scholarly journals Lack of Autologous Neutralizing Antibody to Human Immunodeficiency Virus Type 1 (HIV‐1) and Macrophage Tropism Are Associated with Mother‐to‐Infant Transmission

1999 ◽  
Vol 180 (2) ◽  
pp. 344-350 ◽  
Author(s):  
Janet L. Lathey ◽  
Jeff Tsou ◽  
Karen Brinker ◽  
Karen Hsia ◽  
William A. Meyer III ◽  
...  
2007 ◽  
Vol 81 (12) ◽  
pp. 6187-6196 ◽  
Author(s):  
E. S. Gray ◽  
P. L. Moore ◽  
I. A. Choge ◽  
J. M. Decker ◽  
F. Bibollet-Ruche ◽  
...  

ABSTRACT The study of the evolution and specificities of neutralizing antibodies during the course of human immunodeficiency virus type 1 (HIV-1) infection may be important in the discovery of possible targets for vaccine design. In this study, we assessed the autologous and heterologous neutralization responses of 14 HIV-1 subtype C-infected individuals, using envelope clones obtained within the first 2 months postinfection. Our data show that potent but relatively strain-specific neutralizing antibodies develop within 3 to 12 months of HIV-1 infection. The magnitude of this response was associated with shorter V1-to-V5 envelope lengths and fewer glycosylation sites, particularly in the V1-V2 region. Anti-MPER antibodies were detected in 4 of 14 individuals within a year of infection, while antibodies to CD4-induced (CD4i) epitopes developed to high titers in 12 participants, in most cases before the development of autologous neutralizing antibodies. However, neither anti-MPER nor anti-CD4i antibody specificity conferred neutralization breadth. These data provide insights into the kinetics, potency, breadth, and epitope specificity of neutralizing antibody responses in acute HIV-1 subtype C infection.


2009 ◽  
Vol 83 (19) ◽  
pp. 10269-10274 ◽  
Author(s):  
Anne Piantadosi ◽  
Dana Panteleeff ◽  
Catherine A. Blish ◽  
Jared M. Baeten ◽  
Walter Jaoko ◽  
...  

ABSTRACT The determinants of a broad neutralizing antibody (NAb) response and its effect on human immunodeficiency virus type 1 (HIV-1) disease progression are not well defined, partly because most prior studies of a broad NAb response were cross-sectional. We examined correlates of NAb response breadth among 70 HIV-infected, antiretroviral-naïve Kenyan women from a longitudinal seroincident cohort. NAb response breadth was measured 5 years after infection against five subtype A viruses and one subtype B virus. Greater NAb response breadth was associated with a higher viral load set point and greater HIV-1 env diversity early in infection. However, greater NAb response breadth was not associated with a delayed time to a CD4+ T-cell count of <200, antiretroviral therapy, or death. Thus, a broad NAb response results from a high level of antigenic stimulation early in infection, which likely accounts for prior observations that greater NAb response breadth is associated with a higher viral load later in infection.


2007 ◽  
Vol 81 (17) ◽  
pp. 9268-9278 ◽  
Author(s):  
Erin E. Verity ◽  
Dimitra Zotos ◽  
Kim Wilson ◽  
Catherine Chatfield ◽  
Victoria A. Lawson ◽  
...  

ABSTRACT The Sydney Blood Bank Cohort (SBBC) consists of eight blood transfusion recipients infected with nef-attenuated human immunodeficiency virus type 1 (HIV-1) acquired from a single donor. Here, we show that viral phenotypes and antibody responses differ considerably between individual cohort members, despite the single source of infection. Replication of isolated virus varied from barely detectable to similar to that of the wild-type virus, and virus isolated from five SBBC members showed coreceptor usage signatures unique to each individual. Higher viral loads and stronger neutralizing antibody responses were associated with better-replicating viral strains, and detectable viral replication was essential for the development of strong and sustained humoral immune responses. Despite the presence of strong neutralizing antibodies in a number of SBBC members, disease progression was not prevented, and each cohort member studied displayed a unique outcome of infection with nef-attenuated HIV-1.


2007 ◽  
Vol 82 (5) ◽  
pp. 2367-2375 ◽  
Author(s):  
Elin S. Gray ◽  
Penny L. Moore ◽  
Frederic Bibollet-Ruche ◽  
Hui Li ◽  
Julie M. Decker ◽  
...  

