Biomedical subjects
Publications and source records attributed to J Goudsmit.
The human immunodeficiency virus (HIV) exanthem can be the primary manifestation of HIV infection. We report three cases of an exanthematous skin eruption associated with acute HIV infection. HIV antigen (p24 core antigen) was present, whereas results of the HIV antibody test were negative.
The principal neutralization epitope of human immunodeficiency virus 1 is localized in the third variable (V3) domain of the external envelope and has been shown to bind isolate-specific antibodies. Therefore, the extent of variation within the nucleic acid sequence encoding this epitope was studied in DNA directly obtained from peripheral blood mononuclear cells of six children and their plasma donor. This revealed that the quasi-species distribution of sequences obtained after cloning varied from recipient to recipient and that the distance from the donor sequences increased over time. V3 nucleotide evolution rates averaged 9.5 x 10(-3) per site per year for silent sites and 11.4 x 10(-3) per site per year for nonsilent sites (vs. 9.7 and 9.8 x 10(-3) per site per year for a control region 5' adjacent to the V3 region) and, although individual differences were observed, did not correlate with the serum antigen levels or disease progression. Sequences of both the epitope coding region itself (V3) and the control region upstream diverted more from the donor sequence among children not progressing to AIDS than among children progressing to AIDS. The evolution of V3 sequences is apparently host dependent, rapid, and independent of the level of antigen expression.
A human Epstein-Barr virus-transformed lymphoblastoid B-cell line was generated from peripheral blood mononuclear cells (PBMC) of an asymptomatic human immunodeficiency virus type I (HIV-1) seropositive donor, which produces a human monoclonal antibody K14 (IgG1), reactive with an epitope on the transmembrane part (gp41) of the envelope glycoprotein of HIV-1. This monoclonal antibody reacts with a lysate of HIV-1-infected H9 cells, gradient purified HIV-1, and a vaccinia recombinant HIV-1 gp160 protein, but not with HIV-2 antigens in an enzyme-linked immunosorbent assay (ELISA). When used as an immobilized ligand in an immune affinity column, K14 selectively purifies gp41 from a HIV-1-infected H9 cell lysate. Although no reactivity was observed in ELISA with a panel of partially overlapping synthetic nonapeptides spanning the whole length of HIV-1 gp41, it was shown to react with recombinant envelope proteins, provided that they did contain amino acids 643-692: deletion of this part resulted in the disappearance of the reactivity. Testing of an extensive panel of the sera from HIV-1 seropositive or seronegative donors from Europe and Africa, including a selected group of donors before and after HIV-1 seroconversion, in a competition ELISA with horseradish peroxidase-conjugated K14, showed that the epitope recognized on gp41 is immunodominant and conserved. K14 does not neutralize HIV-1 infectivity or virus-mediated cell fusion, and does not mediate antibody-dependent cellular cytotoxicity.
Like particular monoclonal antibodies to CD4, monoclonal antibodies to epitopes localized at the top of the alpha-subunit (CD11a) and at the stem of the beta-subunit (CD18) of the lymphocyte function associated antigen-1 (LFA-1) block syncytium formation when added to CD4+ T-cells before or shortly after (5 min) cell free HIV-1 is added. This indicates involvement of LFA-1 epitopes in the early stage of cell-free infection. Syncytium formation is still blocked by CD4 antibodies when added two hours after virus adsorption, CD11a and CD18 antibodies are ineffective at this late stage. Radio-immune precipitation experiments in acutely infected T-cells with the appropriate CD11a and CD18 antibodies suggested a link between CD18 and CD4 in the cell lines studied, possibly mediated by the CD3/TCR complex. In chronically infected cells, where little CD4 is expressed, LFA-1 antibodies still precipitate the viral envelope, pointing to a direct LFA-1 envelope interaction in that late stage of infection. Our results indicate that a limited number of LFA-1 epitopes is involved in syncytium formation among T-cells, none of which is required for virus entry in the cell or virus spread in the culture.
