scholarly journals Multiantibody Strategies for HIV

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Andrew Hiatt ◽  
Larry Zeitlin ◽  
Kevin J. Whaley

Vaccination strategies depend entirely on the appropriate responsiveness of our immune system against particular antigens. For this active immunization to be truly effective, neutralizing antibodies (nAbs) need to efficiently counter the infectivity or propagation of the pathogen. Some viruses, including HIV, are able to take advantage of this immune response in order to evade nAbs. This review focuses on viral immune evasion strategies that result directly from a robust immune response to infection or vaccination. A rationale for multi-Ab therapy to circumvent this phenomenon is discussed. Progress in the formulation, production, and regulatory approval of monoclonal antibodies (mAbs) is presented.

2021 ◽  
pp. 1-10
Author(s):  
Bader Alshehri

Breast cancer being the most malignant and lethal disease persistent among women globally. Immunotherapy as a new treatment modality has emerged in understanding the loopholes in the treatment of breast cancer which is mainly attributed to the potential of tumor cells to evade and survive the immune response by developing various strategies. Therefore, improved understanding of the immune evasion by cancer cells and the monoclonal antibodies against PD- and PD-L1 can help us in the diagnosis of this malignancy. Here in this article, I have highlighted that in addition to focusing on other strategies for breast cancer treatment, the involvement of immune system in breast cancer is vital for the understanding of this malignancy. Further, the complete involvement of immune system in the relapse or recurrence of the breast tumor and have also highlighted the role of vaccines, PD-1 and CTLA-4 with the recent advances in the field. Moreover, in addition to the application of immunotherapy as a sole therapy, combinations of immunotherapy with various strategies like targeting it with MEK inhibitors, Vaccines, chemotherapy and PARP inhibitor has shown to have significant benefits is also discussed in this article.


Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 700
Author(s):  
Franziska Neumann ◽  
Ruben Rose ◽  
Janine Römpke ◽  
Olaf Grobe ◽  
Thomas Lorentz ◽  
...  

The humoral immunity after SARS-CoV-2 infection or vaccination was examined. Convalescent sera after infection with variants of concern (VOCs: B.1.1.7, n = 10; B.1.351, n = 1) and sera from 100 vaccinees (Pfizer/BioNTech, BNT162b2, n = 33; Moderna, mRNA-1273, n = 11; AstraZeneca, ChAdOx1 nCoV-19/AZD1222, n = 56) were tested for the presence of immunoglobulin G (IgG) directed against the viral spike (S)-protein, its receptor-binding domain (RBD), the nucleoprotein (N) and for virus-neutralizing antibodies (VNA). For the latter, surrogate assays (sVNT) and a Vero-cell based neutralization test (cVNT) were used. Maturity of IgG was determined by measuring the avidity in an immunoblot (IB). Past VOC infection resulted in a broad reactivity of anti-S IgG (100%), anti-RBD IgG (100%), and anti-N IgG (91%), while latter were absent in 99% of vaccinees. Starting approximately two weeks after the first vaccine dose, anti-S IgG (75–100%) and particularly anti-RBD IgG (98–100%) were detectable. After the second dose, their titers increased and were higher than in the convalescents. The sVNT showed evidence of VNA in 91% of convalescents and in 80–100%/100% after first/second vaccine dose, respectively. After the second dose, an increase in VNA titer and IgGs of high avidity were demonstrated by cVNT and IB, respectively. Re-vaccination contributes to a more robust immune response.


