Thesis (Ph.D.)--University of Alabama at Birmingham, 2007. / Title from PDF title page (viewed on Sept. 16, 2009). Includes bibliographical references.

A esclerose sistêmica (ES) é uma doença difusa do tecido conjuntivo caracterizada por anormalidades fibróticas, imunológicas e vasculares. O fator nuclear-kB (NF-kB), como um fator de transcrição essencial envolvido na regulação de respostas imunitárias, parece ser um bom candidato para estudos sobre a patogênese de doenças autoimunes, bem como a interleucina-10 (IL-10) e as quimiocinas, CXCL8 e CXCR2. Vários estudos demonstram o envolvimento dos genes CXCR2 e IL-10 na patogênese das doenças autoimunes. Acredita-se que combinações desses genes possam ser favoráveis para o desenvolvimento da ES, podendo seu conhecimento ser benéfico para o entendimento da patogênese da ES. O objetivo deste estudo é investigar o polimorfismo dos genes IL-10, CXCR2, CXCL8 e NFKB1 em um grupo de pacientes com ES, incluindo a forma difusa e limitada da doença. Nossos resultados confirmam a associação do fenótipo de alta produção (GCC + / GCC +) com risco aumentado para ES, mas não encontrou nenhuma correlação com polimorfismos do NF-KB. Nossos achados também sugerem um papel protetor da CXCL8 (- 251) A nos genótipos TT e TC do gene CXCR2 (+1208) e um risco aumentado do CXCL8 (-251) A em associação com o genótipo CC do CXCR2 (+1208) em pacientes com ES. Nenhuma diferença estatística no polimorfismo dos genes IL-10, CXCR2, CXCL8 e NFKB1 foram encontradas entre a forma difusa e a forma limitada. Estes resultados indicam um potencial papel do gene IL-10 e da combinação CXCR2/CXCL8 na patogênese da ES. / Systemic sclerosis (SSc) is a connective tissue disease characterized by fibrotic, immunological and vascular abnormalities. Nuclear factor-kB (NF-kB), as a key transcription factor involved in the regulation of immune responses, appears to be a good candidate for studies on the pathogenesis of autoimmune diseases, as well as the interleukin-10 (IL-10) polymorphism, and CXCL8 and CXCR2 chemokines. Several studies have demonstrated the involvement of genes CXCR2 and IL-10 in the pathogenesis of autoimmune diseases. It is believed that combinations of these genes may be favorable for the development of SSc, and this knowledge can contribute to the understanding of the pathogenesis of SSc. The objective of this study is to investigate the polymorphism of IL-10, CXCR2, CXCL8 and NFKB1 in a group of patients with SSc, including diffuse and limited subtypes of the disease. Our results confirm the association of high-producing phenotype (GCC/GCC) with increased risk for SSc, but found no correlation with NFKB1 polymorphisms. Our findings also suggest a protective role of CXCL8 (-251) A in the CXCR2 (+1208) TT and TC genotypes and an increased risk of CXCL8 (-251) A in association with the CXCR2 (+1208) CC genotype in SSc patients. No statistical difference in the polymorphism of IL-10, NFKB1, CXCR2 and CXCL8 were found between the diffuse and limited SSc. These results indicate a potential role of the IL-10 gene and the combination CXCR2/CXCL8 in the pathogenesis of SSc.

