scholarly journals Cross-Reactions between the Cytotoxic T-Lymphocyte Responses of Human Immunodeficiency Virus-Infected African and European Patients

1998 ◽  
Vol 72 (5) ◽  
pp. 3547-3553 ◽  
Author(s):  
Deniz Durali ◽  
Jacques Morvan ◽  
Franck Letourneur ◽  
Doris Schmitt ◽  
Nelly Guegan ◽  
...  

ABSTRACT The great variability of protein sequences from human immunodeficiency virus (HIV) type 1 (HIV-1) isolates represents a major obstacle to the development of an effective vaccine against this virus. The surface protein (Env), which is the predominant target of neutralizing antibodies, is particularly variable. Here we examine the impact of variability among different HIV-1 subtypes (clades) on cytotoxic T-lymphocyte (CTL) activities, the other major component of the antiviral immune response. CTLs are produced not only against Env but also against other structural proteins, as well as some regulatory proteins. The genetic subtypes of HIV-1 were determined for Env and Gag from several patients infected either in France or in Africa. The cross-reactivities of the CTLs were tested with target cells expressing selected proteins from HIV-1 isolates of clade A or B or from HIV type 2 isolates. All African patients were infected with viruses belonging to clade A for Env and for Gag, except for one patient who was infected with a clade A Env-clade G Gag recombinant virus. All patients infected in France were infected with clade B viruses. The CTL responses obtained from all the African and all the French individuals tested showed frequent cross-reactions with proteins of the heterologous clade. Epitopes conserved between the viruses of clades A and B appeared especially frequent in Gag p24, Gag p18, integrase, and the central region of Nef. Cross-reactivity also existed among Gag epitopes of clades A, B, and G, as shown by the results for the patient infected with the clade A Env-clade G Gag recombinant virus. These results show that CTLs raised against viral antigens from different clades are able to cross-react, emphasizing the possibility of obtaining cross-immunizations for this part of the immune response in vaccinated individuals.

Blood ◽  
1994 ◽  
Vol 84 (5) ◽  
pp. 1567-1572 ◽  
Author(s):  
ST Fan ◽  
K Hsia ◽  
TS Edgington

Abstract Cells of monocytic lineage (Mo) persistently infected with human immunodeficiency virus (HIV) have been suspected to be a major reservoir for in vivo transmission of virus to susceptible target cells. Cellular events and mechanisms that upregulate viral gene expression in such cells are important issues. Because the traffic of such cells is central to biodistribution of HIV, we have explored the impact of interaction of endothelium with HIV-1-infected U1 promonocytic cells. Coculturing of U1 with human umbilical endothelial cells (HUVEC) for 24 to 72 hours in the absence of stimulation induced HIV-1 p24 biosynthesis significantly. Antibody-blocking experiments indicated that CD11/CD18 integrins play a role in upregulation of HIV expression elicited by interaction with HUVEC. Engagement of CD11b/CD18 by adherence of U1 to surfaces coated with either the cognate ligand fibrinogen or monoclonal antibody specific for CD11b/CD18 also enhanced p24 biosynthesis. Furthermore, endothelial cells were found to constitutively synthesize and secrete soluble factors that enhanced HIV- 1 synthesis. The enhancing factors, of estimated size 10 to 45 kD, were induced in HUVEC to high levels by monokines or by lipopolysaccharide, resulting in markedly enhanced HIV-1 expression by U1. These endothelial cell-derived HIV-1-enhancing factors consist of, among others, interleukin-6 (IL-6), IL-1 beta, and granulocyte-macrophage CSF (GM-CSF). Our results suggest that activation of HIV biosynthesis in infected Mo via interaction with endothelium may impact significantly on the tissue distribution and pathogenesis of HIV infections.


2001 ◽  
Vol 75 (9) ◽  
pp. 4430-4434 ◽  
Author(s):  
James P. McGettigan ◽  
Heather D. Foley ◽  
Igor M. Belyakov ◽  
Jay A. Berzofsky ◽  
Roger J. Pomerantz ◽  
...  

ABSTRACT Novel viral vectors that are able to induce both strong and long-lasting immune responses may be required as effective vaccines for human immunodeficiency virus type 1 (HIV-1) infection. Our previous experiments with a replication-competent vaccine strain-based rabies virus (RV) expressing HIV-1 envelope protein from a laboratory-adapted HIV-1 strain (NL4–3) and a primary HIV-1 isolate (89.6) showed that RV-based vectors are excellent for B-cell priming. Here we report that cytotoxic T-lymphocyte (CTL) responses against HIV-1 gp160 are induced by recombinant RVs. Our results indicated that a single inoculation of mice with an RV expressing HIV-1 gp160 induced a solid and long-lasting memory CTL response specific for HIV-1 envelope protein. Moreover, CTLs from immunized mice were not restricted to the homologous HIV-1 envelope protein and were able to cross-kill target cells expressing HIV-1 gp160 from heterologous HIV-1 strains. These studies further suggest promise for RV-based vectors to elicit a persistent immune response against HIV-1 and their potential utility as efficacious anti-HIV-1 vaccines.


