Association between HIV-specific T helper responses and CTL activities in pediatric AIDS.

We examined the relationship between the profile of HIV-specific T helper (Th) cell responses, cytotoxic T lymphocyte (CTL) activity, HIV viral load, and CD4(+) T cell counts during longitudinal studies in children with perinatal HIV infection. Patients with AIDS demonstrated undetectable or low levels of HIV-specific Th and CTL activities, and exhibited almost exclusively Th0 type of responses with low IFN-gamma and IL-4 production. The levels of IL-2 expression in the envelope (env) peptide-stimulated peripheral blood mononuclear cells were increased in children with a slowly progressive disease, concomitant with higher numbers of CD45RO(+) memory T cells and increased proportions of Th1 clones. In these patients, high levels of env peptide-specific IL-2 expression correlated with increases in HIV-specific CTL responses, whereas a delay in the generation of HIV-specific CTL activity was associated with lower IL-2 production and elevated Th2 responses. Patients with slow disease progression produced higher levels of beta-chemokines than those detected in children with AIDS. These results suggest that an impaired development of HIV-specific cellular responses and inhibition of T cell differentiation during infancy are associated with fast disease progression. They also point to a protective role of noncytotoxic antiviral activity that might complement HIV-specific CTL responses in children with a slowly progressive disease.

Combination therapy with efavirenz, nelfinavir, and nucleoside reverse-transcriptase inhibitors in children infected with human immunodeficiency virus type 1. Pediatric AIDS Clinical Trials Group 382 Team.

BACKGROUND: Consistent long-term viral suppression has been difficult to achieve in children with human immunodeficiency virus type 1 (HIV-1) infection. We tested the safety and antiviral efficacy of a novel combination consisting of efavirenz, nelfinavir, and one or more nucleoside reverse-transcriptase inhibitors in 57 children previously treated with only nucleoside reverse-transcriptase inhibitors. METHODS: The children were monitored for 48 weeks after the initiation of therapy. We assessed plasma concentrations of efavirenz and nelfinavir, plasma HIV-1 RNA levels, and lymphocyte subpopulations. RESULTS: At base line, the 57 HIV-1-infected children (age range, 3.8 to 16.8 years) had a median of 699 CD4 cells per cubic millimeter and 10,000 copies of HIV-1 RNA per milliliter of plasma. The most common treatment-related effects of at least moderate severity were rash (in 30 percent of children), diarrhea (in 18 percent), neutropenia (in 12 percent), and biochemical abnormalities (in 12 percent). Serious side effects were uncommon. The mean values for the area under the curve for efavirenz and nelfinavir corresponded to expected values. In an intention-to-treat analysis, 76 percent of children had plasma HIV-1 RNA levels of less than 400 copies per milliliter after 48 weeks of therapy and 63 percent had levels of less than 50 copies per milliliter. A high plasma HIV-1 RNA level at base line significantly decreased the likelihood that plasma levels of HIV-1 RNA would become undetectable during treatment. CONCLUSIONS: In HIV-1-infected children who were previously treated with nucleoside reverse-transcriptase inhibitors, the combination of efavirenz, nelfinavir, and nucleoside reverse-transcriptase inhibitors was generally well tolerated and had a potent and sustained antiviral effect.

Protective role of beta-chemokines associated with HIV-specific Th responses against perinatal HIV transmission.

To examine the protective role of cellular immunity in the vertical transmission of HIV, we analyzed HIV-specific IL-2 and CTL responses, as well as beta-chemokine expression in HIV-infected and uninfected infants of HIV+ mothers. Our results showed that HIV envelope (env) peptide-specific IL-2 responses associated with beta-chemokine production were detectable at birth in the majority of uninfected infants of HIV+ mothers. The responses falling to background before the infants were 1 yr old were rarely associated with HIV-specific CTL activity. Conversely, HIV-specific Th and CTL cellular responses were absent at birth in HIV-infected infants. Infants with AIDS-related symptoms exhibited undetectable or very low levels of HIV-specific cellular immunity during the first year of life, whereas those with a slowly progressive disease showed evidence of such immunity between their second and ninth month. The latter group of infected infants tested negative for plasma HIV RNA levels shortly after birth, suggesting lack of intrauterine exposure to HIV. The presence of HIV-specific Th responses at birth in uninfected newborns of HIV+ mothers, but absence of such activities in HIV-infected infants without evidence of intrauterine HIV infection, suggests that in utero development of HIV-specific Th responses associated with beta-chemokines could mediate nonlytic inhibition of infection during vertical transmission of HIV.