2012 ◽  
Vol 6 (2) ◽  
pp. 17 ◽  
Author(s):  
Masachika Senba ◽  
Naoki Mori

Human papillomavirus (HPV) has developed strategies to escape eradication by innate and adaptive immunity. Immune response evasion has been considered an important aspect of HPV persistence, which is the main contributing factor leading to HPV-related cancers. HPV-induced cancers expressing viral oncogenes E6 and E7 are potentially recognized by the immune system. The major histocompatibility complex (MHC) class I molecules are patrolled by natural killer cells and CD8<sup>+</sup> cytotoxic T lymphocytes, respectively. This system of recognition is a main target for the strategies of immune evasion deployed by viruses. The viral immune evasion proteins constitute useful tools to block defined stages of the MHC class I presentation pathway, and in this way HPV avoids the host immune response. The long latency period from initial infection to persistence signifies that HPV evolves mechanisms to escape the immune response. It has now been established that there are oncogenic mechanisms by which E7 binds to and degrades tumor suppressor Rb, while E6 binds to and inactivates tumor suppressor p53. Therefore, interaction of p53 and pRb proteins can give rise to an increased immortalization and genomic instability. Overexpression of NF-kB in cervical and penile cancers suggests that NF-kB activation is a key modulator in driving chronic inflammation to cancer. HPV oncogene-mediated suppression of NF-kB activity contributes to HPV escape from the immune system. This review focuses on the diverse mechanisms of the virus immune evasion with HPV that leads to chronic inflammation and cancer.


2018 ◽  
Vol 12 ◽  
pp. 117822341877480 ◽  
Author(s):  
Issam Makhoul ◽  
Mohammad Atiq ◽  
Ahmed Alwbari ◽  
Thomas Kieber-Emmons

The immune system plays a major role in cancer surveillance. Harnessing its power to treat many cancers is now a reality that has led to cures in hopeless situations where no other solutions were available from traditional anticancer drugs. These spectacular achievements rekindled the oncology community’s interest in extending the benefits to all cancers including breast cancer. The first section of this article reviews the biological foundations of the immune response to different subtypes of breast cancer and the ways cancer may overcome the immune attack leading to cancer disease. The second section is dedicated to the actual immune treatments including breast cancer vaccines, checkpoint inhibitors, monoclonal antibodies, and the “unconventional” immune role of chemotherapy.


Principles 250 Immunotherapy 252 Monoclonal antibodies 254 Other biological therapies 258 Biological therapies aim to produce an anti-tumour effect, either by activating the patient's immune system, or by administering natural substances present in the immune system as treatments. These treatments cause an immune response in the patient that eliminates or delays tumour growth....


2020 ◽  
Vol 35 (9) ◽  
pp. 398-402
Author(s):  
Daylin Barranco ◽  
Elias B. Chahine

Advanced age is associated with an increase in morbidity and mortality from influenza. Immunization is the best option to protect individuals against influenza and its complications. Older people are less likely than their younger counterparts to mount an appropriate immune response to influenza vaccines. The adjuvanted inactivated influenza vaccine quadrivalent (aIIV4) is designed to elicit a more robust immune response in older people compared with traditional inactivated influenza vaccines. The aIIV4 is indicated for active immunization against influenza caused by influenza virus subtypes A and types B contained in the vaccine and is licensed by the Food and Drug Administration for use in persons 65 years of age and older. The aIIV4 should be administered by intramuscular injection. Like other influenza vaccines, aIIV4 carries a warning regarding the occurrence of Guillain-Barré syndrome. The most common adverse reactions associated with aIIV4 are injection site pain, fatigue, headache, arthralgia, and myalgia.


2021 ◽  
Author(s):  
Carlos A Sariol ◽  
Petraleigh Pantoja ◽  
Crisanta Serrano-Collazo ◽  
Tiffant Rosa-Arocho ◽  
Albersy Armina ◽  
...  