The prevalence, risk factors, and incidence of hepatitis C virus (HCV) infection were studied in a cohort of drug users in Amsterdam. In intravenous drug users, the seroprevalence was 74% (224/304) versus 10% (4/42) in nonintravenous drug users. Risk factors independently associated with HCV antibody seropositivity were history and duration of intravenous drug use and frequency of injections. Daily smoking of heroin in the previous 6 months was independently associated with the absence of HCV antibodies. Periods of fever, tiredness, and diarrhea in the preceding 6 months were associated with HCV antibodies even after correction for human immunodeficiency virus infection. The incidence rate of HCV infection appeared high and stable over the years 1986 to 1989. Thus, HCV infections are common among intravenous drug users and are mainly due to the intravenous use of drugs.
For identification of risk factors for progression of human immunodeficiency virus (HIV) infection, 746 homosexual men participating in a cohort study in Amsterdam, The Netherlands, were studied since October 1984. A total of 234 of these men were HIV antibody-positive at baseline, and 52 seroconverted during follow-up. These 286 individuals were categorized as high- and low-risk for progression to the acquired immunodeficiency syndrome (AIDS) on the basis of the presence or absence of HIV antigenemia, antibody to HIV core antigen, or a number of T helper lymphocytes less than 0.5 x 10(9)/liter during three or more subsequential blood samples. Ninety-six (41%) of the seropositives and 32 (62%) of those who seroconverted remained low-risk throughout the study period. Bivariate analyses revealed that educational level and a history of herpes zoster were associated with a low- and high-risk status, respectively. In multivariate analyses, a history of herpes zoster and a history of sexual intercourse with a person who had AIDS were associated with a more rapid disease progression. While herpes zoster is considered to be a marker of progressive immunodeficiency, a history of having sexual intercourse with a person who had AIDS points to the more virulent properties of HIV in these persons. Because both seropositives and seroconverters who had sexual intercourse with a person with AIDS had a more rapid disease progression, it seems plausible that being infected by a person with AIDS is a risk factor for a relative short incubation period.
In a previous study we have shown that peripheral blood mononuclear cells (PBMC) from asymptomatic HIV-seropositive male homosexuals, who had seroconverted more than 2 years before, were unable to mount a secondary immune response in vitro to certain viral and bacterial antigens. We have extended this study by investigating the secondary immune responses of five male homosexuals, who, by regular screening, were found to have seroconverted for HIV-1 during the preceding 3 months and were subsequently vaccinated with tetanus toxoid and poliovirus vaccine. Six weeks after the booster vaccination, PBMC of the five recently seroconverted individuals were assayed for in vitro mitogen or recall antigen-induced antibody synthesis and lymphocyte proliferation. The results of this study indicate that certain of the in vitro abnormalities of immune reactions, observed in both symptomatic and asymptomatic HIV-seropositive individuals, can already be found within 3 months after seroconversion.
Beta 2-microglobulin (beta 2-M) levels were determined in the serum of 24 patients treated with high-dose human recombinant interferon-alpha (IFN alpha) for AIDS-associated Kaposi's sarcoma. There was a significant increase in serum beta 2-M levels, irrespective of the response to treatment. However, the increase of serum beta 2-M levels in responders appeared to be more pronounced than in those with progressive disease, but this difference was not significant. The increase was only found during the initial 8 weeks; thereafter, beta 2-M levels declined in patients with continuing clinical improvement during ongoing treatment with IFN alpha. This may have been related to IFN alpha dose modification at 8 weeks for all patients. The initial rise in serum beta 2-M might be related to the immunomodulation properties of IFN alpha. Because serum beta 2-M levels were also enhanced in non-responders, this rise does not demonstrate that immunomodulation by IFN alpha is a mechanism of anti-tumour activity in AIDS-associated Kaposi's sarcoma.
The HIV-1 isolate CBL-4 (RUT), originating from Tanzania, was characterized using a comprehensive virus-typing system. This system included sequence analysis of the region coding for the neutralization domain in the third variable region (V3) of the external envelope and of the tat responsive (TAR) region after polymerase chain reaction (PCR) amplification of these sequences from cellular DNA in the CBL-4 (RUT) producer line. Based on independent cluster analysis of TAR and V3 sequences the CBL-4 (RUT) virus was positioned closest to the Z6 (and ELI) African virus family. The V3 amino acid sequence on the surface of the virus particle was confirmed by the inhibition of neutralization of CBL-4 (RUT) by a synthetic peptide derived from the nucleic acid sequence. Using antisense phosphate-methylated DNA covering the TAR loop region of LAV-1/HTLV-IIIB, inhibition of HTLV-IIIB and HTLV-IIIRF infection was seen, whereas no inhibition was observed for CBL-4 (RUT), indicating two or more mismatches in the TAR loop region, a characteristic shared with Z6 virus, but not with ELI. We propose a virus-typing system based on sequence analysis confirmed by virus neutralization with a peptide binding antibody and inhibition by antisense phosphate-methylated DNA to group viruses for laboratory use and vaccine design.
