Evaluation of SOCS5 mRNA and its association with serum IL-12 levels and rs41379147 SNP in various subsets of allergic disorders: A case control study

BACKGROUND

The SOCS proteins act as suppressors of cytokine signaling by impeding certain signaling pathways. SOCS5, a constituent of the SOCS family, has been associated with the management of allergic reactions, primarily by impeding the signaling of interleukin-4 (IL-4), which is known to have a cardinal function in accelerating the development of an allergic reaction. The key goal of our research was to explore the probable ramifications of the SOCS5 single nucleotide polymorphism (SNP) namely rs41379147 on the expression of SOCS5 mRNA and serum IL-12 levels, as well as to analyze the interaction between SOCS5 genotypes and various clinicopathological parameters in atopic diseases.

METHODS

The study involved the enrollment of 314 subjects comprising 154 atopic individuals and 160 healthy controls. PCR-RFLP was employed to conduct SNP analysis. Real-Time PCR was employed to quantify SOCS5 mRNA. The enzyme-linked immunosorbent assay (ELISA) technique was used for the quantification of interleukin-12 and total IgE levels in the serum while as chemiluminescence was used to determine Vitamin D levels.

RESULTS

The PCR-RFLP analysis indicated a lack of statistically significant variation in genotypic and allelic frequencies between the cases and controls (p > 0.05) for - 9147 C/T SNP either in total atopy (OR-0.70, 95% CI=0.43-1.12, p =0.15), and on subgroup stratifications of chronic urticaria (OR-0.81, 95 % CI = 0.42-1.59, p = 0.61), allergic rhinitis (OR-0.63, 95 % CI = 0.33-1.19, p = 0.16) and bronchial asthma (OR-0.66,95% CI = 0.29-1.4, p=0.32). There was reduced mRNA expression of SOCS5 in total atopic cases, allergic rhinitis, bronchial asthma and chronic urticaria in comparison to controls which advocates the fact that SOCS5 has a protective role in allergic disease development. Despite the reduced amounts of IL-12 in total atopic cases and different allergic disorders in comparison to controls, IL-12 showed significant positive correlation with SOCS5 mRNA expression (p < 0.05).

CONCLUSION

SOCS5 SNP rs41379147(C/T) does not pose any significant risk towards the development of any allergic disorder and has no impact on the expression of SOCS5 and IL-12. Our study has shown the reduced mRNA expression of SOCS5 among individuals diagnosed with chronic urticaria, allergic rhinitis and bronchial asthma and the expression of SOCS5 showed complete dependence on the cytokine milieu of IL12. The modulation of SOCS5 and IL-12 may represent potential curative targets for treating the menace of allergic diseases and present promising avenues for future investigation.

Maturation of Dendritic Cells Accompanies High-Efficiency Gene Transfer by a CD40-Targeted Adenoviral Vector

Important therapeutic applications of genetically modified dendritic cells (DC) have been proposed; however, current vector systems have demonstrated only limited gene delivery efficacy to this cell type. By means of bispecific Abs, we have dramatically enhanced gene transfer to monocyte derived DC (MDDC) by retargeting adenoviral (Ad) vectors to a marker expressed on DC, CD40. Adenovirus targeted to CD40 demonstrated dramatic improvements in gene transfer relative to untargeted Ad vectors. Fundamental to the novelty of this system is the capacity of the vector itself to modulate the immunological status of the MDDC. This vector induces DC maturation as demonstrated phenotypically by increased expression of CD83, MHC, and costimulatory molecules, as well as functionally by production of IL-12 and an enhanced allostimulatory capacity in a MLR. In comparing this vector to other Ad-based gene transfer systems, we have illustrated that the features of DC maturation are not a function of the Ad particle, but rather a consequence of targeting to the CD40 marker. This vector approach may thus mediate not only high-efficiency gene delivery but also serve a proactive role in DC activation that could ultimately strengthen the utility of this vector for immunotherapy strategies.

