scholarly journals Single domain antibody-antigen adducts that target Class II MHC induce antigen-specific tolerance

Author(s):  
Novalia Pishesha ◽  
Thibault Harmand ◽  
Liyan Smeding ◽  
Weiyi Ma ◽  
Leif Ludwig ◽  
...  

Abstract The association of autoimmune diseases with particular allelic variants of Class II MHC (MHCII) products implicates presentation of the offending self-antigen(s) to T cells. Antigen presenting cells are tolerogenic when they encounter antigen under non-inflammatory conditions. Manipulation of antigen presentation would therefore be a possible intervention to induce antigen-specific tolerance. We show that, under non-inflammatory conditions, systemic administration of a single dose of a nanobody that recognizes MHCII (VHH MHCII) conjugated to the relevant self-antigen affords long-lasting protection against induction of experimental autoimmune encephalitis (EAE), type 1 diabetes (T1D), and rheumatoid arthritis (RA). Co-administration of the VHH MHCII-antigen adduct together with dexamethasone, conjugated to VHH MHCII via a cleavable linker, not only halted progression of established EAE in symptomatic mice but even reverted the severity of EAE, establishing this approach as a potential means of treating autoimmune conditions.

1990 ◽  
Vol 172 (2) ◽  
pp. 567-575 ◽  
Author(s):  
R D Moses ◽  
R N Pierson ◽  
H J Winn ◽  
H Auchincloss

We studied proliferation and interleukin 2 production by B6 mouse spleen cells in response to stimulation by irradiated cynomolgus monkey spleen cells and compared the results with responses against whole MHC-disparate allogeneic controls (BALB/c). We found that (a) primary xenogeneic helper responses were absent, whereas primary allogeneic responses were brisk, (b) secondary xenogeneic helper responses were dependent on CD4+ T cells and responder antigen-presenting cells (APCs), whereas allogeneic responses could be mediated by either CD4+ or CD8+ T cells independently and were primarily dependent on the presence of stimulator APCs, and (c) secondary xenogeneic helper responses were blocked by an antibody directed against responder class II MHC molecules. These results suggest that mouse helper T cells recognize disparate xenoantigens as processed peptides in association with self class II MHC molecules, similar to the recognition of nominal antigens and unlike direct allo-recognition.


Reproduction ◽  
2006 ◽  
Vol 131 (4) ◽  
pp. 689-698 ◽  
Author(s):  
Matthew J Cannon ◽  
John S Davis ◽  
Joy L Pate

Luteal cells express class II major histocompatibility complex (MHC) molecules and can stimulate T lymphocyte proliferationin vitro. However, it is unknown whether luteal cells express the intracellular components necessary to process the peptides presented by class II MHC molecules. The objective of the present study was to examine the expression and regulation of three major class II-associated antigen processing components – class II MHC-associated invariant chain (Ii), DMα and DMβ – in luteal tissue. Corpora lutea were collected early in the estrous cycle, during midcycle and late in the estrous cycle, and at various times following administration of a luteolytic dose of prostaglandin F2α(PGF2α) to the cow. Northern analysis revealed the presence of mRNA encoding each of the class II MHC-associated antigen processing proteins in luteal tissue. Ii mRNA concentrations did not change during the estrous cycle, whereas DMα and DMβ mRNA concentrations were highest in midcycle luteal tissue compared with either early or late luteal tissue. Tumor necrosis factor-α (TNF-α) reduced DMα mRNA concentrations in cultured luteal cells in the presence of LH or PGF2α. DMα and DMβ mRNA were also present in highly enriched cultures of luteal endothelial (CLENDO) cells, and DMα mRNA concentrations were greater in CLENDO cultures compared with mixed luteal cell cultures. Expression of invariant chain, DMα and DMβ genes indicates that cells within the corpus luteum express the minimal requirements to act as functional antigen-presenting cells, and the observation that CLENDO cells are a source of DMα and DMβ mRNA indicates that non-immune cells within the corpus luteum may function as antigen-presenting cells.


PLoS ONE ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. e29805 ◽  
Author(s):  
Cristina Maria Costantino ◽  
Eric Spooner ◽  
Hidde L. Ploegh ◽  
David A. Hafler

1998 ◽  
Vol 186 (2) ◽  
pp. 111-120 ◽  
Author(s):  
Mark D. Mannie ◽  
John P. Nardella ◽  
Gregory A. White ◽  
Paula Y. Arnold ◽  
Daniel K. Davidian

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Valeria Messina ◽  
Carla Buccione ◽  
Giulia Marotta ◽  
Giovanna Ziccheddu ◽  
Michele Signore ◽  
...  