ABSTRACT The broadly neutralizing monoclonal antibody (MAb) 4E10 recognizes a linear epitope in the C terminus of the membrane-proximal external region (MPER) of gp41. This epitope is particularly attractive for vaccine design because it is highly conserved among human immunodeficiency virus type 1 (HIV-1) strains and neutralization escape in vivo has not been observed. Multiple env genes were cloned from an HIV-1 subtype C virus isolated from a 7-year-old perinatally infected child who had anti-MPER neutralizing antibodies. One clone (TM20.13) was resistant to 4E10 neutralization as a result of an F673L substitution in the MPER. Frequency analysis showed that F673L was present in 33% of the viral variants and in all cases was linked to the presence of an intact 2F5 epitope. Two other envelope clones were sensitive to 4E10 neutralization, but TM20.5 was 10-fold less sensitive than TM20.6. Substitutions at positions 674 and 677 within the MPER rendered TM20.5 more sensitive to 4E10 but had no effect on TM20.6. Using chimeric and mutant constructs of these two variants, we further demonstrated that the lentivirus lytic peptide-2 domain in the cytoplasmic tail affected the accessibility of the 4E10 epitope, as well as virus infectivity. Collectively, these genetic changes in the face of a neutralizing antibody response to the MPER strongly suggested immune escape from antibody responses targeting this region.


1990 ◽  
Vol 172 (4) ◽  
pp. 1035-1042 ◽  
Author(s):  
C D Pauza ◽  
J E Galindo ◽  
D D Richman

High levels of unintegrated viral DNA accumulate during human immunodeficiency virus type 1 (HIV-1) infection of CEM T cells. Reinfection of already infected cells is required to attain these levels and reinfection also promotes the development of HIV-induced cytopathology. Rates of virus production, however, are independent of the accumulation of unintegrated viral DNA. Neutralizing antibody added soon after infection reduced viral DNA levels without appreciably affecting the production of cell-free viral p24 antigen or reverse transcriptase activity. Only 50 pM AZT were required to reduce the accumulation of unintegrated viral DNA by 50% in contrast to the 25 nM required to inhibit virus production by 50%. Cytopathology, as measured by number of syncytia in infected cell cultures, was correlated with highly elevated levels of unintegrated viral DNA. The minimal levels of unintegrated viral DNA present constitutively in the persistently infected HCEM cell line were consonant with the absence of cytopathic effects in these cells. These data demonstrate that inhibiting the reinfection of already infected cells modulates cytopathic HIV-1 infection to a form that is persistent and noncytopathic.


2009 ◽  
Vol 83 (18) ◽  
pp. 9577-9583 ◽  
Author(s):  
Kurt Vermeire ◽  
Kristel Van Laethem ◽  
Wouter Janssens ◽  
Thomas W. Bell ◽  
Dominique Schols

ABSTRACT Continuous specific downmodulation of CD4 receptor expression in T lymphocytes by the small molecule cyclotriazadisulfonamide (CADA) selected for the CADA-resistant human immunodeficiency virus type 1 (HIV-1) NL4.3 virus containing unique mutations in the C4 and V5 regions of gp120, likely stabilizing the CD4-binding conformation. The amino acid changes in Env were associated with decreased susceptibility to anti-CD4 monoclonal antibody treatment of the cells and with higher susceptibility of the virus to soluble CD4. In addition, the acquired ability of a CADA-resistant virus to infect cells with low CD4 expression was associated with an increased susceptibility of the virus to neutralizing antibodies from sera of several HIV-1-infected patients.


2008 ◽  
Vol 82 (24) ◽  
pp. 12094-12103 ◽  
Author(s):  
Catherine A. Blish ◽  
Ozge C. Dogan ◽  
Nina R. Derby ◽  
Minh-An Nguyen ◽  
Bhavna Chohan ◽  
...  