On this work we report that despite of a decline in the total anti-Spike antibodies the neutralizing antibodies remains at a similar level for an average of 98 days in a longitudinal cohort of 59 Hispanic/Latino exposed to SARS-CoV-2. We are also reporting that the percentage of neutralization correlates with the IgG titers and that in the first collected samples, IgG1 was the predominant isotype (62.71%), followed by IgG4 (15.25%), IgG3 (13.56%), and IgG2 (8.47%) during the tested period. The IgA was detectable in 28.81% of subjects. Only 62.71% of all subjects have detectable IgM in the first sample despite of confirmed infection by a molecular method. Our data suggests that 100% that seroconvert make detectable neutralizing antibody responses measured by a surrogate viral neutralization test. We also found that the IgG titers and neutralizing activity were higher after the first dose in 10 vaccinated subjects out of the 59 with prior infection compare to a subgroup of 21 subjects naive to SARS-CoV-2. One dose was enough but two were necessary to reach the maximum percentage of neutralization in subjects with previous natural infection or naive to SARS-CoV-2 respectively. Like the pattern seen after the natural infection, after the second vaccine dose, the total anti-S antibodies and titers declined but not the neutralizing activity which remains at same levels for more than 80 days after the first vaccine dose. That decline, however, was significantly lower in pre-exposed individuals which denotes the contribution of the natural infection priming a more robust immune response to the vaccine. Also, our data indicates that the natural infection induces a more robust humoral immune response than the first vaccine dose in unexposed subjects. However, the difference was significant only when the neutralization was measured but not by assessing the total anti-S antibodies or the IgG titers. This work is an important contribution to understand the natural immune response to the novel coronavirus in a population severely hit by the virus. Also provide an invaluable data by comparing the dynamic of the immune response after the natural infection vs. the vaccination and suggesting that a functional test is a better marker than the presence or not of antibodies. On this context our results are also highly relevant to consider standardizing methods that in addition to serve as a tool to follow up the immune response to the vaccines may also provide a correlate of protection.


2021 ◽  
Vol 5 (1) ◽  
pp. 077-086
Author(s):  
Nikhra Vinod

Introduction - evolution of SARS-CoV-2 variants: With the unrestrained pandemic for over last one-and-half year, SARS-CoV-2 seems to have adapted to its habitat, the human host, through mutations that facilitate its replication and transmission. The G variant incorporating D614G mutation, potently more transmissible than the ancestral virus arose during January 2020 and spread widely. Since then, various SARS-CoV-2 variants of concern (VOCs) and variants of interest (VOIs) with higher infectivity or virulence or both, have evolved on the background of G variant, and spread widely. SARS-CoV-2 infection and the immunodynamics: As the virus becomes more transmissible, its lethality may drop. Apart from the humoral immunity, T-cell recognition from a previous SARS-CoV-2 infection or vaccination may modify the disease transmission correlates and its clinical manifestations. On the other hand, the immunity generated may reduce probability of re-infection as well as limit evolution of adaptive mutations, and emergence of highly infectious and immune-escape variants. There are complex issues related to the SARS-CoV-2 evolutionary dynamics and host’s immunodynamics. Trending etiopathoimmunological correlates: The evolution potential of SARS-CoV-2 is limited because of proofreading function of nsp14. The S protein mutations affect transmissibility, virulence, and vaccine efficacy. The D614G mutation in G variant with higher infectivity has turned the Chinese epidemic into a pandemic. Other SARS-CoV-2 variants, such as Alpha, Beta, Gamma, and Delta seem to have evolved as result of adaptation to selective pressures during periods of prolonged infections and subsequent transmission. Further, there is issue of convergent association of mutations. Basics of immunity and immune system failure: The nature of the immune response after natural SARS-CoV-2 infection is variable and diverse. There are pre-existing neutralizing antibodies and sensitized T cells elicited during previous infection with seasonal CoVs influencing the disease susceptibility and course. The virus has evolved adaptive mechanisms to reduce its exposure to IFN-I and there are issues related to erratic and overactive immune response. The altered neutralizing epitopes in the S protein in SARS-CoV-2 variants modify the immune landscapes and clinical manifestations. Conclusion: current scenarios and prospects: Presently, the SARS-CoV-2 infection is widespread with multiple evolving infectious variants. There is probability of its transition from epidemic to endemic phase in due course manifesting as a mild disease especially in the younger population. Conversely, the pandemic may continue with enhanced disease severity due to evolving variants, expanded infection pool, and changing immunity landscape. There is need to plan for the transition and continued circulation of the virus during the endemic phase or continuing pandemic for indefinite period.


