Intra-blood-brain-barrier synthesis of HTLV-III-specific IgG in patients with neurologic symptoms associated with AIDS or AIDS-related complex

[Cerebrospinal fluid in acquired immunodeficiency syndrome. Analysis of 50 cases]

Cerebrospinal fluid (CSF) was analysed in 50 AIDS patients in this investigation. CSF analysis included: pressure, aspect, colour, cytology (cell number, cytomorphology, and lymphocyte subpopulations), proteins concentration and their electrophoretic distribution, chloride and glycosis concentration, GOT and LDH activity, immunology for cysticercosis, syphilis and toxoplasmosis, bacteriology, and mycological examinations (direct, cultures, Cryptococcus neoformans antigen test). Diagnostic changes were: lymphoma cells in one patient, cryptococcosis in 10, toxoplasmosis in 4, candidiasis in 1, and syphilis in 3. Cryptococcosis occurred in association with toxoplasmosis in one patient who developed syphilis in the follow-up; oligoclonal distribution of gamma globulins occurred in this case. In another case of cryptococcosis, candidiasis appeared during the course of the disease. Changes in the CSF composition observed are discussed in order to evaluate: aspects of CSF inflammatory response in report to immunodeficiency; blood-brain barrier involvement; CNS damage; intracranial mass effects.

Serologic studies in the diagnosis and management of meningitis due to Sporothrix schenckii

Eight patients have previously been reported to have central nervous system infections caused by Sporothrix schenckii. In those patients the fungus proved quite difficult to culture, delaying correct diagnosis and treatment. We describe seven additional patients with sporotrichosis meningitis, all of whom had antibody to this fungus in cerebrospinal fluid and serum. The antibody in the cerebrospinal fluid was most likely produced locally, as evidenced by its oligoclonality and the relatively high ratio of immunoglobulin to albumin in the cerebrospinal fluid as compared with the serum. Only one of these seven patients, who had active sporotrichosis of the knee joint, had obvious extrameningeal infection. None of 130 patients with meningitis known to be caused by other agents and none of 170 patients with other neurologic disorders had antibody to S. schenckii in their cerebrospinal fluid. We suggest that cerebrospinal fluid should be tested for S. schenckii antibody (in addition to other fungal agents) in any patient with chronic meningitis for which no cause is discovered by the usual diagnostic tests.

Human immunodeficiency virus infection of the developing human nervous system

Human immunodeficiency virus (HIV), the etiologic agent of acquired immune deficiency syndrome (AIDS) and AIDS-related complex, has recently been implicated as a factor in the development of AIDS-related neurologic dysfunction and may be responsible for an increasing number of neonatal immunologic and neurologic disorders. However, as yet there is no model system available to investigate the interaction of HIV with the developing human nervous system in vitro. To approximate the intracellular events associated with HIV infection of the human fetus nervous system we infected cells obtained by enzymatic dissociation of aborted human fetus dorsal root ganglia and their attached spinal roots and nerves. The expression of the HIV gag gene protein products (p17 and p24) was detected in a subpopulation of cells with a nonneuronal morphology, reaching a maximum within 3 days. Although 70% of the nonneuronal cells were p17- and p24-positive 3 days after infection, a majority of the cell population survived acute HIV infection, with the expression of p17 and p24 decreasing below the limit of detection by 12 days postinfection. This system may prove useful for examining the neuropathology and neurobiology of acute, persistent, or latent HIV infection of the developing human nervous system.

Non-cytocidal natural variants of human immunodeficiency virus isolated from AIDS patients with neurological disorders

To understand the mechanism of HIV-mediated neuropathology five viral isolates were obtained from four AIDS cases with central nervous system manifestations as the primary involvement. The isolates were identified as HIVs by antigenic cross-reactivity and nucleic acid hybridizations to HIV-specific antibodies and DNA probes. The replication and cytopathic properties of these isolates were studied and compared with lymphadenopathy-associated virus (HIVLAV). All isolates had replication competence equivalent to LAV, but four isolates did not kill T4 (CD-4) cells. This isolation of non-cytocidal natural variants of HIV raises the possibility that in some AIDS cases the neurological disorders might be due to HIV variants that are non-cytocidal to T4 cells. The results also indicate that virus replication and cytotoxicity are not always concordant functions in HIV.