ABSTRACT Superinfection by a second human immunodeficiency virus type 1 (HIV-1) strain indicates that gaps in protective immunity occur during natural infection. To define the role of HIV-1-specific neutralizing antibodies (NAbs) in this setting, we examined NAb responses in 6 women who became superinfected between ∼1 to 5 years following initial infection compared to 18 women with similar risk factors who did not. Although superinfected individuals had less NAb breadth than matched controls at ∼1 year postinfection, no significant differences in the breadth or potency of NAb responses were observed just prior to the second infection. In fact, four of the six subjects had relatively broad and potent NAb responses prior to infection by the second strain. To more specifically examine the specificity of the NAbs against the superinfecting virus, these variants were cloned from five of the six individuals. The superinfecting variants did not appear to be inherently neutralization resistant, as measured against a pool of plasma from unrelated HIV-infected individuals. Moreover, the superinfected individuals were able to mount autologous NAb responses to these variants following reinfection. In addition, most superinfected individuals had NAbs that could neutralize their second viral strains prior to their reinfection, suggesting that the level of NAbs elicited during natural infection was not sufficient to block infection. These data indicate that preventing infection by vaccination will likely require broader and more potent NAb responses than those found in HIV-1-infected individuals.


2002 ◽  
Vol 76 (2) ◽  
pp. 644-655 ◽  
Author(s):  
Peng Fei Zhang ◽  
Peter Bouma ◽  
Eun Ju Park ◽  
Joseph B. Margolick ◽  
James E. Robinson ◽  
...  

ABSTRACT The human serum human immunodeficiency virus type 1 (HIV-1)-neutralizing serum 2 (HNS2) neutralizes many primary isolates of different clades of HIV-1, and virus expressing envelope from the same donor, clone R2, is neutralized cross-reactively by HIV-immune human sera. The basis for this cross-reactivity was investigated. It was found that a rare mutation in the proximal limb of variable region 3 (V3), 313-4 PM, caused virus pseudotyped with the R2 envelope to be highly sensitive to neutralization by monoclonal antibodies (MAbs) directed against conformation-sensitive epitopes at the tip of the V3 loop, such as 19b, and moderately sensitive to MAbs against CD4 binding site (CD4bs) and CD4-induced (CD4i) epitopes, soluble CD4 (sCD4), and HNS2. In addition, introduction of this sequence by mutagenesis caused enhanced sensitivity to neutralization by 19b, anti-CD4i MAb, and HNS2 in three other primary HIV-1 envelopes and by anti-CD4bs MAb and sCD4 in one of the three. The 313-4 PM sequence also conferred increased infectivity for CD4+ CCR5+ cells and the ability to infect CCR5+ cells upon all of these four and two of these four HIV-1 envelopes, respectively. Neutralization of R2 by HNS2 was substantially inhibited by the cyclized R2 V3 35-mer synthetic peptide. Similarly, the peptide also had some lesser efficacy in blocking neutralization of R2 by other sera or of neutralization of other primary viruses by HNS2. Together, these results indicate that the unusual V3 mutation in the R2 clone accounts for its uncommon neutralization sensitivity phenotype and its capacity to mediate CD4-independent infection, both of which could relate to immunogenicity and the neutralizing activity of HNS2. This is also the first primary HIV-1 isolate envelope glycoprotein found to be competent for CD4-independent infection.


2001 ◽  
Vol 75 (9) ◽  
pp. 4165-4175 ◽  
Author(s):  
Norman L. Letvin ◽  
Suzanne Robinson ◽  
Daniela Rohne ◽  
Michael K. Axthelm ◽  
John W. Fanton ◽  
...  

ABSTRACT Vaccine-elicited antibodies specific for the third hypervariable domain of the surface gp120 of human immunodeficiency virus type 1 (HIV-1) (V3 loop) were assessed for their contribution to protection against infection in the simian-human immunodeficiency virus (SHIV)/rhesus monkey model. Peptide vaccine-elicited anti-V3 loop antibody responses were examined for their ability to contain replication of SHIV-89.6, a nonpathogenic SHIV expressing a primary patient isolate HIV-1 envelope, as well as SHIV-89.6P, a pathogenic variant of that virus. Low-titer neutralizing antibodies to SHIV-89.6 that provided partial protection against viremia following SHIV-89.6 infection were generated. A similarly low-titer neutralizing antibody response to SHIV-89.6P that did not contain viremia after infection with SHIV-89.6P was generated, but a trend toward protection against CD4+ T-lymphocyte loss was seen in these infected monkeys. These observations suggest that the V3 loop on some primary patient HIV-1 isolates may be a partially effective target for neutralizing antibodies induced by peptide immunogens.


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