In Vivo and in Silico Assessment of Ameliorative Effects of Xylopia aethiopica on Testosterone Propionate-Induced Benign Prostatic Hyperplasia

Xylopia aethiopica (XAE) is a commonly used herbal medicine and contains rich active ingredients for a variety of biological activities. The study aimed to explore the role of XAE in the management of benign prostatic hyperplasia (BPH). In the study, testosterone propionate-induced BPH in albino rats was established and treated with different concentrations of ethanol extract of XAE leaf. After treatment, the rats were sacrificed, and the body and prostate weights were recorded. The prostate-specific antigen (PSA) and acid phosphatase (ACP) levels in the blood samples were also determined. Gas chromatography-mass spectrometry was conducted to assess the active chemical compounds. Docking analysis was performed to screen chemical compounds by evaluating their binding affinity with two pro-BPH protein targets (cellular prostatic ACP and PSA). Our data showed the presence of 44 chemical compounds in XAE leaf extract. The body and prostate weights, as well as the levels of PSA and ACP, were significantly increased in BPH induction, and the changing trend was significantly reversed by additional XAE treatment. Interestingly, PSA and ACP levels in XAE-treated groups were reduced to almost the same levels as those in the healthy control. Docking analysis identified four top-posed compounds: β-amyrin, α-amyrin, α-amyrenone, and lupenone with stronger binding energies to prostatic ACP being −9.8, −8.3, −8.4, and −8.6, respectively, compared with the standard drug finasteride (−8.3). Furthermore, the two-dimensional analysis revealed strong interactions through hydrogen bonding, covalent interactions, and several van der Waal forces between the lead compounds and the target proteins. Notably, there was a recurrence interaction between similar residues Asn-1062, Lys-1250, Lys-1059, and Phe-1060 on the protein targets and the lead compounds. The study first revealed the role of XAE in BPH therapy and will help in drug design based on the lead compounds discovered in this work

Association of VH4-59 Antibody Variable Gene Usage with Recognition of an Immunodominant Epitope on the HIV-1 Gag Protein

The human antibody response against HIV-1 infection recognizes diverse antigenic subunits of the virion, and includes a high level of antibodies to the Gag protein. We report here the isolation and characterization of a subset of Gag-specific human monoclonal antibodies (mAbs) that were prevalent in the antibody repertoire of an HIV-infected individual. Several lineages of Gag-specifc mAbs were encoded by a single antibody heavy chain variable region, VH4-59, and a representative antibody from this group designated mAb 3E4 recognized a linear epitope on the globular head of the p17 subunit of Gag. We found no evidence that mAb 3E4 exhibited any function in laboratory studies aimed at elucidating the immunologic activity, including assays for neutralization, Ab-dependent cell-mediated virus inhibition, or enhanced T cell reactivity caused by Gag-3E4 complexes. The findings suggest this immunodominant epitope in Gag protein, which is associated with VH4-59 germline gene usage, may induce a high level of B cells that encode binding but non-functional antibodies that occupy significant repertoire space following HIV infection. The studies define an additional specific molecular mechanism in the immune distraction activity of the HIV virion

Generation of p17 Matrix deletion mutants.

<p>The full amino acid sequence alignment of the wild-type (WT) Matrix protein and the 10 Matrix deletion mutants. Conserved residues in the Matrix deletion mutants are indicated by the <b>*</b> symbol, and deleted resides indicated by the—symbol.</p

Mapping the mAb 3E4 epitope on the surface of HIV Gag protein.

<p><b>(A)</b> Binding of mAb 3E4 to overlapping linear peptides of the HIV-1 Gag protein. <b>(B)</b> Structural depiction of the mAb 3E4 epitope (shown in red) on the HIV-1 Gag protein. <b>(C)</b> Structural depiction of deletion mutants #1, #3, #4, #5, #6, and #7 (shown in blue, yellow, magenta, cyan, orange or wheat) on the surface of the HIV-1 Gag protein. <b>(D)</b> Western blot analysis of Gag, wild-type Matrix protein, or each of 10 different Matrix protein deletion mutants, using mAb 3E4 as a probe.</p

Heavy chain gene analysis of Gag-only VLP binding antibodies.