Inflammation plays a key role during pathological hypertrophy and heart failure. Whilst the roles of pro-inflammatory cytokines are relatively well understood, little is known about the anti-inflammatory cytokines in the heart. Interleukin-10 (IL-10) is a major anti-inflammatory cytokine that is expressed in the heart and may play a crucial role during cardiac remodelling. IL-10 exerts its function by binding to the IL-10 receptor (IL-10R). The primary aim of the PhD study was to investigate the effects of the ubiquitous ablation of IL-10R1 gene during pressure overload induced hypertrophy and to characterise the downstream pathway regulated by IL-10R1 in the heart following pressure overload. The second aim was to investigate the effects of cell specific ablation of IL-10R1 in both the macrophages and cardiomyocytes during pressure overload induced hypertrophy and to identify the specific site where IL-10R1 regulates hypertrophy in the heart. During this study three mouse lines were used: IL-10R1 global knockout (IL-10R1-/-), IL-10R1 macrophage-specific knockout (IL-10R1mKO) and IL-10R1 cardiomyocyte-specific knockout (IL-10R1cKO).Mice with systemic ablation of IL-10 receptor1 (IL-10R1-/-) displayed a significant increase in hypertrophy following two weeks of transverse aortic constriction (TAC) as indicated by heart weight/tibia length ratio (HW/TL). This was accompanied by a significant increase in cardiomyocyte surface area as well as expression of hypertrophic markers such as brain natriuretic peptide (BNP) and Atrial natriuretic peptide (ANP). The IL-10R1-/- mice also had a significant increase in cardiac fibrosis when compared to the WT TAC littermates. Importantly, ejection fraction (EF) and fractional shortening (FS) were significantly reduced in IL-10R1-/- mice compared with WT littermates following TAC. The STAT3 pathway is known as the major downstream signalling pathway regulated by the IL-10R via the activation of the JAK1/STAT3 pathway.  Western blot analysis showed that activation of the STAT3 signalling pathway was significantly reduced in IL-10R1-/- mice following TAC, indicating the possible involvement of this pathway. Furthermore, expression of STAT3 target genes: suppressor of cytokine signalling (SOCS3), tissue inhibitor of metalloproteinases3 (TIMP-3) and heme oxygenase (HO-1) were downregulated in the IL-10R1-/- mice following TAC. Overall the data obtain from the IL-10R1-/- mice indicate that IL-10R1 signalling plays a protective role in reducing pathological hypertrophy in the heart. Interestingly, IL-10R1mKO mice showed no difference in the hypertrophic response following TAC. Analysis of cardiac function and STAT3 activation also showed no difference between IL-10R1mKO and WT controls. This indicated that the protective effects of IL-10R1 mediated signalling during cardiac pressure overload was unlikely due to the effects in residential macrophages. In contrast, IL-10R1cKO mice displayed an elevated hypertrophic response, reduction of cardiac function and less STAT3 activation after TAC. This phenotype resembled those of IL-10R1 global knockout mice. In conclusion, this PhD study has shown that IL-10R1 mediated signalling in the heart is important in controlling pressure-overload hypertrophy. Using cell-specific knockout mice I have shown that IL-10R signalling in cardiomyocytes and not in macrophages is important in this process. These results will open a new insight in targeting IL-10 receptor in the treatment of myocardial hypertrophy in future.

A esclerose sistêmica (ES) é uma doença difusa do tecido conjuntivo caracterizada por anormalidades fibróticas, imunológicas e vasculares. O fator nuclear-kB (NF-kB), como um fator de transcrição essencial envolvido na regulação de respostas imunitárias, parece ser um bom candidato para estudos sobre a patogênese de doenças autoimunes, bem como a interleucina-10 (IL-10) e as quimiocinas, CXCL8 e CXCR2. Vários estudos demonstram o envolvimento dos genes CXCR2 e IL-10 na patogênese das doenças autoimunes. Acredita-se que combinações desses genes possam ser favoráveis para o desenvolvimento da ES, podendo seu conhecimento ser benéfico para o entendimento da patogênese da ES. O objetivo deste estudo é investigar o polimorfismo dos genes IL-10, CXCR2, CXCL8 e NFKB1 em um grupo de pacientes com ES, incluindo a forma difusa e limitada da doença. Nossos resultados confirmam a associação do fenótipo de alta produção (GCC + / GCC +) com risco aumentado para ES, mas não encontrou nenhuma correlação com polimorfismos do NF-KB. Nossos achados também sugerem um papel protetor da CXCL8 (- 251) A nos genótipos TT e TC do gene CXCR2 (+1208) e um risco aumentado do CXCL8 (-251) A em associação com o genótipo CC do CXCR2 (+1208) em pacientes com ES. Nenhuma diferença estatística no polimorfismo dos genes IL-10, CXCR2, CXCL8 e NFKB1 foram encontradas entre a forma difusa e a forma limitada. Estes resultados indicam um potencial papel do gene IL-10 e da combinação CXCR2/CXCL8 na patogênese da