Role of Circulating T Follicular Helper Cells and Stem-Like Memory CD4 T Cells in the Pathogenesis of HIV-2 Infection and Disease Progression.

CD4 T cells are critical players in the host adaptive immune response. Emerging evidence suggests that certain CD4 T cell subsets contribute significantly to the production of neutralizing antibodies and help in the control of virus replication. Circulating T follicular helper cells (Tfh) constitute a key T cell subset that triggers the adaptive immune response and stimulates the production of neutralizing antibodies (NAbs).

Role of neutrophils in tuberculosis: A bird's eye view.

Neutrophils are innate immune cells implicated in the process of killing early during infection. Once the mycobacteria enter the human system, neutrophils sense and engulf them. By secreting bactericidal enzymes and α-defensins like human neutrophil peptides loaded in their granule armory, neutrophils kill the pathogen.

TLR stimulation of human neutrophils lead to increased release of MCP-1, MIP-1α, IL-1β, IL-8 and TNF during tuberculosis.

Neutrophils inform and shape immune responses. Toll-like receptors (TLRs) play an essential part in the perception of microbes and shape the complex host responses that occur during infection. The TLRs present on neutrophils play an indispensable role in neutrophil mediated pathogen recognition and elimination.

Mycobacterium tuberculosis strains modify granular enzyme secretion and apoptosis of human neutrophils.

Mycobacterium tuberculosis has evolved to employ multiple strategies to avoid an efficient host immune response. Accordingly, enzymes are important antimycobacterial elements and apoptosis decides the fate of any cell. Hence, we carried out this study to discern the amplitude of two clinical stains (S7 & S10) and a laboratory strain (H37Rv) of M.

Neutrophils from pulmonary tuberculosis patients show augmented levels of chemokines MIP-1α, IL-8 and MCP-1 which further increase upon in vitro infection with mycobacterial strains.

Neutrophils being innate cells initiate the immune defence against mycobacteria by sending signals to other immune cells. Chemokines being the vital link in signaling processes, it is of interest to study their secretion by neutrophils as a response to tuberculosis infection. The levels of various chemokines (MIP-1α, MCP-1, IL-8 and IP-10) and chemokine receptors (CXCR1, CXCR2 and CCR1) in neutrophils from healthy individuals and pulmonary tuberculosis patients were studied following infection with Mycobacterium tuberculosis strains (clinical--S7 and S10 and laboratory--H37Rv).