Nucleotide sequence analysis of equine infectious anemia virus proviral DNA

The nucleotide sequence of the integrated form of the genome of the equine infectious anemia virus was determined. By comparison with LTR sequences of other retroviruses, signals for the control of viral gene transcription and translation could be identified in the EIAV LTR. Open reading frames for gag and pol genes were identified and their sequences matched very closely to those determined previously by others. However, in the present study, the pol gene reading frame was open throughout its entire length. The open reading frame for the env gene product was constructed from the sequences of two independent EIAV clones. Thus, a noninfectious genomic-length clone was shown to contain a frameshift mutation approximately in the middle of the presumed env gene coding sequence, whereas the sequence of another clone was open in this region. The deduced amino acid sequences of the EIAV gag and pol products showed closer evolutionary relationships to those of known lentiviruses than to other retroviruses. There was also partial sequence homology between predicted env gene products of EIAV, visna virus, and HTLV-III/LAV. Sequences analogous to the sor region of other lentiviruses could not be identified in our EIAV clone. A short open reading frame at the 3' end of the genome that overlapped env but not the 3' LTR was present but lacked significant sequence similarity to the 3' open reading frames of other lentiviruses. Thus, the sequence and general structure of EIAV most closely resemble those of known lentiviruses.

Neurological complications in AIDS

Neurological complications in the acquired immunodeficiency syndrome (AIDS) are an important aspect of this new infectious disease and occur frequently. The existence of neurotropic variants of the human immunodeficiency virus (HIV), the causative agent of AIDS, is probable. Direct infection of the nervous system with HIV leads to a variety of HIV-induced neurological syndromes, the AIDS dementia complex being its most important representative. In addition, a large number of opportunistic infections and malignancies of the nervous system may complicate the disease. Major aspects of the clinical pictures, rational diagnostic approaches and treatment options of the most important sequels of HIV infection of the nervous system are discussed.

Intra-blood-brain barrier synthesis of human immunodeficiency virus antigen and antibody in humans and chimpanzees

The presence of human immunodeficiency virus (HIV) antigens in cerebrospinal fluid (CSF) was associated with progressive encephalopathy in adult and pediatric patients with acquired immunodeficiency syndrome (AIDS). HIV antigen was detected in CSF from 6 of 7 AIDS patients with progressive encephalopathy. By contrast, HIV antigen, whether free or complexed, was detected in CSF from only 1 of 18 HIV antibody seropositive patients without progressive encephalopathy and from 0 of 8 experimentally infected chimpanzees without clinical signs. Intra-blood-brain barrier synthesis of HIV-specific antibody was demonstrated in the majority of patients with AIDS (9/12) or at risk for AIDS (8/13) as well as in the experimentally infected chimpanzees, indicating HIV-specific B-cell reactivity in the brain without apparent neurological signs. In 6 of 11 patients with HIV infection, antibodies synthesized in the central nervous system were directed against HIV envelope proteins. Active viral expression appears to be necessary for both the immunodeficiency and progressive encephalopathy associated with HIV infection.

Dual infection of the central nervous system by AIDS viruses with distinct cellular tropisms

Human immunodeficiency virus (HIV) is the causative agent of the acquired immune deficiency syndrome (AIDS). A large number of AIDS patients show evidence of neurologic involvement, known as AIDS-related subacute encephalopathy, which has been correlated with the presence of HIV in the brain. In this study, two genetically distinct but related viruses were isolated from one patient from two different sources in the central nervous system: brain tissue and cerebrospinal fluid. Both viruses were found to replicate in peripheral blood lymphocytes, but only virus from brain tissue will efficiently infect macrophage/monocytes. The viruses also differ in their ability to infect a brain glioma explant culture. This infection of the brain-derived cells in vitro is generally nonproductive, and appears to be some form of persistent or latent infection. These results indicate that genetic variation of HIV in vivo may result in altered cell tropisms and possibly implicate strains of HIV with glial cell tropism in the pathogenesis of some neurologic disorders of AIDS.