2000 ◽  
Vol 74 (19) ◽  
pp. 9222-9233 ◽  
Author(s):  
Miguel E. Quiñones-Mateu ◽  
Sarah C. Ball ◽  
Andre J. Marozsan ◽  
Vincent S. Torre ◽  
Jamie L. Albright ◽  
...  

ABSTRACT This study was designed to examine the impact of human immunodeficiency virus type 1 (HIV-1) fitness on disease progression through the use of a dual competition/heteroduplex tracking assay (HTA). Despite numerous studies on the impact of HIV-1 diversity and HIV-specific immune response on disease progression, we still do not have a firm understanding of the long-term pathogenesis of this virus. Strong and early CD8-positive cytotoxic T-cell and CD4-positive T-helper cell responses directed toward HIV-infected cells appear to curb HIV pathogenesis. However, the rate at which the virus infects the CD4+ T-cell population and possibly destroys the HIV-specific immune response may also alter the rate of disease progression. For HIV-1 fitness studies, we established conditions for dual HIV-1 infections of peripheral blood mononuclear cells (PBMC) and a sensitive HTA to measure relative virus production. A pairwise comparison was then performed to estimate the relative fitness of various non-syncytium-inducing/CCR5-tropic (NSI/R5) and syncytium-inducing/CXCR4-tropic (SI/X4) HIV-1 isolates. Four HIV-1 strains (two NSI/R5 and two SI/X4) with moderate ex vivo fitness were then selected as controls and competed against primary HIV-1 isolates from an HIV-infected Belgian cohort. HIV-1 isolates from long-term survivors (LTS) were outcompeted by control strains and were significantly less fit than HIV-1 isolates from patients with accelerated progression to AIDS (PRO). In addition, NSI/R5 HIV-1 isolates from PRO overgrew control SI/X4 strains, suggesting that not all SI/X4 HIV-1 isolates replicate more efficiently than all NSI/R5 isolates. Finally, there were strong, independent correlations between viral load and the total relative fitness values of HIV-1 isolates from PRO (r = 0.84, P = 0.033) and LTS (r = 0.86, P = 0.028). Separation of the PRO and LTS plots suggest that HIV-1 fitness together with viral load may be a strong predictor for the rate of disease progression.


2005 ◽  
Vol 79 (18) ◽  
pp. 12100-12105 ◽  
Author(s):  
Thillagavathie Pillay ◽  
Hua-Tang Zhang ◽  
Jan W. Drijfhout ◽  
Nicola Robinson ◽  
Helen Brown ◽  
...  

ABSTRACT The role of cytotoxic T-lymphocyte (CTL) escape in rapidly progressive infant human immunodeficiency virus type 1 (HIV-1) infection is undefined. The data presented here demonstrate that infant HIV-1-specific CTL can select for viral escape variants very early in life. These variants, furthermore, may be selected specifically in the infant, despite the same CTL specificity being present in the mother. Additionally, pediatric CTL activity may be compromised both by the transmission of maternal escape variants and by mother-to-child transmission of escape variants that originally arose in the father. The unique acquisition of these CTL escape forms may help to explain the severe nature of some pediatric HIV infections.


1998 ◽  
Vol 72 (4) ◽  
pp. 3472-3474 ◽  
Author(s):  
James M. Binley ◽  
Xia Jin ◽  
Yaoxing Huang ◽  
Linqi Zhang ◽  
Yunzhen Cao ◽  
...  

ABSTRACT Long-term nonprogressor AD-18 has been infected with human immunodeficiency virus type 1 (HIV-1) for at least 16 years. During the past 5 years, he has had undetectable levels of plasma viremia, and HIV-1 cannot be isolated from him. Sequencing of proviral DNA indicates that the only HIV-1 sequences that can be identified in AD-18 have gross defects in the p17-encoding regions of the gag gene (Y. Huang, L. Zhang, and D. D. Ho, Virology 240:36–49, 1998). However, AD-18 has strong, sustained antibody responses to several HIV-1 antigens, including p17. Cytotoxic T-lymphocyte responses to Env and Gag antigens have gradually diminished over the past 4 years, at a time when the titers of antibodies to the same proteins have remained stable. We discuss what these observations might mean for the generation and maintenance of immunological memory.