ES. / Systemic sclerosis (SSc) is a connective tissue disease characterized by fibrotic, immunological and vascular abnormalities. Nuclear factor-kB (NF-kB), as a key transcription factor involved in the regulation of immune responses, appears to be a good candidate for studies on the pathogenesis of autoimmune diseases, as well as the interleukin-10 (IL-10) polymorphism, and CXCL8 and CXCR2 chemokines. Several studies have demonstrated the involvement of genes CXCR2 and IL-10 in the pathogenesis of autoimmune diseases. It is believed that combinations of these genes may be favorable for the development of SSc, and this knowledge can contribute to the understanding of the pathogenesis of SSc. The objective of this study is to investigate the polymorphism of IL-10, CXCR2, CXCL8 and NFKB1 in a group of patients with SSc, including diffuse and limited subtypes of the disease. Our results confirm the association of high-producing phenotype (GCC/GCC) with increased risk for SSc, but found no correlation with NFKB1 polymorphisms. Our findings also suggest a protective role of CXCL8 (-251) A in the CXCR2 (+1208) TT and TC genotypes and an increased risk of CXCL8 (-251) A in association with the CXCR2 (+1208) CC genotype in SSc patients. No statistical difference in the polymorphism of IL-10, NFKB1, CXCR2 and CXCL8 were found between the diffuse and limited SSc. These results indicate a potential role of the IL-10 gene and the combination CXCR2/CXCL8 in the pathogenesis of SSc.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / PeptÃdeos bioativos naturais sÃo substÃncias encontradas em diversas espÃcies que podem alterar a resposta imune contra patÃgenos, seja de forma prejudicial ou proteÃÃo para o hospedeiro. Hà um crescente interesse na utilizaÃÃo de produtos naturais para a modulaÃÃo de processos inflamatÃrios, alguns deles derivados de fungos nÃo patogÃnicos. Fungos patogÃnicos, no entanto, tambÃm apresentam componentes imunomoduladores. Estudos prÃvios mostraram que extratos obtidos de nematÃdeos modularam a resposta imune em modelo experimental. Seguindo a mesma linha de pesquisa, foi investigado o efeito de um extrato obtido do fungo Coccidioides posadasii em modelo de artrite induzida por zymosan (AZy). Ratos e camundongos receberam 1 mg e 0,1 mg de zymosan intra-articular (i.a.), respectivamente. Grupos receberam o extrato de C. posadasii por via oral (v.o.) ou intraperitoneal (i.p.) 30 min antes do zymosan i.a. Grupos-controle receberam apenas soluÃÃo salina. A hipernocicepÃÃo foi medida utilizando o teste de incapacitaÃÃo articular e o von Frey eletrÃnico. O influxo celular agudo e crÃnico, bem como os nÃveis de nitrito e citocinas, foram avaliados no exudato sinovial. A sinÃvia foi utilizada para exame histopatolÃgico. O dano na cartilagem foi avaliado mediante determinaÃÃo de conteÃdo de glicosaminoglicanos (GAG). O prÃ-tratamento com o extrato de C. posadasii, seja i.p. ou v.o., inibiu significativamente e de forma dose-dependente, o influxo de cÃlulas tanto na fase aguda como na fase crÃnica, bem como a hipernocicepÃÃo, acompanhada por uma ligeira reduÃÃo na perda de GAG e uma melhora significativa da sinovite crÃnica. ReduÃÃo e alquilaÃÃo do extrato reverteram os efeitos protetores observados anteriormente. A administraÃÃo do extrato de C. posadasii nÃo alterou os nÃveis i.a. de NO, IL-1β, TNF-α, IFN-γ e IL-17 em ratos e camundongos submetidos à AZy, enquanto nÃveis de IL-10 foram significativamente reduzidos. Os dados revelam que um extrato de C. posadasii reduz a expressÃo de iNOS, que està associado com a inibiÃÃo da apoptose sinovial e diminuiÃÃo dos nÃveis de IL-10 liberados. Esses dados mostram um papel anti-inflamatÃrio sistÃmico e imunomodulador para o extrato de C. posadasii em AZy. Uma abordagem preliminar, utilizando tÃcnicas eletroforÃticas, para caracterizar componentes ativos excluiu carboidratos carregados enquanto aponta para fraÃÃes proteicas ou polipeptÃdeo como responsÃveis pela atividade biolÃgica. O efeito do extrato de C. posadasii à espÃcie-independente. CaracterizaÃÃo adicional dos componentes ativos no extrato pode revelar mecanismos relevantes para compreender a resposta do hospedeiro contra os componentes fÃngicos. AlÃm disso, o efeito anti-inflamatÃrio do extrato ilustra a importÃncia da realizaÃÃo de estudos, uma vez que a atividade oral pode tambÃm ser relevante para o tratamento de doenÃas inflamatÃrias. / Bioactive Natural Peptides are substances found in diverse species and may alter the immune response against pathogens, being either protective or harmful to the host. There is a growing interest in using natural products for the modulation of inflammatory processes, some of them derived from non-pathogenic fungi. However, pathogenic fungi also have immunomodulatory components. Previous studies showed that extracts of nematodes modulate the immune response in experimental model. Following the same line of research, it was investigated the effect of a protein-rich extract from Coccidioides posadasii in model of