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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human immunodeficiency virus-1 (HIV-1) expression in monocyte-derived macrophages (MDM) infected in vitro is known to be inhibited by lipopolysaccharide (LPS). However, the mechanisms are incompletely understood. We show here that HIV-1 suppression is mediated by soluble factors released by MDM stimulated with physiologically significant concentrations of LPS. LPS-conditioned supernatants from MDM inhibited HIV-1 replication in both MDM and T cells. Depletion of C-C chemokines (RANTES, MIP-1 alpha, and MIP-1 beta) neutralized the ability of LPS-conditioned supernatants to inhibit HIV-1 replication in MDM. A combination of recombinant C-C chemokines blocked HIV-1 infection as effectively as LPS. Here, we report an inhibitory effect of C-C chemokines on HIV replication in primary macrophages. Our results raise the possibility that monocytes may play a dual role in HIV infection: while representing a reservoir for the virus, they may contribute to the containment of the infection by releasing factors that suppress HIV replication not only in monocytes but also in T lymphocytes.
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PMID:C-C chemokines released by lipopolysaccharide (LPS)-stimulated human macrophages suppress HIV-1 infection in both macrophages and T cells. 912 Mar 86

The C-C chemokine RANTES, a T lymphocyte chemoattractant, is considered an important mediator of inflammation, allergy, and host defense against HIV-1 infection. In this study, we investigated the modulation of binding of RANTES to T lymphocytes. Human peripheral blood CD3+ T cells, when freshly isolated from buffy-coat blood, expressed a considerable number of high-affinity binding sites for RANTES. These cells also showed significant chemotactic migration in response to RANTES in vitro. After 6-15 h incubation at 37 degrees C, the binding of RANTES, but not of macrophage inflammatory protein-1 alpha (MIP-1 alpha) or of monocyte chemotactic protein-3 (MCP-3), consistently increased. Scatchard analyses indicated that the number of binding sites for RANTES increased about threefold by 15 h without any change in the affinity. The increase in RANTES binding was no longer detected by 24 h. This increase in the specific binding was mainly attributable to CD4+ T cells and was not associated with increased chemotactic activity of these cells in response to RANTES. Incubation with anti-CD3 antibody for 15 h markedly reduced the binding capability of T cells for RANTES and was associated with decreased chemotactic activity. On the other hand, when T cells were incubated with interleukin-2 (IL-2) for 1 week, the specific binding for all three C-C chemokines, RANTES, MIP-1 alpha, and MCP-3 was markedly increased in comparison to cells cultured in the absence of IL-2. These results suggest that the expression of binding sites on T cells for RANTES is differentially modulated, indicating the existence of novel receptors for RANTES that do not bind MIP-1 alpha.
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PMID:Differential expression of binding sites for chemokine RANTES on human T lymphocytes. 920 92

Approximately 10% of HIV-infected patients, the rapid progressors, progress to AIDS within the first 2 to 3 years of HIV infection. Their biological characteristics are not clearly known. They have a particular phenotype (DR) of major histocompatibility complex class-II. Anti-HIV antibodies are not neutralizing and may even be facilitators in vitro. Progressors CTL responses are also defective and the production of the cytokines, specially the chemokines RANTES, MIP-1 alpha et MIP-1 beta which may have a role in inhibition of cellular infection by HIV, is impaired. In addition, the rapid progressors have high levels of inflammatory markers which suppose a chronic activation of the immune system. The virological findings are more inconsistent. A uniform finding is a high viral load that does not fall dramatically after primary HIV infection. Some rapid progressors may be infected with more rapidly replicating, virulent HIV strains. However, the question regarding the homogeneity or the other characteristics of viral load remains to be resolved.
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PMID:[Characteristics of rapid progressors in HIV infection]. 923 42

Chemokines are a group of small, homologous proteins that regulate leukocyte migration, hemopoiesis, and HIV-1 absorption. We report here the cloning and characterization of a novel murine and human C-C chemokine termed Exodus-2 for its similarity to Exodus-1/MIP-3alpha/LARC, and its chemotactic ability. This novel chemokine has a unique 36 or 37 (murine and human, respectively) amino acid carboxyl-terminal extension not seen in any other chemokine family member. Purified recombinant Exodus-2 was found to have two activities classically associated with chemokines: inhibiting hemopoiesis and stimulating chemotaxis. However, Exodus-2 also had unusual characteristics for C-C chemokines. It selectively stimulated the chemotaxis of T-lymphocytes and was preferentially expressed in lymph node tissue. The combination of these characteristics may be a functional correlate for the unique carboxyl-terminal structure of Exodus-2.
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PMID:Isolation and characterization of Exodus-2, a novel C-C chemokine with a unique 37-amino acid carboxyl-terminal extension. 930 Jun 71