1998 ◽  
Vol 66 (2) ◽  
pp. 815-819 ◽  
Author(s):  
Nils Burman ◽  
Alireza Shamaei-Tousi ◽  
Sven Bergström

ABSTRACT Several species of the genus Borrelia exhibit antigenic variation of variable major proteins on their surface during relapsing fever. We have investigated the African relapsing fever speciesBorrelia crocidurae during infections in mice and compared it with the thoroughly studied North American species Borrelia hermsii. A major difference between the two species is thatB. crocidurae can bind and become completely covered with erythrocytes. In addition, B. crocidurae causes a prolonged spirochetemia which coincides with a delayed appearance of antiborrelial antibodies. We show that the antibody response against an unrelated antigen is not delayed and that antibiotic treatment, which dissociates rosettes and inhibits the spirochetes, also leads to an early antibody response. Taken together, the erythrocyte aggregation and prolonged spirochetemia hint at a new mode of immune evasion where erythrocyte-covered spirochetes may avoid contact with the phagocytic cells and B cells of the immune system, thereby delaying the onset of a specific immune response.


2020 ◽  
Vol 95 (1) ◽  
Author(s):  
Wanzhi Huang ◽  
Victoria Soeung ◽  
David M. Boragine ◽  
Liya Hu ◽  
B. V. Venkataram Prasad ◽  
...  

ABSTRACT Norovirus (NoV) infections are a leading cause of gastroenteritis. The humoral immune response plays an important role in the control of NoV, and recent studies have identified neutralizing antibodies that bind the capsid protein VP1 to block viral infection. Here, we utilize a NoV GI.1 Jun-Fos-assisted phage display library constructed from randomly fragmented genomic DNA coupled with affinity selection for antibody binding and subsequent deep sequencing to map epitopes. The epitopes were identified by quantitating the phage clones before and after affinity selection and aligning the sequences of the most enriched peptides. The HJT-R3-A9 single-chain variable fragment (scFv) antibody epitope was mapped to a 12-amino-acid region of VP1 that is also the binding site for several previously identified monoclonal antibodies. We synthesized the 12-mer peptide and found that it binds the scFv antibody with a KD (equilibrium dissociation constant) of 46 nM. Further, alignment of enriched peptides after affinity selection on rabbit anti-NoV polyclonal antisera revealed five families of overlapping sequences that define distinct epitopes in VP1. One of these is identical to the HJT-R3-A9 scFv epitope, further suggesting that it is immunodominant. Similarly, other epitopes identified using the polyclonal antisera overlap binding sites for previously reported monoclonal antibodies, suggesting that they are also dominant epitopes. The results demonstrate that affinity selection and deep sequencing of the phage library provide sufficient resolution to map multiple epitopes simultaneously from complex samples such as polyclonal antisera. This approach can be extended to examine the antigenic landscape in patient sera to facilitate investigation of the immune response to NoV. IMPORTANCE NoV infections are a leading cause of gastroenteritis in the United States. Human NoVs exhibit extensive genetic and antigenic diversity, which makes it challenging to design a vaccine that provides broad protection against infection. Antibodies developed during the immune response play an important role in the control of NoV infections. Neutralizing antibodies that act by sterically blocking the site on the virus used to bind human cells have been identified. Identification of other antibody binding sites associated with virus neutralization is therefore of interest. Here, we use a high-resolution method to map multiple antibody binding sites simultaneously from complex serum samples. The results show that a relatively small number of sites on the virus bind a large number of independently generated antibodies, suggesting that immunodominance plays a role in the humoral immune response to NoV infections.


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