<p>Heavy chain gene analysis of Gag-only VLP binding antibodies.</p

Binding of V_H4-59 encoded antibodies to HIV antigens.

<p>Binding of mAb b12 or V_H4-59 gene-encoded mAbs at a concentration of 1 μg/mL to Env VLP (black), Gag-only VLP (grey), BaL gp120 (white), or YU2 gp140 (pattern) tested by ELISA.</p

Heavy chain amino acid sequence alignment of V_H4-59 encoded mAbs.

<p>The heavy chain amino acid sequence of HIV-specific V_H4-59 encoded mAbs are shown aligned to the V_H4-59 germline gene. Conservation with the germline gene sequence is indicated by a <b>*</b> symbol in the alignments.</p

Human Antibodies that Recognize Novel Immunodominant Quaternary Epitopes on the HIV-1 Env Protein

<div><p>Numerous broadly neutralizing antibodies (Abs) target epitopes that are formed or enhanced during mature HIV envelope formation (<i>i</i>.<i>e</i>. quaternary epitopes). Generally, it is thought that Env epitopes that induce broadly neutralizing Abs are difficult to access and poorly immunogenic because of the characteristic oligomerization, conformational flexibility, sequence diversity and extensive glycosylation of Env protein. To enhance for isolation of quaternary epitope-targeting Abs (QtAbs), we previously used HIV virus-like particles (VLPs) to bind B cells from long-term non-progressor subjects to identify a panel of monoclonal Abs. When expressed as recombinant full-length Abs, a subset of these novel Abs exhibited the binding profiles of QtAbs, as they either failed to bind to monomeric Env protein or showed much higher affinity for Env trimers and VLPs. These QtAbs represented a significant proportion of the B-cell response identified with VLPs. The Ab genes of these clones were highly mutated, but they did not neutralize common HIV strains. We sought to further define the epitopes targeted by these QtAbs. Competition-binding and mapping studies revealed these Abs targeted four separate epitopes; they also failed to compete for binding by Abs to known major neutralizing epitopes. Detailed epitope mapping studies revealed that two of the four epitopes were located in the gp41 subunit of Env. These QtAbs bound pre-fusion forms of antigen and showed differential binding kinetics depending on whether oligomers were produced as recombinant gp140 trimers or as full-length Env incorporated into VLPs. Antigenic regions within gp41 present unexpectedly diverse structural epitopes, including these QtAb epitopes, which may be targeted by the naturally occurring Ab response to HIV infection.</p></div

Increased breadth of HIV-1 neutralization achieved by diverse antibody clones each with limited neutralization breadth.

Broadly neutralizing antibodies (bNAbs) are rarely elicited by current human immunodeficiency virus type 1 (HIV-1) vaccine designs, but the presence of bNAbs in naturally infected individuals may be associated with high plasma viral loads, suggesting that the magnitude, duration, and diversity of viral exposure may contribute to the development of bNAbs. Here, we report the isolation and characterization of a panel of human monoclonal antibodies (mAbs) from two subjects who developed broadly neutralizing autologous antibody responses during HIV-1 infection. In both subjects, we identified collections of mAbs that exhibited specificity only to a few autologous envelopes (Envs), with some mAbs exhibiting specificity only to a subset of Envs within the quasispecies of a particular sample at one time point. Neutralizing antibodies (NAbs) isolated from these subjects mapped mostly to epitopes in the Env V3 loop region and the CD4 binding site. None of the individual neutralizing mAbs recovered exhibited the cumulative breadth of neutralization present in the serum of the subjects. Surprisingly, however, the activity of polyclonal mixtures comprising individual mAbs that each possessed limited neutralizing activity, could achieve increased breadth of neutralizing activity against autologous isolates. While a single broadly neutralizing antibody targeting one epitope can mediate neutralization breadth, the findings presented here suggest that a cooperative polyclonal process mediated by diverse antibodies with more limited breadth targeting multiple epitopes also can achieve neutralization breadth against HIV-1

Epitope competition group (CG) assignment, binding kinetics and preference of quaternary-epitope targeting Abs for binding to Env in VLPs gp140 trimers.

<p>Epitope competition group (CG) assignment, binding kinetics and preference of quaternary-epitope targeting Abs for binding to Env in VLPs gp140 trimers.</p