To investigate the role played by chemokines in the natural history of human immunodeficiency virus (HIV) infection, we measured the plasma levels of RANTES. MIP-1 alpha and MIP-1 beta in a cohort of patients with primary HIV-1 infection (PHI) followed longitudinally. The cohort included 17 patients with well-documented history of acute HIV syndrome within two months of the first observation. The mean plasma concentration of RANTES, but not that of MIP-1 alpha or MIP-1 beta, was significantly higher in patients with PHI (192.3 ng/ml) than in five HIV-seronegative controls (8.0 ng/ml) studied during the same time period. Treatment of blood with a cocktail of drugs preventing platelet activation, followed by high-speed centrifugation, reduced the levels of RANTES by approximately 2 logs both in patients and in controls, indicating that the bulk of RANTES was released by platelets, which are known to store this chemokine in their alpha-granules, in the immediate aftermath of blood drawing. No correlation was seen between the levels of RANTES and the number of HIV genome equivalents in plasma. These data suggest that large amounts of pre-formed RANTES are stored in platelets and, possibly, in other blood cells during the early phases of HIV infection. The possible role of this HIV-suppressive chemokine in the control of viral replication during PHI remains to be established.
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PMID:Increased plasma levels of the C-C chemokine RANTES in patients with primary HIV-1 infection. 941 60

Recently beta-chemokines have been shown to inhibit HIV-1 infection of human macrophages. Here, we show that the beta-chemokines RANTES, MIP-1alpha and MIP-1beta enhance the uptake and cause intracellular destruction of Trypanosoma cruzi trypomastigotes by human macrophages obtained from healthy individuals. The trypanosome enhancing uptake and the trypanocidal effect induced by these beta-chemokines in human macrophages are abrogated by neutralizing antibodies to RANTES, MIP-1alpha and MIP-beta, whereas irrelevant antibodies of the same class do not affect these parameters. These results indicate that the effects seen are beta-chemokine specific. Pretreatment of human macrophages with RANTES, MIP-1alpha and MIP-1beta induced strong tyrosine phosphorylation of several proteins, suggesting that signal transduction events are involved in enhanced trypanosome uptake and parasite killing. Taken together these results suggest that the beta-chemokines RANTES, MIP-1alpha and MIP-1beta, might play a beneficial role in parasite clearance and destruction in individuals infected with T. cruzi. Alternatively, these three beta-chemokines may play a beneficial role in individuals concurrently infected with T. cruzi and HIV-1.
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PMID:Beta-chemokines that inhibit HIV-1 infection of human macrophages stimulate uptake and promote destruction of Trypanosoma cruzi by human macrophages. 944 40

Prevention of sexually transmitted HIV infection was first investigated in non-human primates by mucosal immunization via the rectal, vaginal or male urethral route. This was compared with subcutaneous targeted iliac lymph node (TILN) and systemic intramuscular immunization in non-human primates. TILN immunization elicited the most consistent mucosal sIgA and IgG antibody response in the rectum, vagina, urine and seminal fluid, as well as in blood. Both mucosal and TILN immunization induced a specific CD4+ T cell proliferative response in the iliac lymph nodes which drain these mucosal surfaces, and in the splenic and circulating T cells. In the next experiment macaques were immunized by the TILN route with SIV gp120 and p27 in alum. Rectal mucosal challenge with SIVmac 32H J5 molecular clone (or cell-free virus) induced total protection in four out of seven macaques, compared with infection in 13 of 14 unimmunized macaques or immunized by other routes (p = 0.025). The remaining three macaques immunized by the TILN route showed either decrease in viral load (> 90%) or transient viraemia, indicating that all seven TILN immunized macaques showed total or partial protection of rectal transmission by SIV (p = 0.001). Protection was associated with significant increase in the iliac lymph nodes IgA antibody secreting cells to p27 (p < 0.02), CD8-suppressor factor inhibiting replication of SIV in CD4+ T cells (p < 0.01) and the chemokines RANTES and MIP-1 beta (p < 0.01). We suggest that administration of gp120 and p27 by the TILN route may elicit protective B and T cell immunity which can significantly prevent rectal transmission of SIV or HIV.
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PMID:Protective mucosal immunity elicited by targeted lymph node immunization with a subunit SIV envelope and core vaccine in macaques. 955 79