Angiocentric CD3(+) T-cell infiltrates in human immunodeficiency virus type 1-associated central nervous system disease in children.

A significant proportion of brain tissue specimens from children with AIDS show evidence of vascular inflammation in the form of transmural and/or perivascular mononuclear-cell infiltrates at autopsy. Previous studies have shown that in contrast to inflammatory lesions observed in human immunodeficiency virus type 1 (HIV-1) encephalitis, in which monocytes/macrophages are the prevailing mononuclear cells, these infiltrates consist mostly of lymphocytes. Perivascular mononuclear-cell infiltrates were found in brain tissue specimens collected at autopsy from five of six children with AIDS and consisted of CD3(+) T cells and equal or greater proportions of CD68(+) monocytes/macrophages. Transmural (including endothelial) mononuclear-cell infiltrates were evident in one patient and comprised predominantly CD3(+) T cells and small or, in certain vessels, approximately equal proportions of CD68(+) monocytes/macrophages. There was a clear preponderance of CD3(+) CD8(+) T cells on the endothelial side of transmural infiltrates. In active lesions of transmural vasculitis, CD3(+) T-cell infiltrates exhibited a distinctive zonal distribution. The majority of CD3(+) cells were also CD8(+) and CD45RO+. Scattered perivascular monocytes/macrophages in foci of florid vasculitis were immunoreactive for the p24 core protein. In contrast to the perivascular space, the intervening brain neuropil was dominated by monocytes/macrophages, microglia, and reactive astrocytes, containing only scant CD3(+) CD8(+) cells. Five of six patients showed evidence of calcific vasculopathy, but only two exhibited HIV-1 encephalitis. One patient had multiple subacute cerebral and brainstem infarcts associated with a widespread, fulminant mononuclear-cell vasculitis. A second patient had an old brain infarct associated with fibrointimal thickening of large leptomeningeal vessels. These infiltrating CD3(+) T cells may be responsible for HIV-1-associated CNS vasculitis and vasculopathy and for endothelial-cell injury and the opening of the blood-brain barrier in children with AIDS.

A newly recognized cause of wheezing: AIDS-related bronchial leiomyomas.

We present two human immunodeficiency virus-infected children who developed wheezing and radiological evidence of pulmonary air trapping due to intra- and peribronchial leiomyomas. At autopsy, leiomyomas were also found in their spleens, which to our knowledge, has never been reported. The smooth muscle tumors were strongly positive for the Epstein-Barr virus, as demonstrated by in situ hybridization to Epstein-Barr virus-encoded ribonucleic acid, confirming the findings of recent investigators and linking these tumors to the Epstein-Barr virus.

Diminished HIV-specific CTL activity is associated with lower type 1 and enhanced type 2 responses to HIV-specific peptides during perinatal HIV infection.

The early development of symptoms and the rapid progression of disease in some vertically infected infants are thought to reflect in part the immaturity of their immune systems. We examined the relationship between HIV-specific CTL activity and the profile of cytokine production induced by mAb to CD3 and HIV envelope (env) peptides P18 and T1 in PBMC derived from 0.6- to 3.6-yr-old children with perinatal HIV infection. Cellular immunity against HIV was demonstrated only during early stages of disease, whereas the responses were either undetectable or at background levels in HIV-infected children with rapidly progressing disease and in uninfected children of HIV+ and HIV- mothers. Levels of IL-2 mRNA in anti-CD3 mAb- and env peptide-induced PBMC varied and were increased in the infected children with high frequencies of HIV-specific CTL precursors. Analysis of IFN-gamma and IL-4 production by CD4+ T cell clones obtained from cultures stimulated with anti-CD3 mAb or the env peptides showed an increased proportion of Th2 and Th0 clones in HIV-infected children with lower HIV-specific CTL activity, whereas children with high CTL activity had increased numbers of Th1 clones. The results of these studies suggest that decreases in CTL activity to the virus might be associated with the induction of a type 2 cytokine response. These findings underline the role of cytokines in the generation of HIV-specific CTL responses and may be important for the development of immunomodulatory and vaccine strategies to interrupt vertical transmission of HIV.

Evidence for B cell-mediated activation of V delta 1+ T lymphocytes during progression of HIV infection.