AIDS and the geriatrician

Ten percent of acquired immune deficiency syndrome (AIDS) cases are in persons over 50 years of age with 25% of these cases in persons over 60, and 4% in persons over 70 years of age. If the present age distribution holds, there will be 27,000 AIDS cases in persons over 50, and 1100 cases in persons over 70 years of age, by 1991. Older persons are more likely to acquire AIDS through blood transfusions than to homosexual exposure or drug abuse. Changes in the management of blood products will benefit older persons. The nearly 1 million elderly homosexual men, who have been sheltered from the virus by their pattern of sexual activity, will face greater risks as the prevalence of the virus and the age of the carriers increases. The underappreciated neurological consequences of human T-cell lymphotrophic virus type III (HTLV-III) infection, subacute encephalitis, vacuolar myelopathy, and psychiatric disorders will be of particular interest to geriatricians who are often consulted to evaluate neurological dysfunction. Geriatricians will need to become familiar with the spectrum of HTLV-III infection and prepared to counsel patients and extended-care facilities.

CSF protein and cellular profiles in various stages of HIV infection related to neurological manifestations

CSF protein and cellular profiles were studied in 28 HIV-infected patients. Twenty of them had neurological complaints, but only 6 patients had objective neurological deficits such as dementia, ocular motility disorders or polyneuropathy. The serum/CSF HIV antibody ratio was on average lowest in acquired immunodeficiency syndrome (AIDS) (4 patients) and highest or almost normal in lymphadenopathy syndrome (LAS) (11) and asymptomatic seropositivity (ASX) (7), while it varied between these extremes in AIDS-related complex (ARC) (6). However, low values of the ratio were also found in the HIV-infected patients free of neurological symptoms and even in one ASX patient. The CSF IgG index was elevated in all these 4 general stages of HIV infection without any significant differences between them. The CSF/serum albumin ratio was slightly increased in patients with neurological deficits, but this ratio showed no association with any other clinical factor analysed. CSF leucocytes were increased in the early stages of the disease, but later the cellular reaction subsided. HIV was isolated from post mortem brain tissue of two AIDS patients and from the CSF of one of them. The results suggest increased intrathecal virus-specific IgG synthesis, not only in patients with neurological deficits and at advanced stages of infection, but also in neurologically symptom-free subjects and at early infection. The lack of correlation between the increased virus-specific IgG synthesis within the CNS and the presence of neurological symptoms suggests that neurologically "silent" areas of brain white matter are often affected in HIV infection.

Acquired immunodeficiency syndrome (AIDS)

The Acquired Immunodeficiency Syndrome (AIDS), caused by the human immunodeficiency virus (HIV), also called the human T-lymphotropic virus type III/lymphadenopathy-associated virus [HTLV-III/LAV], has affected over 23,000 people; more than half of those with the disease have died. The actual case fatality rate approaches 100%. AIDS affects all groups and classes of people, although some are at special risk. Distribution of the disease is worldwide. The illness' effects on the body are widespread; of special interest are the ophthalmologic manifestations. The eye may be infected by various viruses (cytomegalovirus, varicella-zoster virus, herpes simplex virus or HIV itself), toxoplasma gondii, candida sp, cryptococcus neoformans, M. tuberculosis, or M. avium-intracellulare. Kaposi's sarcoma may affect the eye as well. Retinal vascular abnormalities (e.g., cotton-wool spots, vasculitis) are not uncommon in AIDS. The syndrome may present with neuro-ophthalmologic manifestations. No effective treatment for the illness is currently available, although several hold promise and there is hope for an AIDS vaccine. Prevention of infection through reduction of risks appears to be the only defense against AIDS at this time.

HIV antigen in the brains of patients with the AIDS dementia complex

Human immunodeficiency virus infection was identified immunohistochemically in the brains of 8 patients with acquired immune deficiency syndrome dementia complex. Using a monoclonal antibody against a structural viral protein (p25), infection was detected in white matter and basal ganglia in a distribution paralleling that of the major neuropathological abnormalities. Viral antigen was identified principally in perivascular and parenchymal macrophages and in multinucleated cells of macrophage origin that were identified morphologically and by immunocytochemical staining for acid phosphatase isozyme. In 4 of the 8 patients, viral antigen was also detected in acid-phosphatase-negative, process-bearing neuroglial cells; in 2 patients, antigen was detected in basal ganglion cells that were morphologically consistent with neurons and in alkaline-phosphatase-positive cells with elongated nuclei that were most likely of endothelial origin.

