Altered peptide ligands of myelin basic protein (MBP_87–99) conjugated to reduced mannan modulate immune responses in mice

Abstract

Mutations of peptides to generate altered peptide ligands, capable of switching immune responses from T helper 1 (Th1) to T helper 2 (Th2), are promising candidates for the immunotherapy of autoimmune diseases such as multiple sclerosis (MS). We synthesized two mutant peptides from myelin basic protein 87-99 (MBP(87-99)), an immunodominant peptide epitope identified in MS. Mutations of residues K(91) and P(96), known to be critical T-cell receptor (TCR) contact sites, resulted in the mutant peptides [R(91), A(96)]MBP(87-99) and [A(91), A(96)]MBP(87-99). Immunization of mice with these altered peptide ligands emulsified in complete Freund's adjuvant induced both interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) responses compared with only IFN-gamma responses induced to the native MBP(87-99) peptide. It was of interest that [R(91), A(96)]MBP(87-99) conjugated to reduced mannan induced 70% less IFN-gamma compared with the native MBP(87-99) peptide. However, [A(91), A(96)]MBP(87-99) conjugated to reduced mannan did not induce IFN-gamma-secreting T cells, but elicited very high levels of interleukin-4 (IL-4). Furthermore, antibodies generated to [A(91), A(96)]MBP(87-99) peptide conjugated to reduced mannan did not cross-react with the native MBP(87-99) peptide. By molecular modelling of the mutant peptides in complex with major histocompatibility complex (MHC) class II, I-A(s), novel interactions were noted. It is clear that the double-mutant peptide analogue [A(91), A(96)]MBP(87-99) conjugated to reduced mannan is able to divert immune responses from Th1 to Th2 and is a promising mutant peptide analogue for use in studies investigating potential treatments for MS.

Properties of myelin altered peptide ligand cyclo(87-99)(Ala91,Ala96)MBP87-99 render it a promising drug lead for immunotherapy of multiple sclerosis

“…It is presumed that similar contacts between TCR and peptides bound to MHC class II could also result in antagonist activity [17]. These observations are further supported by our previous studies with SJL/J mice that showed that injection of cyclo(87-99)(Ala91,Ala96)MBP87-99 resulted in reduced Th1 cytokine production [18,19]. Furthermore, using an EAE chronic pain model it was shown that vaccination with this analog ameliorated EAE and selectively mediated an analgesic effect on the animals [20].…”

“…We have chosen to study the MBP87-99 sequence, because MBP peptides 83-99 and 87-99 are encephalitogenic in rodent strains susceptible to acute (Lewis rat) and chronic (SJL/J mouse) EAE [19,21]. In addition, MBP epitopes are major autoantigens in MS, and the MBP87-99 sequence is an immunodominant epitope [3][4][5]12,16].…”

Effects of active immunisation with myelin basic protein and myelin-derived altered peptide ligand on pain hypersensitivity and neuroinflammation

“…They have been shown to ameliorate clinical EAE (Katsara et al, 2009, Tselios et al, 2001, Nicholson et al, 1995, reduce depressive behaviour (Lewitus et al, 2009), and promote recovery following incomplete spinal cord injury (Hauben et al, 2001) (Tian et al, 2013a). A subsequent study revealed that active immunisation with the same MBP-derived APL significantly reduced mechanical pain hypersensitivity and neuroinflammation in nerve-injured rats (Perera et al, 2015).…”

Carbohydrate-Based Adjuvants for Vaccine Production

“…В клиническом исследовании антигена MUC-1 (антиген, экс-прессируемый различными опухолями, в данном случае аде-нокарциномой), конъюгированного с окисленным маннаном, частота рецидивирования опухоли была более чем в четыре С. С. Курашова, Т. К. Дзагурова, А. А. Ишмухаметов, М. С. Егорова, М. В. Баловнева, С. Е. Соцкова, Е. А. Ткаченко S. S. Kurashova, Т. К. Dzagurova, А. А. Ishmukhametov, М. S. Egorova, М. V. Balovneva, S. E. Sotskova, Е. А. Tkachenko раза ниже [43]. При конъюгации основного миелинового белка (ОМБ) с восстановленным маннаном иммунный ответ против ОМБ реализовывался не Th1, а Th2, что предотвращало раз-витие экспериментального аллергического энцефаломиелита у мышей [44]. На модели болезни Альцгеймера у гипореактив-ных трансгенных мышей было показано, что маннан, конъюги-рованный с антигеном Aβ, усиливал продукцию антител против данного антигена, что указывает на способность адъюванта маннана преодолевать аутотолерантность [45].…”