Progression of HIV-induced immunodeficiency is associated with both B cell activation and an increased proportion of Vdelta1+ T cells in PBL. To examine whether the peripheral expansion of Vdelta1+ cells is driven by activated B cells, we isolated CD19+ PBL from HIV+ individuals at different stages of infection and used them to stimulate Vdelta1+ T cell clones. The Vdelta1+ T cell clones were isolated from HIV+ individuals and selected on the basis of cytotoxic activity and IFN-gamma expression in response to lymphoblastoid cell lines (LCLs) established from patients with AIDS (AIDS-related LCLs) but not LCLs of HIV- donors. Peripheral blood B cells from HIV+ patients induced IFN-gamma expression in these Vdelta1+ clones, and their stimulatory ability was associated with up-regulated expression of the CD38 activation Ag and with a 6- to 10-fold increased spontaneous Ig production. Stimulation of CD19+ PBL from HIV+ individuals with cross-linked anti-CD40 mAb or rgpl20 further augmented induction of IFN-gamma expression in the Vdelta1+ cells. The isolated Vdelta1+ T cell clones expressed the Jdelta1 gene segment, but differed in Vgamma gene segment usage and in the junctional region of TCR-delta chains, indicating Vdelta gene-determined recognition. These results provide evidence that the peripheral expansion of Vdelta1+ cells in HIV infection is associated with phenotypic and functional alterations of B cells, due to chronic activation during progression to AIDS.

Cytokine patterns during progression to AIDS in children with perinatal HIV infection.

Patterns of cytokine expression were analyzed in polyclonal and antigenic responses in children with perinatal HIV infection. Responses of PBL to PMA and A23187 calcium ionophore studied in patients in different stages of HIV infection revealed reduced levels of IL-2 in HIV-infected children beginning before 6 mo of age, and age-dependent increases in expression of IL-4, IL-10, and IFN-gamma. The levels of IL-4, IL-10, and IFN-gamma expression did not differ significantly between HIV-infected and age-matched uninfected children of HIV-seropositive mothers, except for a small reduction in HIV-infected children in late stages of infection. Responses to PHA, HLA alloantigens, HIV envelope peptides T1 and P18, and tetanus toxoid were studied in PBMC derived from asymptomatic and mildly symptomatic HIV-infected children. IL-2, IFN-gamma, IL-4, and IL-5 expression was detected in PHA-stimulated PBMC from all analyzed patients. HIV-infected children who failed to respond to HLA alloantigens, tetanus toxoid, or the envelope peptides had lower numbers of CD4+ cells and expressed, on PHA stimulation, higher levels of IL-4 and IL-5 and lower levels of IL-2 and IFN-gamma than patients who responded to the antigenic stimulation. Results of these analyses suggest that cytokine expression in HIV-infected children depends on the character of the stimuli as well as the phenotype of PBMC, and indicate possible prevalence of Th2 Ag-specific responses during the progression of HIV-induced immunodeficiency.

Pulmonary hypertension and HIV infection: new observations and review of the syndrome.

This report describes the case of a 14-yr-old hemophiliac who died of complications of primary pulmonary hypertension. He was infected with the human immunodeficiency virus. The autopsy disclosed that he also had membranoproliferative glomerulonephritis type III and hepatic cirrhosis, both clinically unsuspected. This is the second report describing the association of membranoproliferative glomerulonephritis type III and primary pulmonary hypertension in an HIV-infected patient and the first to consider cirrhosis as a possible additional element of the syndrome.

Human studies on alcohol and susceptibility to HIV infection.

Here we review existing evidence that alcohol intake may influence the susceptibility to human immunodeficiency virus type 1 (HIV-1) infection and the effect that alcohol may have on accelerating the onset of AIDS after the initial infection. Possible immunological and psychosocial mechanisms to explain the increased incidence of HIV-1 infection in alcoholism are discussed.

Analysis of gamma delta+ T cells in peripheral blood of children with perinatal human immunodeficiency virus (HIV) infection.

The present study examined CD8 antigen expression and variable (V) gene segment usage by T cell receptor (TCR)-gamma delta+ lymphocytes in peripheral blood of symptomatic children with perinatal HIV infection. The relative number of gamma delta+, CD8+ T cells in most of the infected children was higher than that in uninfected children from HIV+ or HIV- mothers and correlated with the immunodeficiency status of the patients. Infected infants and children over 1 year old also showed an increased proportion of V delta 1-J delta 1+ T lymphocytes. CD8 expression on those cells was higher in infected than in uninfected infants and children. Sequence analysis of the delta gene rearrangement of the predominant V delta 1 family in peripheral blood of three HIV+ donors revealed extensive junctional diversity. These results suggest that the V delta skewing in the majority of HIV+ children reflects peripheral expansion of V delta 1-J delta 1+ T lymphocytes early in life, which might be involved in the mechanisms of HIV-induced immunodeficiency.