Mesenchymal stromal cells (MSCs), first found in bone marrow (BM), are the structural architects of all organs, participating in most biological functions. MSCs possess tissue-specific signatures that allow their discrimination according to their origin and location. Among their multiple functions, MSCs closely interact with immune cells, orchestrating their activity to maintain overall homeostasis. The phenotype of tissue MSCs residing in the bowel overlaps with myofibroblasts, lining the bottom walls of intestinal crypts (pericryptal) or interspersed within intestinal submucosa (intercryptal). In Crohn’s disease, intestinal MSCs are tightly stacked in a chronic inflammatory milieu, which causes their enforced expression of Class II major histocompatibility complex (MHC). The absence of Class II MHC is a hallmark for immune-modulator and tolerogenic properties of normal MSCs and, vice versa, the expression of HLA-DR is peculiar to antigen presenting cells, that is, immune-activator cells. Interferon gamma (IFNγ) is responsible for induction of Class II MHC expression on intestinal MSCs. The reversal of myofibroblasts/MSCs from an immune-modulator to an activator phenotype in Crohn’s disease results in the formation of a fibrotic tube subverting the intestinal structure. Epithelial metaplastic areas in this context can progress to dysplasia and cancer.


2021 ◽  
Vol 118 (44) ◽  
pp. e2116147118
Author(s):  
Novalia Pishesha ◽  
Thibault J. Harmand ◽  
Paul W. Rothlauf ◽  
Patrique Praest ◽  
Ryan K. Alexander ◽  
...  

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in over 100 million infections and millions of deaths. Effective vaccines remain the best hope of curtailing SARS-CoV-2 transmission, morbidity, and mortality. The vaccines in current use require cold storage and sophisticated manufacturing capacity, which complicates their distribution, especially in less developed countries. We report the development of a candidate SARS-CoV-2 vaccine that is purely protein based and directly targets antigen-presenting cells. It consists of the SARS-CoV-2 Spike receptor-binding domain (SpikeRBD) fused to an alpaca-derived nanobody that recognizes class II major histocompatibility complex antigens (VHHMHCII). This vaccine elicits robust humoral and cellular immunity against SARS-CoV-2 and its variants. Both young and aged mice immunized with two doses of VHHMHCII-SpikeRBD elicit high-titer binding and neutralizing antibodies. Immunization also induces strong cellular immunity, including a robust CD8 T cell response. VHHMHCII-SpikeRBD is stable for at least 7 d at room temperature and can be lyophilized without loss of efficacy.


2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A20.2-A20
Author(s):  
V Pinamonti ◽  
N Felix ◽  
JM Lindner

BackgroundThe identification of neo-antigens presented by tumor cells is an essential tool for cancer prevention, diagnosis, and therapy. Current approaches frequently involve mass spectrometric analysis, but these workflows do not concomitantly identify the cognate T-cell receptor. Likewise, TCR functional screens are often limited to a subset of predicted neo-epitopes.Materials and MethodsHere, we present a new method for the generation of an un-biased antigen-presenting library. Due to the genomic instability of tumors, patient-specific libraries will be cloned using random primers, ensuring the cloning of tumor-specific transcribed regions. This approach will not only address class I presentation of intracellular tumor antigens, but is also designed to simultaneously screen for cross-presentation on class II MHC complexes by professional antigen-presenting cells, an increasingly important component of anti-tumor immune responses. To guarantee presentation of genetically encoded antigens on class II MHC complexes, a signal motif for chaperone-mediated autophagy (CMA) is introduced in front of the cDNA sequence. Furthermore, antigens will be processed by the intracellular machinery, avoiding potential restrictions on spliced peptides.ConclusionsOnce established, these libraries can be exploited in high-throughput screens to functionally identify neo-antigens together with their corresponding T-cell receptor.Disclosure InformationV. Pinamonti: Other; Significant; Janssen. N. Felix: Other; Significant; Janssen. J.M. Lindner: Other; Significant; Janssen.


1992 ◽  
Vol 176 (1) ◽  
pp. 47-58 ◽  
Author(s):  
D Vremec ◽  
M Zorbas ◽  
R Scollay ◽  
D J Saunders ◽  
C F Ardavin ◽  
...  

A new procedure for rapid isolation of dendritic cells (DC) was devised, involving collagenase digestion of tissues, dissociation of lymphoid-DC complexes, selection of light-density cells, then depletion of lymphocytes and other non-DC by treatment with a mixture of lineage-specific monoclonal antibodies (mAbs) and removal with anti-immunoglobulin-coupled magnetic beads. This enriched population (approximately 80% DC) was further purified when required by fluorescence-activated cell sorting for cells expressing high levels of class II major histocompatibility complex (MHC). The isolated DC were characterized by immunofluorescent staining using a panel of 30 mAbs. Thymic DC were surface positive for a number of markers characteristic of T cells, but they were distinct from T-lineage cells in expressing high levels of class II MHC, in lacking expression of the T cell receptor (TCR)-CD3 complex, and having TCR beta and gamma genes in germline state. Splenic DC shared many markers with thymic DC, but were negative for most T cell markers, with the exception of CD8. A substantial proportion of DC from both thymus and spleen expressed CD8 at high levels, comparable with that on T cells. This appeared to be authentic CD8, and was produced by the DC themselves, since they contained CD8 alpha mRNA. Thymic DC presented both the CD8 alpha and beta chains on the cell surface (Ly-2+3+), although the alpha chain was in excess; the splenic DC expressed only the CD8 alpha chain (Ly-2+3-). It is suggested that the expression of CD8 could endow certain antigen-presenting DC with a veto function.


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