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A panel of murine monoclonal antibodies (MAbs) to the human immunodeficiency virus type 1 trans-activator tat protein were characterized. The anti-tat MAbs were mapped to the different domains of the tat protein by Western blot (immunoblot) and Pepscan analyses. One-half of the MAbs tested mapped to the amino-terminal proline-rich region, and one-third of the MAbs tested mapped to the lysine-arginine-rich region of tat. The individual MAbs were tested for inhibition of tat-mediated trans activation, using a cell-based in vitro assay system. MAbs which mapped to the amino-terminal region of the tat protein demonstrated the highest degree of inhibition, whereas MAbs reactive to other portions of the molecule exhibited a less pronounced effect on tat function.
Emergence in two chimpanzees of human immunodeficiency virus type 1 (HIV-1) IIIB variants resistant to neutralization by the preexisting antibody is described. Viruses isolated from the HIV-1 IIIB gp120-vaccinated and -challenged animal were more resistant to neutralization by the chimpanzee's own serum than viruses isolated from the naive infected animal, indicating immune pressure as the selective mechanism. However, all reisolated viruses were 16- to 256-fold more neutralization resistant than the inoculum virus to antibodies binding to the third variable domain (V3) of the HIV-1 external envelope. Early chimpanzee serum samples that neutralized the inoculum strain but not the reisolated viruses were found to bind an HIV-1 IIIB common nonapeptide (IQRGPGRAF) derived from the gp120 isolate-specific V3 domain shown to induce isolate-specific neutralization in other animals. Amplification of the V3 coding sequence by polymerase chain reaction and subsequent sequence analysis of the neutralization-resistant variants obtained from in vivo-infected animals indicated that early resistance to neutralization by an HIV-1 IIIB monoclonal antibody (0.5 beta) was conferred by changes outside the direct binding site for the selective neutralizing antibody. The reisolated neutralization-resistant isolates consisted of the lower-replication-competent virus subpopulations of the HIV-1 IIIB stock, as confirmed by biological and sequence analyses. In vitro passage of the HIV-1 IIIB stock through chimpanzee and human peripheral blood mononuclear cell cultures void of HIV-specific antibody resulted in homogenic amplification of the more-replication-competent subpopulation preexisting in the original viral stock, suggesting a role for the immune system in suppressing the more-replication-competent viruses.
The time of survival in 176 AIDS patients was investigated in relation to the presence or absence of HIV-1 p24 antigenaemia at the moment of diagnosis. The median time of survival in p24 antigen positive patients was 12 months, in p24 antigen negative patients it was 13 months; no difference in survival curves was found. Also no difference was found in survival between patients with high and low p24 antigen levels. The median time of survival in patients for whom a diagnosis of AIDS was made in the period before the introduction of zidovudine treatment was 10 months; in patients diagnosed in the period thereafter it was 18 months (p less than 0.005). However, when each period was analysed separately, no difference in survival between p24 antigen positive and negative patients was found. Separate analysis of patients with a diagnosis of Kaposi's sarcoma alone showed similar results. HIV-1 p24 antigenaemia at the moment of diagnosis of AIDS (both in the period before and in the period after the introduction of zidovudine) is not a predictor for time of survival.
