Rescuing of deficient killing and phagocytic activities of macrophages derived from non-obese diabetic mice by treatment with geldanamycin or heat shock: potential clinical implications

Abstract

Diabetes mellitus type 1 (DMT1) is an autoimmune disease characterized by the destruction of insulinproducing cells in the pancreas. Diabetic patients are more susceptible to recurrent and uncontrolled infections, with worse prognoses than in healthy individuals. Macrophages (Mfs) derived from DMT1 individuals have compromised mounting of inflammatory and immune responses. The mechanisms responsible for these alterations remain unknown. It has been shown that the presence of extra-and intracellular heat shock proteins (hsp) positively modulates immune cell function. Using naive Mfs derived from nonobese diabetic (NOD) mice, a well-established mouse model for DMT1, we demonstrate that heat shock (HS) as well as treatment with geldanamycin (GA), significantly improves diabetic Mf activation, resulting in increased phagocytosis and killing of bacteria. Induction of HS did not affect the aberrant NOD-Mf cytokine profile, which is characterized by elevated IL-10 levels and normal tumor necrosis factor alpha. Our observations were consistent at pre-diabetic (normal random blood glucose) and diabetic (random blood glucose greater than 250 mg/dl) stages, suggesting that HS and GA treatment may compensate for intrinsic genetic alterations present in diabetic cells regardless of the stage of the disease. The mechanisms associated to this phenomenon are unknown, but they may likely be associated with the induction of hsp expression, a common factor between HS and GA treatment. Our results may open a new field for non-classical function of hsp and indicate that hsp expression may be used as a part of therapeutic approaches for the treatment of complications associated with DMT1 as well as other autoimmune diseases.

Activation of the stress response in macrophages alters the M1/M2 balance by enhancing bacterial killing and IL-10 expression

“…Under sterile conditions alveolar (AMϕs) and peritoneal (PMϕs) were isolated by bronchoalveolar lavage and peritoneal lavage from naïve mice utilizing cold SF RPMI1640 medium, as described in detail previously [24][25][26]. In some studies, mice were subjected to thermal stress as previously described [27].…”

“…In earlier studies, we had shown that increased killing activity by stressed cells was not due to the activation of membrane NADPH-oxidase during respiratory burst [25]. Thus, we evaluated the effect of the SR on other Mϕ killing mechanisms such as antibacterial DNA-based extracellular trap (ET) formation [32][33][34][35][36] and the expression of antimicrobial peptides (AMPs).…”

Macrophage Activity Test of Pulmonary Tuberculosis Patients with Diabetes Mellitus (TB-DM)

“…This phagocytosis disruption is due to the intrinsic defect of the PMN. 12 This results showed that there were decreased production of TNF-α in pulmonary tuberculosis patients with DM rather than non tients. It is according to the literature mentioned that Th-1 response levels, IFN-γ, as well as the production of IL-1 β and IL-6 are more profound in pulmonary tuberculosis patients with DM rather than non-diabetic TB patients.…”

“…12,13,14 Supernatant layer was discarded, the pellet was rinsed and added with 4000 µl RPMI 1640 (+) medium (heated RPMI 1640 medium supplemented with 10% inactivated human serum with 56°C for 30 minutes/HI-PHS/Heat Inactivated Pooled Human Serum), and then continued by mix pipetting. Monocyte viability was determined using tryphan blue exclusion (≥95%).…”

“…While lymphocytes appeared as having large nuclei, round shape, heterochromatin features with a large nucleus-cytoplasm ratio. 11,12,19,20 This study eliminated the presence of the lymphocytes using the PBS rinsing method in order to avoid the bias results from the process of intracellular killing because the lymphocytes have a role in producing IFN-γ as a mediator of macrophage activation.…”