zymosan-induced arthritis (ZYA). Rats and mice received 1 mg and 0.1 mg zymosan intra-articularly (i.a.), respectively. Test groups received C. posadasii extract either per os or intraperitoneally (i.p.) 30 min prior to zymosan i.a. Controls received saline. Hypernociception was measured using the articular incapacitation test and the von Frey electronic test. Cell influx, nitrite, and cytokines levels were assessed in joint exudates. The synovia was used for histopathology. Cartilage damage was assessed through determining glycosaminoglycan (GAG) content. Pretreatment with the C. posadasii extract, either i.p. or per os, significantly and dose-dependently inhibited both acute and chronic cell influx as well as hypernociception, with a mild reduction of GAG loss and significant amelioration of the chronic synovitis. Reduction and alkylation of the extract abrogated protector effects seen previously. Administration of the C. posadasii extract did not alter i.a. levels of NO, IL-1β, and TNF-α in rats subjected to ZYA, whereas intra-articularly levels of IL-10 were significantly reduced. Data reveal that a C. posadasii extract reduces iNOS expression that is associated to inhibition of synovial apoptosis and decrease of IL-10 levels released into zymosan-inflamed joints.These data show a systemic anti-inflammatory and immunomodulatory role for the C. posadasii extract in ZYA. A preliminary approach, using electrophoresis, to characterize active components excluded the presence of carbohydrates while pointing to a protein or polypeptide present in extract as responsible for the biological activity. The protective effect of the C. posadasii extract is species-independent. Further characterization of the active components in this extract may unravel mechanistic effects relevant to understand the host response against fungal components. In addition, the anti-inflammatory effect of the extract illustrates the relevance of pursuing studies, since the oral activity may also be of relevance to the treatment of inflammatory diseases.

A esclerose sistêmica (ES) é uma doença difusa do tecido conjuntivo caracterizada por anormalidades fibróticas, imunológicas e vasculares. O fator nuclear-kB (NF-kB), como um fator de transcrição essencial envolvido na regulação de respostas imunitárias, parece ser um bom candidato para estudos sobre a patogênese de doenças autoimunes, bem como a interleucina-10 (IL-10) e as quimiocinas, CXCL8 e CXCR2. Vários estudos demonstram o envolvimento dos genes CXCR2 e IL-10 na patogênese das doenças autoimunes. Acredita-se que combinações desses genes possam ser favoráveis para o desenvolvimento da ES, podendo seu conhecimento ser benéfico para o entendimento da patogênese da ES. O objetivo deste estudo é investigar o polimorfismo dos genes IL-10, CXCR2, CXCL8 e NFKB1 em um grupo de pacientes com ES, incluindo a forma difusa e limitada da doença. Nossos resultados confirmam a associação do fenótipo de alta produção (GCC + / GCC +) com risco aumentado para ES, mas não encontrou nenhuma correlação com polimorfismos do NF-KB. Nossos achados também sugerem um papel protetor da CXCL8 (- 251) A nos genótipos TT e TC do gene CXCR2 (+1208) e um risco aumentado do CXCL8 (-251) A em associação com o genótipo CC do CXCR2 (+1208) em pacientes com ES. Nenhuma diferença estatística no polimorfismo dos genes IL-10, CXCR2, CXCL8 e NFKB1 foram encontradas entre a forma difusa e a forma limitada. Estes resultados indicam um potencial papel do gene IL-10 e da combinação CXCR2/CXCL8 na patogênese da ES. / Systemic sclerosis (SSc) is a connective tissue disease characterized by fibrotic, immunological and vascular abnormalities. Nuclear factor-kB (NF-kB), as a key transcription factor involved in the regulation of immune responses, appears to be a good candidate for studies on the pathogenesis of autoimmune diseases, as well as the interleukin-10 (IL-10) polymorphism, and CXCL8 and CXCR2 chemokines. Several studies have demonstrated the involvement of genes CXCR2 and IL-10 in the pathogenesis of autoimmune diseases. It is believed that combinations of these genes may be favorable for the development of SSc, and this knowledge can contribute to the understanding of the pathogenesis of SSc. The objective of this study is to investigate the polymorphism of IL-10, CXCR2, CXCL8 and NFKB1 in a group of patients with SSc, including diffuse and limited subtypes of the disease. Our results confirm the association of high-producing phenotype (GCC/GCC) with increased risk for SSc, but found no correlation with NFKB1 polymorphisms. Our findings also suggest a protective role of CXCL8 (-251) A in the CXCR2 (+1208) TT and TC genotypes and an increased risk of CXCL8 (-251) A in association with the CXCR2 (+1208) CC genotype in SSc patients. No statistical difference in the polymorphism of IL-10, NFKB1, CXCR2 and CXCL8 were found between the diffuse and limited SSc. These results indicate a potential role of the IL-10 gene and the combination CXCR2/CXCL8 in the pathogenesis of SSc.

