Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0021051 (immunodeficiency)
71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Changes in T cell receptor (TCR) V beta repertoire and their correlation with virologic events were investigated in rhesus monkeys after acute infection with the simian immunodeficiency virus (SIV). 11 genetically defined rhesus monkeys were experimentally infected with SIVmac or a chimeric simian-human immunodeficiency virus (SHIV), and their peripheral blood lymphocytes (PBL) and lymph nodes were prospectively assessed for TCR V beta gene expression. PBL and lymph nodes of the acutely infected monkeys demonstrated an expansion of selected V beta-expressing T lymphocyte subpopulations as early as 3 d after infection. These expanded V beta-expressing lymphocyte subpopulations were comprised predominantly of CD8+ cells. Six of seven infected monkeys sharing a single electrophoretically defined major histocompatibility complex class I allele exhibited a similar expansion of V beta 14-expressing PBL. Sequence analyses of V-D-J segments of TCR-beta cDNA indicated that the V beta-expressing T cell subpopulation expansion can be oligoclonal. SIVmac-specific CD8+ cytotoxic T lymphocytes were demonstrated in both PBL and lymph nodes of the infected monkeys at the time expansion of the selected V beta-expressing cell subpopulations was seen. Finally, the expansion of the selected V beta-expressing lymphocytes in PBL coincided with the emergence and clearance of SIV p27 from the plasma of the infected monkeys. These results demonstrate that acute infection of rhesus monkeys with SIVmac or SHIV results in an expansion of CD8+ lymphocyte subpopulations expressing selected V beta gene families. The selectively expanded T lymphocytes may contribute to early viral clearance after acute SIVmac or SHIV infection.
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PMID:T cell receptor V beta repertoire in an acute infection of rhesus monkeys with simian immunodeficiency viruses and a chimeric simian-human immunodeficiency virus. 754 Jun 51

To evaluate the role of humoral immunity against simian immunodeficiency virus (SIV), we tested whether passive immunization with plasma from SIVmac251 vaccine-protected or healthy infected animals would protect rhesus monkeys against intravenous infection with ten 50% animal infectious doses of the cell-free homologous virus. The challenge dose of this SIVmac251 virus stock had previously caused persistent infection in all (21 of 21) nonimmunized controls. A plasma pool was obtained from a donor that had been immunized with an inactivated whole SIVmac251 vaccine produced in human T cells. This plasma pool contained low levels of SIVmac binding and neutralizing antibody but had a high titer of antibodies recognizing human cell proteins. Given 4 or 18 hr before intravenous challenge, this plasma completely protected three of eight recipients from infection and delayed virus detection in one recipient. The five unprotected animals had only a transient or undetectable p27 antigenemia and low virus load in their PBMCs, and all survived at least 7 months after infection. By contrast, no protection was observed in 6 monkeys given inactivated, pooled plasma or purified immunoglobulin (Ig) from healthy SIVmac251-infected animals. This plasma pool and the Ig preparation contained high levels of SIV-binding and neutralizing antibody but no reactivity to human cellular components. Five of the six recipients had persistent antigenemia after challenge and four died acutely from simian AIDS in 4-7 months. These studies suggest that passive transfer of antibody to human cellular antigens can confer protection against SIVmac whereas passive transfer of neutralizing antibodies without human cellular antibodies does not protect against the homologous virus and may enhance infection.
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PMID:Passive immunization of rhesus macaques against SIV infection and disease. 754 12

Experimental evidence from the simian immunodeficiency virus (SIV) model of AIDS has shown that the nef gene is critical in the pathogenesis of AIDS. Consequently, nef is of considerable interest in both antiviral drug and vaccine development. Preliminary findings in two rhesus macaques indicated that a deletion of only 12 bp found in the overlapping nef/3' long terminal repeat (LTR) region (9501 to 9512) of the SIVmacC8 molecular clone was associated with reduced virus isolation frequency. We show that this deletion can be repaired in vivo by a sequence duplication event and that sequence evolution continues until the predicted amino acid sequence of the repair is virtually indistinguishable from that of the virulent wild type. These changes occurred concomitantly with reversion to virulence, evidenced by a high virus isolation frequency and load, decline in anti-p27 antibody, substantial reduction in the CD4/CD8 ratio, and development of opportunistic infections associated with AIDS. These findings clearly illustrate the capacity for repair of small attenuating deletions in primate lentiviruses and also strongly suggest that the region from 9501 to 9512 in the SIV nef/3' LTR region is of biological relevance. In addition, the ability of attenuated virus to revert to virulence raises fundamental questions regarding the nature of superinfection immunity.
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PMID:Repair and evolution of nef in vivo modulates simian immunodeficiency virus virulence. 760 80

