scholarly journals Monophosphoryl-Lipid A (MPLA) is an Efficacious Adjuvant for Inactivated Rabies Vaccines

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1118 ◽  
Author(s):  
Chen Chen ◽  
Chengguang Zhang ◽  
Ruiming Li ◽  
Zongmei Wang ◽  
Yueming Yuan ◽  
...  

Rabies, as one of the most threatening zoonoses in the world, causes a fatal central nervous system (CNS) disease. So far, vaccination with rabies vaccines has been the most effective measure to prevent and control this disease. At present, inactivated rabies vaccines are widely used in humans and domestic animals. However, humoral immune responses induced by inactivated rabies vaccines are relatively low and multiple shots are required to achieve protective immunity. Supplementation with an adjuvant is a practical way to improve the immunogenicity of inactivated rabies vaccines. In this study, we found that monophosphoryl-lipid A (MPLA), a well-known TLR4 agonist, could significantly promote the maturation of bone marrow-derived dendritic cells (BMDC) through a TLR4-dependent pathway in vitro and the maturation of conventional DCs (cDCs) in vivo. We also found that MPLA, serving as an adjuvant for inactivated rabies vaccines, could significantly facilitate the generation of T follicular helper (Tfh) cells, germinal center (GC) B cells, and plasma cells (PCs), consequently enhancing the production of RABV-specific total-IgG, IgG2a, IgG2b, and the virus-neutralizing antibodies (VNAs). Furthermore, MPLA could increase the survival ratio of mice challenged with virulent RABV. In conclusion, our results demonstrate that MPLA serving as an adjuvant enhances the intensity of humoral immune responses by activating the cDC–Tfh–GC B axis. Our findings will contribute to the improvement of the efficiency of traditional rabies vaccines.

2019 ◽  
Author(s):  
Harald Hartweger ◽  
Andrew T. McGuire ◽  
Marcel Horning ◽  
Justin J. Taylor ◽  
Pia Dosenovic ◽  
...  

AbstractA small number of HIV-1 infected individuals develop broadly neutralizing-antibodies to the virus (bNAbs). These antibodies are protective against infection in animal models. However, they only emerge 1 - 3 years after infection, and show a number of highly unusual features including exceedingly high levels of somatic mutations. It is therefore not surprising that elicitation of protective immunity to HIV-1 has not yet been possible. Here we show that mature, primary mouse and human B cells can be editedin vitrousing CRISPR/Cas9 to express mature bNAbs from the endogenousIghlocus. Moreover, edited B cells retain the ability to participate in humoral immune responses. Immunization with cognate antigen in wild type mouse recipients of edited B cells elicits bNAb titers that neutralize HIV-1 at levels associated with protection against infection. This approach enables humoral immune responses that may be difficult to elicit by traditional immunization.One-sentence summaryB cells edited by CRISPR/Cas9 to produce antibodies participate in humoral immune reactions and secrete neutralizing serum titers of anti-HIV bNAbs.


2000 ◽  
Vol 68 (2) ◽  
pp. 791-795 ◽  
Author(s):  
Lise Brandt ◽  
Martin Elhay ◽  
Ida Rosenkrands ◽  
Erik B. Lindblad ◽  
Peter Andersen

ABSTRACT The ESAT-6 antigen from Mycobacterium tuberculosis is a dominant target for cell-mediated immunity in the early phase of tuberculosis (TB) in TB patients as well as in various animal models. The purpose of our study was to evaluate the potential of ESAT-6 in an experimental TB vaccine. We started out using dimethyl dioctadecylammonium bromide (DDA), an adjuvant which has been demonstrated to be efficient for the induction of cellular immune responses and has been used successfully before as a delivery system for TB vaccines. Here we demonstrate that, whereas immune responses to both short-term-culture filtrate and Ag85B are efficiently induced with DDA, this adjuvant was inefficient for the induction of immune responses to ESAT-6. Therefore, we investigated the modulatory effect of monophosphoryl lipid A (MPL), an immunomodulator which in different combinations has demonstrated strong adjuvant activity for both cellular and humoral immune responses. We show in the present study that vaccination with ESAT-6 delivered in a combination of MPL and DDA elicited a strong ESAT-6-specific T-cell response and protective immunity comparable to that achieved withMycobacterium bovis BCG.


Vaccines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1061
Author(s):  
Chau Thuy Tien Le ◽  
So Yeon Ahn ◽  
Sang-Moo Kang ◽  
Eun-Ju Ko

Natural killer (NK) cells are one of the types of innate immune cells to remove pathogen-infected cells and modulate inflammatory immune responses. Recent studies have revealed that NK cells could enhance vaccine efficacy by coordinating the innate and adaptive immune responses. In this study, we have evaluated the efficacy of intranasal ovalbumin (OVA) immunization with a monophosphoryl lipid A (MPL) and polyriboinosinic polyribocytidylic acid (poly I:C) combination adjuvant in promoting NK cell recruitment, differentiation, and activation. The frequencies of NK cells were positively correlated with those of dendritic cells (DCs) at the site of immunization. Moreover, the activated NK cells and DCs by the MPL + poly I:C combination adjuvant induced activations of each other cells in vitro. Taken together, this study suggested that the MPL and poly I:C combination adjuvant in OVA vaccination mediated NK cell activation and cellular crosstalk between NK cells and DCs, suggesting a promising vaccine adjuvant candidate for promoting cellular immune responses.


