Induction of Th1 (cell-mediated) immunity and associated production of IFN-γ by CD4+ T cells has been widely used as a marker of protective immunity against tuberculosis (TB). This is based on two assumptions. The first is the widely accepted view that Mycobacterium tuberculosis (Mtb), the causative agent of TB is an obligate intracellular pathogen, and the second is based on the Th1/Th2 paradigm, which posits that polarization of CD4+ T cells into type1 (cell-mediated) and type 2 (humoral) is central for proper induction of protective immunity against pathogens. However, almost all licensed vaccines currently in use are primarily anti-body based whether intracellular or extra-cellular. In addition, converging data from both animal models and humans indicate that the production of IFN-γ alone is not sufficient to confer protection against TB. In addition, a substantial body of the literature suggests that, in addition to Th1 cells, antibody classes and sub-classes are protective against TB. In a recent study, we have shown that there is a synergy between IFN-γ (cell-mediated) and IgA (humoral) in human population in an endemic setting. In this review, current data from both animal and human studies that support mixed Th1 and Th2 responses that are protective against Mtb and other pathogens are presented.

CD4 + T细胞诱导Th1（细胞介导的）免疫力和相关的IFN-γ产生已广泛用作抗结核病（TB）保护性免疫的标志物。这是基于两个假设。第一个是结核分枝杆菌（Mtb），结核病的病原体是专性的细胞内病原体，第二种病原是基于Th1 / Th2范式，它假定CD4 + T细胞的极化为1型（细胞介导）和2型（体液）是正确的中心诱导针对病原体的保护性免疫。但是，目前使用的几乎所有许可疫苗都主要基于抗体，无论是细胞内还是细胞外。另外，来自动物模型和人类的一致数据表明，仅产生IFN-γ不足以赋予针对结核的保护。此外，大量文献表明，除了Th1细胞外，抗体类别和亚类还具有针对TB的保护作用。在最近的一项研究中 我们已经证明，在地方性流行的人群中，IFN-γ（细胞介导的）和IgA（体液）之间存在协同作用。在这篇综述中，来自动物和人类研究的最新数据均支持对Th1和Th2的混合反应，可预防介绍了Mtb和其他病原体。