We have tested the ability of a monoclonal antibody-based simian immunodeficiency virus (SIV) p27 capsid antigen assay to detect SIV antigen in supernatants from a variety of infected cell cultures. The antigen capture assay has a sensitivity of approximately 30 pg of SIV p27 capsid antigen/ml. The assay detected SIV p27 capsid antigen in cell culture supernatants from all six strains tested, detected the replication of SIV following the inoculation of the virus in peripheral blood mononuclear cell cultures earlier compared to reverse transcriptase assay, and was more sensitive in detection of the SIV antigen compared to human immunodeficiency virus type 1 (HIV-1) antigen capture assays. The SIV antigen capture assay was used to detect SIV antigen from serum samples and tissue cultures from eight of eight SIVB670-infected rhesus macaques (Macaca mulatta). Similar samples from four control rhesus macaques were negative when tested by the assay. The SIV antigen was detected in virus-infected monkeys during early time periods following inoculation (1 to 3 weeks) or during episodes of CD4+ lymphocytopenia and clinically evident disease. In addition, the SIV antigen capture assay positively identified each of three different HIV-2 strains in cell culture supernatants. The SIV antigen capture assay provides a sensitive and specific method to monitor SIV and HIV-2 capsid antigen in cell cultures and from infected animals. The assay will be an important tool in the utilization of SIV and HIV-2 primate models for HIV-induced acquired immunodeficiency disease syndrome.
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PMID:Detection of simian immunodeficiency virus and human immunodeficiency virus type 2 capsid antigens by a monoclonal antibody-based antigen capture assay. 768 21

Transmission of human immunodeficiency virus (HIV) in North America and Europe occurs most commonly through the rectal mucosa during homosexual intercourse. The simian immunodeficiency virus (SIV) macaque model has been used to investigate rectal immunization. The vaccine used was a recombinant SIV gag p27 expressed as hybrid Ty virus-like particles (Ty-VLP). Sequential ororectal (OR) mucosal immunization was compared with i.m. immunization. Whereas both routes of immunization induced serum IgA and IgG p27 antibodies, only OR immunization induced rectal secretory IgA antibodies. Specific CD4+ T-cell proliferative responses to stimulation with p27 were found after i.m. immunization only in the blood and spleen, but after OR immunization they were found in the internal iliac and inferior mesenteric lymph nodes in addition to the blood and spleen. T-cell epitope mapping of the proliferative responses of short-term cell lines (STCLs) grown from peripheral blood or lymphoid cells revealed a major epitope within the polypeptide 121-150 after either route of immunization. Two minor T-cell epitopes were found within peptide 41-80 in STCLs from splenic and circulating cells. B-cell epitope mapping of serum or biliary IgA and IgG antibodies revealed two overlapping or adjacent immunodominant epitopes to the T-cell epitopes within the polypeptides 121-170 and 51-90. The results suggest that rectal augmented by oral immunization with a recombinant particulate antigen in nonhuman primates elicits secretory IgA and to a lesser extent IgG responses in the draining lymph nodes and the rectal mucosa, whereas systemic immunization targets predominantly splenic and circulating T- and B-cell responses. These findings may have important implications in the strategy of designing vaccines in prevention of homosexual transmission of HIV infection.
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PMID:T- and B-cell functions and epitope expression in nonhuman primates immunized with simian immunodeficiency virus antigen by the rectal route. 769 Sep 67

Simian immunodeficiency virus (SIV)-specific CD8+ CTL were isolated from blood, cerebrospinal fluid, and brains of rhesus macaques infected i.v. with SIV. CTL were found as early as 1 wk postinfection and their appearance correlated with a decrease of viral Ag (p27) found in the blood. CTL isolated from cerebrospinal fluid and/or brain often recognized different viral proteins than CTL isolated from blood, suggesting either a unique migratory pattern to the central nervous system or a difference in activation/retention of lymphocytes in these compartments.
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PMID:Simian immunodeficiency virus (SIV)-specific CTL in cerebrospinal fluid and brains of SIV-infected rhesus macaques. 773 Jun 57

In order to investigate the prevalence of infections with three feline retroviruses feline immunodeficiency virus (FIV), feline leukemia virus (FeLV) and feline syncytial virus (FSV) in Taiwan, we collected a total of 75 blood samples from cats from veterinary hospitals, a breeding cattery and a homeless shelter in 1993 and 1994. We examined the presences of anti-FIV and FSV antibodies and FeLV-p27 antigen in these samples by the indirect immunofluorescence and/or enzyme-linked immunosorbent assays. All of the serum samples positive for FIV were obtained from homeless cats and the overall FIV positive rate was 4%. The overall positive rates of FSV and FeLV were 28% and 1.3%, respectively. From these results, together with previous seroepidemiological surveys by others, it was revealed that the prevalence of FIV and FeLV infections appeared to be lower in Taiwan than in the United States or Japan. In contrast, the prevalence of FSV infection in Taiwan was as high as that in Japan.
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PMID:Seroepidemiological survey of feline retrovirus infections in cats in Taiwan in 1993 and 1994. 775 12