Expression of human immunodeficiency virus in cerebrospinal fluid of children with progressive encephalopathy

The retrovirus that causes acquired immune deficiency syndrome (AIDS) is now designated the human immunodeficiency virus (HIV). The cerebrospinal fluid (CSF) of 27 children with HIV infection was assayed for intra-blood-brain barrier (IBBB) synthesis of HIV-specific antibodies and for the presence of HIV antigen. In this cohort, 11 children had a progressive encephalopathy (PE), 9 had a static encephalopathy (SE), and 7 had normal neurological findings (N). IBBB synthesis of HIV-specific antibodies was identified (using matched serum and CSF specimens) in 7 of 11 children with PE, 4 of 9 children with SE, and 2 of 7 children with N. HIV antigen was found (using a highly sensitive solid-phase enzyme immunoassay) in the CSF of 8 of 11 children with PE, none of the children with SE, and none of the 7 children with N. On the basis of these data, we conclude that: IBBB synthesis of HIV antibodies indicates invasion of the central nervous system but may reflect prior or current infection; and HIV antigen in CSF indicates viral expression and correlates with the occurrence of PE. These findings strongly implicate HIV as the causative agent of PE in these children. The assay for HIV antigen in the CSF may be of value in determining the prognosis of children with HIV infection and for evaluating the efficacy of therapeutic agents against this retrovirus.

Evidence for different immune responses to HIV in CSF and serum?

A case of acquired immune deficiency syndrome (AIDS) and a case of AIDS-related complex (ARC) are described. In both instances comparative Western blot analysis of cerebrospinal fluid (CSF) and serum samples show evidence of qualitative differences in antibody-binding patterns to viral polypeptides.

Cytomegalovirus encephalitis in patients with acquired immunodeficiency syndrome: an autopsy study of 30 cases and a review of the literature

The pathology of cytomegalovirus (CMV) encephalitis was studied at autopsy in thirty patients with acquired immunodeficiency syndrome. Lesions could be segregated into five major categories: microglial nodules, isolated inclusion-bearing cells, focal parenchymal necrosis, necrotizing ventriculo-encephalitis, and necrotizing radiculo-myelitis. Microglial nodules and CMV inclusions were present in all brains. Microglial nodules were found with variable frequency and had greatest density in subcortical grey matter. Only a small percentage (average, 6.5 per cent) contained CMV inclusion-bearing cells. Isolated inclusion-bearing cells unaccompanied by microglial nodules or inflammatory infiltrates were seen in half the patients. CMV inclusions were identified in capillary endothelia, astrocytes, and neurons. Focal CMV necrosis, ventriculo-encephalitis, and radiculo-myelitis were less frequent. The presence of CMV inclusions in capillary endothelia suggests a vascular portal of entry for the virus into the central nervous system. The diffuse ependymal and/or subpial distribution of CMV in several patients suggests additional dissemination via the cerebrospinal fluid. Isolated inclusion-bearing cells may reflect the relative nonpermissiveness of surrounding central nervous system parenchyma for CMV infection.

MRI appearance of AIDS subacute encephalopathy

A case of biopsy documented subacute encephalopathy of AIDS was evaluated by CT and MRI. CT scanning revealed ventriculomegaly and ill-defined nonspecific periventricular white matter hypodensities. MRI, however, demonstrated extensive unequivocal diffuse white matter disease as the cause of the ventriculomegaly. MRI findings in this patient support the preliminary suggestion that MRI is more useful than computed tomography (CT) in demonstrating AIDS subacute encephalopathy.

Detection of HTLV-III/LAV-specific IgG and antigen in bronchoalveolar lavage fluid from two patients with lymphocytic interstitial pneumonitis associated with AIDS-related complex

Lymphocytic interstitial pneumonitis, a disorder of unknown cause, has been described in association with infection by the retrovirus human T lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV). This report describes the isolation of HTLV-III/LAV in bronchoalveolar lavage fluid and the quantitation of antibodies directed against HTLV-III/LAV in bronchoalveolar lavage fluid and peripheral blood of two patients with lymphocytic interstitial pneumonitis associated with acquired immune deficiency syndrome-related complex. The ratio of the concentrations of HTLV-III/LAV-specific IgG to total IgG in the bronchoalveolar lavage fluid of both patients was higher than that of the peripheral blood. These findings are consistent with the hypothesis that lymphocytic interstitial pneumonitis is sometimes associated with HTLV-III/LAV infection of pulmonary tissue that evokes a specific humoral immune response locally in the lung.