O desenvolvimento do câncer está associado a falhas no sistema imune. Investigamos como o microambiente tumoral de mama afetaria a diferenciação de monócitos. Observamos que a alta frequência de macrófagos (MΦ) CD163+ associou-se à baixa sobrevida das pacientes e a um baixo infiltrado de células T CD3+ nos tumores. Sobrenadantes obtidos da dilaceração des tumores (SNDil) induziram a diferenciação de monócitos para MΦ CD163highIL-10high, os quais suprimiram células T CD4+. O fenótipo CD163highIL-10high associou-se a altos níveis de M-CSF, TGF-β e VEGF nos tumores. Monócitos circulantes de pacientes falharam em diferenciar-se em M1-M Φ; deram origem à DCs capazes de induzir alta frequência de células T reguladoras (Tregs) e produziram altos níveis de citocinas anti-inflamatórias sob ativação por LPS. Em conclusão, o microambiente tumoral favorece a diferenciação de MΦ CD163highIL-10high supressivos e afeta sistemicamente o potencial de diferenciação de monócitos de pacientes. / Cancer development is associated with failures in the immune system. We investigated here if breast tumor microenvironment affect the differentiation of monocytes. We observed that the high frequency of macrophages (MΦ) CD163+ was associated with poor patients survival and a low infiltration of CD3+ T cells in tumors. Supernatants obtained from dilacerated tumors (SNDil) skewed the differentiation of monocytes into CD163highIL10high MΦ, which suppressed CD4+ T cells. The CD163highIL-10high phenotype was associated with high levels of M-CSF, TGF-β and VEGF in tumors. Circulating monocytes from patients failed to differentiate into M1-MΦ; gave rise to DCs able to induce high frequency of regulatory T cells (Tregs) and produced high levels of anti-inflammatory cytokines under LPS activation. In conclusion, the tumor microenvironment promotes the differentiation of suppressive CD163highIL10high MΦ and affects the potential of differentiation of patients\' monocytes systemically.

京都大学 / 0048 / 新制・課程博士 / 博士(医科学) / 甲第22122号 / 医科博第107号 / 新制||医科||7(附属図書館) / 京都大学大学院医学研究科医科学専攻 / (主査)教授 生田 宏一, 教授 濵﨑 洋子, 教授 杉田 昌彦 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Skeletal muscle insulin resistance is a major characteristic of obesity and type 2 diabetes. Although obesity-mediated inflammation is causally associated with insulin resistance, the underlying mechanism is unclear. Our lab and others have shown that a chronic low-grade inflammation takes place in skeletal muscles during diet-induced obesity, as evidenced by increased macrophage markers and pro-inflammatory cytokine levels. Interleukin (IL)-10 is a Th2-type cytokine that inhibits the synthesis and activity of pro-inflammatory cytokines and counteracts the Toll-like receptor-mediated inflammation. Our lab has previously demonstrated the preventive role of IL-10 against insulin resistance. Here, I have analyzed the effects of IL-10 on the skeletal muscle glucose metabolism and myogenesis in three different insulin resistant states (high fat diet-induced, leptin-deficiency-induced and aging-induced). The first model involved long-term (16 weeks) high-fat diet (HFD) feeding that resulted in markedly obese and hyperglycemic mice, representative of obese type 2 diabetic subjects. In mice overexpressing IL-10 specifically in the skeletal muscle (MIL10), we observed improved whole-body and skeletal muscle insulin sensitivity as compared to wild-types after long-term high fat diet feeding. The improved insulin sensitivity in the skeletal muscle was due to increased Akt signaling and decreased muscle inflammation. Leptin is an important adipocyte-derived hormone that is elevated in obesity, and it regulates numerous physiological functions including the energy balance and inflammation. Thus, my second model examined the effects of muscle-specific overexpression of IL-10 on glucose metabolism in the hyperphagic, leptin-deficient ob/ob mice. We detected improved whole-body insulin sensitivity compared to the control mice. My third model examined the effects of increased IL-10 expression using MIL10 mice during aging-induced insulin resistance. In 18-month old MIL10 mice, we found enhanced whole-body and skeletal muscle insulin sensitivity due to improved insulin signaling and decreased muscle inflammation as compared to wild-type mice. Last, to test whether direct signaling of IL-10 on skeletal muscle is responsible for the beneficial effects of IL-10 on muscle glucose metabolism, I generated mice lacking IL-10 receptor 1 type chain selectively in skeletal muscle (M-IL10R-/-). We