2019 ◽  
Vol 216 (6) ◽  
pp. 1301-1310 ◽  
Author(s):  
Harald Hartweger ◽  
Andrew T. McGuire ◽  
Marcel Horning ◽  
Justin J. Taylor ◽  
Pia Dosenovic ◽  
...  

A small number of HIV-1–infected individuals develop broadly neutralizing antibodies to the virus (bNAbs). These antibodies are protective against infection in animal models. However, they only emerge 1–3 yr after infection, and show a number of highly unusual features including exceedingly high levels of somatic mutations. It is therefore not surprising that elicitation of protective immunity to HIV-1 has not yet been possible. Here we show that mature, primary mouse and human B cells can be edited in vitro using CRISPR/Cas9 to express mature bNAbs from the endogenous Igh locus. Moreover, edited B cells retain the ability to participate in humoral immune responses. Immunization with cognate antigen in wild-type mouse recipients of edited B cells elicits bNAb titers that neutralize HIV-1 at levels associated with protection against infection. This approach enables humoral immune responses that may be difficult to elicit by traditional immunization.


1999 ◽  
Vol 5 (3) ◽  
pp. 181-182 ◽  
Author(s):  
Suzanne M. Michalek ◽  
Noel K. Childers ◽  
Terry Greenway ◽  
George Hajishengallis ◽  
J. Terry Ulrich

2017 ◽  
Vol 313 (1) ◽  
pp. F103-F115 ◽  
Author(s):  
Bruns A. Watts ◽  
Thampi George ◽  
Edward R. Sherwood ◽  
David W. Good

Monophosphoryl lipid A (MPLA) is a detoxified derivative of LPS that induces tolerance to LPS and augments host resistance to bacterial infections. Previously, we demonstrated that LPS inhibits [Formula: see text] absorption in the medullary thick ascending limb (MTAL) through a basolateral Toll-like receptor 4 (TLR4)-myeloid differentiation factor 88 (MyD88)-ERK pathway. Here we examined whether pretreatment with MPLA would attenuate LPS inhibition. MTALs from rats were perfused in vitro with MPLA (1 µg/ml) in bath and lumen or bath alone for 2 h, and then LPS was added to (and MPLA removed from) the bath solution. Pretreatment with MPLA eliminated LPS-induced inhibition of [Formula: see text] absorption. In MTALs pretreated with MPLA plus a phosphatidylinositol 3-kinase (PI3K) or Akt inhibitor, LPS decreased [Formula: see text] absorption. MPLA increased Akt phosphorylation in dissected MTALs. The Akt activation was eliminated by a PI3K inhibitor and in MTALs from TLR4−/−or Toll/IL-1 receptor domain-containing adaptor-inducing IFN-β (TRIF)−/−mice. The effect of MPLA to prevent LPS inhibition of [Formula: see text] absorption also was TRIF dependent. Pretreatment with MPLA prevented LPS-induced ERK activation; this effect was dependent on PI3K. MPLA alone had no effect on [Formula: see text] absorption, and MPLA pretreatment did not prevent ERK-mediated inhibition of [Formula: see text] absorption by aldosterone, consistent with MPLA's low toxicity profile. These results demonstrate that pretreatment with MPLA prevents the effect of LPS to inhibit [Formula: see text] absorption in the MTAL. This protective effect is mediated directly through MPLA stimulation of a TLR4-TRIF-PI3K-Akt pathway that prevents LPS-induced ERK activation. These studies identify detoxified TLR4-based immunomodulators as novel potential therapeutic agents to prevent or treat renal tubule dysfunction in response to bacterial infections.


2021 ◽  
Author(s):  
Preethi Eldi ◽  
Tamara H Cooper ◽  
Natalie A Prow ◽  
Liang Liu ◽  
Gary K Heinemann ◽  
...  

The ongoing COVID-19 pandemic perpetuated by SARS-CoV-2 variants, has highlighted the continued need for broadly protective vaccines that elicit robust and durable protection. Here, the vaccinia virus-based, replication-defective Sementis Copenhagen Vector (SCV) was used to develop a first-generation COVID-19 vaccine encoding the spike glycoprotein (SCV-S). Vaccination of mice rapidly induced polyfunctional CD8 T cells with cytotoxic activity and robust Th1-biased, spike-specific neutralizing antibodies, which are significantly increased following a second vaccination, and contained neutralizing activity against the alpha and beta variants of concern. Longitudinal studies indicated neutralizing antibody activity was maintained up to 9 months post-vaccination in both young and aging mice, with durable immune memory evident even in the presence of pre-existing vector immunity. This immunogenicity profile suggests a potential to expand protection generated by current vaccines in a heterologous boost format, and presents a solid basis for second-generation SCV-based COVID-19 vaccine candidates incorporating additional SARS-CoV-2 immunogens.


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