Development of antiretroviral therapy for the acquired immunodeficiency syndrome and related disorders. A progress report

We review the rationale for, and progress in, the development of antiviral therapy for the acquired immunodeficiency syndrome (AIDS). A consideration of the replicative cycle of the human immunodeficiency virus (HIV) can lead to the identification of several steps that represent potential targets for antiretroviral therapy, and several substances that can inhibit the replication of HIV in vitro have already been identified. The 2',3'-dideoxynucleosides are a class of nucleoside analogues in which the 3'-hydroxy group is modified so that it cannot form phosphodiester linkages for nucleic acid chains. Some are potent in vitro inhibitors of HIV replication, possibly acting as chain terminators of viral DNA during reverse transcription. One of these dideoxynucleoside analogues, 3'-azido-2',3'-dideoxythymidine (AZT), has now been administered for up to 18 months to patients with AIDS. The drug has been shown to improve immunologic function, to reverse, at least partially, HIV-induced neurologic dysfunction in some patients, and to improve certain other clinical abnormalities associated with AIDS. The principal toxic effect associated with AZT is dose-dependent suppression of bone marrow, resulting particularly in anemia and leukopenia; however, most patients in whom this toxic effect occurs can subsequently tolerate a lower dose of the drug. The demonstration that AZT can be beneficial in patients with AIDS has removed some of the uncertainty about the rationale for an antiretroviral intervention in HIV infection.

Strategies for antiviral therapy in AIDS

The retrovirus that causes AIDS has revealed enough of its life history for a variety of therapeutic strategies to be apparent. Some of these are suitable for immediate application in clinical trials or have already yielded positive results in some patients.

Acquired immunodeficiency syndrome of childhood

AIDS of childhood is reviewed in this timely article, including care of the child with infectious complications, and other current and future management concerns.

Developmental abnormalities in children with acquired immunodeficiency syndrome (AIDS): a follow-up study

Developmental abnormalities in 16 pediatric patients with AIDS or AIDS-Related Complex (ARC) were previously described. Neurological deterioration was in evidence on follow-up in 9 of the children, 5 died since the original assessments were performed. Ten patients were reevaluated 14 months later by cognitive testing. Two showed greater progress than expected on the basis of earlier test results; 6 showed the expected level of developmental progress; and the remaining 2 showed regression in cognitive functioning. All patients who exhibited regression in their developmental course showed deterioration in their neurological examinations. Developmental progression was noted in some children who on follow-up serial examinations exhibited a clinically deteriorating neurological picture. Pediatric AIDS patients manifest variable neurodevelopmental courses. As a result, rehabilitative intervention services must be tailored to meet individual needs.

Response of human-immunodeficiency-virus-associated neurological disease to 3'-azido-3'-deoxythymidine

Four patients with human-immuno-deficiency-virus-associated neurological disease were treated with 3'-azido-3'-deoxythymidine (AZT). Three (two with chronic dementia, and one with chronic dementia and peripheral neuropathy) improved as assessed by clinical examination, psychometric tests, nerve conduction studies, and/or positron emission tomography; there was no improvement in the fourth patient who presented with paraplegia. These results support the hypothesis that certain AIDS-virus-associated neurological abnormalities are reversible by antiretroviral chemotherapy.

Human immunodeficiency virus (HIV) infection in brains with AIDS-related leukoencephalopathy

In addition to central nervous system (CNS) opportunistic infections and neoplasms, patients with acquired immunodeficiency syndrome (AIDS) develop unexplained dementia and encephalopathy and degeneration of the white matter. We studied autopsied brains from 20 adult patients who expired from AIDS to determine the relationship of human immunodeficiency virus (HIV) infection to white matter lesions and to clinical findings. In four patients with dementia/encephalopathy and abnormalities of the white matter, there was evidence of HIV infection as shown by in situ hybridization. In contrast, the remaining 16 patients who had no evidence of white matter degeneration revealed no hybridization to the HIV probe. The cells infected with HIV included endothelial cells, perivascular macrophages/monocytes, and multinucleated giant cells and were found in or adjacent to white matter degeneration. These results demonstrate a correlation between HIV-infected cells and AIDS leukoencephalopathy and provide further evidence for HIV-related dementia/encephalopathy.