1999 ◽  
Vol 73 (8) ◽  
pp. 6721-6728 ◽  
Author(s):  
Spyros A. Kalams ◽  
Philip J. Goulder ◽  
Amy K. Shea ◽  
Norman G. Jones ◽  
Alicja K. Trocha ◽  
...  

ABSTRACT Therapeutic suppression of human immunodeficiency virus type 1 (HIV-1) replication may help elucidate interactions between the host cellular immune responses and HIV-1 infection. We performed a detailed longitudinal evaluation of two subjects before and after the start of highly active antiretroviral therapy (HAART). Both subjects had evidence of in vivo-activated and memory cytotoxic T-lymphocyte precursor (CTLp) activity against multiple HIV-1 gene products. After the start of therapy, both subjects had declines in the levels of in vivo-activated HIV-1-specific CTLs and had immediate increases in circulating HIV-1-specific CTL memory cells. With continued therapy, and continued suppression of viral load, levels of memory CTLps declined. HLA A*0201 peptide tetramer staining demonstrated that declining levels of in vivo-activated CTL activity were associated with a decrease in the expression of the CD38+ activation marker. Transient increases in viral load during continued therapy were associated with increases in the levels of virus-specific CTLps in both individuals. The results were confirmed by measuring CTL responses to discrete optimal epitopes. These studies illustrate the dynamic equilibrium between the host immune response and levels of viral antigen burden and suggest that efforts to augment HIV-1-specific immune responses in subjects on HAART may decrease the incidence of virologic relapse.


1998 ◽  
Vol 72 (10) ◽  
pp. 8264-8272 ◽  
Author(s):  
Igor M. Belyakov ◽  
Linda S. Wyatt ◽  
Jeffrey D. Ahlers ◽  
Patricia Earl ◽  
C. David Pendleton ◽  
...  

ABSTRACT To improve the safety of recombinant vaccinia virus vaccines, modified vaccinia virus Ankara (MVA) has been employed, because it has a replication defect in most mammalian cells. Here we apply MVA to human immunodeficiency virus type 1 (HIV-1) vaccine development by incorporating the envelope protein gp160 of HIV-1 primary isolate strain 89.6 (MVA 89.6) and use it to induce mucosal cytotoxic-T-lymphocyte (CTL) immunity. In initial studies to define a dominant CTL epitope for HIV-1 89.6 gp160, we mapped the epitope to a sequence, IGPGRAFYAR (from the V3 loop), homologous to that recognized by HIV MN loop-specific CTL and showed that HIV-1 MN-specific CTLs cross-reactively recognize the corresponding epitope from strain 89.6 presented by H-2Dd. Having defined the CTL specificity, we immunized BALB/c mice intrarectally with recombinant MVA 89.6. A single mucosal immunization with MVA 89.6 was able to elicit long-lasting antigen-specific mucosal (Peyer’s patch and lamina propria) and systemic (spleen) CTL responses as effective as or more effective than those of a replication-competent vaccinia virus expressing 89.6 gp160. Immunization with MVA 89.6 led to (i) the loading of antigen-presenting cells in vivo, as measured by the ex vivo active presentation of the P18-89.6 peptide to an antigen-specific CTL line, and (ii) the significant production of the proinflammatory cytokines (interleukin-6 and tumor necrosis factor alpha) in the mucosal sites. These results indicate that nonreplicating recombinant MVA may be at least as effective for mucosal immunization as replicating recombinant vaccinia virus.


1999 ◽  
Vol 73 (8) ◽  
pp. 6715-6720 ◽  
Author(s):  
Spyros A. Kalams ◽  
S. P. Buchbinder ◽  
E. S. Rosenberg ◽  
J. M. Billingsley ◽  
D. S. Colbert ◽  
...  

ABSTRACT Cellular immune responses are thought to be an important antiviral host defense, but the relationship between virus-specific T-helper and cytotoxic-T-lymphocyte (CTL) responses has not been defined. To investigate a potential link between these responses, we examined functional human immunodeficiency virus type 1 (HIV-1)-specific memory CTL precursor frequencies and p24-specific proliferative responses in a cohort of infected untreated persons with a wide range of viral loads and CD4 cell counts. Levels of p24-specific proliferative responses positively correlated with levels of Gag-specific CTL precursors and negatively correlated with levels of plasma HIV-1 RNA. These data linking the levels of HIV-specific CTL with virus-specific helper cell function during chronic viral infection provide cellular immunologic parameters to guide therapeutic and prophylactic vaccine development.


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