Resistance to Fas-Mediated T Cell Apoptosis in Asthma

Over activation of CD4+ T cells in the peripheral blood and airway tissues is characteristic of asthma; therefore, we investigated whether activated T cells from asthmatic subjects have altered apoptotic potential through the Fas death receptor. We found that mitogen-stimulated peripheral blood T cells of asthmatic subjects expressed cell surface Fas, but failed to undergo the normal degree of apoptosis after Fas receptor ligation. T cells from asthmatics exhibited normal apoptotic responses to γ-irradiation (dependent on IL-1 converting enzyme family proteases), ceramide, and mitogen challenge, suggesting functional integrity of the apoptotic pathway. Furthermore, the defect in Fas-dependent apoptosis was overcome by prestimulation with allogeneic accessory cells instead of mitogen. Taken together, the findings suggest that selective resistance to Fas-dependent apoptosis reflects altered Ag-driven, accessory cell-dependent signaling and that ineffective activation of Fas signal transduction may contribute to T cell-dependent immunoinflammation in asthma.

Fcε Receptor I on Dendritic Cells Delivers IgE-Bound Multivalent Antigens into a Cathepsin S-Dependent Pathway of MHC Class II Presentation

In this study, we elucidate the FcεRI-mediated Ag uptake and presentation mechanisms of dendritic cells (DC). We found that FcεRI-bound IgE, after polyvalent but not after monovalent ligation, is efficiently internalized into acidic, proteolytic compartments, degraded, and delivered into organelles containing MHC class II, HLA-DM, and lysosomal proteins. To follow the fate of the fragmented ligand, we sought to interfere with invariant chain (Ii) degradation, a process critical for peptide loading of nascent MHC class II molecules. We found DC to express cathepsin (Cat) S, a cysteine protease involved in li processing by B cells. Exposure of DC to a specific, active-site inhibitor of Cat S resulted in the loss of anti-Cat S immunoreactivity, led to the appearance of an N-terminal Ii remnant, and decreased the export of newly synthesized MHC class II to the DC surface. Furthermore, inactivation of Cat S as well as blockade of protein neosynthesis by cycloheximide strongly reduced IgE/FcεRI-mediated Ag presentation by DC. Thus, multimeric ligands of FcεRI, instead of being delivered into a recycling MHC class II pathway, are channeled efficiently into MIIC (MHC class II compartment)-like organelles of DC, in which Cat S-dependent li processing and peptide loading of newly synthesized MHC class II molecules occur. This IgE/FcεRI-dependent signaling pathway in DC may be a particularly effective route for immunization and a promising target for interfering with the early steps of allergen presentation.

IFN-α Priming of Human Monocytes Differentially Regulates Gram-Positive and Gram-Negative Bacteria-Induced IL-10 Release and Selectively Enhances IL-12p70, CD80, and MHC Class I Expression

Administration of IFN-γ and IFN-α may protect or induce autoimmune diseases. Although the in vitro regulation of monokine secretion by IFN-γ have been extensively studied, the regulatory function of IFN-α has not yet been elucidated. We compared IFN-α and IFN-γ, added alone or simultaneously before bacterial stimulation, for the control of monokine release and the expression of costimulatory molecules by human monocytes. Our data show that: 1) IFN-α primes monocytes for increased production of IL-10 in response to Staphylococcus aureus Cowan I strain (SAC) but not to LPS, leading to a lack of IFN-α priming for TNF-α secretion; 2) pretreatment of monocytes with IFN-α inhibits LPS- or SAC-induced IL-12p40 production but unexpectedly enhances the release of the biologically active form of IL-12 (IL-12p70); 3) IFN-α and IFN-γ exert an antagonistic effect on LPS- and SAC-induced IL-10 as well as IL-12p40 release, whereas they further enhance IL-12p70 production when added simultaneously; 4) in contrast to IFN-α, IFN-γ primes monocytes to enhance LPS- or SAC-induced TNF-α and IL-12 production, but surprisingly, it increases IL-10 production by monocytes following LPS but not SAC stimulation; and finally, 5) IFN-α pretreatment selectively up-regulates CD80 and MHC class I expression on monocytes. It is proposed that the outcome of the immune response at the site of inflammation may depend on both the type of bacterial injury (Gram-positive or -negative) and of locally produced IFNs, and that the differential and opposite effects of type I and type II IFNs on monocytes may account for the beneficial or detrimental effects of IFN-α therapy.