observed more prominent muscle inflammation and whole-body insulin resistance in HFD-fed M-IL10R-/- mice as compared to wild-type mice. Interestingly, when studying insulin resistance in the IL-10 transgenic mouse models, we identified a consistent increased lean mass phenotype, and conversely decreased lean mass in the HFD-fed M-IL10R-/- mice. Quantitative RT-PCR on HFD-fed MIL10 group muscles to measure myogenesis-related gene expression identified a correlation between lean mass and both IL-10 and MyoD mRNA expression levels. In support of this, I showed that IL-10 caused an increase in in vitro cultured myoblast proliferation rates. Together, these results highlight the potential benefits of IL-10 expression not only in muscle glucose metabolism but also in maintaining muscle mass during insulin resistant states. Overall, these results demonstrate that selective expression of IL-10 in skeletal muscle suppresses inflammation, improves glucose metabolism and muscle growth in obese and aging mice, and further establishes that these effects are at least partially mediated by direct activation of IL-10 signaling in skeletal muscle.

Class II cytokine receptors are important pleiotropic regulators of the immune system that play a central role in pathogen defense, tumor surveillance and immune system homeostasis. Most of these activities are very promising for biomedical applications, which, however, have so far failed to succeed due to severe undesired side effects resulting from the pleiotropic nature of these cytokine receptors. Controlling the functional plasticity of class I/II cytokine receptor signaling by engineered cytokines has recently emerged as a promising approach to selectively reduce such side effects. In this context, systematic studies on the IFNalpha/beta receptor and other systems have identified that the binding kinetics of the ligand-receptor interaction play an important role in defining signaling specificity. This has been explained by altered equilibrium and dynamics of the signaling complex in the plasma membrane. In this work, I have investigated how the spatiotemporal organization and dynamics of signaling complexes regulate activation and signaling specificity of other members of the class II cytokine receptors. I focused on the type II IFN and IL-10 systems that supposedly form hexameric ligand-receptor signaling complexes in the plasma membrane. To this end, we developed an orthogonal multicolor anti-GFP nanobody-based labeling strategy, that allowed imaging of up to four different class II cytokine receptor subunits simultaneously. Using this labeling strategy, I investigated the spatiotemporal dynamics of IFNGR and IL-10R complex assembly by co-localization and co-tracking of single receptor subunits. Thereby, I did show that unliganded receptor subunits of IFNGR and IL-10R remain monomeric at the cell surface, whereas binding of the ligand led to fast and efficient receptor homo- and hetero-dimerization, verifying a ligand-induced receptor complex assembly model for both cytokine receptors. Moreover, I verified the hexameric ligand-receptor complex structure in cellulo. Analysis of single molecule trajectories and co-trajectories revealed a decrease in mobility and diffusion of IFNGR and IL-10R subunits upon ligand stimulation indicating receptor confinement and endocytosis. In this context, I identified an abnormal diffusion behavior of IL-10R2 that was dependent on the length of its transmembrane helix. We used partial agonists for both receptor complexes to systematically alter receptor binding stoichiometry and complex stability in the plasma membrane and correlated these with downstream signaling responses. Our analysis revealed a minor contribution of the second low affinity receptor subunit and its associated kinase to the overall signaling activity. However, the second high affinity binding subunit was indispensable to acquire full signaling potential. We managed to obtained decoupling of gene expression for both hexameric class II cytokine receptors by utilizing engineered ligands with altered receptor binding affinities. Our findings could pave the way for new biomedical approaches with engineered IFNgamma and IL-10 in the future. Furthermore, we uncovered pathogenic mechanisms behind the IFNGR2-T168N mutant and auto-IFNgamma antibodies, both of which prominently cause the Mendelian Susceptibility to Mycobacteria Disease (MSMD) syndrome, showing that both interfere with IFNGR activation by preventing recruitment of IFNGR2 into receptor complexes.