Brain pathology induced by infection with the human immunodeficiency virus (HIV). A histological, immunocytochemical, and electron microscopical study of 100 autopsy cases

Neuropathological examination of brain tissue of 100 patients with infection by the human immunodeficiency virus (HIV), including 98 with clinically manifest acquired immune deficiency syndrome (AIDS), revealed distinct multifocal-disseminated and diffuse brain tissue lesions, which can be regarded as HIV-induced brain lesions: multifocal giant cell encephalitis (MGCE; 4) and progressive diffuse leukoencephalopathy (PDL; 25). These lesions were found in 38 brains, and in 17 in absence of infectious, necrotizing or inflammatory changes of other types. In 13 brains, a combination of MGCE with PDL was seen, suggesting a spectrum of HIV-induced brain lesions. MGCE is characterized by perivascular accumulations predominantly of rod cells, monohistiocytes and macrophages, all of which are strongly labeled with a monoclonal antibody to macrophages. Most conspicuous are multinucleated giant cells which are also labeled by anti-macrophage antibody, and which can be regarded as evidence of the local presence of HIV, as confirmed by electron microscopical detection of HIV particles in four MGCE brains, and by immunocytochemical detection of HIV proteins in two MGCE brains. PDL is characterized by a triad: diffuse myelin loss, astroglial proliferation, and infiltration by mono- and multinucleated macrophages. HIV-induced lesions can be morphologically differentiated from histopathological brain lesions known in immunosuppression, including what is called here nodular encephalitis ["subacute encephalitis" of the literature, in most cases attributable to cytomegalovirus (CMV) or toxoplasmosis], by their characteristic histopathology including the hallmark presence of multinucleated giant cells, by direct immunocytochemical and electron microscopical demonstration of HIV in the lesions, and by the absence of opportunistic agents (bacteria, fungi, Toxoplasma, CMV, HSV or papovaviruses). Diffuse poliodystrophy (diffuse proliferation of astroglia with swollen nuclei, occasionally minor neuronal loss and rod cell proliferation) was found in the cerebral cortex and other gray matter in half of all brains, including cases with gyral atrophy, and may be another correlate of HIV damage to the brain. Morphological delineation of HIV-induced brain lesions is a necessary prerequisite for a meaningful clinical definition of HIV-induced cerebral disease.

A human T-cell line resistant to cytopathic effects of the human immunodeficiency virus (HIV)

Infection of human helper T lymphocytes with the human immunodeficiency virus (HIV) results in a rapid induction of cytopathic effects and cell lysis. We isolated a variant of the human T-lymphoblastoid cell line, CEM, that is fully susceptible to HIV infection but resistant to virally induced cytopathic effects. Exposure of the cells, designated CR-10, to HIV resulted in the expression of viral antigens in 100% of cells within 6-9 days. Virus-infected cells remained fully viable and could be cultivated under standard culture conditions for a desired period of time. Parental CEM cells died within 9-12 days after HIV infection. Proviral DNA could be detected in the HIV-infected CR-10 cells by Southern blot and molecular hybridization 4-5 days after infection; the relative amount of proviral DNA reached maximum at Days 6-10 and remained stable during an 8-month follow-up period. Virus production by HIV-infected CR-10 cells was documented by electron microscopy and detection of reverse transcriptase activity in cell culture supernatants. HIV-infected CR-10 cells exhibited a down modulation of the OKT-3, OKT-4, OKT-4A, OKT-8, and OKT-11 T-cell surface markers, but not of the OKT-9 (transferrin receptor). One of the HIV persistently infected CR-10 cell clones has been kept in continuous culture for over 8 months. During this period, the cells remained fully viable, 100% positive for HIV antigens, and negative for most of the T-cell surface markers tested and continued to produce biologically active HIV. The CR-10 and HIV-infected CR-10 cell lines will be useful in studies on the biology of HIV and in the isolation and large-scale propagation of this virus.