Alcohol intake increases human immunodeficiency virus type 1 replication in human peripheral blood mononuclear cells.

The effects of alcohol consumption on various T lymphocyte subset functions and on the degree of susceptibility of peripheral blood mononuclear cells (PBMC) to human immunodeficiency virus (HIV) type 1 infection and replication in vitro were investigated. PBMC from 60 HIV-1-seronegative healthy volunteers were studied before and after ingestion of alcohol beverages. After alcohol consumption, there was significantly increased HIV-1 replication (P < .001) in PBMC, as determined by HIV-1 p24 antigen levels in the culture supernatants, than in cultures obtained before alcohol ingestion. There was a decreased ability of lymphocytes, obtained after alcohol consumption, to produce interleukin-2 and soluble immune response suppressor activity after stimulation with concanavalin A. The data show that alcohol ingestion increases HIV-1 replication in human PBMC infected with HIV-1 in cell culture. This may be due to alcohol-induced functional impairment of various subsets of lymphocytes in the peripheral blood. Thus, HIV-1 replication may be augmented by alcohol in HIV-1-infected individuals, and alcohol intake may increase an individual's risk for acquiring HIV-1 infection.

Detection of human immunodeficiency virus type 1 provirus in mononuclear cells by in situ polymerase chain reaction.

BACKGROUND: Studies of human immunodeficiency virus type 1 (HIV-1) infection have attempted to quantitate the viral load correlate it with the degree of immune deficiency. In one study, only about 1 in 10,000 peripheral-blood mononuclear cells (PBMC) expressed HIV-1, but in other studies, at least 1 in 100 CD4-positive cells was infected and harbored the HIV-1 provirus. METHODS: We developed a new, highly sensitive in situ polymerase-chain-reaction (PCR) method that amplifies selected genetic regions within intact single cells. We used this technique to determine the proportion of PBMC carrying HIV-1 provirus in infected patients in different stages of disease. RESULTS: None of the PBMC from 11 HIV-1--seronegative patients were found to be positive for HIV-1 provirus by the in situ PCR method. In 56 patients infected with HIV-1, the percentage of PBMC with HIV-1 ranged from 0.1 percent to 13.5 percent. The mean percentage of infected mononuclear cells was greater in 13 patients with persistent generalized adenopathy (mean, 6.6 percent) and 19 with the acquired immunodeficiency syndrome (Stages IV-A to IV-C) (4.6 percent) than in 19 patients with asymptomatic HIV-1 infection (0.9 percent) (P less than 0.001). However, in five patients with Kaposi's sarcoma (Stage IV-D), an average of only 1.6 percent of mononuclear cells were infected. CONCLUSIONS: In HIV-1 infection, the proportion of PBMC that are infected appears to be at least 10 times higher than previously described. It is likely that most infected cells contain HIV-1 provirus in a latent or defective form that was not detected in some earlier studies.

Serologic evidence of subclinical pertussis in immunized children.

Incidental to a vaccine study involving 783 immunized children conducted at two study sites, inner city children had significantly higher geometric mean pertussis agglutinin titers compared with suburban children just before the fourth dose of diphtheria-tetanus-whole cell pertussis vaccine (47 vs. 25; P less than 0.001). Higher titers in the inner city were correlated with residence in census tracts where cases of pertussis were reported. Three hundred thirty-two children in a placebo arm of the study who were clinically observed and had paired serum samples taken during a 2- to 4-month period were analyzed for evidence of natural Bordetella infection. Twelve (11%) inner city children and three (1.3%) suburban children had spontaneous 4-fold or greater rises in at least two different pertussis antibodies measured (agglutinin, antitoxin or enzyme-linked immunosorbent assay for IgG to pertussis toxin, IgG and IgA to filamentous hemagglutinin). Eighty percent of these children had IgA to filamentous hemagglutinin. Nine of 12 inner city children with serologic evidence of pertussis lived within 6 blocks of a case of pertussis reported within 1 month of the observed antibody rise in study subjects; none had a household member with pertussis and none had symptomatic disease.