Elucidating the effect of pro and anti-inflammatory recombinant cytokines TNF-α and TGF-ß in tuberculosis.

Tuberculosis (TB) is a leading cause of death caused by Mycobacterium tuberculosis (M tb) and about one-third of the world's population is infected with TB. The household contacts of TB patients are at higher risk towards TB than general population. During the initial stages of infection, pro and anti-inflammatory cytokines are induced by innate immune cells, and the course of infection is influenced by general cytokine environment. These cytokines play an important role in the regulation of host immune responses against M tb. Therefore, it is necessary to understand the cytokines role in the immune mechanism to evaluate the correlation between the disease and the immune responses involved in TB. Our current study has focused on recombinant cytokines to understand their effects on cell proliferation and cytokine levels in culture supernatants. We observed that the mean proliferative responses to recombinant rhTNF-α were high and TNF-α levels were significantly low in APTB patients compared to their HHC and HC with p < 0.0375 and p < 0.0051 respectively. The mean proliferative responses to recombinant rhTGF-ß were significantly low in APTB when compared to HHC and HC with p < 0.0376, p < 0.0247 respectively, and TGF-ß levels were also significantly low in APTB and HHC compared to HC with p < 0.0468 and p < 0.0001 respectively. The lower cytokine secretions in culture supernatants might be due the autocrine signaling by recombinant cytokines towards the inflammatory response. Further, to validate these recombinant cytokines, a larger sample size could aid in identifying individuals at high risk for TB.

Immune profiles of MCP-1 with M tb antigens and recombinant cytokines stimulation in tuberculosis.

Tuberculosis is caused by Mycobacterium tuberculosis (M tb), which is recognized by macrophages and produces inflammatory cytokines, and chemokines at the site of infection. The present study was proposed to understand the interaction of M tb antigens, cytokines, and chemokines. We have evaluated the chemokine MCP-1 levels and its expression in PBMCs stimulated with M tb antigens Ag85A, ESAT6 and recombinant cytokines rhTNF-α, rhIFN-γ, rhTGF-ß, and rhIL-10 in active pulmonary TB (APTB) patients, household contacts (HHC) at 0 months, 6 months and healthy controls (HC). We have observed low levels of MCP-1 with Ag85A, ESAT6, and rhTNF-α stimulations in APTB 0M compared to HHC and HC (p < 0.0067, p < 0.0001, p < 0.01, p < 0.005, p < 0.0065, p < 0.0001) and significantly increased after treatment with rhTNF-α. The MCP-1 levels with rhIFN-γ were high in APTB, HHC at 0 M and significant between APTB 0 M vs. 6 M, HHC vs. HC, and HHC 0M vs. 6M (p < 0.0352, p < 0.0252, p < 0.00062). The rhTGF-ß, rhIL-10 induced high MCP-1 levels in APTB, HHC compared to HC (p < 0.0414, p < 0.0312, p < 0.004, p < 0.0001) and significantly decreased after treatment with rhIL-10 (p < 0.0001). The MCP-1 expression was low with all the stimulations in APTB 0M when compared to HC and after treatment. Whereas, HHC shown low MCP-1 expression with rhTNF-α, rhIFN-γ and Ag85A and high with rhTGF-ß, rhIL-10 and ESAT6. In conclusion, the study determined the differential expression and production of MCP-1 with M tb antigens and recombinant cytokines. Further, cohort studies are required to study these interaction to identify the high risk individuals, which might help for TB control.

Toll-like receptor 2 polymorphisms and their effect on the immune response to ESAT-6, Pam3CSK4 TLR2 agonist in pulmonary tuberculosis patients and household contacts.

Toll-like receptors (TLRs) play a pivotal role in organizing the effective immune response through inducing the pro-inflammatory cytokines for control of tuberculosis infection and TLR polymorphisms are associated with altered cytokine levels have been described. Therefore, the main aim of the present study was to confirm whether TLR2 (C2029T, G2258A) polymorphisms effects the cytokine production in PTB patients and Household contacts (HHC), healthy controls (HC). The polymorphisms were performed by amplification refractory mutation system-polymerase chain reaction (ARMS) & Restriction Fragment Length Polymorphism (RFLP) in 336 subjects. Cytokine levels were estimated in Pam3CSK4, antigen ESAT-6 stimulated culture supernatants by Enzyme-Linked Immunosorbent Assay. Under the over-dominant model GA genotype of G2258A SNP and CT genotype of the co-dominant model in C2029T SNP showed a susceptible effect in patients, whereas in HHC, CT genotype showed a protective effect. A significant decreased TNF-α, IL-12 and increased IL-1ß levels were observed after Pam3CSK4, antigen ESAT-6stimulation; our results showed the following associations: TLR2 G2258A SNP of GA with decreased TNF-α; TLR2 C2029T SNP of CT, TT with decreased IL-12 and increased IL-1ß levels. Regression analysis demonstrated that age, BCG, gender and T allele were significantly associated with TB. Pre-mRNA secondary structure of the A, T alleles are more stable than G, C alleles. Altogether, we suggest that cytokine levels, 2029T allele, TLR2 polymorphisms were considered as predictive markers for identification of high-risk individuals in TB.