Antibodies of individuals infected with the human immunodeficiency virus type 1 (HIV-1) were used to probe the antigenicity of the HIV-1 transmembrane protein of 41 kD (gp41) by antibody-reactive peptide scanning (Pepscan). Eleven distinct sequential antibody-binding sites were defined by testing reactivity to 339 overlapping nonapeptides spanning the complete gp41 amino acid sequence. Such analysis only maps continuous antibody-binding sites of nine amino acids in length and does not identify putative discontinuous or assembled epitopes. Three B cell epitopes (aa 609-622; aa 655-699; aa 664-681) at the amino-terminal border of the putative transmembrane anchor and two (aa 732-748; aa 744-762) at the carboxyl-terminal border of this domain were the most antigenic. One antibody-binding domain (aa 834-852) with four amino acids homologous to the beta-1 domain of HLA class II beta-chain was recognized by the serum in 1 of 4 AIDS patients tested and not by any of the eight sera from symptom-free individuals. Although functional domains of gp41 involved in virus replication, cytopathicity and possibly immunosuppression were shown to bind antibodies of HIV-1-infected individuals, no relationship between antibody recognition patterns and disease progression was apparent.
Anti-interferon (IFN)-alpha antibodies were determined in the serum of 28 patients treated with high-dose human recombinant IFN-alpha-2a for AIDS-associated Kaposi's sarcoma. After a median treatment duration of 3 months, 3 patients developed anti-IFN-alpha antibodies, of whom 2 showed a long lasting tumour response despite the development of these antibodies. None of 3 patients with tumour progression after an initial treatment response had developed IFN-alpha neutralizing antibodies. In conclusion, a low incidence of anti-IFN-alpha antibodies during treatment with high dose IFN-alpha was found, but the appearance had no detrimental effect on the duration of tumour responses in a small number of patients.
Follicular dendritic cells (FDC) from axillary lymphoid tissue of a patient with acquired immune deficiency syndrome (AIDS) were analyzed for the presence of gag and env proteins and env mRNA of human immunodeficiency virus type-1 (HIV-1), both in a purified FDC suspension and on frozen sections. Isolated cells with morphologic and immunocytochemical features of FDC expressed HIV-1 core (gag) proteins p15, p17, p24, and envelope (env) protein gp41; in addition HIV-1 env mRNA was detected in some of these cells. This corresponded with intense expression of HIV-1 proteins by FDC in germinal centers in situ, and the presence of HIV-1 mRNA-positive cells in germinal follicles. These findings led us to conclude that FDC are infected and able to produce HIV-1. Such infection may contribute significantly to the destruction of the FDC network during the lymphadenopathy phase after HIV-1 infection.
HIV-1 p24 antigen levels were determined in sequential serum samples from 71 subjects with persistent p24 antigenaemia, obtained over a period of 6-36 months during which no antiretroviral treatment was given. Fifty-six subjects were initially symptom free: 39 remained so during follow-up and 17 developed AIDS. Fifteen subjects were studied from the moment AIDS was diagnosed. Median serum p24 levels rose in all groups. In 50/71 individuals, p24 levels rose with time; in 21 they declined. The mean change in p24 levels was +194%. Twelve of the symptom-free subjects were subsequently treated with 1000 mg zidovudine daily for 12 months, over which period p24 levels declined in all 12 (mean change -56%). The difference in number of subjects with rising and declining p24 antigen levels between the untreated and zidovudine treated group was significant (P less than 0.001). Triton X-100 pretreatment (which presumably enables detection of virion-associated p24 in addition to free p24) of serum samples from 2 subjects who seroconverted for p24 antigen, from 2 AIDS patients who did not receive antiretroviral treatment and from 2 zidovudine-treated symptom-free subjects, did not lead to a substantial increase in p24 levels, except in the case of one of the p24 antigen seroconverters. It is concluded that the decline in serum p24 levels reported to occur during treatment with putative antiretroviral drugs can largely be ascribed to this treatment.
Antibodies to E. coli-produced HIV-1 vpr and vpu were determined by enzyme immunoassay in serial sets of sera from 72 men seroconverting for antibodies to HIV-1 structural proteins, and from 196 initially symptom-free men who were positive for such antibodies at study entry. First detection of vpr- and vpu-specific antibodies always was within 12 months of seroconversion for antibodies to structural proteins. In the combined cohort of 268 men, vpr- and vpu-specific antibodies were found persistently in 26 and 43% of men, respectively. Vpr- and vpu-specific antibodies were transiently detected in 3 and 7%, respectively, and intermittently detected in 18 and 13% of men, respectively. No association was found between the patterns of vpr- or vpu-specific antibody response and clinical outcome. In subjects with different patterns of vpr- and vpu-specific antibody response, no clear temporal relationship existed between the appearance or disappearance of antibodies and the onset of HIV-1-related disease.