pairs.