Hypothesis: AIDS is an autoimmune disease directed at the immune system and triggered by a lymphotropic retrovirus

By attaching to the CD4 (T4) molecule of the helper-inducer lymphocyte, the human immunodeficiency virus (HIV) envelope imitates the normal ligand for this receptor, namely, an invariant component of the class II major histocompatibility antigen (MHC). Depending on the degree of antigen mimicry, the normal immune response to retrovirus envelope would be expected to recognize and cross-react to self-MHC. By disguising as "self" the virus then provokes an autoimmune attack of class-II-bearing cells and an anti-idiotypic response to the CD4 antigen. As a consequence of this immune response to virus infection, communication between CD4 lymphocytes and antigen-processing cells becomes blocked, resulting in progressive disruption of antigen recognition, immunodysregulation, and dysfunctional responses of catastrophic proportion. If this hypothesis gains support, then there are profound implications for prevention and treatment.

Isolation of the human T-cell leukemia/lymphotropic virus type III from aqueous humor in two patients with perivasculitis of the retinal vessels

The human T-cell leukemia/lymphotropic virus type III (HTLV-III) has been isolated from aqueous humor in two patients with perivasculitis of the peripheral retinal vessels, an AIDS-related ocular manifestation. Both patients had antibodies to HTLV-III and although they presented with herpes zoster ophthalmicus, they did not present other symptoms known to be associated with HTLV-III infection. The isolation of HTLV-III from aqueous humor in these two patients with retinal perivasculitis suggests that the virus itself may play a role in the etiology of this ocular sign. The presence of infectious HTLV-III in the anterior chamber further emphasises the necessity to discard corneas from HTLV-III infected donors.

Stimulatory and inhibitory influences of human immunodeficiency virus on normal B lymphocytes

B-lymphocyte dysfunction is a characteristic feature of the acquired immunodeficiency syndrome (AIDS) and of the AIDS-related complex. The aim of the present study was to further examine the influences exercised by the human immunodeficiency virus (HIV; formerly called human T-lymphotropic virus type III or lymphadenopathy-associated virus, HTLV-III/LAV) on normal human B lymphocytes. An unfractionated protein preparation, made from HIV purified by density gradient centrifugation, was previously shown to induce differentiation of normal human B lymphocytes into immunoglobulin-secreting cells. In the present analyses, this B-lymphocyte response peaked on day 6 or 7 after culture initiation and was found to be independent of the requirement for monocytes but to require T cells. Responses could also be elicited in cultures of purified B cells by the addition of T cells that had been exposed to HIV antigen. Inhibitors of protein synthesis (puromycin and cycloheximide) abrogated the responses. In contrast to its stimulatory effects, the same virus preparation was previously shown to inhibit polyclonal responses that are normally elicited in peripheral blood lymphocyte cultures by a T-dependent stimulus (pokeweed mitogen) and T-independent stimulus (Epstein-Barr virus). The present studies suggest that the inhibitory effects of the HIV antigen studied herein are targeted primarily at the B lymphocytes. The role of T lymphocytes in the HIV antigen-mediated inhibitory effects, although demonstrated, could not be conclusively established as an essential pathway. These findings elucidate mechanisms by which components of HIV exert stimulatory as well as inhibitory effects on human B lymphocytes and thereby lead to the dysfunction of these cells in HIV infection.

Neurological complications and concomitants of AIDS

A survey of the literature of neurological manifestations associated with the acquired immune deficiency syndrome (AIDS) shows a broad disease spectrum affecting approximately one third of the patients in large hospital series. The complications include focal cerebral lesions caused by abscesses, lymphomas, leucoencephalopathy or infarcts as well as encephalitis, meningitis and myelitis. Most opportunistic infections of the central nervous system presumably are caused by toxoplasma gondii, cytomegalovirus and cryptococcus neoformans. One tenth of all patients have neurological disease as their initial symptom of AIDS. The diagnosis should always be considered in patients at risk and in males with an unusual neurological history or with a peculiar CT scan of the brain. Besides the opportunistic complications of AIDS, LAV/HTLV-III itself probably attacks the nervous system and gives rise to concomitant lesions of the long tracts of the spinal cord with ataxia, paresis and spasticity and to subacute encephalopathy and peripheral nerve abnormalities as well.

