Findings reported in Nature Immunology are contrary to previous studies that showed this interaction occurred deeper within the organ.
Researchers from the NIAID say that immune cells confront viruses just inside of the lymph node and not deep within these organs as previously thought. The results are significant, the authors say, as they observed in detail the interaction of viruses and immune cells inside a living organism, in this case, mice.
Combining expertise from disciplines such as imaging, immunology, and virology, the scientists extracted and purified killer T cells. They labeled the T cells with a fluorescent marker, injected them back into the mice, and then infected the animals with vaccinia virus.
Using a multiphoton microscope, the team observed the viruses infect cells just inside the lymph node surface, triggering a swarm of T cells. These virus-specific T cells form an elaborate and dynamic communications network that activates them to divide and travel to the site of viral infection, where they kill virus-infected cells.
The NIAID team stresses that pinpointing where in the lymph node immune cells fight the virus should help efforts to design effective antivirus vaccines. “A key challenge in viral vaccine research is developing strategies for immunizing against lethal viruses such as HIV that have eluded the standard vaccine approaches,” notes Jonathan Yewdell, M.D., Ph.D., chief of the NIAID cellular biology section, and one of the lead authors. “We have contributed a page to the handbook of understanding how to rationally design vaccines to elicit a T-cell response.”
Investigators from the University of Miami School of Medicine also took part in this research. The study is described online in Nature Immunology.