We analyzed the kinetics of the virological and immunological events that occurred in four AZT-treated cynomolgus macaques during the acute infection that followed their exposure to the simian immunodeficiency virus (SIVmac251) grown on monkey PBMCs in a cell-free stock solution. These events included changes in the CD4+ and CD8+ T lymphocyte subsets, p27 antigenemia, infectious serum virus, and cell-associated virus loads. The kinetics of these changes proved strikingly similar to those reported in human HIV-1 infection. Four other SIV-exposed macaques were treated with placebo instead of AZT. We demonstrated that AZT does not prevent SIV infection, even when administered before SIV inoculation. However, the peaks of p27 antigenemia and of serum and cellular viremia were significantly smaller and occurred significantly later in the monkeys given AZT than in those given placebo.
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PMID:An animal model for antilentiviral therapy: effect of zidovudine on viral load during acute infection after exposure of macaques to simian immunodeficiency virus. 784 83

A retrospective study of pathologically confirmed cases of feline spinal lymphosarcoma (FSL) admitted to the Colleges of Veterinary Medicine at the University of Georgia and North Carolina State University from 1973 to 1988 was conducted. Two hundred fourteen cases of feline lymphosarcoma were diagnosed histopathologically; involvement of the central nervous system (CNS) was identified in 26 (12.1%). Twenty-three of these tumors involved the spinal cord, and 22 of the 23 were solitary. A predilection for the thoracic and lumbar vertebral canal was noted. Most cats with spinal disease were young, with mean and median ages of 43 and 24 months, respectively; 67 cats were 36 months of age or younger. In most cases, affected cats had acute neurological deterioration after an initial insidious course. Extraneural abnormalities were not consistently present. Neoplastic lymphocytes diagnostic of FSL were identified on cerebrospinal fluid (CSF) analysis in 6 of 17 cats evaluated. Sixteen of 17 cats evaluated had serologically positive test results for feline leukemia virus (FeLV) p27 antigen, and all cats tested for feline immunodeficiency virus (FIV) antibodies had negative test results.
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PMID:Feline spinal lymphosarcoma: a retrospective evaluation of 23 cats. 804 83

Two commercially available expression vectors were modified to generate plasmids pGEXcPk and pQ9cPk. Proteins expressed from pGEXcPk and pQ9cPk had a short oligopeptide tag termed Pk at their carboxy termini and either glutathione S-transferase (GST) or a small histidine (His) tag, respectively, at their N termini. GST fusion proteins can be purified on immobilized glutathione and proteins coupled to the His tag selectively bind to Ni(2+)-NTA columns. The Pk tag is recognized by monoclonal antibody (MAb) SV5-P-k, previously produced in our laboratory. Thus proteins expressed from the pGEXcPk and pQ9cPk vectors can be purified in a two-step procedure, first via the N-terminal tag and second via the C-terminal tag. The combination of two affinity purification steps significantly improves the antigen purity and selects for full-size proteins. Moreover, by using the MAbSV5-P-k in the second purification step, Pk-linked antigens can be assembled directly into solid matrix-antibody-antigen (SMAA) complexes for use as vaccines. The genes for nef, endonuclease, p15, p17, p27, protease, Rev, reverse transcriptase (rt), tat, vif, vpr, and vpx of simian immunodeficiency virus (SIV mac 251) were cloned and expressed as both GST-SIV-Pk and His-SIV-Pk proteins. Multivalent SMAA complexes were made that contained His-p17-Pk, His-p27-Pk, His-rt-Pk, His-vpx-Pk, and His-vpr-Pk. Following two immunizations of mice with this mixture, antibodies could be detected to all five SIV antigens. When compared to single-protein immunizations, the immunogenicity of some of the proteins in this cocktail was either enhanced or decreased. Mice were also immunized with His-p17-Pk or His-p17-Pk-antibody complexes in the presence or absence of alum. The antibody-antigen complexes induced two- to four-fold higher antibody levels than antigen alone but did not appear to be more immunogenic in inducing lymphoproliferative responses. Sera from SIV-infected macaques were tested for the presence of antibodies reacting with the recombinant proteins by Western blot analysis. Antibodies to endonuclease, p15, p17, p27, rt, and vif were readily detected, antibodies against protease and vpx were present at much lower levels, but no antibodies were detected to nef, rev, tat, or vpr. Thus, we have developed a comprehensive range of reagents (available on request) that can be used to examine immune responses to SIV in both mice and monkeys.
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PMID:Expression and purification of nonglycosylated SIV proteins, and their use in induction and detection of SIV-specific immune responses. 807 30


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