Effects of mutations within the 3' orf open reading frame region of human T-cell lymphotropic virus type III (HTLV-III/LAV) on replication and cytopathogenicity

Mutations that eliminated the ability of the human T-cell lymphotropic virus type III to produce the 27-kilodalton 3' orf product did not eliminate the ability of the virus to replicate in and kill T4+ cells. A mutant carrying a mutation that deleted carboxy-terminal sequences from the envelope gene as well as the 3' orf sequences retained the ability to kill T4+ lymphocytes, but had a retarded replication rate.

Neuroleukin: a lymphokine product of lectin-stimulated T cells

Neuroleukin is a lymphokine product of lectin-stimulated T cells that induces immunoglobulin secretion by cultured human peripheral blood mononuclear cells. Neuroleukin acts early in the in vitro response that leads to formation of antibody-secreting cells, but continued production of immunoglobulin by differentiated antibody-secreting cells is neuroleukin-independent. Although the factor is not directly mitogenic, cellular proliferation is a late component of the response to neuroleukin. Neuroleukin does not have B-cell growth factor (BCGF) or B-cell differentiation factor (BCDF) activity in defined assays. Neuroleukin-evoked induction of immunoglobulin secretion is both monocyte- and T-cell-dependent.

Molecular cloning and physical characterization of integrated equine infectious anemia virus: molecular and immunologic evidence of its close relationship to ovine and caprine lentiviruses

Molecular clones of the integrated form of the genome of equine infectious anemia virus (EIAV), the etiologic agent of a naturally occurring, worldwide disease of horses, were obtained. The restriction map of a full-length genome was determined. Additional evidence for the close evolutionary relationship between EIAV and a prototype lentivirus (caprine arthritis encephalitis virus) was acquired by Southern blotting and immunological analyses. An interspecies radioimmunoassay was developed in which EIAV and ovine and caprine lentiviruses could be detected equally well. These studies make available precisely defined reagents to pursue the study of the mechanisms of pathogenesis of lentiviral induced diseases.

Cerebral granulomatous angiitis associated with isolation of human T-lymphotropic virus type III from the central nervous system

A 42-year-old homosexual man without evidence of immune deficiency developed cerebral granulomatous angiitis in association with the isolation of human T-lymphotropic virus type III (HTLV-III) from brain tissue and cerebrospinal fluid. This syndrome may be an additional neurological sequela of HTLV-III infection.

Hypothesis: AIDS encephalopathy is due to primary and persistent infection of the brain with a human retrovirus of the lentivirus subfamily

Recent evidence has demonstrated that human T-lymphotropic retroviruses are present in the brain of patients with acquired immunodeficiency syndrome (AIDS). Studies by neuropathological, ultrastructural and nucleic acid hybridization techniques indicate that these human retroviruses are neurotropic as well as lymphotropic. Striking similarities to the animal retroviruses of the lentivirus subfamily provide a rationale to implicate these human retroviruses (lentiviruses) in the pathogenesis of AIDS encephalopathy.

Immunohistochemical identification of HTLV-III antigen in brains of patients with AIDS

Human T-cell lymphotropic virus type III (HTLV-III) has been isolated from neural tissues and cerebrospinal fluid (CSF) of patients with neurological syndromes associated with the acquired immune deficiency syndrome (AIDS) and the virus may be directly involved in the pathogenesis of the syndromes. To detect HTLV-III antigen in neural tissues from patients with AIDS, immunoperoxidase studies using a goat anti-HTLV-III serum were performed on frozen tissue sections of brain, spinal cord, and nerve from 13 patients with AIDS or HTLV-III-related neurological syndromes. HTLV-III was cultured from neural tissues or CSF in 11 of 13 of these patients. HTLV-III antigen was detected in the brains of 5 patients with AIDS and in none of the 13 non-AIDS control subjects. Rare positively stained cells were seen, frequently associated with capillaries and often located near microglial nodules. Morphologically, the cells resembled monocyte/macrophages and were found most frequently in the cortex of the frontal, temporal, and parietal lobes. These results provide further evidence that the subacute encephalitis of AIDS is associated with central nervous system infection by HTLV-III and that monocyte/macrophages are among the infected cell populations.