The mc2-CMX vaccine induces an enhanced immune response against Mycobacterium tuberculosis compared to Bacillus Calmette-Guérin but with similar lung inflammatory effects

Although the attenuated Mycobacterium bovis Bacillus Calmette-Guérin (BCG) vaccine has been used since 1921, tuberculosis (TB) control still proceeds at a slow pace. The main reason is the variable efficacy of BCG protection against TB among adults, which ranges from 0-80%. Subsequently, the mc2-CMX vaccine was developed with promising results. Nonetheless, this recombinant vaccine needs to be compared to the standard BCG vaccine. The objective of this study was to evaluate the immune response induced by mc2-CMX and compare it to the response generated by BCG. BALB/c mice were immunised with both vaccines and challenged withMycobacterium tuberculosis (Mtb). The immune and inflammatory responses were evaluated by ELISA, flow cytometry, and histopathology. Mice vaccinated with mc2-CMX and challenged with Mtb induced an increase in the IgG1 and IgG2 levels against CMX as well as recalled specific CD4+ T-cells that produced T-helper 1 cytokines in the lungs and spleen compared with BCG vaccinated and challenged mice. Both vaccines reduced the lung inflammatory pathology induced by the Mtb infection. The mc2-CMX vaccine induces a humoral and cellular response that is superior to BCG and is efficiently recalled after challenge with Mtb, although both vaccines induced similar inflammatory reductions.

Resposta imune humoral ao antígeno rGroES do mycobacterium tuberculosis em pacientes com tuberculose e seus contatos domiciliares / Humoral immune response to mycobacterium tuberculosis rGroES antigen in patients with tuberculosis and their household contacts

A tuberculose (TB) continua sendo um dos mais urgentes problemas de saúde pública do mundo, com 8 a 10 milhões de novos casos e 2 a 3 milhões de mortes a cada ano. Cerca de 50 milhõesde pessoas estão infectadas com o Mycobacterium tuberculosis. A fim de desenvolver testes para imunodiagnóstico da TB, vários antígenos têm sido testados na resposta imune humoral de pacientes com TB ativa. O teste imunoenzimático de ELISA realizado com amostras de plasma de 45 pacientes com tuberculose pulmonar e 172 contatos (96 prova tuberculínica negativa e 76, positiva) foi conduzido para avaliação da resposta imune humoral, com pesquisa de anticorpos das classesIgM e IgG contra o antígeno recombinante GroEs do Mycobacterium tuberculosis (MtGroEs). Pacientes com tuberculose pulmonar ativa apresentaram maiores níveis de IgG anti-rGroEs do que indivíduos saudáveis, o que permitiu a discriminação entre os dois grupos e sugeriu resposta imune humoral específica a este antígeno.

Tuberculosis (TB) remains one of the most important public health problems ofthe world, with 8-10 million new cases and 2-3 million deaths each year. About 50 million people are infected with Mycobacterium tuberculosis. In order to develop immunodiagnostic tests for TB, several antigens have been tested for the humoral immune response of patients with active TB. ELISA was performed with plasma samples from 45 patients with pulmonary TB and 172 contacts (96 negative and 76 positive for the tuberculin skin test). The humoral immune response was evaluated through assessment of IgM and IgG antibodies against recombinant Mycobacterium tuberculosis GroES (MtGroEs). Patients with active pulmonary tuberculosis had higher levels of IgG anti-rGroEs than healthy individuals, allowing discriminationbetween the two groups.