The plasma levels of HIV-1 RNA, tumor necrosis factor alpha (TNF-alpha), soluble receptors type II of TNF-alpha (sTNF-alpha RII), soluble receptors of interleukin-4 (sR IL-4), interleukin-6 (IL-6), soluble receptors of interleukin-6 (sR IL-6), granulocyte macrophage colony stimulating factor (GM-CSF), soluble receptors of GM-CSF (sR GM-CSF), RANTES, MIP-1 alpha and MIP-1 beta were measured in 80 HIV-infected patients. All patients had not been treated previously with antiretroviral drugs and did not present a recent history of opportunistic infection. A statistically significant correlation was found between HIV-1 RNA and TNF-alpha (p = 0.005) or sTNF-alpha RII levels (p < 0.001). RANTES and MIP-1 alpha levels did not correlate with HIV-1 RNA. MIP-1 beta levels were correlated with plasma RNA titers in patients with CD4+ T cells < 200 x 10(6)/l (p = 0.03). MIP-1 alpha and sR IL-4 levels were significantly different according to the CD4+ T cell range (p = 0.003 and p = 0.0002, respectively). GM-CSF and sR GM-CSF were undetectable in each case. These data confirm that HIV-1 replication in the plasma is correlated with TNF-alpha levels, but do not show a clear correlation with levels of the chemokines studied.
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PMID:Correlation between plasma levels of cytokines and HIV-1 RNA copy number in HIV-infected patients. 956 79

In this study, the effects were examined of dose and adjuvant of whole-killed gp120-depleted HIV-1 antigen on antibody and cytokine responses in a murine model. Immunization with increasing doses of inactivated HIV-1 antigen in Incomplete Freund's Adjuvant (IFA) resulted in increased production of IL-4 and IgG1 antibody with decreased production of interferon gamma. Immunization with inactivated HIV-1 antigen in Detox PC adjuvant produced TH1 type predominant cytokine patterns along with IgG2a subclass antibody. Higher levels of interferon gamma were associated with immunization with inactivated HIV-1 antigen in Detox PC compared with inactivated HIV-1 in IFA or inactivated HIV-1 in saline. Inactivated HIV-1 antigen in Detox PC adjuvant produced a trend of lower levels of the beta-chemokine MIP-1 alpha compared with inactivated HIV-1 in IFA or saline. Dose and adjuvant play an important role in the type of immune response elicited to a whole-killed HIV vaccine. Low doses of inactivated HIV-1 antigen in Detox PC adjuvant are currently being studied in animal models in order to optimize cell-mediated immunity against HIV infection.
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PMID:Whole-killed gp120-depleted HIV-1 antigen in a murine model for prophylactic vaccination. 956 93

Leukocyte infiltration into the central nervous system (CNS) is a key event in the inflammatory processes of neuroimmunologic diseases. Microglia, resident macrophages of the CNS, may contribute to this process by elaborating chemoattractants that are capable of recruiting leukocytes across the blood-brain barrier. Such factors have been detected in the CNS of animal models of multiple sclerosis and in the brains of human and nonhuman primates with AIDS encephalitis. As the expression of these chemoattractants may play an important role in the initiation and progression of neuroimmunologic diseases, we analyzed expression of the chemokines MIP-1 alpha, MIP-1 beta, MCP-1, and RANTES in human fetal microglial cultures. Unstimulated microglia expressed minimal levels of MIP-1 alpha, MIP-1 beta, and MCP-1, while RANTES was undetectable. In response to LPS, TNF-alpha, or IL-1 beta, both MIP-1 alpha and MIP-1 beta were induced at the mRNA and protein levels in a dose- and time-dependent manner. IFN-gamma did not significantly induce chemokine expression. MCP-1 was detectable in LPS- and cytokine-treated microglia. TGF-beta, a cytokine with down-modulatory effects on other cell types, had little effect on chemokine expression in microglia when used concomitantly before or during treatment with LPS. These results illustrate the ability of certain inflammatory stimuli to induce expression of MIP-1 alpha, MIP-1 beta, and MCP-1 by human fetal microglia. The expression of these chemoattractants may function to recruit inflammatory cells into the CNS during the course of neuroimmunologic diseases and may modulate the ability of HIV to infect the CNS.
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PMID:Cytokine induction of MIP-1 alpha and MIP-1 beta in human fetal microglia. 957 May 66


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